JP7594753B2 - Cylindrical structure inspection system - Google Patents

Description

The present invention relates to an inspection system for cylindrical structures that takes images of the inner surface of a cylindrical structure such as a chimney using a camera mounted on an unmanned aerial vehicle and inspects the condition of the inner surface from the images of the cylindrical structure.

As a technique for inspecting chimneys, Patent Document 1 discloses an inspection method using an unmanned small aerial vehicle. The unmanned small aerial vehicle is guided by a guide disposed on the unmanned small aerial vehicle and a guide wire installed inside the chimney, and flies upward or downward into the interior of the chimney. The unmanned small aerial vehicle has a camera that captures images of the inner surface of the chimney.

Patent No. 6733925

In Patent Document 1, an unmanned small aerial vehicle is guided by a guide and a guide wire while flying inside the chimney, and images of the chimney are taken with the camera of the unmanned small aerial vehicle, so that the condition of the inside surface of the chimney can be confirmed. However, since the altitude and direction of the camera cannot be recognized, there is a risk that the position of the abnormality occurring on the inside surface of the chimney (the location of the abnormality) cannot be identified.

The present invention provides an inspection system for cylindrical structures that can determine the shooting altitude and shooting direction of an inspection camera that captures images of the inner surface of a cylindrical structure.

Claim 1 of the present invention relates to an unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground, a light emitting device arranged inside the cylindrical structure, a photographing device mounted on the unmanned aerial vehicle, and a position calculation device, wherein the light emitting device is located at the center of the cylindrical structure and arranged on the bottom surface of the cylindrical structure, and emits light into the inside of the cylindrical structure to display the flight mode of the unmanned aerial vehicle, and a flight indicator that is arranged at a distance from the flight indicator on the inner surface of the cylindrical structure and on the bottom surface of the cylindrical structure between the flight indicators, and A first light emitter that emits light to the inside, the first light emitter being spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, and the second light emitter that emits light to the inside of the cylindrical structure being spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, the second light emitter being spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, and disposed between the first light emitter and the flight indicator, and disposed between the second light emitter and the flight indicator, and disposed between the first light emitter and the flight indicator, and disposed between the second light emitter and the flight indicator, a third light-emitting body arranged on the bottom surface of the cylindrical structure at a distance therefrom and emitting light into the interior of the cylindrical structure; and a fourth light-emitting body arranged between the inner surface of the cylindrical structure and the flight indicator at a distance therefrom, and also arranged on the bottom surface of the cylindrical structure at a distance from the second light-emitting body in the second direction and from the third light-emitting body in the first direction, emitting light into the interior of the cylindrical structure; and the photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle, and the unmanned aerial vehicle photographs the cylindrical structure from the inner surface of the cylindrical structure and the flight indicator at a distance therefrom, The unmanned aerial vehicle is flown hovering in the air inside the cylindrical structure, the reference camera takes images including the flight indicator and each light-emitting element while the unmanned aerial vehicle is in hovering flight , and the inspection camera takes images of the inner surface of the cylindrical structure while the unmanned aerial vehicle is in hovering flight, and the position calculation device determines the shooting altitude of the inspection camera based on the image taken by the reference camera at the same time as taking pictures with the inspection camera, and determines the shooting direction of the inspection camera based on the image taken by the reference camera at the same time as taking pictures with the inspection camera.

A second aspect of the present invention relates to an unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground, a light emitting device disposed inside the cylindrical structure, a photographing device mounted on the unmanned aerial vehicle, and a position calculation device, the light emitting device comprising: a flight indicator located at the center of the cylindrical structure and disposed on the bottom surface of the cylindrical structure, emitting light into the inside of the cylindrical structure to display the flight mode of the unmanned aerial vehicle; a first light emitting body that is disposed on the inner surface of the cylindrical structure and between the flight indicators at a distance from the flight indicators, the first light emitting body that emits light into the inside of the cylindrical structure, and a second light emitting body that is disposed between the inner surface of the cylindrical structure and the flight indicators at a distance from the flight indicators, the first light emitting body that emits light into the inside of the cylindrical structure, and a second light emitting body that is disposed on the inner surface of the cylindrical structure and between the flight indicators at a distance from the flight indicators, the first light emitting body that emits light into the inside of the cylindrical structure, a second light emitter arranged on the bottom surface of the cylindrical structure at a distance from the first direction in the radial direction of the cylindrical structure, emitting light into the interior of the cylindrical structure; a third light emitter arranged between the inner surface of the cylindrical structure and the flight indicator at a distance from the first light emitter, and arranged on the bottom surface of the cylindrical structure at a distance from the second light emitter, emitting light into the interior of the cylindrical structure; and a third light emitter arranged between the inner surface of the cylindrical structure and the flight indicator at a distance from the second light emitter, and arranged at a distance from the flight indicator in the second direction and at a distance from the third light emitter in the first direction. and a fourth light-emitting body arranged on the bottom surface of the cylindrical structure and emitting light into the interior of the cylindrical structure, the photographing device comprising an inspection camera mounted on the unmanned aerial vehicle , a fixed-focus first reference camera mounted on the unmanned aerial vehicle and photographing images including the flight indicator and each light-emitting body , a fixed-focus second reference camera mounted on the unmanned aerial vehicle and having a longer focal length than the first reference camera and photographing images including the flight indicator and each light-emitting body , and a camera control unit, the unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure, the camera control unit starts photographing with the first reference camera from the start of takeoff of the unmanned aerial vehicle , and controls the first reference camera to start photographing when the first reference camera starts photographing. When the resolution of the image including the flight indicator and each light-emitting element falls below a predetermined resolution, the system switches from taking pictures with the first reference camera to taking pictures with the second reference camera, the inspection camera photographs the inner surface of the cylindrical structure while the unmanned aerial vehicle is in stopped flight, and the first or second reference camera photographs images including the flight indicator and each light-emitting element while the unmanned aerial vehicle is in stopped flight, and the position calculation device determines the shooting altitude of the inspection camera based on the image taken by the first or second reference camera simultaneously with the shooting of the inspection camera, and determines the shooting direction of the inspection camera based on the image taken by the first or second reference camera simultaneously with the shooting of the inspection camera.

Claim 3 of the present invention is an inspection system for cylindrical structures as described in claim 1, characterized in that the inspection camera is mounted on the unmanned aerial vehicle with its camera optical axis passing through the center point of the camera lens of the inspection camera facing in a direction perpendicular to the center line of the unmanned aerial vehicle, the reference camera is mounted on the unmanned aerial vehicle with its camera optical axis passing through the center point of the camera lens of the reference camera parallel to the center line of the unmanned aerial vehicle and is positioned at a shooting distance from the inspection camera in the direction of the center line of the unmanned aerial vehicle, and the position calculation device, simultaneously with shooting with the inspection camera, calculates the shooting altitude of the inspection camera using a first area formed by the first to third light-emitting elements in the image captured by the reference camera, a second area formed by the first to third light-emitting elements arranged on the bottom surface of the cylindrical structure, the center distance between the center point of the camera lens of the reference camera and the camera optical axis of the inspection camera in the direction of the center line of the unmanned aerial vehicle, and the focal length of the reference camera .

Claim 4 of the present invention is an inspection system for cylindrical structures as described in claim 2, characterized in that the unmanned aerial vehicle is equipped with a control device for remotely operating the unmanned aerial vehicle, and the unmanned aerial vehicle has an aircraft control unit for controlling the flight of the unmanned aerial vehicle, and the aircraft control unit causes the unmanned aerial vehicle to take off from the bottom surface of the cylindrical structure and fly upward in the direction of the center line of the cylindrical structure based on an ascending flight command from the control device, and controls the flight of the unmanned aerial vehicle based on the flight pattern displayed on the flight indicator in the image captured by the first or second reference camera.

A fifth aspect of the present invention relates to an unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground, a light emitting device disposed inside the cylindrical structure, a photographing device mounted on the unmanned aerial vehicle, and a position calculation device, the light emitting device being located at the center of the cylindrical structure and disposed on the bottom surface of the cylindrical structure, and emitting light into the inside of the cylindrical structure to display the flight mode of the unmanned aerial vehicle, and a flight indicator being disposed at a distance from the flight indicator on the inner surface of the cylindrical structure and on the bottom surface of the cylindrical structure between the flight indicators, A first light emitter that emits light into the interior of the structure, the first light emitter being spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, and the second light emitter being spaced apart from the flight indicator in a first radial direction of the cylindrical structure and disposed on the bottom surface of the cylindrical structure, the second light emitter that emits light into the interior of the cylindrical structure, the second light emitter being spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, and disposed on the bottom surface of the cylindrical structure, the second light emitter being spaced apart from the flight indicator in a second radial direction of the cylindrical structure perpendicular to the first direction, a third light emitter arranged on the bottom surface of the cylindrical structure at a distance from the second light emitter and emitting light into the interior of the cylindrical structure; and a fourth light emitter arranged between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and arranged on the bottom surface of the cylindrical structure at a distance from the second light emitter in the second direction and at a distance from the third light emitter in the first direction, emitting light into the interior of the cylindrical structure; and the photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle, This is an inspection system for cylindrical structures, characterized in that the unmanned aerial vehicle flies hovering in the air inside the cylindrical structure, the reference camera takes images including the flight indicator and each light source, and the inspection camera takes images of the inner surface of the cylindrical structure while the unmanned aerial vehicle is in hovering flight, and the position calculation device determines the shooting altitude of the inspection camera based on the images taken by the reference camera while the unmanned aerial vehicle is in hovering flight, and simultaneously with taking images with the inspection camera, determines the shooting direction of the inspection camera based on the images taken by the reference camera .

A sixth aspect of the present invention relates to an unmanned aerial vehicle that flies inside a cylindrical structure erected on the ground, a light emitting device disposed inside the cylindrical structure, a photographing device mounted on the unmanned aerial vehicle, and a position calculation device, the light emitting device being disposed at the center of the cylindrical structure and on the bottom surface of the cylindrical structure, emitting light into the interior of the cylindrical structure to display the flight mode of the unmanned aerial vehicle, a first light emitting body that is disposed on the inner surface of the cylindrical structure and between the flight indicators at a distance from the flight indicators, emitting light into the interior of the cylindrical structure, and a second light emitting body that is disposed on the inner surface of the cylindrical structure and between the flight indicators at a distance from the flight indicators, emitting light into the interior of the cylindrical structure, and a third light emitting body that is disposed on the inner surface of the cylindrical structure and between the flight indicators at a distance from the flight indicators. a second light emitter that is spaced apart from the first light emitter and disposed on the bottom surface of the cylindrical structure in a first direction in the radial direction of the cylindrical structure, and emits light into the interior of the cylindrical structure; a third light emitter that is spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, and is spaced apart from the first light emitter in a second direction in the radial direction of the cylindrical structure perpendicular to the first direction, and disposed on the bottom surface of the cylindrical structure at a distance from the second light emitter, and emits light into the interior of the cylindrical structure; a third light emitter that is spaced apart from the flight indicator and disposed between the inner surface of the cylindrical structure and the flight indicator, and is spaced apart from the second light emitter in the second direction; and a fourth light-emitting body arranged on the bottom surface of the cylindrical structure at a distance from the third light-emitting body in the first direction and emitting light into the interior of the cylindrical structure. The photographing device comprises an inspection camera mounted on the unmanned aerial vehicle , a fixed-focus first reference camera mounted on the unmanned aerial vehicle and photographing an image including the flight indicator and each light-emitting body, a fixed-focus second reference camera mounted on the unmanned aerial vehicle and having a longer focal length than the first reference camera and photographing an image including the flight indicator and each light-emitting body, and a camera control unit. The unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure, and the camera control unit controls the unmanned aerial vehicle to take off from the bottom surface of the cylindrical structure and fly hovering in the air inside the cylindrical structure. This is an inspection system for cylindrical structures, characterized in that the first reference camera starts taking pictures when the unmanned aerial vehicle starts taking off, and when the resolution of an image including the flight indicator and each of the light emitters taken by the first reference camera falls below a predetermined resolution, the inspection camera switches from taking pictures with the first reference camera to taking pictures with the second reference camera, and the inspection camera takes pictures of the inner surface of the cylindrical structure while the unmanned aerial vehicle is stopped in flight, and the position calculation device determines the shooting altitude of the inspection camera based on the image taken by the first or second reference camera while the unmanned aerial vehicle is stopped in flight, and simultaneously with taking pictures with the inspection camera, determines the shooting direction of the inspection camera based on the image taken by the first or second reference camera.

Claim 7 of the present invention is an inspection system for cylindrical structures as described in claim 5, characterized in that the inspection camera is mounted on the unmanned aerial vehicle with its camera optical axis passing through the center point of the camera lens of the inspection camera facing in a direction perpendicular to the center line of the unmanned aerial vehicle, the reference camera is mounted on the unmanned aerial vehicle with its camera optical axis passing through the center point of the camera lens of the reference camera parallel to the center line of the unmanned aerial vehicle and is positioned at a shooting distance from the inspection camera in the direction of the center line of the unmanned aerial vehicle, and the position calculation device, simultaneously with shooting with the inspection camera, calculates the shooting altitude of the inspection camera using a first area formed by the first to third light-emitting elements in the image captured by the reference camera, a second area formed by the first to third light-emitting elements arranged on the bottom surface of the cylindrical structure, the center distance between the center point of the camera lens of the reference camera and the camera optical axis of the inspection camera in the direction of the center line of the unmanned aerial vehicle, and the focal length of the reference camera .

An eighth aspect of the present invention provides an unmanned aerial vehicle that flies inside a cylindrical structure erected on the ground, a light emitting device arranged inside the cylindrical structure, an imaging device mounted on the unmanned aerial vehicle, and a position calculation device, the light emitting device comprising: a first light emitter arranged on a bottom surface of the cylindrical structure and emitting light into the inside of the cylindrical structure; a second light emitter arranged on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in the radial direction of the cylindrical structure, the second light emitter emitting light into the inside of the cylindrical structure, the second light emitter arranged on the bottom surface of the cylindrical structure at a distance from the first light emitter in a second direction in the radial direction of the cylindrical structure intersecting the first direction, and at a distance from the second light emitter; and a third light-emitting body that emits light inside the cylindrical structure, the photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle, the unmanned aerial vehicle flies hovering in the air inside the cylindrical structure, the reference camera photographs images including each light-emitting body during the hovering flight of the unmanned aerial vehicle, and the inspection camera photographs the inner surface of the cylindrical structure during the hovering flight of the unmanned aerial vehicle, and the position calculation device determines the photographing altitude of the inspection camera based on the image taken by the reference camera simultaneously with the photographing by the inspection camera, and determines the photographing direction of the inspection camera based on the image taken by the reference camera simultaneously with the photographing by the inspection camera.

A ninth aspect of the present invention provides an unmanned aerial vehicle that flies inside a cylindrical structure erected on the ground, comprising: an illumination device disposed inside the cylindrical structure; an imaging device mounted on the unmanned aerial vehicle; and a position calculation device, wherein the illumination device comprises a first light-emitting body disposed on a bottom surface of the cylindrical structure and emitting light into the inside of the cylindrical structure; a second light-emitting body disposed on the bottom surface of the cylindrical structure at a distance from the first light-emitting body in a first direction in the radial direction of the cylindrical structure and emitting light into the inside of the cylindrical structure; and a third light-emitting body disposed on the bottom surface of the cylindrical structure at a distance from the first light-emitting body in a second direction in the radial direction of the cylindrical structure intersecting the first direction and at a distance from the second light-emitting body, emitting light into the inside of the cylindrical structure, and the imaging device comprises an inspection camera mounted on the unmanned aerial vehicle; a fixed-focus type first reference camera mounted on the unmanned aerial vehicle and capturing an image including each of the light-emitting bodies; and a position calculation device mounted on the unmanned aerial vehicle and capturing an image including each of the light-emitting bodies, the third light-emitting body being spaced apart from the first light-emitting body in a second direction in the radial direction of the cylindrical structure intersecting the first direction and spaced apart from the second light-emitting body ... second light-emitting body, emitting light into the inside of the cylindrical structure. This is an inspection system for cylindrical structures, comprising: a fixed-focus second reference camera with a long point distance; and a camera control unit, wherein the unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure; the camera control unit starts taking pictures with the first reference camera when the unmanned aerial vehicle starts to take off; and when the resolution of an image including each of the light-emitting objects taken by the first reference camera becomes equal to or lower than a predetermined resolution, the camera control unit switches from taking pictures with the first reference camera to taking pictures with the second reference camera; the inspection camera takes pictures of the inner surface of the cylindrical structure while the unmanned aerial vehicle is stopped in flight; and the first or second reference camera takes pictures including each of the light-emitting objects while the unmanned aerial vehicle is stopped in flight ; and the position calculation device calculates the shooting altitude of the inspection camera based on the image taken by the first or second reference camera simultaneously with the shooting of the inspection camera, and calculates the shooting direction of the inspection camera based on the image taken by the first or second reference camera simultaneously with the shooting of the inspection camera .

A tenth aspect of the present invention provides an unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground, a light emitting device disposed inside the cylindrical structure, a photographing device mounted on the unmanned aerial vehicle, and a position calculation device, the light emitting device comprising a first light emitting body disposed on a bottom surface of the cylindrical structure and emitting light into the inside of the cylindrical structure, a second light emitting body disposed on the bottom surface of the cylindrical structure at a distance from the first light emitting body in a first direction in the radial direction of the cylindrical structure, the second light emitting body emitting light into the inside of the cylindrical structure, a second light emitting body disposed on the bottom surface of the cylindrical structure at a distance from the first light emitting body in a second direction in the radial direction of the cylindrical structure intersecting the first direction, and at a distance from the second light emitting body, the front light emitting body being disposed on the bottom surface of the cylindrical structure at a distance from the first light emitting body, and a third light-emitting body that emits light inside the cylindrical structure, the photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle, the unmanned aerial vehicle flies hovering in the air inside the cylindrical structure, the reference camera photographs images including each light-emitting body, and the inspection camera photographs images of the inner surface of the cylindrical structure while the unmanned aerial vehicle is hovering in the air, and the position calculation device determines the photographing altitude of the inspection camera based on the image taken by the reference camera while the unmanned aerial vehicle is hovering in the air, and simultaneously with photographing with the inspection camera, determines the photographing direction of the inspection camera based on the image taken by the reference camera.

An eleventh aspect of the present invention provides an unmanned aerial vehicle that flies inside a cylindrical structure erected on the ground, comprising: an illumination device disposed inside the cylindrical structure; an imaging device mounted on the unmanned aerial vehicle; and a position calculation device, wherein the illumination device comprises a first light-emitting body disposed on a bottom surface of the cylindrical structure and emitting light into the interior of the cylindrical structure; a second light-emitting body disposed on the bottom surface of the cylindrical structure at a distance from the first light-emitting body in a first direction in the radial direction of the cylindrical structure and emitting light into the interior of the cylindrical structure; and a third light-emitting body disposed on the bottom surface of the cylindrical structure at a distance from the first light-emitting body in a second direction in the radial direction of the cylindrical structure intersecting the first direction and at a distance from the second light-emitting body, emitting light into the interior of the cylindrical structure, and the imaging device comprises an inspection camera mounted on the unmanned aerial vehicle; a fixed focus type first reference camera mounted on the unmanned aerial vehicle and capturing an image including each of the light-emitting bodies; and a position calculation device mounted on the unmanned aerial vehicle and capturing an image including each of the light-emitting bodies. and a camera control unit. The unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure. The camera control unit starts taking pictures with the first reference camera when the unmanned aerial vehicle starts to take off, and when the resolution of the image including each light-emitting body taken by the first reference camera falls below a predetermined resolution, switches from taking pictures with the first reference camera to taking pictures with the second reference camera. The inspection camera photographs the inner surface of the cylindrical structure while the unmanned aerial vehicle is stopped in flight. The position calculation device determines the shooting altitude of the inspection camera based on the image taken by the first or second reference camera while the unmanned aerial vehicle is stopped in flight, and determines the shooting direction of the inspection camera based on the image taken by the first or second reference camera simultaneously with taking pictures with the inspection camera .

According to the present invention, during stationary flight of an unmanned aerial vehicle, the shooting altitude of the inspection camera can be determined based on an image taken by the reference camera (first or second reference camera) or an image taken by the reference camera (first or second reference camera) simultaneously with shooting by the inspection camera, and the shooting direction of the inspection camera can be determined based on an image taken by the reference camera (first or second reference camera) simultaneously with shooting by the inspection camera.
An inspector inspecting a cylindrical structure can check the condition of the inner surface of the cylindrical structure by referring to the shooting height and shooting direction of the inspection camera and the images taken by the inspection camera. If the inspector notices an abnormality (cracks, defects in the inner surface coating material (lining material, etc.)) in the images taken by the inspection camera, he or she can identify the location of the abnormality that has occurred on the inner surface of the cylindrical structure by referring to the shooting height and shooting direction of the inspection camera.

A side view showing a cylindrical structure and a light-emitting device (flight indicator and each light-emitting body) in the cylindrical structure inspection system of the first embodiment. This is a top view showing the cylindrical structure and the light-emitting device (flight indicator and each light-emitting body) in the cylindrical structure inspection system of the first embodiment. A side view showing an unmanned aerial vehicle, an inspection camera, and an imaging device (first and second reference cameras) in the cylindrical structure inspection system of the first and second embodiments. This is a top view (surface view) showing the unmanned aerial vehicle and inspection camera in the cylindrical structure inspection system of the first and second embodiments. This is a bottom view (rear view) showing the unmanned aerial vehicle and the imaging device (first and second reference cameras) in the cylindrical structure inspection system of the first and second embodiments. A diagram showing the positional relationship between an inspection camera and an imaging device (first and second reference cameras) in the cylindrical structure inspection system of the first and second embodiments. This is a block diagram showing an aircraft control unit, a camera control unit, a position calculation device, etc. mounted on an unmanned aerial vehicle (inside the aircraft) in the cylindrical structure inspection system of the first embodiment. 1 is a plan view showing a flight instruction body (flight instruction panel) in the cylindrical structure inspection system of the first embodiment. FIG. 8A is a side view showing a flight instruction body (flight instruction panel) of the cylindrical structure inspection system of the first embodiment, and FIG. 8B is an enlarged view of part A in FIG. 1 is a plan view showing an illuminant (light-emitting panel) in the cylindrical structure inspection system of the first and second embodiments. FIG. 10A is a side view showing a light-emitting body (light-emitting panel) in the cylindrical structure inspection system of the first and second embodiments, and FIG. 10B is an enlarged view of part B in FIG. FIG. 3 is a partially enlarged view of FIG. 2 in the cylindrical structure inspection system of the first embodiment, showing the positional relationship between the flight indicator and the first to fourth light emitters. FIG. 3 is a partially enlarged view of FIG. 2 in the cylindrical structure inspection system of the first embodiment, showing the positional relationship between the flight indicator and the first to fourth light emitters. FIG. 2 is an enlarged view of a portion of FIG. 1 in the inspection system for a cylindrical structure according to the first embodiment. A top view showing a flight indicator displaying "information indicating ascending flight" and the first to fourth light-emitting bodies in the cylindrical structure inspection system of the first embodiment. A top view showing a flight indicator displaying "information indicating descending flight" and the first to fourth light-emitting bodies in the cylindrical structure inspection system of the first embodiment. A top view showing a flight indicator displaying "information indicating hovering flight" and the first to fourth light-emitting elements in the cylindrical structure inspection system of the first embodiment. 3 is a block diagram showing a light-emitting device in the cylindrical structure inspection system of the first embodiment. FIG. 1 is a schematic diagram showing the relationship between the photographing screen (image sensor) of the first or second reference camera, the ground screen of the photographing reference surface, the focal length (screen distance) of the first or second reference camera, and the altitude above the ground. This is a diagram showing an image (image data) captured by the first or second reference camera in the cylindrical structure inspection system of the first embodiment, and showing the area S1 (first area/area of an equilateral triangle) formed by three light-emitting bodies (first to third light-emitting bodies) in the image. FIG. 21 is an enlarged view of part C in FIG. 20 . FIG. 21 is an enlarged view of part D in FIG. 20 . FIG. 21 is an enlarged view of part E in FIG. 20 . This is a top view showing the area S2 (second area/area of an equilateral triangle) formed by three light-emitting bodies (first to third light-emitting bodies) arranged (installed) on the bottom surface of a cylindrical structure in the cylindrical structure inspection system of the first embodiment. This is a top view showing the relationship between the flight indicators and each light-emitting element arranged on the bottom surface of the cylindrical structure and the diagonal directions of the direction correspondence data in the cylindrical structure inspection system of the first embodiment. A figure showing the relationship between the capture screens of the first and second reference cameras and the diagonal directions of the direction correspondence data in the cylindrical structure inspection system of the first embodiment. This is a top view showing the relationship between an image captured by the first or second reference camera (reference camera) and the diagonal direction of the direction correspondence data in the inspection system for cylindrical structures of the first embodiment. 2 is a block diagram showing a control device in the inspection system for the cylindrical structure of the first embodiment. FIG. A side view showing the state in which an unmanned aerial vehicle has landed on the bottom surface of a cylindrical structure in the cylindrical structure inspection system of the first embodiment. FIG. 30 is a partially enlarged view of FIG. 29 . This is a top view (plan view) showing the state in which the unmanned aerial vehicle has landed on the bottom surface of the cylindrical structure in the cylindrical structure inspection system of the first embodiment. This is a side view showing the state in which the unmanned aerial vehicle has taken off and stopped flying in the cylindrical structure inspection system of the first embodiment. In the first embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle at 0 degrees when it starts to rotate, and the state after the unmanned aerial vehicle has been rotated 360 degrees, and (b) is a figure showing images taken by a reference camera (first or second reference camera) simultaneously with the inspection camera, with the unmanned aerial vehicle at 0 degrees and the unmanned aerial vehicle rotated 360 degrees. In the first embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle rotated 90 degrees, and (b) is a figure showing an image captured by the reference camera (first or second reference camera) simultaneously with the inspection camera when the unmanned aerial vehicle is rotated 90 degrees. In the first embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle rotated 180 degrees, and (b) is a figure showing an image captured by the reference camera (first or second reference camera) simultaneously with the inspection camera when the unmanned aerial vehicle is rotated 180 degrees. In the first embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle rotated 270 degrees, and (b) is a figure showing an image taken by the reference camera (first or second reference camera) simultaneously with the inspection camera when the unmanned aerial vehicle is rotated 270 degrees. This is a side view showing the state in which the unmanned aerial vehicle is caused to ascend and then stop flying in the cylindrical structure inspection system of the first embodiment. FIG. 1 is a flowchart (part 1) showing the control of the aircraft control unit in the cylindrical structure inspection system of the first embodiment. FIG. 2 is a flowchart (part 2) showing the control of the aircraft control unit in the cylindrical structure inspection system of the first embodiment. FIG. 1 is a flowchart (part 1) showing the control of the camera control unit in the cylindrical structure inspection system of the first embodiment. FIG. 2 is a flowchart (part 2) showing the control of the camera control unit in the cylindrical structure inspection system of the first embodiment. FIG. 3 is a flowchart (part 3) showing the control of the camera control unit in the cylindrical structure inspection system of the first embodiment. FIG. 4 is a flowchart showing the control of a position calculation device in the cylindrical structure inspection system of the first embodiment. A side view showing a cylindrical structure and a light-emitting device (each light-emitting body) in a cylindrical structure inspection system of a second embodiment. A top view showing a cylindrical structure and a light-emitting device (each light-emitting body) in a cylindrical structure inspection system of a second embodiment. A block diagram showing an aircraft control unit, a camera control unit, a position calculation device, etc. mounted on an unmanned aerial vehicle (inside the aircraft) in the cylindrical structure inspection system of the second embodiment. FIG. 45 is a partially enlarged view of the cylindrical structure inspection system of the second embodiment, showing the positional relationship of the first to third light-emitting bodies. FIG. 45 is an enlarged view of a portion of FIG. 44 in the inspection system for a cylindrical structure of the second embodiment. 13 is a block diagram showing a light-emitting device in the cylindrical structure inspection system of the second embodiment. FIG. This is a diagram showing an image (image data) captured by the first or second reference camera in the cylindrical structure inspection system of the second embodiment, and showing the area S1 (first area/area of an equilateral triangle) formed by the first to third light-emitting elements in the image. This is a top view showing the area S2 (second area/area of an equilateral triangle) formed by the first to third light-emitting bodies arranged (installed) on the bottom surface of a cylindrical structure in the cylindrical structure inspection system of the second embodiment. A top view showing the relationship between each light-emitting body arranged on the bottom surface of a cylindrical structure and the diagonal direction of the direction correspondence data in a cylindrical structure inspection system of the second embodiment. A figure showing the relationship between the capture screens of the first and second reference cameras and the diagonal directions of the direction correspondence data in the cylindrical structure inspection system of the second embodiment. A top view showing the relationship between an image captured by the first or second reference camera (reference camera) and the diagonal direction of the direction correspondence data in the inspection system for cylindrical structures of the second embodiment. FIG. 11 is a side view showing a state in which the unmanned aerial vehicle has landed on the bottom surface of the cylindrical structure in the inspection system for the cylindrical structure of the second embodiment. FIG. 56 is a partially enlarged view of FIG. 55. This is a top view (plan view) showing the state in which an unmanned aerial vehicle has landed on the bottom surface of a cylindrical structure in the cylindrical structure inspection system of the second embodiment. A side view showing the state in which the unmanned aerial vehicle has taken off and stopped flying in the second embodiment of the cylindrical structure inspection system. In the second embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle at 0 degrees when it starts to rotate, and the state after the unmanned aerial vehicle has been rotated 360 degrees, and (b) is a figure showing images taken by the reference camera (first or second reference camera) simultaneously with the inspection camera, at the unmanned aerial vehicle's 0 degree angle and after the unmanned aerial vehicle has been rotated 360 degrees. In the second embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle rotated 90 degrees, and (b) is a figure showing an image captured by the reference camera (first or second reference camera) simultaneously with the inspection camera when the unmanned aerial vehicle is rotated 90 degrees. In the second embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle rotated 180 degrees, and (b) is a figure showing an image captured by the reference camera (first or second reference camera) simultaneously with the inspection camera when the unmanned aerial vehicle is rotated 180 degrees. In the second embodiment of the inspection system for cylindrical structures, (a) is a top view (plan view) showing the unmanned aerial vehicle rotated 270 degrees, and (b) is a figure showing an image captured by the reference camera (first or second reference camera) simultaneously with the inspection camera when the unmanned aerial vehicle is rotated 270 degrees. A side view showing the state in which the unmanned aerial vehicle is caused to ascend and then stop flying in the cylindrical structure inspection system of the second embodiment. FIG. 11 is a flowchart (part 1) showing the control of the aircraft control unit in the cylindrical structure inspection system of the second embodiment. FIG. 11 is a flowchart (part 2) showing the control of the aircraft control unit in the cylindrical structure inspection system of the second embodiment. FIG. 11 is a flowchart (part 1) showing the control of the camera control unit in the cylindrical structure inspection system of the second embodiment. FIG. 11 is a flowchart (part 2) showing the control of the camera control unit in the cylindrical structure inspection system of the second embodiment. FIG. 11 is a flowchart showing the control of the position calculation device in the cylindrical structure inspection system of the second embodiment.

The cylindrical structure inspection system according to the present invention will be described with reference to FIGS.
The inspection system for a cylindrical structure according to the first and second embodiments will be described with reference to FIGS. 1 to 68. FIG.

The first embodiment of the cylindrical structure inspection system will be described with reference to Figures 1 to 43.

In Figures 1 to 43, the first embodiment of the cylindrical structure inspection system Xα (hereinafter referred to as the "cylindrical structure inspection system Xα") takes an image of the inner surface Ya of the cylindrical structure Yλ and inspects the condition of the inner surface Ya from the image of the cylindrical structure Yλ.
As shown in Fig. 1 and Fig. 2, the cylindrical structure Yλ is formed in a cylindrical shape, and is, for example, a chimney of an incineration facility, a chimney of a power plant (thermal power plant), a chimney of a steelworks, or a chimney of a chemical plant. The cylindrical structure Yλ (chimney) is erected on the ground. The cylindrical structure Yλ is erected on the ground with the bottom surface YA (bottom surface of the chimney) of one cylinder end in the direction Z of the center line a (cylinder center line a) (hereinafter referred to as "center line direction Z (cylinder center line direction/Z direction)") facing the ground. Note that the cylindrical structure Yλ is not limited to a chimney.

As shown in Figures 1 to 29, the inspection system Xα for cylindrical structures (chimneys) includes an unmanned aerial vehicle 1, a light-emitting device 2 (light-emitting unit/display device), a photographing device 4 (photographing unit/camera device), a position calculation device 5 (position calculation unit), and a control device 6.

As shown in Figures 32 and 37, the unmanned aerial vehicle 1 is flown inside the cylindrical structure Yλ. As shown in Figures 3 to 5, the unmanned aerial vehicle Y is an unmanned aerial vehicle (UAV), for example, an octocopter (drone). As shown in Figures 3 to 5 and 7, the unmanned aerial vehicle 1 has an airframe 11, multiple (eight) rotor units 12, a wireless communication unit 13 (wireless communication unit), an image transmission unit 14, a lighting receiving unit 15, an aircraft control unit 16, a memory unit 17, and a power source 18.

As shown in FIGS. 3 to 5 , the airframe 11 has an airframe section 21, a plurality of (eight) rotor arms 24, and a plurality of (two) support legs 23.
Each rotor arm 24 extends radially outward from the aircraft body 21. Each support leg 23 is attached to a rear surface 21B (lower surface) of the aircraft body 21 and extends downward from the rear surface 21B of the aircraft body 21.

As shown in Figures 3 to 5, each rotor unit 12 is attached to the tip side of each rotor arm 24. Each rotor unit 12 has a propeller 25 and a rotor motor 26 (motor). The propeller 25 is connected to the motor shaft 26A of the rotor motor 26 and is rotated by the rotor motor 26.

As shown in FIG. 7, the wireless communication unit 13 (receiving side) is mounted (placed) inside the aircraft unit 21 (inside the aircraft 11) and is connected to the aircraft control unit 16 and power supply 18. The wireless communication unit 13 receives flight mode commands (flight mode signals) from the pilot device 6 and outputs flight mode commands (ascent flight commands, descent flight commands, hovering flight commands, etc.) to the aircraft control unit 16.

As shown in FIG. 7, the image transmission unit 14 is mounted (placed) inside the aircraft unit 21 (inside the aircraft 11) and is connected to the inspection camera 3, the photographing device 4, and the power source 18. The image transmission unit 14 transmits images (image data) captured by the inspection camera 3 and images (image data) captured by the photographing device 4 to the control device 6.

As shown in FIG. 7, the lighting receiver 15 is mounted (placed) inside the aircraft unit 21 (inside the aircraft 11) and is connected to the aircraft control unit 16 and the power source 18. The lighting receiver 15 receives a lighting start command (lighting start signal) from the display device 2 and outputs the lighting start command to the aircraft control unit 16.

The aircraft control unit 16 is, for example, a CPU (central processing unit) and is mounted (placed) in the aircraft unit 21 (aircraft 11) as shown in FIG. 7. The aircraft control unit 16 is connected to the rotor motor 26 of each rotor unit 12, the wireless communication unit 13, the lighting receiving unit 15, and the power source 18.

7, the aircraft control unit 16 is connected to the rotor motors 26 of each rotor unit 12. The aircraft control unit 16 inputs a flight mode command (flight mode signal) from the wireless communication unit 13 and inputs a lighting start command (lighting start signal) from the lighting receiving unit 15 to start rotation of the rotor motors 26 of each rotor unit 12, thereby controlling the start of flight of the unmanned aerial vehicle 1 and the flight of the unmanned aerial vehicle 1.
The aircraft control unit 16 controls the rotor motors 26 of each rotor unit 12 to have the same rotation speed, thereby generating lift in the aircraft 11. The aircraft control unit 16 controls the rotation (rotation speed, rotation direction) of the rotor motors 26 of each rotor unit 12, thereby causing the unmanned aerial vehicle 1 to ascend, descend, hover, or rotate.

The storage unit 17 is, for example, a RAM (Random Access Memory), and stores the focal lengths f1 and f2 (screen distance), the center distances (center-to-center distances) ψ1 and ψ2, the area S2, and the position image data GF (each of the position image data GF1 to GF4).

The light emitting device 2 is arranged (installed) inside the cylindrical structure Yλ, as shown in Figures 1, 2, 12 to 17. As shown in Figures 8 to 18, the light emitting device 2 has a flight indicator 31, a first light emitting body 32 (first light emitting panel), a second light emitting body 33 (second light emitting panel), a third light emitting body 34 (third light emitting panel), a fourth light emitting body 35 (fourth light emitting panel), a signal receiving unit 36, a lighting transmitting unit 37, a display control unit 38, and a memory unit 39.

As shown in Figures 8 and 9, the flight indicator 31 is, for example, a flight instruction panel (flight instruction light-emitting panel) and has a panel body 41 (flat body) and multiple (multiple) light-emitting elements 42.

The panel body 41 is formed, for example, from a synthetic resin. As shown in Figures 8 and 9, the panel body 41 is formed in a flat plate shape (flat plate) having a plate thickness T. The panel body 41 is formed, for example, in a square shape with a length L1 (side length) of each of the sides 41a to 41d. The panel body 41 has a plate front surface 41A (plate front plane) and a plate back surface 41B (plate back plane) in the plate thickness direction (the direction of the plate center line b of the panel body 41).
The length L1 of each side 41a to 41d of the panel body 41 is shorter than the diameter Da (inner diameter/inner peripheral diameter) of the inner side surface Ya of the cylindrical structural body Yλ (chimney).

Each light-emitting element 42 is, for example, a light-emitting diode (LED). Each light-emitting element 42 is arranged in the panel body 41 and attached to the panel body 41 as shown in FIG. 8. Each light-emitting element 42 is arranged in a plurality of columns (N columns) between a pair of opposing sides 41a, 41b (vertical sides/vertical plate end faces) of the panel body 41, and arranged in a plurality of rows (n rows) between a pair of opposing sides 41c, 41d (horizontal sides/horizontal plate end faces) of the panel body 41, and attached to the panel body 41. Each light-emitting element 42 is arranged in a lattice pattern of a plurality of columns and rows and attached to the panel body 41.
As shown in FIGS. 8 and 9B, the light-emitting elements 42 are arranged (fixed) on the panel body 41 with the same interval α (element arrangement interval) between each of the light-emitting elements 42 .
The light emitting elements 42 are attached to the panel body 41 in a grid arrangement of, for example, 64 columns and 64 rows (total number: 4096).

The flight indicator 31 emits light from each light-emitting element 42 from the plate surface 41A of the panel body 41. As shown in Figures 15 to 17, the flight indicator 31 displays the flight mode [information (visual information) indicating the flight mode] of the unmanned aerial vehicle 1 by emitting (lighting) each light-emitting element 42. The flight mode is, for example, the ascending flight β, descending flight γ, and hovering flight τ of the unmanned aerial vehicle 1.
As shown in Fig. 15, the flight indicator 31 illuminates (lights) each light-emitting element 42 to display, for example, information "up arrow, UP" indicating ascending flight β. As shown in Fig. 16, the flight indicator 31 illuminates (lights) each light-emitting element 42 to display, for example, information "down arrow" indicating descending flight γ. As shown in Fig. 17, the flight indicator 31 illuminates (lights) each light-emitting element 42 to display, for example, information "horizontal line, ST" indicating hovering flight τ.

As shown in Figs. 1, 2 and 12 to 14, the flight indicator 31 is arranged inside the cylindrical structure Yλ (chimney) with the center line b (plate center line of the panel body 41) of the flight indicator 31 parallel to the center line a of the cylindrical structure Yλ. The flight indicator 31 is arranged (installed) on the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ. The flight indicator 31 is arranged inside the cylindrical structure Yλ with the plate back surface 41B of the panel body 41 facing the bottom surface YA (bottom) of the cylindrical structure Yλ and the plate front surface 41A of the panel body 41 facing the upper end opening YB (tip opening) of the cylindrical structure Yλ (chimney). The flight indicator 31 is arranged (installed) on the bottom surface YA of the cylindrical structure Yλ with the plate back surface 41B of the panel body 41 abutting against the bottom surface YA of the cylindrical structure Yλ. The flight indicator 31 is arranged (installed) on the bottom surface YA of the cylindrical structure Yλ with the center line b (plate center line of the panel body 41) of the flight indicator 31 positioned (coinciding) with the center line a (cylinder center line) of the cylindrical structure Yλ. The center line b of the flight indicator 31 is the center of the flight indicator 31 (plate center of the panel body 41).
The flight indicator 31 emits light from each light-emitting element 42 inside the cylindrical structure Yλ (chimney) to display (illuminate) information indicating the flight mode of the unmanned aerial vehicle 1 (e.g., ascending flight β, descending flight γ, hovering flight τ).

As shown in Figures 10 and 11, the first to fourth light emitters 32, 33, 34, and 35 are, for example, light emitting panels and have a panel body 43 and multiple (multiple) light emitting elements 42.

The panel body 43 is formed, for example, from a synthetic resin. As shown in Figures 10 and 11, the panel body 43 is formed in a flat plate shape (flat plate) having a plate thickness T (the same plate thickness as the panel body 41). The panel body 43 is formed, for example, in a square shape with a length L2 (side length) of each of the sides 43a to 43d. The panel body 43 has a plate surface 43A (plate front plane) and a plate back surface 43B (plate back plane) in the plate thickness direction (the direction of the plate center line c of the panel body 43).
The length L2 of each side 43a to 43d of the panel body 43 is shorter than the diameter Da of the inner surface Ya of the cylindrical structure Yλ (chimney) and shorter than the length L1 of each side 41a to 41d of the flight indicator 31 (panel body 41).

In each of the light emitters 32 to 35 (each light emitting panel), the light emitting elements 42 are disposed on the panel body 43 and attached to the panel body 43 as shown in Fig. 10. The light emitting elements 42 are arranged in a plurality of columns (M columns) between a pair of opposing sides 43a, 43b (vertical sides/vertical plate end faces) of the panel body 43, and arranged in a plurality of rows (m rows) between a pair of opposing sides 43c, 43d (horizontal sides/horizontal plate end faces) of the panel body 43, and attached to the panel body 43. The light emitting elements 42 are arranged in a lattice pattern of a plurality of columns and rows, and attached to the panel body 43.
The light emitting elements 42 are attached to the panel body 43 in a grid arrangement of, for example, 32 rows by 32 rows (total number: 1024).
As shown in FIGS. 10 and 11B, the light-emitting elements 42 are arranged (fixed) on the panel body 43 with the same interval α (element arrangement interval) between each of the light-emitting elements 42, 42.
Each of the light emitters 32 to 35 emits light from each light emitting element 42 from a plate surface 43 A of the panel body 43 .

Each light emitter 32-35 is disposed inside the cylindrical structure Yλ as shown in Figures 1, 2, and 12 to 14.

As shown in FIG. 12, the first light emitter 32 (first light emitter panel) is spaced apart from the inner surface Ya (inner circumferential surface/inner wall surface) of the cylindrical structure Yλ (chimney) and is spaced apart from the flight indicator 31 (flight instruction panel), and is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ between the inner surface Ya of the cylindrical structure Yλ and the flight indicator 31.

As shown in FIG. 12, the first light emitter 32 is arranged so that the side 43a (vertical side) of the panel body 43 is parallel to the side 41b (vertical side) of the panel body 41 (flight indicator). The first light emitter 32 is arranged so that the side 43d (horizontal side) of the panel body 43 is parallel to the side 41c (horizontal side) of the panel body 41 (flight indicator).

As shown in FIG. 12, the first light emitter 32 is arranged at an interval δA (first arrangement interval) in the first direction X (first direction/X direction perpendicular to the center line a of the cylindrical structure Yλ) of the cylindrical structure Yλ relative to the flight indicator 31. The first light emitter 32 is arranged at an interval δA in the first direction X between the side 43a (vertical side) of the panel body 43 (first light emitter) and the side 41b (vertical side) of the panel body 41 (flight indicator).

As shown in FIG. 12, the first light emitters 32 are arranged at intervals δB (second arrangement interval) in the second direction Y (direction perpendicular to the center line a of the cylindrical structure Yλ and the first direction/Y direction) of the diameter of the cylindrical structure Yλ that is perpendicular (intersecting) with the first direction X with respect to the flight indicator 31. The first light emitters 32 are arranged at intervals δB in the second direction Y between the side 43d (horizontal side) of the panel body 43 (first light emitter) and the side 41c (vertical side) of the panel body 41 (flight indicator). The interval δB (second arrangement interval) is, for example, the same interval as the interval δA (first arrangement interval) (δB=δA).

The first light emitter 32 (first light emitting panel) is disposed (installed) on the bottom surface YA (bottom) of the cylindrical structure Yλ inside the cylindrical structure Yλ, as shown in Figures 1, 2, 12 and 14. The first light emitter 32 is disposed inside the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 facing the bottom surface YA of the cylindrical structure Yλ and the plate front surface 43A of the panel body 43 facing the upper end opening YB of the cylindrical structure Yλ. The first light emitter 32 is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 abutting against the bottom surface YA of the cylindrical structure Yλ.
The first light emitter 32 emits light from each light emitting element 42 inside the cylindrical structure Yλ (chimney).

As shown in FIG. 12, the second light emitter 33 (second light emitter panel) is disposed between the inner surface Ya of the cylindrical structure Yλ (chimney) and the flight indicator 31, with a gap between them and the inner surface Ya of the cylindrical structure Yλ (chimney) and with a gap between them and the flight indicator 31.

As shown in FIG. 12, the second light emitter 33 is arranged so that the side 43b (vertical side) of the panel body 43 is parallel to the side 41a (vertical side) of the panel body 41 (flight indicator). The second light emitter 33 is arranged so that the side 43d (horizontal side) of the panel body 43 is parallel to the side 41c (horizontal side) of the panel body 41 (flight indicator).

As shown in FIG. 12, the second light emitter 33 is arranged at a distance δC (third placement distance) in the first direction X relative to the flight indicator 31. The second light emitter 33 is arranged at a distance δC between the side 43b (vertical side) of the panel body 43 (second light emitter) and the side 41a (vertical side) of the panel body 41 (flight indicator) in the first direction X. The distance δC (third placement distance) is, for example, the same distance as the distance δA (first placement distance) (δC=δA).

As shown in FIG. 12, the second light emitter 33 is arranged at a distance δD (fourth placement distance) in the second direction Y relative to the flight indicator 31. The second light emitter 33 is arranged at a distance δD between the side 43d (horizontal side) of the panel body 43 (second light emitter) and the side 41c (horizontal side) of the panel body 41 (flight indicator). The distance δD (fourth placement distance) is, for example, the same distance as the distance δA (first placement distance) (δD=δA).

As shown in FIG. 12 , the second light emitter 33 is disposed with a side 43 b (vertical side) of the panel body 43 (second light emitter) parallel to a side 43 a (vertical side) of the panel body 43 of the first light emitter 32 .
The second light emitter 33 is disposed (placed) on the bottom surface YA of the cylindrical structure Yλ at a distance δ1 (first distance) in the first direction X from the first light emitter 32 .
The second light emitter 33 is disposed in the first direction X between the side 43b (vertical side) of the panel body 43 (second light emitter) and the side 43a (vertical side) of the panel body 43 of the first light emitter 32 at a distance δ1.

The second light emitter 33 (second light emitting panel) is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ, as shown in Figures 1, 2, 12 and 14. The second light emitter 33 is disposed inside the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 facing the bottom surface YA of the cylindrical structure Yλ and the plate front surface 43A of the panel body 43 facing the upper end opening YB of the cylindrical structure Yλ. The second light emitter 33 is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 abutting against the bottom surface YA of the cylindrical structure Yλ, as shown in Figure 14.
The second light emitter 33 emits light from each light emitting element 42 inside the cylindrical structure Yλ.

As shown in FIG. 12, the third light emitter 34 (third light emitter panel) is disposed between the inner surface Ya of the cylindrical structure Yλ (chimney) and the flight indicator 31, with a gap between them and the inner surface Ya of the cylindrical structure Yλ (chimney) and with a gap between them and the flight indicator 31.

As shown in FIG. 12, the third light emitter 34 is arranged so that the side 43a (vertical side) of the panel body 43 is parallel to the side 41b (vertical side) of the panel body 41 (flight indicator). The third light emitter 34 is arranged so that the side 43c (horizontal side) of the panel body 43 is parallel to the side 41d (horizontal side) of the panel body 41 (flight indicator).

As shown in FIG. 12, the third light emitter 34 is arranged at a distance δE (fifth placement distance) in the first direction X relative to the flight indicator 31. The third light emitter 34 is arranged at a distance δE between the side 43a (vertical side) of the panel body 43 (third light emitter) and the side 41b (vertical side) of the panel body 41 (flight indicator) in the first direction X. The distance δE (fifth placement distance) is, for example, the same distance as the distance δA (first placement distance) (δE=δA).

As shown in FIG. 12, the third light emitter 34 is arranged at a distance δF (sixth placement distance) in the second direction Y relative to the flight indicator 31. The third light emitter 34 is arranged at a distance δF in the second direction Y between the side 43c (horizontal side) of the panel body 43 (third light emitter) and the side 41d (horizontal side) of the panel body 41 (flight indicator). The distance δF (sixth placement distance) is, for example, the same distance as the distance δA (first placement distance) (δF = δA).

As shown in FIG. 12 , the third light emitter 34 is disposed with a side 43 c (horizontal side) of the panel body 43 (third light emitter) parallel to a side 43 d (horizontal side) of the panel body 43 of the first light emitter 32 .
The third light emitter 34 is arranged (installed) on the bottom surface YA of the cylindrical structure Yλ at a distance δ2 (second distance) from the first light emitter 32 in the second direction Y and at a distance δ3 (third distance) from the second light emitter 33.
The third light emitter 34 is disposed in the second direction Y between the side 43c (horizontal side) of the panel body 43 (third light emitter) and the side 43d (horizontal side) of the panel body 43 of the first light emitter 32 at a distance δ2. The distance δ2 (second distance) is, for example, the same distance as the distance δ1 (first distance) (δ2=δ1).
The third light emitter 33 is disposed between the plate center line c (plate center) of the panel body 43 (third light emitter) and the plate center line c (plate center) of the panel body 43 of the second light emitter 33 with a distance δ3 therebetween.

The third light emitter 33 (third light emitting panel) is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ, as shown in Figures 1, 2, 12 and 14. The third light emitter 34 is disposed inside the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 facing the bottom surface YA of the cylindrical structure Yλ and the plate front surface 43A of the panel body 43 facing the upper end opening YB of the cylindrical structure Yλ. The third light emitter 34 is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 abutting against the bottom surface YA of the cylindrical structure Yλ.
The third light emitter 34 emits light from each light emitting element 42 inside the cylindrical structure Yλ.

As shown in Figures 1, 2, 13, and 14, the fourth light emitter 35 (fourth light emitting panel) is disposed between the inner surface Ya of the cylindrical structure Yλ (chimney) and the flight indicator 31, with a gap between them and the inner surface Ya of the cylindrical structure Yλ (chimney) and with a gap between them and the flight indicator 31.

As shown in FIG. 13, the fourth light emitter 35 is arranged so that the side 43b (vertical side) of the panel body 43 is parallel to the side 41a (vertical side) of the panel body 41 (flight indicator). The fourth light emitter 35 is arranged so that the side 43c (horizontal side) of the panel body 43 is parallel to the side 41d (horizontal side) of the panel body 41.

As shown in FIG. 13, the fourth light emitter 35 is arranged at a distance δG (seventh placement distance) in the first direction X relative to the flight indicator 31. The fourth light emitter 35 is arranged at a distance δG between the side 43b (vertical side) of the panel body 43 (fourth light emitter) and the side 41a (vertical side) of the panel body 41 (flight indicator) in the first direction X. The distance δG (seventh placement distance) is, for example, the same distance as the distance δA (first placement distance).

As shown in FIG. 13, the fourth light emitter 35 is arranged at a distance δH (eighth placement distance) in the second direction Y relative to the flight indicator 31. The fourth light emitter 35 is arranged at a distance δH between the side 43c (horizontal side) of the panel body 43 (fourth light emitter) and the side 41d (horizontal side) of the panel body 41 (flight indicator 31) in the second direction Y. The distance δH (eighth placement distance) is, for example, the same distance as the distance δA (first placement distance) (δH=δA).

13 , the fourth light emitter 35 is disposed with a side 43b (vertical side) of the panel body 43 (fourth light emitter) parallel to a side 43a (vertical side) of the panel body 43 of the third light emitter 34. The fourth light emitter 35 is disposed with a side 43c (horizontal side) of the panel body 43 (fourth light emitter) parallel to a side 43d (horizontal side) of the panel body 43 of the second light emitter 33.
13, the fourth light emitter 35 is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ at an interval δ4 (fourth interval) from the third light emitter 34 in the first direction X, an interval δ5 (fifth interval) from the second light emitter 33 in the second direction Y, and an interval δ6 (sixth interval) from the first light emitter 32. The interval δ4 (fourth interval) and the interval δ5 (fifth interval) are, for example, the same interval as the interval δ1 (first interval) (δ4=δ5=δ1). The interval δ6 (sixth interval) is, for example, the same interval as the interval δ3 (third interval) (δ6=δ3).
The fourth light emitter 35 is disposed in the first direction X between the side 43b (vertical side) of the panel body 43 (fourth light emitter) and the side 43a (vertical side) of the panel body 43 of the third light emitter 34 at a distance δ4.
The fourth light emitter 35 is disposed in the second direction Y between the side 43c (horizontal side) of the panel body 43 (fourth light emitter) and the side 43d (horizontal side) of the panel body 43 of the second light emitter 33 at a distance δ5.
The fourth light emitter 35 is disposed between the plate center line c (plate center) of the panel body 43 (fourth light emitter) and the plate center line c (plate center) of the panel body 43 of the first light emitter 32 with a distance δ6 therebetween.

The fourth light emitter 35 (fourth light emitting panel) is disposed (installed) inside the cylindrical structure Yλ on the bottom surface YA of the cylindrical structure Yλ, as shown in Figures 1, 2, 13 and 14. The fourth light emitter 35 is disposed inside the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 facing the bottom surface YA of the cylindrical structure Yλ and the plate front surface 43A of the panel body 43 facing the upper end opening YB of the cylindrical structure Yλ. The fourth light emitter 35 is disposed (installed) on the bottom surface YA of the cylindrical structure Yλ with the plate back surface 43B of the panel body 43 abutting against the bottom surface YA of the cylindrical structure Yλ.
The fourth light emitter 35 emits light from each of the light emitting elements 42 inside the cylindrical structure Yλ.

The first to fourth light emitters 32-35 are arranged at each corner of a square inside the cylindrical structure Yλ, as shown in Figures 12 and 14, and are arranged (installed) on the bottom surface YA of the cylindrical structure Yλ. Inside the cylindrical structure Yλ, the flight indicator 31 is located at the inner center of each of the light emitters 32-35 (the center of the cylindrical structure Yλ), and is arranged (installed) on the bottom surface YA of the cylindrical structure Yλ.

As shown in FIG. 18, the signal receiving unit 36 is connected to the display control unit 38. The signal receiving unit 36 receives lighting color commands (lighting color signals) and display mode commands (ascending display command, descending display command, hovering display command) from the control device 6, and outputs the lighting color commands and lighting mode commands to the display control unit 38.

The lighting transmission unit 37 is connected to the display control unit 38 as shown in FIG. 18. The lighting transmission unit 37 inputs a lighting start command (lighting start signal) from the display control unit 38 and transmits the lighting start command to the lighting reception unit 15 (unmanned aerial vehicle 1).

As shown in FIG. 18, the display control unit 38 is, for example, a CPU (central processing unit) and is connected to the flight indicator 31, the light emitters 32 to 35, the signal receiving unit 36, the lighting transmitting unit 37, and the memory unit 39.

As shown in FIG. 18, the display control unit 38 inputs a lighting color command (lighting color signal) from the signal receiving unit 36 (control device 6) and causes the first to fourth light emitters 32-35 (each light-emitting element 42) to emit light (light up). The display control unit 38 causes one light emitter and the other three light emitters of the first to fourth light emitters 32-35 to emit light (light up) in different colors (light emission colors). For example, the display control unit 38 causes the first light emitter 32 (each light-emitting element 42) and the second to fourth light emitters 33-35 (each light-emitting element 42) to emit light in different colors (light emission colors) and causes the second to fourth light emitters 33-35 to emit light in the same color (light emission color).

The display control unit 38, for example, causes the first light emitter 32 to emit green light (turn on in green) and the second to fourth light emitters 33 to 35 to emit red light (turn on in red). Each light emitting element 42 of the first light emitter 32 emits green light (turns on) and emits green light (green light) inside the cylindrical structure Yλ. Each light emitting element 42 of the second to fourth light emitters 33 to 35 is of the same color, emits red light (turns on) and emits red light (red light) inside the cylindrical structure Yλ.

As shown in FIG. 18, the display control unit 38 inputs a display mode command (ascend display command, descend display command, stop display command) from the signal receiving unit 36 (pilot device 6), reads out display mode data corresponding to the display mode command (display mode signal) from the memory unit 39, and causes the flight indicator 31 to emit light according to the read display mode data.
The display mode command (display mode signal) is a command (signal) corresponding to the flight mode (ascending flight, descending flight, hovering flight) of the unmanned aerial vehicle 1, and is an ascending display command (ascending display signal), a descending display command (descending display signal), and a stop display command (stop display signal).
The display mode data (display pattern data) includes ascent display mode data (ascent display pattern data), descent display mode data (descent display pattern data), and hovering display mode data (hovering display pattern data).

When the display control unit 38 receives an ascent display command from the signal receiving unit 36, as shown in FIG. 18, the display control unit 38 reads out ascent display mode data from the memory unit 39 (display memory unit) and, based on the ascent display mode data, causes each light-emitting element 42 of the flight indicator 31 to emit light (light up), causing the flight indicator 31 to display the information "up arrow UP" (see FIG. 15) indicating ascending flight. When the display control unit 38 receives a descent display command from the signal receiving unit 36, the display control unit 38 reads out descent display mode data from the memory unit 39 and, based on the descent display mode data, causes each light-emitting element 42 of the flight indicator 31 to emit light (light up), causing the flight indicator 31 to display the information "down arrow" (see FIG. 16) indicating descending flight. When the display control unit 38 receives a stop display command (hovering display command) from the signal receiving unit 36, it reads out the stop display mode data from the storage unit 39, and based on the stop display mode data, it causes each light-emitting element 42 of the flight indicator 31 to emit light (light up), causing the flight indicator 31 to display information indicating the stop flight τ, "horizontal line ST" (see FIG. 17).

As shown in FIG. 18, when the display control unit 38 causes each light-emitting element 42 of the flight indicator 31 to emit light (light up), and when it causes each light-emitting element 42 of each light-emitting body 32 to 35 to emit light (light up), it outputs a lighting start command (lighting start signal) to the lighting transmission unit 37.

As shown in FIG. 18, the memory unit 39 (display memory unit) is, for example, a RAM (Random Access Memory), is connected to the display control unit 38, and stores display mode data, such as ascent display mode data (ascent display pattern data), descent display mode data (descent display pattern data), and hovering display mode data (hovering display pattern data).

The imaging device 4 is mounted on the unmanned aerial vehicle 1 as shown in Figures 3 to 7. The imaging device 4 has an inspection camera 3, a fixed-focus first reference camera 51 (reference camera), a fixed-focus second reference camera 52 (reference camera), and a camera control unit 55.

The inspection camera 3 captures an image of the inner surface Ya (inner circumferential surface/inner wall surface) of the cylindrical structure Yλ.
The inspection camera 3 is, for example, a single-lens reflex digital camera. As shown in Figures 3 to 7, the inspection camera 3 is mounted on the unmanned aerial vehicle 1 (airframe unit 21) and connected to a camera control unit 55 and a power source 18.
3 to 5, the inspection camera 3 is attached to the surface 21A (upper surface) of the airframe section 21 (airframe 11) via a gimbal 27. The inspection camera 3 is disposed on the center line e of the airframe 11 (airframe section 21) and attached to the surface 21A of the airframe section 21 (airframe 11) in the direction Z of the center line e of the airframe 11 (unmanned aerial vehicle 1). The inspection camera 3 is attached to the surface 21A of the airframe section 21 (airframe 11) in the direction Z of the center line e of the airframe 11 (unmanned aerial vehicle 1).
As shown in Figure 4, the inspection camera 3 is attached to the surface 21A of the aircraft section 21 (aircraft 11) via a gimbal 27 so that the camera optical axis σ1 passing through the center point O1 (center of photography) of the camera lens 3A is oriented in a direction perpendicular to the center line e of the aircraft 11.

The first reference camera 51 (first camera/reference camera) captures an image including the flight indicator 31 and each light emitter 32-35.

The first reference camera 51 is, for example, a fixed-focus digital camera (fixed-focus camera) with a focal length f1. The first reference camera 51 is mounted on the unmanned aerial vehicle 1 and connected to the camera control unit 55 and the power supply 18. The first reference camera 51 is a fixed-focus wide-angle digital camera (wide-angle lens digital camera).
The first reference camera 51 is attached to the back surface 21B (lower surface) of the aircraft section 21 (aircraft 11) in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1) as shown in Figures 3 and 5. The first reference camera 51 is attached to the back surface 21B of the aircraft section 21 (aircraft 11) in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1). The first reference camera 51 is attached to the back surface 21B (lower surface) of the aircraft section 21 with the camera optical axis σ2 passing through the center point O2 (photography center) of the camera lens 53 parallel to the center line e of the aircraft 11 as shown in Figures 3, 5 and 6. The first reference camera 51 is attached to the aircraft section 21 (aircraft 11) with the camera optical axis σ2 facing downward to the back surface 21B (lower surface) of the aircraft section 21 (aircraft 11). As shown in Fig. 6, the first reference camera 51 is attached to the unmanned aerial vehicle 1 (aircraft section 21) with a distance ε1 between the camera optical axis σ2 and the center line e of the airframe 11 in a direction perpendicular to the center line e of the airframe 11 (airframe section 21). As shown in Fig. 6, the first reference camera 51 is disposed with a distance ω1 (screen distance/screen distance) between the photographing screen 56 (photographic surface/image sensor) of the first reference camera 51 and the rear surface 21B of the airframe section 21 in the direction Z of the center line e of the airframe 11 (unmanned aerial vehicle 1), and the photographing screen 56 is attached to the airframe section 21 perpendicular to the center line e of the airframe 11 (airframe section 21).

As shown in Figure 6, the first reference camera 51 is attached to the underside 21B of the fuselage section 21 at a shooting distance ω2 (shooting distance) in the direction Z of the center line e of the unmanned aerial vehicle 1 (aircraft 11) relative to the inspection camera 3.
The shooting interval ω2 (first shooting interval/first shooting distance) is the interval (distance) obtained by subtracting the focal length f1 (screen distance/screen distance) of the first reference camera 51 from the center distance ψ1 (first center distance/first center distance) between the center point O2 of the camera lens 53 of the first reference camera 51 and the camera optical axis σ1 (center point O1 of the camera lens 3A) of the inspection camera 3 in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1) (ω2 = ψ1 - f1). The shooting interval ω2 is the interval (distance) between the shooting screen 56 of the first reference camera 51 and the center point O1 (camera optical axis σ1) of the camera lens 3A of the inspection camera 3 in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1).
The focal length f1 and center interval ψ1 of the second reference camera 52 are stored in the storage unit 17 .
The center distance ψ1 (center-to-center distance) is the distance (distance) obtained by adding the shooting distance ω2 and the focal length f1 (ψ1=f1+ω2).

The second reference camera 52 (second camera/reference camera) captures an image including the flight indicator 31 and each light emitter 32-35.

The second reference camera 52 is a fixed-focus digital camera (fixed-focus camera) with a focal length f2. The second reference camera 52 is mounted on the unmanned aerial vehicle 1 and connected to the camera control unit 55 and the power supply 18. The second reference camera 52 is a fixed-focus digital camera with a longer focal length than the first reference camera 51. The second reference camera 52 is a fixed-focus telephoto digital camera (fixed-focus telephoto lens digital camera).
The second reference camera 52 is attached to the back surface 21B (lower surface) of the fuselage section 21 (airframe 11) of the unmanned aerial vehicle 1, as shown in Figures 3 and 5. The second reference camera 52 is attached to the back surface 21B of the fuselage section 21 (airframe 11) in the direction Z of the center line e of the fuselage 11 (unmanned aerial vehicle 1). The second reference camera 52 is attached to the back surface 21B of the fuselage section 21 (airframe 11) with the camera optical axis σ3 passing through the center point O3 (photography center) of the camera lens 54 parallel to the center line e of the fuselage 11 and the camera optical axis σ2 of the first reference camera 51, as shown in Figures 3 and 6. The second reference camera 52 is attached to the fuselage section 21 (airframe 11) with the camera optical axis σ3 facing downward toward the lower surface 21B of the fuselage section 21 (airframe 11). As shown in Fig. 6, the second reference camera 52 is attached to the unmanned aerial vehicle 1 (aircraft section 21) with a distance ε2 between the camera optical axis σ3 and the center line e of the airframe 11 in a direction perpendicular to the center line e of the airframe 11. As shown in Fig. 6, the second reference camera 52 is disposed with a distance ω1 (screen distance/screen distance) between the photographing screen 57 (photographic surface/image sensor) of the second reference camera 52 and the rear surface 21B of the airframe section 21 in the direction Z of the center line e of the airframe 11 (unmanned aerial vehicle 1), and the photographing screen 57 is attached to the airframe section 21 perpendicular to the center line e of the airframe 11 (airframe section 21).
The shooting screen 57 of the second reference camera 52 is positioned at the same position as the shooting screen 56 of the first reference camera 51 in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1) and is attached to the back surface 21B of the aircraft section 21 (aircraft 11).

As shown in Figure 6, the second reference camera 52 is attached to the underside 21B of the fuselage section 21 at a shooting distance ω3 (shooting distance) in the direction Z of the center line e of the unmanned aerial vehicle 1 (aircraft 11) relative to the inspection camera 3.
As shown in Fig. 6, the shooting interval ω3 (second shooting interval/second shooting distance) is the interval (distance) obtained by subtracting the focal length f2 of the second reference camera 52 from the center interval ψ2 (second center interval/second center distance) between the center point O3 of the camera lens 54 of the second reference camera 52 and the camera optical axis σ1 (center point O1 of the camera lens 3A) of the inspection camera 3 in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1) (ω3 = ψ2 - f2). The shooting interval ω3 is the interval (distance) between the shooting screen 57 of the second reference camera 52 and the center point O1 (camera optical axis σ1) of the camera lens 3A of the inspection camera 3 in the direction Z of the center line e of the aircraft 11 (unmanned aerial vehicle 1), and is the same interval (distance) as the shooting distance ω2 (first shooting distance).
The focal length f2 and the center distance ψ2 of the first reference camera 51 are stored in the memory unit 17.
The center distance ψ2 (center-to-center distance) is the distance (distance) obtained by adding the shooting distance ω3 and the focal length f1 (ψ2=f2+ω3).

As shown in FIG. 32, the unmanned aerial vehicle 1 is flown in a flight posture in which the inspection camera 3 is directed toward the inner surface YA of the cylindrical structure Yλ, and the first and second reference cameras 51, 52 (reference cameras) are directed toward the flight indicator 31 and each of the light-emitting bodies 32 to 35. The unmanned aerial vehicle 1 is flown in the center line direction Z of the cylindrical structure Yλ, with the inspection camera 3 (camera optical axis σ1) directed toward the inner surface YA of the cylindrical structure Yλ, and the first and second reference cameras 51, 52 (camera optical axes σ2, σ3) directed toward the flight indicator 31 and each of the light-emitting bodies 32 to 35, and is also flown in a stationary flight (hovering flight/hovering) in the air inside the cylindrical structure Yλ, and is also flown in a rotational flight [rotational flight in a state of stationary flight in the air inside the cylindrical structure Yλ (hovering flight state)]. The unmanned aerial vehicle 1 is stopped in the air, for example, by hovering flight in the air inside the cylindrical structure Yλ. Rotational flight is flight in which the unmanned aerial vehicle 1 rotates around the center line e (central axis) of the airframe 11 (airframe section 21).
The unmanned aerial vehicle 1 flies (ascending or descending) in the center line direction Z of the cylindrical structure Yλ, with the camera optical axes σ2, σ3 (center line e of the aircraft 11) of the first and second reference cameras 51, 52 parallel to the center line a (cylinder center line) of the cylindrical structure Yλ (chimney). The unmanned aerial vehicle 1 flies in the center line direction Z of the cylindrical structure Yλ, with the center line e of the aircraft 11 (unmanned aerial vehicle 1) coinciding (positioning) with the center line a (cylinder center line) of the cylindrical structure Yλ.
The unmanned aerial vehicle 1 takes off from the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ and flies in the center line direction Z of the cylindrical structure Yλ.
The inspection camera 3 captures images of the inner surface Ya of the cylindrical structure Yλ while the unmanned aerial vehicle 1 is in stopped flight.
During the rotational flight of the unmanned aerial vehicle 1, the inspection camera 3 photographs the entire circumference of the inner surface Ya of the cylindrical structure Yλ (chimney) multiple times.
The first and second reference cameras 51, 52 capture images including the flight indicator 31 and each of the light emitters 32 to 35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ during flight, including stationary flight (hovering flight/hovering) and rotational flight, of the unmanned aerial vehicle 1. The first reference camera 51 or the second reference camera 52 is a reference camera (camera) of the imaging device 4.

7, the camera control unit 55 is, for example, a CPU (central processing unit) and is mounted (mounted on the unmanned aerial vehicle 1) inside the aircraft 11 (inside the aircraft unit 21). The camera control unit 55 is connected to the inspection camera 3, the position calculation device 5, the image transmission unit 14, the aircraft control unit 16, the first and second reference cameras 51, 52, and the power supply 18, as shown in FIG.
The camera control unit 55 inputs a shooting command (shooting signal) from the aircraft control unit 16 and starts and controls shooting by the inspection camera 3 and the first and second reference cameras 51 and 52.

7, the camera control unit 55 inputs a reference camera shooting command (reference camera shooting signal) from the aircraft control unit 16 and starts shooting with the first reference camera 51. The camera control unit 55 starts shooting with the first reference camera 51 from the start of takeoff of the unmanned aerial vehicle 1, and switches from shooting with the first reference camera 51 to shooting with the second reference camera 52 when the resolution (image resolution) of the image including the flight indicator 31 and each of the light emitters 32 to 35 photographed by the first reference camera 51 becomes equal to or lower than a predetermined resolution.
As shown in FIG. 7, the camera control unit 55 inputs an inspection camera shooting command (inspection camera shooting signal) from the machine control unit 16, starts shooting with the inspection camera 3, and controls shooting (shooting timing).
7, the aircraft control unit 16 is connected to the camera control unit 55. When the aircraft control unit 16 inputs a flight mode command (flight mode start signal) and a lighting start command (lighting start signal) from the pilot device 6, it outputs a reference camera shooting command (reference camera shooting signal) to the camera control unit 55. The aircraft control unit 16 outputs the lighting camera shooting command (lighting camera shooting signal) to the camera control unit 55.

As shown in Figure 7, the camera control unit 55 inputs an image of the inner surface Ya of the cylindrical structure Yλ photographed by the inspection camera 3 from the inspection camera 3, and inputs images including the flight indicator 31 and each light-emitting element 32 to 35 photographed by the first and second reference cameras 51, 52 from the first and second reference cameras 51, 52, and outputs each of the input images to the image transmission unit 14 and the position calculation device 5.
As shown in FIG. 7, when the camera control unit 55 inputs an image including the flight indicator 31 and each of the light emitters 32 to 35 from the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera), it outputs a display mode command (display mode signal) to the aircraft control unit 16 based on the flight modes β, γ, τ displayed on the flight indicator of the image. The camera control unit 55 outputs an ascent display state command (ascent display state signal) to the aircraft control unit 16 based on the "information indicating ascending flight β" (see FIG. 15) displayed on the flight indicator of the image. The camera control unit 55 outputs a descent display state command (descent display state signal) to the aircraft control unit 16 based on the "information indicating descending flight γ" (see FIG. 16) displayed on the flight indicator of the image. The camera control unit 55 outputs a stop display state command (stop display state signal) to the aircraft control unit 16 based on the "information indicating stop flight τ" (see FIG. 17) displayed on the flight indicator of the image.
17, when an ascending display state command is input from the camera control unit 55, the aircraft control unit 16 causes the unmanned aerial vehicle 1 to fly upward. When a descending display state command is input from the camera control unit 55, the aircraft control unit 16 causes the unmanned aerial vehicle 1 to fly downward. When a stopped display mode command (hovering display mode command) is input from the camera control unit 55, the aircraft control unit 16 causes the unmanned aerial vehicle 1 to fly in a stopped state (hovering flight/hovering) in the air inside the cylindrical structure Yλ.

The position calculation device 5 determines the shooting position of the inspection camera 3 (the shooting altitude H of the inspection camera 3, the shooting direction V of the inspection camera 3).
As shown in FIG. 7 , the position calculation device 5 is mounted, for example, inside the airframe 11 (inside the airframe section 21 ) of the unmanned aerial vehicle 1 , and is connected to a camera control section 55 , a memory section 17 , and a power supply 18 .

The position calculation device 5 calculates the shooting altitude H of the inspection camera 3 based on an image (three light-emitting objects in the image) including the flight indicator 31 and each light-emitting object 32-35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) during the stopped flight of the unmanned aerial vehicle 1. The position calculation device 5 calculates the shooting altitude H of the inspection camera 3 based on an image (image captured by the first or second reference camera 51, 52) including the flight indicator 31 and each light-emitting object 32-35 captured by the first or second reference camera 51, 52 at the same time as the inspection camera 3 captures images during the stopped flight of the unmanned aerial vehicle 1 (at the time the inspection camera 3 captures images during the stopped flight of the unmanned aerial vehicle 1). The position calculation device 5 determines the shooting altitude H of the inspection camera 3 using an image (image taken by the first or second reference camera 51, 52) including the flight indicator 31 and each light-emitting element 32-35 taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) during the stopped flight of the unmanned aerial vehicle 1 (or simultaneously with the shooting by the inspection camera 3 during the stopped flight of the unmanned aerial vehicle 1).

When the camera optical axes σ2, σ3 of the first and second reference cameras 51, 52 are directed toward the bottom surface YA of the cylindrical structure Yλ and the camera optical axes σ2, σ3 of the first and second reference cameras 51, 52 are parallel to the center line a of the cylindrical structure Yλ, and the unmanned aerial vehicle 1 is flown in the direction Z of the center line of the cylindrical structure Yλ, the shooting screens 56, 57 (image sensors) of the first and second reference cameras 51, 52 and the shooting reference surface (bottom surface YA of the cylindrical structure Yλ) have the relationship shown in Figure 19.
In FIG. 19, a triangle K1 formed between the shooting screens 56, 57 (image sensors) of the reference cameras 51, 52 and the center points O2, O3 of the camera lenses 53, 54 of the reference cameras 51, 52, and a triangle K2 formed between the center points O2, O3 of the camera lenses 53, 54 of the reference cameras 51, 52 and the floor surface YA (shooting reference surface) of the cylindrical structure Yλ are similar in shape, and the relationship of the formula (1) is established when the focal lengths f1, f2 (screen distance) of the reference cameras 51, 52, the pixel dimensions g1 (dimension of one image) of the shooting screens 56, 57 (image sensors) of the reference cameras 51, 52, the ground pixel dimensions g2 (dimension of one ground pixel) of the ground screen AX of the shooting reference surface (bottom surface YA of the cylindrical structure Yλ), and the altitude above the ground are h.
g1:f1 (or f2)=g2:h Formula (1)

From equation (1), the altitude h above the ground is given by equation (2).
The ground altitude h is the distance (interval) between the shooting reference surface (bottom surface YA of cylindrical structure Yλ) and the center point O2, O3 of the camera lens 53, 54 of the first or second reference camera 51, 52 in the center line direction Z of the cylindrical structure Yλ.

The position calculation device 5 expands (adapts) equation (2) to areas S1, S2 (first area S1, second area S2) that are similar between the shooting screens 56, 57 and the reference shooting surface (the bottom surface YA of the cylindrical structure Yλ) to calculate the altitude h above the ground.
The similar areas are an area S1 (e.g., the area of an equilateral triangle) formed (composed) of three light-emitting elements of the first to fourth light-emitting elements 32 to 35, for example, the first to third light-emitting elements 32 to 34, for an image (image data) including the flight indicator 31 and each light-emitting element 32 to 34 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the photographing by the inspection camera 3 (photographing of the image of the inspection camera 3), and an area S2 (e.g., the area of an equilateral triangle) formed (composed) of three light-emitting elements of the first to fourth light-emitting elements 32 to 35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ, for example, the first to third light-emitting elements 32 to 34.
Applying the similar area S1 (image area) and area S2 (placement area/installation area) to equation (2) results in equation (3).

The area S1 (area of an equilateral triangle) formed (composed) by the first to third light emitters 32-34 in the image (image data) including the flight indicator 31 and each light emitter 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera (reference camera) is calculated from formula (4) as shown in Figures 20 to 23, where the distance between the center line c of the first light emitter 32 and the second light emitter 33 is δα (first light emission distance/first light emitter distance) and the distance between the center line c of the first light emitter 32 and the center line c of the third light emitter 34 is δβ (second light emitter distance/second light emitter distance).

In equation (4), the spacing δα is calculated by multiplying the number of pixels p between the center lines c of the first and second light-emitting bodies 32, 33 in an image (image data) captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) by the dimension q of one pixel (δα = p × q).
In equation (4), the spacing δβ is calculated by multiplying the number of pixels s between the center lines c of the first and third light-emitting bodies 32, 33 in an image (image data) captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) by the dimension q of one pixel (δβ = s × q).

The area S2 (area of an equilateral triangle) formed (configured) by each of the light emitters 32 to 34 (first to third light emitters) arranged (installed) on the bottom surface YA of the cylindrical structure Yλ is calculated from formula (5) as shown in FIG. 24, where the measured distance δγ (first measured distance/first measured distance) between the centers c (panel centers) of the first and second light emitters 32, 33 and the measured distance δτ (second measured distance/second measured distance) between the centers c (panel centers) of the first and third light emitters 32, 34 are:

In formula (5), the intervals δγ and δτ are measured in advance (actually measured) for each of the light emitters 32 to 34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ.
The area S2 is calculated by substituting the measured intervals δγ and δτ into the formula (5). The area S2 (layout area/installation area) is stored in the storage unit 17 in advance.

When the position calculation device 5 receives an image of the flight indicator 31 and each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the camera control unit 55, it reads out the focal lengths f1, f2, area S2 (area of an equilateral triangle) and center intervals ψ1, ψ2 (center-to-center distance) from the memory unit 17, and calculates the area S1 (area of an equilateral triangle) from the image (image data) including the flight indicator 31 and each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera).

After calculating the area S1 (image area), the position calculation device 5 substitutes the areas S1 and S2 and the focal lengths f1 and f2 into equation (3) to calculate the altitude above ground h.

After calculating the ground altitude h, the position calculation device 5 substitutes the ground altitude h and the center intervals ψ1, ψ2 into equation (6) to obtain the shooting altitude H of the inspection camera 3. The shooting altitude H of the inspection camera 3 is obtained by adding the ground altitude h and the center interval ψ1 (or center interval ψ2).
The shooting altitude H of the inspection camera 3 is the height (distance) from the bottom surface YA of the cylindrical structure Yλ in the center line direction Z of the cylindrical structure Yλ when the inspection camera 3 (camera optical axis σ1) is pointed toward the inner surface Ya of the cylindrical structure Yλ, and is the distance (spacing) between the camera optical axis σ1 of the inspection camera 3 (center point O1 of the camera lens 3A) and the bottom surface YA of the cylindrical structure Yλ in the center line direction Z of the cylindrical structure Yλ (the same applies below).
H = h + ψ1, or H = h + ψ2 ... Equation (6)

The position calculation device 5 calculates the shooting altitude H of the inspection camera 3 from equations (5) and (6) using the area S1 (first area S1/first area of the triangle) formed (configured) by three light emitters (e.g., the first to third light emitters 32-34) of the first to fourth light emitters 32-35 in the image captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera), the area S2 (second area/second area of the triangle) formed (configured) by three light emitters (e.g., the first to third light emitters 32-34) of the first to fourth light emitters 32-35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ and similar to the first area S1, the focal lengths f1, f2 of the reference cameras 51, 52, and the center intervals ψ1, ψ2 of the respective cameras.

The position calculation device 5 (position calculation unit) determines the shooting direction V of the inspection camera 3 based on an image (image taken by the first or second reference camera 51, 52) including the flight indicator 31 and each light-emitting element 32-35 taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 takes an image (when the inspection camera 3 takes an image while the unmanned aerial vehicle 1 is stopped and flying).The position calculation device 5 determines the shooting direction V of the inspection camera 3 based on an image (image taken by the first or second reference camera 51, 52) including the flight indicator 31 and each light-emitting element 32-35 taken by the first reference camera 51 or the second reference camera 52 at the same time as the inspection camera 3 takes an image (taking an image of the inspection camera 3).

As shown in Figures 25 to 27, the position calculation device 5 uses the direction correspondence data and the image (image data) including the flight indicator 31 and each light emitting element 32 to 34 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, to determine the photographing direction V of the inspection camera 3. The direction correspondence data is data that represents the correspondence between the direction of the image (image data) photographed by the first reference camera 51 or the second reference camera 52 and the direction of the camera optical axis σ1 of the inspection camera 3 (the photographing direction V of the inspection camera 3). The direction correspondence data defines the diagonal direction WL of the photographing screens 56, 57 (image sensors) of the first and second reference cameras 51, 52 as the direction of the camera optical axis σ1 of the inspection camera 3. As shown in Figures 25 and 26, the diagonal direction WL is, for example, a diagonal direction from the flight indicator 31 (center line b of the flight indicator 31) to one light-emitting element (center line c of the one light-emitting element) at an angle θ with respect to a reference line U that passes through the center line b of the flight indicator 31 and extends in the first direction X, in each of the light-emitting elements 32 to 35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ. In the diagonal direction WL, the one light-emitting element is a light-emitting element that emits light in a color (emission color) different from the other three light-emitting elements, and is, for example, the first light-emitting element 32.

As shown in FIG. 27, when the position calculation device 5 inputs an image GP (image data) including the flight indicator 31 and each light-emitting element 32-35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the camera control unit 55 at the same time as capturing an image by the inspection camera 3, the position calculation device 5 calculates the angle θX (for example, the angle θX between the diagonal direction WL and the center line c of the first light-emitting element 32) of the image GP (image data) captured by the first or second reference camera 51, 52, and determines the capturing direction V of the inspection camera 3.
The shooting direction V of the inspection camera 3 (the direction of the camera optical axis σ1 of the inspection camera 3) is, as shown in Figure 27, a direction in which the inspection camera 3 (camera optical axis σ1 of the inspection camera 3) is rotated by an angle θX in the circumferential direction of the cylindrical structure Yλ based on one light-emitting body (center line c of one light-emitting body) of the first to fourth light-emitting bodies 32 to 35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ when the inspection camera 3 (camera optical axis σ1) is directed toward the inner surface Ya of the cylindrical structure Yλ (the same applies below).

The position calculation device 5, at the same time as the inspection camera 3 takes an image, associates the shooting altitude H (shooting altitude data) and shooting direction V (shooting direction data) of the inspection camera 3 calculated based on the image taken by the first reference camera 51 or the second reference camera 52 with the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ taken by the inspection camera 3 at the same time as the image of the first or second reference camera 51, 52 is taken, and stores the result as one position image data GF in the memory unit 17.

The control device 6 remotely controls the unmanned aerial vehicle 1 and the light-emitting device 2. The control device 6 remotely controls the unmanned aerial vehicle 1 and the light-emitting device 2, for example, from outside the cylindrical structure Yλ.
As shown in Figure 28, the control device 6 has an illumination pattern input unit 71, a signal transmission unit 72, a control unit 73, a flight switching unit 74, a wireless communication unit 75, an image receiving unit 76, a display unit 77, and a power source 78.

As shown in FIG. 28, the light emission pattern input unit 71 is connected to the signal transmission unit 72 and the power supply 78. The light emission pattern input unit 71 inputs a lighting command (lighting signal) and a display mode command (ascending display command, descending display command, hovering display command), and outputs the lighting command and the display mode command (ascending display command, descending display command, hovering display command) to the signal transmission unit 72.

As shown in FIG. 28, when the signal transmitting unit 72 receives a lighting command (lighting signal) and a display mode command (ascending display command, descending display command, hovering display command) from the light emission pattern input unit 71, the signal transmitting unit 72 transmits a lighting command (lighting signal) and a display mode command (ascending display command, descending display command, hovering display command) to the signal receiving unit 36 (light emitting device 2).

As shown in FIG. 28 , the control unit 73 is, for example, a control lever that controls the flight of the unmanned aerial vehicle 1 , and is connected to a wireless communication unit 75 (wireless communication unit) and a power source 78 .
Through operation, the control unit 73 outputs commands (signals) regarding the flight mode of the unmanned aerial vehicle 1, such as an ascending flight command (ascending flight signal), a descending flight command (descending flight signal), and a stopping flight command (stopping flight signal), to the wireless communication unit 75 (transmitting side).

As shown in Figure 28, the flight switching unit 74 is, for example, a switching button that switches the flight of the unmanned aerial vehicle 1 from manual flight (flight by operating the control unit 73) to automatic flight, and is connected to the wireless communication unit 75 and the power source 78.
When operated, the flight switching unit 74 outputs a flight switching command (signal) for the unmanned aerial vehicle 1 to the wireless communication unit 75 (transmitting side).

The wireless communication unit 75 (transmitting side) is connected to the control unit 73 and the power source 78, as shown in Fig. 28. The wireless communication unit 75 inputs flight mode commands (flight mode signals) for the unmanned aerial vehicle 1 from the control unit 73, and transmits commands for the flight mode of the unmanned aerial vehicle 1 to the wireless communication unit 13 (unmanned aerial vehicle 1).
The wireless communication unit 75 is connected to the flight switching unit 74 as shown in Fig. 28. The wireless communication unit 75 inputs a flight switching command (flight switching signal) for the unmanned aerial vehicle 1 from the flight switching unit 74, and transmits the flight switching command to the unmanned aerial vehicle 1 to the wireless communication unit 13 (unmanned aerial vehicle 1).

As shown in FIG. 28, the image receiving unit 76 is connected to the display unit 77 and the power supply 78. The image receiving unit 76 receives images (images taken by the first or second reference camera 51, 52, and images taken by the inspection camera 3) from the image transmitting unit 14 (unmanned aerial vehicle 1) and outputs the images (image data) to the display unit 77.

As shown in FIG. 28, the display unit 77 is, for example, a liquid crystal display, and is connected to the image receiving unit 76 and the power source 78. When the display unit 77 receives an image (image data) from the image receiving unit 76, it displays an image including the flight indicator 31 and each of the light emitters 32-35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera), and an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3.

Next, we will explain the series of processing steps in the cylindrical structure inspection system Xα with reference to the drawings.

A person inspecting the cylindrical structure Yλ (hereinafter, "inspector") transports the unmanned aerial vehicle 1 and the light-emitting device 2 into the interior of the cylindrical structure Yλ, and places (installs) the flight indicator 31 and each light-emitting body 32-35 of the light-emitting device 2 on the bottom surface YA of the cylindrical structure Yλ, as shown in Figures 29 to 31. The flight indicator 31 and each light-emitting body 32-35 are placed (installed) on the bottom surface YA of the cylindrical structure Yλ, in the same manner as described in Figures 1, 2, and 12 to 14.
As shown in Figures 29 to 31, the unmanned aerial vehicle 1 is placed (landed) on the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ with the center line e of the airframe 11 (airframe section 21) coinciding (positioning) with the center line a of the cylindrical structure Yλ (center line b of the flight indicator 31). The unmanned aerial vehicle 1 is placed (landed) on the bottom surface YA of the cylindrical structure Yλ with the camera optical axis σ1 of the inspection camera 3 directed toward the inner surface Ya of the cylindrical structure Yλ and the camera optical axes σ2 and σ3 of the first and second reference cameras 51 and 52 directed toward the bottom surface YA of the cylindrical structure Yλ (the flight indicator 31 and each light-emitting body 32 to 35). The unmanned aerial vehicle 1 is placed (landed) on the bottom surface YA of the cylindrical structure Yλ with the camera optical axes σ2, σ2 of the first and second reference cameras 51, 52 parallel to the center line a of the cylindrical structure Yλ and each support leg 23 abutting against the bottom surface YA of the cylindrical structure Yλ. The unmanned aerial vehicle 1 is placed (installed) on the bottom surface YA of the cylindrical structure Yλ at a distance from the inner side surface Ya of the cylindrical structure Yλ in the radial direction of the cylindrical structure Yλ.

As shown in FIG. 28, the inspector operates the light pattern input unit 71 on the control device 6 to output a light-on command (inspection signal) and an ascent display command (ascent display signal) to the signal transmission unit 72. When the signal transmission unit 72 receives the light-on command and ascent display command, it outputs the light-on command and ascent display command to the signal receiving unit 36 (light-emitting device 2).

In the light-emitting device 2, when a turn-on command and an increase display command are input from a signal transmission unit 72 (control device 6), the signal receiving unit 36 outputs the turn-on command and the increase display command to the display control unit 38, as shown in FIG.
18, when a lighting command (lighting signal) is input, the display control unit 38 causes, for example, each light-emitting element 42 of the first light-emitting body 32 to emit green light (light up in green) and each light-emitting element 42 of the second to fourth light-emitting bodies 33 to 35 to emit red light (light up in red). The first light-emitting body 32 causes each light-emitting element 42 to emit green light (light up) and emit green light inside the cylindrical structure Yλ. The second to fourth light-emitting bodies 33 to 35 cause each light-emitting element 42 to emit red light (light up) and emit red light inside the cylindrical structure Yλ.
18, when the display control unit 38 inputs an ascent display command, it reads out ascent display mode data from the storage unit 39, and based on the ascent display mode data, causes each light-emitting element 42 of the flight indicator 31 to emit light, causing the flight indicator 31 to display information indicating ascent flight α, "up arrow UP" (see FIG. 15). The flight indicator 31 causes each light-emitting element 42 to emit light, displays information indicating ascent flight α, and emits light inside the cylindrical structure Yλ.

As shown in FIG. 18, when the display control unit 38 causes the flight indicator 31 (each light-emitting element 42) to emit light (light up) and the first to fourth light-emitting elements 32 to 35 to emit light (light up), it outputs a lighting start command (lighting start signal) to the lighting transmission unit 37. When the lighting transmission unit 37 receives the lighting start command from the display control unit 38, it transmits the lighting start command to the lighting reception unit 15 (unmanned aerial vehicle 1).

In the unmanned aerial vehicle 1, when the lighting receiver 15 receives a lighting start command from the lighting transmitter 37 (light-emitting device 2) as shown in FIG. 7, it outputs a lighting start command (lighting start signal) to the aircraft control unit 16.

As shown in FIG. 28, the inspector operates the control unit 73 (control lever) to output an ascent command (ascent signal) to the wireless communication unit 75 (transmitter). When the wireless communication unit 75 receives an ascent command from the control unit 73, it transmits the ascent command to the wireless communication unit 13 (unmanned aerial vehicle 1).

In the unmanned aerial vehicle 1, when the wireless communication unit 13 (receiving side) receives an ascent flight command from the wireless communication unit 75 (control device 6), as shown in FIG. 7, it outputs the ascent flight command to the aircraft control unit 16.

As shown in Fig. 7, when the aircraft control unit 16 receives a lighting start command from the lighting receiving unit 15 (Fig. 38: ST01, Yes) and receives an ascending flight command from the wireless communication unit 13 (Fig. 38: ST02, Yes), it rotates the rotor motors 26 (propellers 25) of each rotor unit 12 (Fig. 38: ST03), causing the unmanned aerial vehicle 1 to take off from the bottom surface YA of the cylindrical structure Yλ and ascend. The aircraft control unit 16 controls the flight of the unmanned aerial vehicle 1 so that the center line e of the aircraft 11 (aircraft unit 21) coincides (is located) with the center line a of the cylindrical structure Yλ.
As shown in FIG. 7, when the aircraft control unit 16 inputs a lighting start command from the lighting receiving unit 15 and an ascending flight command from the wireless communication unit 13, it outputs a reference camera shooting command (reference camera start signal) to the camera control unit 55 (FIG. 38: ST04).

As shown in FIG. 7, when the camera control unit 55 receives a reference camera shooting command from the aircraft control unit 16 (FIG. 40: ST51), it starts shooting with the first reference camera 51 (reference camera) (FIG. 40: ST52). The camera control unit 55 starts shooting with the first reference camera 51 (reference camera) from the start of takeoff of the unmanned aerial vehicle 1, and inputs the image captured by the first reference camera 51 (reference camera). The first reference camera 51 starts shooting from the start of takeoff of the unmanned aerial vehicle 1, and outputs the captured image to the camera control unit 55.

As shown in FIG. 7, when the camera control unit 55 inputs an image (image data) captured by the first reference camera 51 from the start of takeoff (start of ascent) of the unmanned aerial vehicle 1 (FIG. 40: ST53), it determines the "information indicating the flight mode" displayed on the flight indicator 31 in the image including the flight indicator 31 and each light-emitting element 32-35 captured by the first reference camera 51, and if the display of the flight indicator 31 in the image (within the image) is "information indicating ascending flight β" (FIG. 40: ST54, Yes), it outputs an ascent display mode command (ascent display mode signal) to the aircraft control unit 16 (FIG. 40: ST50).

As shown in FIG. 7, when the camera control unit 55 inputs an image (image data) captured by the first reference camera 51 from the start of takeoff (start of ascent) of the unmanned aerial vehicle 1 (FIG. 40: ST53), it outputs the image captured by the first reference camera 51 (images of the flight indicator 31 and each light-emitting body 32-35) to the image transmission unit 14.

As shown in FIG. 7, when the image transmission unit 14 receives an image captured by the first reference camera 51 from the camera control unit 55, it transmits the image (image data) captured by the first reference camera 51 to the image receiving unit 76 (control device 6).

As shown in Figure 28, when the image receiving unit 76 receives an image taken by the first reference camera 51 from the image transmitting unit 14 (unmanned aerial vehicle 1), it outputs the image taken by the first reference camera 51 to the display unit 77.
The display unit 77 displays the image captured by the first reference camera 51 .

The inspector checks the image captured by the first reference camera 51 displayed on the display unit 77, and when an image of "information indicating ascending flight β" of the flight indicator 31 (see Figure 15) is displayed on the display unit 77, he operates the flight switching unit 74.
28, the inspector operates the flight switching unit 74 (switch button) to output a flight switching command (flight switching signal) to the wireless communication unit 75. When the wireless communication unit 75 inputs the flight switching command (flight switching signal) from the flight switching unit 74, it transmits the flight switching command to the wireless communication unit 13 (unmanned aerial vehicle 1).

As shown in FIG. 7, when the wireless communication unit 13 receives a flight switching command from the wireless communication unit 75, it outputs the flight switching command to the aircraft control unit 16.

As shown in Figure 7, when the aircraft control unit 16 inputs a flight switching command (flight switching signal) from the wireless communication unit 13 (Figure 38: ST05, Yes), it switches the flight control of the unmanned aerial vehicle 1 (Figure 38: ST06).
When the aircraft control unit 16 inputs a flight switch command (flight switch signal), it switches from flight control of the unmanned aerial vehicle 1 based on operation (remote control) of the control device 6 (control unit 73) to flight control of the unmanned aerial vehicle 1 based on the ``information indicating the flight mode'' displayed on the flight indicator 31 in the image (in the image) captured by the first or second reference camera 51, 52 (Figure 38: ST06).
Based on an ascending flight command from the control device 6 (wireless communication unit 75), the aircraft control unit 16 causes the unmanned aerial vehicle 1 to take off from the bottom surface YA of the cylindrical structure Yλ and fly (ascending flight) the unmanned aerial vehicle 1 in the center line direction Z of the cylindrical structure Yλ, and controls the flight of the unmanned aerial vehicle 1 based on the ``information indicating the flight mode'' displayed on the flight indicator 31 in the image (in the image) captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) based on the input of a flight switching command (flight switching signal) from the wireless communication unit 13 (flight switching unit 74).
As shown in Figure 7, when the aircraft control unit 16 inputs a flight switching command (flight switching signal) from the wireless communication unit 13 and an ascending display mode command (ascending display mode signal) from the camera control unit 55 (Figure 38: ST05, Yes, ST07, Yes), it causes the unmanned aerial vehicle 1 to fly upward (Figure 39: ST08).
The unmanned aerial vehicle 1 takes off from the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ, and flies upward in the center line direction Z of the cylindrical structure Yλ while pointing the camera optical axes σ2, σ3 of the first and second reference cameras 51, 52 toward the flight indicator 31 and each light-emitting element 32-35 arranged on the bottom surface YA of the cylindrical structure Yλ, and while pointing the camera optical axis σ1 of the inspection camera 3 toward the inner surface Ya of the cylindrical structure Yλ.

As shown in FIG. 7, the camera control unit 55 inputs an image including the flight indicator 31 and each light-emitting object 32-35 captured by the first reference camera 51 from the first reference camera 51 (reference camera), detects (calculates) the image resolution of the image including the flight indicator 31 and each light-emitting object 32-35, and if the image resolution is lower than a predetermined resolution (FIG. 42: ST56, No, ST57, Yes), switches from capturing images with the first reference camera 51 (reference camera) to capturing images with the second reference camera 52 (reference camera) (FIG. 42: ST58).
The camera control unit 55, for example, detects (calculates) the image resolution of the flight indicator 31 in an image (in the image) including the flight indicator 31 and each light-emitting element 32 to 35 photographed by the first reference camera 51, and if the image resolution of the flight indicator 31 in the image (in the image) is equal to or lower than a predetermined resolution, switches from photographing with the first reference camera 51 to photographing with the second reference camera 52.
The camera control unit 55 switches from taking pictures with the first reference camera 51 (reference camera) to taking pictures with the second reference camera (reference camera) during the ascending flight of the unmanned aerial vehicle 1, causes the second reference camera 52 to take pictures including the flight indicator 31 and each of the light-emitting bodies 32 to 35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ, and inputs the image taken by the second reference camera 52 (reference camera) including the flight indicator 31 and each of the light-emitting bodies 32 to 35. The second reference camera 52 takes pictures of images including the flight indicator 31 and each of the light-emitting bodies 32 to 35 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ during the ascending flight of the unmanned aerial vehicle 1 (during flight in the center line direction Z of the cylindrical structure Y).

As shown in Figure 7, the camera control unit 55 inputs images including the flight indicator 31 and each light-emitting element 32 to 35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the first or second reference camera 51, 52, and outputs the images captured by the first or second reference camera 51, 52 to the image transmission unit 14.
The camera control unit 55 outputs images captured by the first reference camera 51 (reference camera) to the image transmission unit 14 from the start of takeoff of the unmanned aerial vehicle 1 until the shooting switch, and outputs images including the flight indicator 31 and each light-emitting element 32 to 35 captured by the second reference camera 52 to the image transmission unit 14 upon shooting switch.

As shown in FIG. 7, when the image transmission unit 14 receives an image captured by the first or second reference camera 51, 52 from the camera control unit 55, it transmits the image to the image receiving unit 76 (control device 6).
28, when the image receiving unit 76 receives an image captured by the first or second reference camera 51, 52 from the image transmitting unit 14 (unmanned aerial vehicle 1), the image receiving unit 76 outputs the image to the display unit 77. The display unit 77 displays the image captured by the first or second reference camera 51, 52.

As shown in FIG. 28, while the unmanned aerial vehicle 1 is flying upward, the inspector operates the light emission pattern input unit 71 to input a stop display command (stop display signal) and output the stop display command to the signal transmission unit 72. The signal transmission unit 72 transmits the stop display command (stop display signal) to the signal receiving unit 36 (light-emitting device 2).

In the light-emitting device 2, as shown in FIG. 18, when a stop display command is transmitted from the signal transmission unit 72, the signal reception unit 36 outputs the stop display command to the display control unit 38.
As shown in Fig. 18, when the display control unit 38 receives a stop display command (stop display signal) from the signal receiving unit 36, it reads out the stop display mode data from the storage unit 39, and based on the stop display mode data, it causes each light-emitting element 42 of the flight indicator 31 to emit light, thereby displaying information indicating stop flight τ, "horizontal line ST" (see Fig. 17), on the flight indicator 31. When the display control unit 38 receives a stop display command, it switches from information indicating ascending flight β (see Fig. 14) to information indicating stop flight τ (see Fig. 17), and causes the flight indicator 31 to display the information indicating stop flight τ.
The flight indicator 31 illuminates each of the light-emitting elements 42, switches the display from information indicating the ascending flight α to information indicating the stopping flight τ, and emits light inside the cylindrical structure Yλ.

As shown in FIG. 7, the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) captures an image (image data) including the flight indicator 31 displaying "information indicating stationary flight τ" and each of the light-emitting elements 32-35 by switching the display of the flight indicator 31 during the ascending flight of the unmanned aerial vehicle 1, and outputs the image including the flight indicator 31 displaying "information indicating hovering flight τ" and each of the light-emitting elements 32-35 to the camera control unit 55.

As shown in FIG. 7, when the camera control unit 55 inputs an image including the flight indicator 31 and each light-emitting element 32-35 displaying "information indicating a stopped flight τ" from the first reference camera 51 or the second reference camera 52, the camera control unit 55 determines the display mode of the flight indicator 31 in the image (within the image), and if the display of the flight indicator 31 in the image (within the image) is "information indicating a stopped flight τ" (FIG. 41: ST59, Yes), outputs a stopped display mode command (stop display mode command) to the aircraft control unit 16 (FIG. 41: ST60).

As shown in Figure 7, when the aircraft control unit 16 inputs a stop display mode command (stop display mode signal) from the camera control unit 55 (Figure 39: ST09, Yes), it controls the rotation (rotation speed, rotation direction) of the rotor motors 26 (propellers 25) of each rotor unit 12 to cause the unmanned aerial vehicle 1 to fly hovering (hovering flight/hovering) in the air inside the cylindrical structure Yλ (Figure 39: ST10).
As shown in Fig. 32, the unmanned aerial vehicle 1 is hovered in the air inside the cylindrical structure Yλ with the first and second reference cameras 51, 52 (camera optical axes σ2, σ3) directed toward the flight indicator 31 and each light-emitting body 32-35 (bottom surface YA of the cylindrical structure Yλ) and the inspection camera 3 directed toward the inner surface Ya of the cylindrical structure Yλ, and flies (hovered) in the air at an altitude Z1 from the bottom surface YA of the cylindrical structure Yλ (chimney) in the center line direction Z of the cylindrical structure Yλ, as shown in Fig. 32 and Fig. 33.

As shown in Figure 7, when the aircraft control unit 16 causes the unmanned aerial vehicle 1 to fly in a stopped state (hovering flight/hovering) (Figure 39: ST10), it controls the rotation and stopping of the rotation of the unmanned aerial vehicle 1 by causing the unmanned aerial vehicle 1 to fly in a rotational motion while the unmanned aerial vehicle 1 is in a stopped flight.
For example, while maintaining the stopped flight of the unmanned aerial vehicle 1 (during the stopped flight of the unmanned aerial vehicle 1), the aircraft control unit 16 rotates the unmanned aerial vehicle 1 around the center line a (center line e of the unmanned aerial vehicle 1) of the cylindrical structure Yλ by a predetermined angle (rotation angle) in the circumferential direction of the cylindrical structure Yλ, and repeats the rotation stop of the unmanned aerial vehicle 1 after the rotation of the predetermined angle, thereby rotating the unmanned aerial vehicle 1 (FIG. 39: ST11). As shown in FIG. 33(a), FIG. 34(a), FIG. 35(a) and FIG. 36(a), for example, during the flight stop of the unmanned aerial vehicle 1, the aircraft control unit 16 rotates the unmanned aerial vehicle 1 by an angle (rotation angle): 90 degrees increments, and repeats the rotation stop after the rotation of an angle: 90 degrees, thereby rotating the unmanned aerial vehicle 1 once in the circumferential direction of the cylindrical structure Yλ around the center line a of the cylindrical structure Yλ. During the stopped flight of the unmanned aerial vehicle 1, the aircraft control unit 16 rotates the unmanned aerial vehicle 1 at an angle (rotation angle) of 90 degrees from the start of rotation [0 degrees] and stops it [see Figure 34 (a)], then rotates the unmanned aerial vehicle 1 at an angle (rotation angle) of 180 degrees from the start of rotation and stops it [see Figure 35 (a)], then rotates the unmanned aerial vehicle 1 at an angle (rotation angle) of 270 degrees from the start of rotation and stops it [see Figure 36 (a)], and then rotates the unmanned aerial vehicle 1 at an angle (rotation angle) of 360 degrees from the start of rotation and stops it [see Figure 33 (a)], thereby rotating the unmanned aerial vehicle 1 once.
During stationary flight, the unmanned aerial vehicle 1 rotates in the circumferential direction of the cylindrical structure Yλ (chimney) by a predetermined angle (rotation angle), and then stops rotating after rotating by the predetermined angle, thereby completing one rotation in the circumferential direction of the cylindrical structure Yλ around the center line a of the cylindrical structure Yλ (center line e of the unmanned aerial vehicle 1).

As shown in Fig. 7, when the aircraft control unit 16 causes the unmanned aerial vehicle 1 to fly stationary (hovering flight/hovering), it outputs an inspection camera photography command (inspection camera photography signal) to the camera control unit 55. For example, while the unmanned aerial vehicle 1 is flying stationary, the aircraft control unit 16 rotates the unmanned aerial vehicle 1 at predetermined angles, and when the unmanned aerial vehicle 1 is stopped after each rotation at each predetermined angle, it outputs an inspection camera photography command (inspection camera photography signal) to the camera control unit 55 at each predetermined angle (Fig. 39: ST12).
For example, when the unmanned aerial vehicle 1 starts to rotate, the aircraft control unit 16 outputs a 0-degree inspection camera shooting command to the camera control unit 55, and when the unmanned aerial vehicle 1 rotates 90 degrees from the start of rotation and stops, it outputs a 90-degree inspection camera shooting command to the camera control unit 55, when the unmanned aerial vehicle 1 rotates 180 degrees from the start of rotation and stops, it outputs a 180-degree inspection camera shooting command to the camera control unit 55, and when the unmanned aerial vehicle 1 rotates 270 degrees from the start of rotation and stops, it outputs a 270-degree inspection camera shooting command to the camera control unit 55 (Figure 39: ST12).

As shown in FIG. 7, when the camera control unit 55 inputs an inspection camera shooting command (inspection camera shooting signal) from the aircraft control unit 16 (FIG. 41: ST61, Yes), it starts shooting with the inspection camera 3, inputs an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3 from the inspection camera 3, and simultaneously with the shooting by the inspection camera 3, inputs an image including the flight indicator 31 and each light-emitting element 32-35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the first or second reference camera 51, 52 (FIG. 41: ST62).
When the camera control unit 55 receives an inspection camera shooting command for each angle (inspection camera shooting command for each angle) from the aircraft control unit 16 (FIG. 41: ST61, Yes), it starts shooting the inspection camera 3 for each inspection camera shooting command, inputs an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3 from the inspection camera 3, and simultaneously with the shooting of the inspection camera 3 (synchronized with the shooting of the inspection camera 3), inputs an image including the flight indicator 31 and each light-emitting body 32-35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the first or second reference camera 51, 52 (FIG. 41: ST62). Before switching the shooting of the reference camera (FIG. 42: ST57, No), the camera control unit 55 inputs an image including the flight indicator 31 and each light-emitting body 32-35 captured by the first reference camera 51 (reference camera) from the first reference camera 51 simultaneously with the shooting of the inspection camera 3. After switching the reference camera's shooting (Figure 42: ST57, Yes, ST58), the camera control unit 55 inputs from the second reference camera 52 an image including the flight indicator 31 and each light-emitting element 32 to 35 captured by the second reference camera 52 (reference camera) at the same time as capturing images by the inspection camera 3.

As shown in Figure 7, when the camera control unit 55 inputs an inspection camera shooting command at 0 degrees from the aircraft control unit 16, it starts shooting with the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ captured by the inspection camera 3, and simultaneously with the shooting by the inspection camera 3 (when shooting with the inspection camera 3), inputs an image GP1 including the flight indicator 31 and each light-emitting element 32 to 35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see Figure 33 (b)]. When the camera control unit 55 receives a 90-degree inspection camera shooting command from the aircraft control unit 16, it starts shooting with the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3, and simultaneously with the shooting by the inspection camera 3 (when shooting with the inspection camera 3), inputs an image GP2 including the flight indicator 31 and each light-emitting element 32 to 35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see Figure 34 (b)]. When the camera control unit 55 receives a command to shoot 180 degrees with the inspection camera from the aircraft control unit 16, it starts shooting with the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3, and simultaneously with the shooting with the inspection camera 3 (when shooting with the inspection camera 3), it inputs an image GP3 including the flight indicator 31 and each of the light-emitting elements 32 to 35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see Figure 35 (b)]. When the camera control unit 55 inputs a 270-degree inspection camera shooting command from the aircraft control unit 16, it starts shooting with the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3, and simultaneously with the shooting by the inspection camera 3 (when shooting with the inspection camera 3), inputs an image GP4 including the flight indicator 31 and each light-emitting element 32 to 35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see Figure 36 (b)].
The inspection camera 3 captures images of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ (chimney) at predetermined angles by the rotational flight of the unmanned aerial vehicle 1, and captures images of the entire circumference of the inner surface YA of the cylindrical structure Yλ in multiple installments.
The first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) captures images including the flight indicator 31 and each light-emitting element 32-35 while the unmanned aerial vehicle 1 is in stopped flight (during hovering flight/while hovering) (it captures images including the flight indicator 31 and each light-emitting element 32-35 simultaneously with the inspection camera 3).

As shown in FIG. 7, while the unmanned aerial vehicle 1 is stopped in flight, the camera control unit 55 outputs to the position calculation device 5 an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3, and an image including the flight indicator 31 and each light-emitting body 32 to 35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the image is captured by the inspection camera 3 (FIG. 41: ST65).

The camera control unit 55, for example, for each specified angle (for each inspection camera shooting command), associates an image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3 with an image including the flight indicator 31 and each light-emitting element 32 to 35 photographed by the first reference camera (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, and outputs the images to the position calculation device 5 (Figure 41: ST63).
The camera control unit 55 corresponds the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera input based on the inspection camera shooting specification of 0 degrees, and the image GP1 [see FIG. 33 (b)] including the flight indicator 31 and each light-emitting body 32-35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3, and outputs it to the position calculation device 5. The camera control unit 55 corresponds the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3 input based on the inspection camera shooting command of 90 degrees, and the image GP2 [see FIG. 34 (b)] including the flight indicator 31 and each light-emitting body 32-35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3, and outputs it to the position calculation device 5. The camera control unit 55 corresponds the image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3, which was input based on the 180-degree inspection camera shooting command, and the image GP3 [see FIG. 35(b)] including the flight indicator 31 and each light-emitting body 32-35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, and outputs it to the position calculation device 5. The camera control unit 55 corresponds the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera, which was input based on the 270-degree inspection camera shooting command, and the image GP4 [see FIG. 36(b)] including the flight indicator 31 and each light-emitting body 32-35 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, and outputs it to the position calculation device 5 (FIG. 41: ST63).

As shown in FIG. 7, the camera control unit 55 outputs to the image transmission unit 14 an image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ input from the inspection camera 3 at each predetermined angle (each inspection camera command at a predetermined angle), and an image taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the image is taken by the inspection camera 3.

As shown in FIG. 7, when the image transmission unit 14 receives from the camera control unit 55 the image captured by the inspection camera 3 and the image captured by the first or second reference camera 51, 52 at the same time as the image is captured by the inspection camera 3, the image transmission unit 14 transmits the image captured by the inspection camera 3 and the image captured by the first or second reference camera 51, 52 to the image receiving unit 76 (control device 6).

In the control device 6, as shown in FIG. 28, when the image receiving unit 76 receives from the image transmitting unit 14 (unmanned aerial vehicle 1) images taken by the inspection camera 3 and images GP1 to GP44 taken by the first or second reference camera 51 at the same time as the images are taken by the inspection camera 3 [see FIG. 33(b), FIG. 34(b), FIG. 35(b) and FIG. 36(b)], the image receiving unit 76 outputs the images taken by the inspection camera 3 and the images taken by the first or second reference camera 51, 52 to the display unit 77 and displays them on the display unit 77.

As shown in FIG. 7, when the position calculation device 5 receives from the camera control unit 55 an image captured by the inspection camera 3 and an image including the flight indicator 31 and each light-emitting body 32-35 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the image captured by the inspection camera 3 (FIG. 43: ST101, Yes, ST102, Yes), it reads each focal length f1, f2, each center interval ψ1, ψ2 and area S2 from the memory unit 17 in the same manner as described in FIG. 19 to FIG. 24. At the same time as the image is taken by the inspection camera 3, the area S1 (area of an equilateral triangle) formed (composed) by three of the first to fourth light emitters 32-35, for example the first to third light emitters 32-34, is calculated in the image (within the image) taken by the first reference camera 51 (reference camera) or the second reference camera 52), and the shooting altitude H of the inspection camera 3 is calculated from equations (5) and (6) using the focal lengths f1, f2, center intervals ψ1, ψ2, and areas S1, S2 (Figure 43: ST103).

As shown in Figure 33, based on an inspection camera shooting command of 0 degrees, the position calculation device 5 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-34 of the image GP1 (in the image) captured by the first or second reference camera 51, 52 at the same time as shooting with the inspection camera 3, and calculates the shooting altitude H1 of the inspection camera M1 from equations (5) and (6) using the respective focal lengths f1, f2, the respective center intervals ψ1, ψ2 and the respective areas S1, S2.
As shown in Figure 34, based on a 90-degree inspection camera shooting command, the position calculation device 5 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-34 of the image GP2 (in the image) captured by the first or second reference camera 51, 52, simultaneously with the inspection camera 3, and calculates the shooting altitude H2 of the inspection camera 3 from equations (5) and (6) using the respective focal lengths f1, f2, center spacing ψ1, ψ2 and respective areas S1, S2. As shown in Figure 35, based on a 180-degree inspection camera shooting command, the position calculation device 5 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-33 of the image GP3 (in the image) captured by the first or second reference camera 51, 52, at the same time as the shooting by the inspection camera 3, and calculates the shooting altitude H3 of the inspection camera 3 from equations (5) and (6) using the respective focal lengths f1, f2, respective center intervals ψ1, ψ2 and respective areas S1, S2. As shown in FIG. 36, based on a 270-degree inspection camera 3 shooting command, the position calculation device 5 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-34 of the image GP3 (in the image) captured by the first or second reference camera 51, 52 at the same time as shooting with the inspection camera 3, and determines the shooting altitude H4 of the inspection camera 3 from equations (5) and (6) using the respective focal lengths f1, f2, the respective center intervals ψ1, ψ2 and the respective areas S1, S2 (FIG. 43: ST103).

As explained in Figures 25 to 27, the position calculation device 5, at the same time as the inspection camera 3 takes an image, determines the shooting direction V of the inspection camera 3 using the image including the flight indicator 31 and each light-emitting element 32 to 35 taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) and the direction correspondence data (diagonal direction WL) (Figure 43: ST104).

As shown in FIG. 33, the position calculation device 5 calculates the angle θa between the first light emitter 32 (center line c of the first light emitter 32) of the image GP1 captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data, based on the inspection camera shooting command of 0 degrees, and obtains the shooting direction V1 of the inspection camera 3. The shooting direction V1 of the inspection camera 3 is the direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θa in the circumferential direction of the cylindrical structure Yλ, based on the first light emitter 32 (center line c of the first light emitter 32), as shown in FIG. 33. As shown in FIG. 34, the position calculation device 5 calculates the angle θb between the first light emitter 32 (center line c of the first light emitter 32) of the image GP2 captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data, based on the inspection camera shooting command of 90 degrees, and obtains the shooting direction V2 of the inspection camera 3. The shooting direction V2 of the inspection camera 3 is a direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θb in the circumferential direction of the cylindrical structure Yλ based on the first light emitter 32 (center line c of the first light emitter 32) as shown in FIG. 34. The position calculation device 5 calculates the angle θc between the first light emitter 32 (center line c of the first light emitter 32) of the image GP3 (in the image) captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data, based on the inspection camera shooting command of 180 degrees as shown in FIG. 35, and obtains the shooting direction V3 of the inspection camera 3. The shooting direction V3 of the inspection camera 3 is a direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θc in the circumferential direction of the cylindrical structure Yλ based on the first light emitter 32 (center line c of the first light emitter 32) as shown in FIG. 35. As shown in FIG. 36, the position calculation device 5 calculates the angle θd between the first light emitter 32 (center line c of the first light emitter 32) of the image GP4 (in the image) captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data at the same time as the inspection camera 3 captures the image based on the 270-degree inspection camera capture command, and determines the capture direction V3 of the inspection camera 3. As shown in FIG. 36, the capture direction V3 of the inspection camera 3 is the direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θd in the circumferential direction of the cylindrical structure Yλ based on the first light emitter 32 (center line c of the first light emitter 32) (FIG. 43: ST104).

When the position calculation device 5 determines the shooting altitude H and shooting direction V of the inspection camera 3, it associates the shooting altitude H and shooting direction V of the inspection camera 3 determined based on the image captured by the first or second reference camera 51, 52 at the same time as the inspection camera 3 captures the image (capturing the image of the inspection camera 3), with the inner surface Ya of the cylindrical structure Yλ (chimney) captured by the inspection camera 3 at the same time as the first or second reference camera 51, 52 captures the image (capturing the image of the first or second reference camera 51, 52), and stores this as position image data GF in the memory unit 17 (Figure 43: ST105, ST106).

The position calculation device 5 associates the shooting altitude H1 and shooting direction V1 of the inspection camera 3 obtained based on the image GP1 taken by the first or second reference camera 51, 52 with the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 at the same time as the image GP1 of the first or second reference camera 51, 52 is taken, and stores the associated image data GF1 in the storage unit 17. The position calculation device 5 associates the shooting altitude H2 and shooting direction V2 of the inspection camera 3 obtained based on the image GP2 taken by the first or second reference camera 51, 52 at the same time as the image GP2 of the first or second reference camera 51, 52 is taken, and stores the associated image data GF2 in the storage unit 17. The position calculation device 5 associates the shooting altitude H3 and shooting direction V3 of the inspection camera 3 obtained based on the image GP3 taken by the first or second reference camera 51, 52 at the same time as the inspection camera 3 takes the image, and the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 at the same time as the image GP3 of the first or second reference camera 51, 52 takes the image, and stores the associated image data GF3 in the storage unit 17. The position calculation device 5 associates the shooting altitude H4 and shooting direction V4 of the inspection camera 3 obtained based on the image GP4 taken by the first or second reference camera 51, 52 at the same time as the inspection camera 3 takes the image, and stores the associated image data GF4 of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 in the storage unit 17 (FIG. 43: ST105, ST106).

As shown in FIG. 7, when the unmanned aerial vehicle 1 rotates once (360 degrees) during the stationary flight of the unmanned aerial vehicle 1, the aircraft control unit 16 outputs an inspection camera photography stop command (inspection camera photography stop signal) to the camera control unit 55 (FIG. 39: ST13, Yes) to maintain the stationary flight of the unmanned aerial vehicle 1 (FIG. 39: ST14).

As shown in FIG. 7, when the camera control unit 55 receives an inspection camera image capture stop command from the aircraft control unit 16 (FIG. 41: ST64, Yes), it stops (pauses) image capture by the inspection camera 3.

As shown in FIG. 28, when the inspector checks the image captured by the inspection camera 3 displayed on the display unit 77 and confirms that the inspection camera 3 has stopped capturing images, he or she operates the light emission pattern input unit 71 to output an increase display command (an increase display signal) to the signal transmission unit 72. When the signal transmission unit 72 receives the increase display command, it outputs the increase display command to the signal receiving unit 36 (light-emitting device 2).

In the light-emitting device 2, when the signal receiving unit 36 receives an increase display command from the signal transmitting unit 72 (control device 6) as shown in FIG. 18, the signal receiving unit 36 outputs the increase display command to the display control unit 38.
18, when the display control unit 38 inputs an ascent display command, it reads out ascent display mode data from the storage unit 39, and based on the ascent display mode data, switches the information indicating the stopping flight τ, "horizontal line ST" (see FIG. 17), to the information indicating the ascending flight α, "up arrow UP" (see FIG. 15), and displays it on the flight indicator 31. The flight indicator 31 displays the information indicating the ascending flight α, instead of the information indicating the stopping flight τ.

As shown in FIG. 7, the camera control unit 55 inputs an image including the flight indicator 31 and each light emitter 32-35 captured by the first or second reference camera 51, 52, determines the "information indicating the flight mode" displayed on the flight indicator 31 in the image, and if the display of the flight indicator 31 in the image is "information indicating ascending flight β" (FIG. 40: ST54, Yes), outputs an ascending flight mode command to the aircraft control unit 16 (FIG. 40: ST55).

As shown in FIG. 7, when the aircraft control unit 16 inputs an ascending display mode command from the camera control unit 55 (FIG. 38: ST07, Yes), it causes the unmanned aerial vehicle 1 (see FIG. 32), which is flying stationary at altitude Z1, to fly upward (FIG. 39: ST08).

As shown in FIG. 28, while the unmanned aerial vehicle 1 is flying upward, the inspector operates the light emission pattern input unit 71 to input a stop display command (stop display signal) and output the stop display command to the signal transmission unit 72. The signal transmission unit 72 transmits the stop display command (stop display signal) to the signal receiving unit 36 (light-emitting device 2).

In the light-emitting device 2, when a stop display command is transmitted from the signal transmission unit 72, the signal reception unit 36 outputs the stop display command to the display control unit 38 as shown in FIG.
As shown in Fig. 18, when the display control unit 38 receives a stop display command (stop display signal) from the signal receiving unit 36, it reads out the stop display mode data from the storage unit 39, and based on the stop display mode data, it causes each light-emitting element 42 of the flight indicator 31 to emit light, thereby displaying information indicating stop flight τ, "horizontal line ST" (see Fig. 17), on the flight indicator 31. When the display control unit 38 receives a stop display command, it switches from information indicating ascending flight β (see Fig. 14) to information indicating stop flight τ (see Fig. 17), and causes the flight indicator 31 to display the information indicating stop flight τ.

As shown in FIG. 7, the camera control unit 55 inputs an image including the flight indicator 31 and each light-emitting element 32-35 displaying "information indicating a stopped flight τ" from the first reference camera 51 or the second reference camera 52, determines the display mode of the flight indicator 31 in the image (in the image), and if the display of the flight indicator 31 in the image (in the image) is "information indicating a stopped flight τ" (FIG. 41: ST59, Yes), outputs a stopped display mode command (stop display mode command) to the aircraft control unit 16 (FIG. 41: ST60).

As shown in Figure 7, when the aircraft control unit 16 inputs a stop display mode command (stop display mode signal) from the camera control unit 55, it controls the rotation (rotation speed, rotation direction) of the rotor motors 26 (propellers 25) of each rotor unit 12 to cause the unmanned aerial vehicle 1 to fly hovering (hovering flight/hovering) in the air inside the cylindrical structure Yλ (Figure 39: ST10).
As shown in Figures 32 and 37, the unmanned aerial vehicle 1 flies hovering in the air from altitude Z1 to altitude Z2 inside the cylindrical structure Yλ (chimney) in the center line direction Z of the cylindrical structure Yλ.

When the aircraft control unit 16 stops the unmanned aerial vehicle 1 in flight (ST10 in Figure 39), it executes ST11 to ST14 shown in Figure 39, and when the camera control unit 55 outputs a stop display mode command to the aircraft control unit 16 (ST60 in Figure 41), it executes ST61 to ST64 shown in Figure 41 to output an image of the inner surface Ya of the cylindrical structure Yλ photographed by the inspection camera 3, and an image including the flight indicator 31 and each light-emitting element 32 to 35 photographed by the first or second reference camera 51, 52 to the position calculation device, and the position calculation device 5 executes ST101 to ST106 shown in Figure 43 to store the position image data GF (the shooting altitude H of the inspection camera 3, the shooting direction V of the inspection camera 3, and the image photographed by the inspection camera 3) in the memory unit 17.
In this way, the inspector operates the light emission pattern input unit 71 to input multiple ascent display commands and stop display commands, the aircraft control unit 16 executes ST07 to ST14 shown in Figures 38 and 39 multiple times, the camera control unit 55 executes ST54 to ST64 shown in Figures 40 and 41 multiple times, and the position calculation device 5 executes ST101 to ST106 shown in Figure 43 multiple times, thereby storing position image data GF at multiple altitudes inside the cylindrical structure Yλ in the memory unit 17.

As shown in FIG. 28, the inspector operates the light emission pattern input unit 71 to output a descent display command (descent display signal) to the signal transmission unit 72. When the signal transmission unit 72 inputs the descent display command, it outputs an ascent display command to the signal receiving unit 36 (light-emitting device 2).

In the light-emitting device 2, as shown in FIG. 18, when a descent display command is transmitted from the signal transmission unit 72, the signal reception unit 36 outputs the descent display command to the display control unit 38.
As shown in Figure 18, when the display control unit 38 inputs a descent display command (stop display signal) from the signal receiving unit 36, it reads out descent display mode data from the memory unit 39 and, based on the descent display mode data, illuminates each light-emitting element 42 of the flight indicator 31 to display information indicating descent flight γ, "horizontal line ST" (see Figure 16), on the flight indicator 31.

As shown in FIG. 7, the camera control unit 55 inputs an image including the flight indicator 31 and each light-emitting element 32-35 displaying "information indicating descending flight γ" from the first reference camera 51 or the second reference camera 52, determines the display mode of the flight indicator 31 in the image (in the image), and if the display of the flight indicator 31 in the image (in the image) is "information indicating descending flight β" (FIG. 41: ST65, Yes; FIG. 42: ST66, Yes), outputs a descending display mode command (stop display mode command) to the aircraft control unit 16 (FIG. 41: ST66).

As shown in Figure 7, when the aircraft control unit 16 inputs a descent display mode command (descent display mode signal) from the camera control unit 55 (Figure 39: ST15, Yes), it controls the rotation (rotation speed, rotation direction) of the rotor motors 26 (propellers 25) of each rotor unit 12 to cause the unmanned aerial vehicle 1 to descend from the air inside the cylindrical structure Yλ toward the bottom surface YA.
As shown in Figures 29, 30 and 37, the unmanned aerial vehicle 1 descends from the air inside the cylindrical structure Yλ (chimney) in the center line direction Z of the cylindrical structure Yλ and lands on the bottom surface YA of the cylindrical structure Yλ.

In the inspection system Xα for cylindrical structures, while the unmanned aerial vehicle 1 is in stopped flight, the shooting altitude of the inspection camera 3 can be determined based on an image taken by the first or second reference camera 51, 52 (reference camera), or an image taken by the first or second reference camera 51, 52 (reference camera) simultaneously with shooting by the inspection camera 3, and the shooting direction V of the inspection camera 3 can be determined based on an image taken by the first or second reference camera 51, 52 (reference camera) simultaneously with shooting by the inspection camera 3.
An inspector can obtain position image data GF (the shooting altitude H and shooting direction V of the inspection camera 3, and the image captured by the inspection camera 3) from the memory unit 17 of the unmanned aerial vehicle 1 that has landed on the bottom surface YA of the cylindrical structure Yλ, and can inspect the condition of the inner surface Ya of the cylindrical structure Yλ by referring to the position image data GF. If the inspector notices an abnormality (cracks, defects in the inner surface coating material (lining material, etc.)) in the image captured by the inspection camera 3, the inspector can identify the position of the abnormality that has occurred on the inner surface Ya of the cylindrical structure Yλ by referring to the shooting altitude H and shooting direction V of the inspection camera 3 that are associated with the image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3.

The second embodiment of the inspection system for a cylindrical structure will be described with reference to Figures 44 to 68.
44 to 68, the same reference numerals as those in FIGS. 1 to 43 denote the same members and configurations, and detailed description thereof will be omitted.

In Figures 44 to 68, the cylindrical structure inspection system Xβ of the first embodiment (hereinafter referred to as "cylindrical structure inspection system β") captures an image of the inner surface Ya of the cylindrical structure Yλ and inspects the condition of the inner surface Ya from the image of the cylindrical structure Yλ.

As shown in Figures 3 to 6 and Figure 46, the inspection system Xβ for cylindrical structures includes an unmanned aerial vehicle 1 and an imaging device 4 (inspection camera 3, first and second reference cameras 51, 52). As shown in Figure 49, the inspection system Xβ for cylindrical structures includes a light emitting device 22. As shown in Figure 46, the inspection system Xβ for cylindrical structures includes a position calculation device 65 (position calculation unit). As shown in Figure 28, the inspection system Xβ for cylindrical structures includes a control device 6.

As shown in Figures 58 and 63, the unmanned aerial vehicle 1 is flown inside the cylindrical structure Yλ. As shown in Figures 3 to 6 and 46, the unmanned aerial vehicle 1 has an airframe 11, multiple (eight) rotor units 12, a wireless communication unit 13 (wireless communication unit), an image transmission unit 14, a lighting reception unit 15, an aircraft control unit 86, a memory unit 17, and a power source 18.

The aircraft control unit 86 is, for example, a CPU (central processing unit) and is mounted (placed) inside the aircraft unit 21 (aircraft 11) as shown in FIG. 46. The aircraft control unit 86 is connected to the rotor motor 26 of each rotor unit 12, the wireless communication unit 13, and the power source 18.

46, the aircraft control unit 86 is connected to the rotor motor 26 of each rotor unit 12. The aircraft control unit 86 inputs a flight mode command (flight mode signal) from the wireless communication unit 13, starts the rotation of the rotor motor 26 of each rotor unit 12, and controls the start of flight of the unmanned aerial vehicle 1 and the flight of the unmanned aerial vehicle 1.
The aircraft control unit 86 controls the rotor motors 26 of each rotor unit 12 to have the same rotation speed, thereby generating lift in the aircraft 11. The aircraft control unit 86 controls the rotation (rotation speed, rotation direction) of the rotor motors 26 of each rotor unit 12, thereby causing the unmanned aerial vehicle 1 to ascend, descend, hover, or rotate.

The light-emitting device 22 is disposed (installed) inside the cylindrical structure Yλ, as shown in Figures 44 and 45. As shown in Figures 44, 45, and 47 to 49, the light-emitting device 22 has a first light emitter 32 (first light-emitting panel), a second light-emitting panel 33 (second light-emitting panel), a third light-emitting panel 34 (third light-emitting panel), a lighting transmitter 37, a signal receiver 96, and a display controller 98.

The first to third light emitters 32 to 34 are arranged (placed) on the bottom surface YA of the cylindrical structure Yλ in the same manner as described with reference to FIG. 12 (see FIGS. 47 and 48).
In addition, the third light emitter 34 may be arranged on the bottom surface YA of the cylindrical structure Yλ at a distance from the first light emitter 32 in the second direction Y intersecting the first direction Z, and at a distance from the second light emitter 33.

As shown in FIG. 49, the signal receiving unit 96 is connected to the display control unit 98. The signal receiving unit 96 receives a lighting color command (lighting color signal) from the control device 6 and outputs the lighting color command to the display control unit 98.

As shown in FIG. 49, the display control unit 98 is, for example, a CPU (central processing unit) and is connected to each of the light emitters 32 to 34 and the signal receiving unit 76.

As shown in FIG. 49, the display control unit 98 receives a lighting color command (lighting color signal) from the signal receiving unit 96 (control device 6) and causes the first to third light emitters 32-34 (each light-emitting element 42) to emit light (light up). The display control unit 98 causes one light emitter and the other three light emitters in the first to third light emitters 32-34 to emit light (light up) in different colors (light emission colors). For example, the display control unit 98 causes the first light emitter 32 (each light-emitting element 42) and the second and third light emitters 33, 34 (each light-emitting element 42) to emit light in different colors (light emission colors), and causes the second and third light emitters 33, 34 to emit light in the same color (light emission color).

The imaging device 4 is mounted on the unmanned aerial vehicle 1 as shown in Figures 3 to 6 and 46. The imaging device 4 has an inspection camera 3, a fixed-focus first reference camera 51 (reference camera), a fixed-focus second reference camera 52 (reference camera), and a camera control unit 105.

The first and second reference cameras 51, 52 capture images including each of the light-emitting elements 32-34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ during flight, including stationary flight (hovering flight/hovering) and rotational flight, of the unmanned aerial vehicle 1.

46, the camera control unit 105 is, for example, a CPU (central processing unit) and is mounted (mounted on the unmanned aerial vehicle 1) inside the aircraft 11 (inside the aircraft unit 21). The camera control unit 105 is connected to the inspection camera 3, the position calculation device 65, the image transmission unit 14, the aircraft control unit 86, the first and second reference cameras 51, 52, and the power supply 18, as shown in FIG.
The camera control unit 105 inputs a shooting command (shooting signal) from the aircraft control unit 86, and starts and controls shooting by the inspection camera 3 and the first and second reference cameras 51, 52.

46, the camera control unit 105 inputs a reference camera shooting command (reference camera shooting signal) from the aircraft control unit 86 and starts shooting with the first reference camera 51. The camera control unit 105 starts shooting with the first reference camera 51 from the start of takeoff of the unmanned aerial vehicle 1, and switches from shooting with the first reference camera 51 to shooting with the second reference camera 52 when the resolution (image resolution) of the image including the flight indicator 31 and each of the light emitters 32 to 34 photographed by the first reference camera 51 becomes equal to or lower than a predetermined resolution.
As shown in FIG. 46, the camera control unit 105 inputs an inspection camera shooting command (inspection camera shooting signal) from the machine control unit 86, starts shooting with the inspection camera 3, and controls shooting (shooting timing).
The aircraft control unit 86 is connected to the camera control unit 105 as shown in Fig. 46. When the aircraft control unit 86 receives a flight mode command (flight mode start signal) from the pilot device 6, it outputs a reference camera shooting command (reference camera shooting signal) to the camera control unit 105. The aircraft control unit 86 outputs a lighted camera shooting command (lighted camera shooting signal) to the camera control unit 105.

As shown in FIG. 46, the camera control unit 105 inputs an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3 from the inspection camera 3, and inputs images including each of the light-emitting bodies 32 to 34 captured by the first and second reference cameras 51, 52 from the first and second reference cameras 51, 52, and outputs each of the input images to the image transmission unit 14 and the position calculation device 65.

The position calculation device 65, as shown in FIG. 46, determines the shooting position of the inspection camera 3 (the shooting altitude H of the inspection camera 3, and the shooting direction V of the inspection camera 3).
As shown in FIG. 46 , the position calculation device 65 is mounted, for example, inside the body 11 (inside the body section 21) of the unmanned aerial vehicle 1 and connected to the camera control section 105, memory section 17 and power supply 18.

The position calculation device 65 calculates the shooting altitude H of the inspection camera 3 based on an image including each light-emitting body 32-34 (first to third light-emitting bodies 32-34 in the image) captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) during the stopped flight of the unmanned aerial vehicle 1. The position calculation device 65 calculates the shooting altitude H of the inspection camera 3 based on an image including each light-emitting body 32-34 (first to third light-emitting bodies 32-34 in the image) captured by the first or second reference camera 51, 52 at the same time as the inspection camera 3 takes an image during the stopped flight of the unmanned aerial vehicle 1. The position calculation device 65 uses images (images taken by the first or second reference camera 51, 52) including each light-emitting element 32-34 taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) during the stopped flight of the unmanned aerial vehicle 1 (or simultaneously with the image taken by the inspection camera 3 during the stopped flight of the unmanned aerial vehicle 1) to determine the shooting altitude H of the inspection camera 3.

As described in Figures 19 to 24, the position calculation device 65 calculates the area S1 (for example, the area of an equilateral triangle) formed (composed) by the first to third light emitters 32 to 34 in the image (in the image) captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) during the stationary flight of the unmanned aerial vehicle 1 (or simultaneously with the shooting of the inspection camera 3) (see Figure 50), reads out each focal length f1, f2, each center interval ψ1, ψ2, and area S2, and substitutes each focal length f1, f2, and each area S1, S2 into equation (3) to calculate the ground altitude h. The position calculation device 65 substitutes the calculated ground altitude h and center interval ψ1, ψ2 into equation (6) to obtain the shooting altitude H of the inspection camera 3. As explained in FIG. 24, area S2 is formed (configured) by the first to third light emitters 32 to 34 arranged on the bottom surface YA of the cylindrical structure Yλ, is an area similar to area S1 (for example, the area of an equilateral triangle) (see FIG. 51), and is stored in the memory unit 17.

As shown in Figures 50 and 51, during the unmanned aerial vehicle 1 is stopped in flight (or simultaneously with the inspection camera 3 taking pictures), the position calculation device 65 uses the area S1 (first area S1/first area of the triangle) formed (composed) by the first to third light emitters 32-34 in the image (in the image) taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera), the area S2 (second area/second area of the triangle) formed (composed) by the first to third light emitters 32-34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ and similar to the first area S1, the focal lengths f1, f2 of each reference camera 51, 52, and the center intervals ψ1, ψ2 to calculate the shooting altitude H of the inspection camera 3 from equations (5) and (6).

As shown in Figures 52 to 54, the position calculation device 65 (position calculation unit) determines the shooting direction V of the inspection camera 3 based on an image (image taken by the first or second reference camera 51, 52) including each light-emitting body 32-34 taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 takes an image (when the inspection camera 3 takes an image while the unmanned aerial vehicle 1 is flying at a halt). The position calculation device 65 determines the shooting direction V of the inspection camera 3 using an image (image taken by the first or second reference camera 51, 52) including each light-emitting body 32-34 taken by the first reference camera 51 or the second reference camera 52 at the same time as the inspection camera 3 takes an image (taking an image of the inspection camera 3).

As shown in Figures 52 to 54, the position calculation device 65 uses the direction correspondence data and the image (image data) including each light-emitting body 32 to 34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 captures the image, to determine the shooting direction V of the inspection camera 3. The direction correspondence data is data that represents the correspondence between the direction of the image (image data) captured by the first reference camera 51 or the second reference camera 52 and the direction of the camera optical axis σ1 of the inspection camera 3 (the shooting direction V of the inspection camera 3). The direction correspondence data defines the diagonal direction WL of the capture screens 56, 57 (image sensors) of the first and second reference cameras 51, 52 as the direction of the camera optical axis σ1 of the inspection camera 3. As shown in Figures 52 and 53, for example, in each of the light emitters 32-34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ, the diagonal direction WL is a diagonal direction from the center line a of the cylindrical structure Yλ to one light emitter (center line c of the first light emitter) at an angle θ with respect to a reference line U that passes through the center line a of the cylindrical structure Yλ and extends in the first direction X. In the diagonal direction WL, the one light emitter is a light emitter that emits light in a color (emission color) different from the other two light emitters, and is, for example, the first light emitter 32.

As shown in FIG. 54, when the position calculation device 65 inputs an image GP (image data) including each light-emitting element 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the camera control unit 55 at the same time as capturing an image by the inspection camera 3, it calculates the angle θX (for example, the angle θX between the diagonal direction WL and the center line c of the first light-emitting element 32) of the image GP (image data) captured by the first or second reference camera 51, 52, and determines the capturing direction V of the inspection camera 3.
The shooting direction V of the inspection camera 3 (the direction of the camera optical axis σ1 of the inspection camera 3) is, as shown in Figure 54, a direction in which the inspection camera 3 (camera optical axis σ1 of the inspection camera 3) is rotated by an angle θX in the circumferential direction of the cylindrical structure Yλ based on one light-emitting body (center line c of one light-emitting body) of the first to third light-emitting bodies 32-34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ when the inspection camera 3 (camera optical axis σ1) is directed toward the inner surface Ya of the cylindrical structure Yλ (the same applies below).

As shown in FIG. 46, the position calculation device 65, at the same time as the image is captured by the inspection camera 3, associates the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ captured by the inspection camera 3 with the image of the inner surface Ya (part of the inner surface Ya) of the inspection camera 3 obtained based on the image captured by the first reference camera 51 or the second reference camera 52, and stores the result as one position image data GF in the memory unit 17.

Next, we will explain the series of processing steps in the cylindrical structure inspection system Xβ with reference to the drawings.

As shown in Figures 55 to 57, the inspector transports the unmanned aerial vehicle 1 and the light-emitting device 2 into the interior of the cylindrical structure Yλ, and places (installs) the flight indicator 31 and each light-emitting body 32 to 35 of the light-emitting device 2 on the bottom surface YA of the cylindrical structure Yλ. The flight indicator 31 and each light-emitting body 32 to 35 are placed (installed) on the bottom surface YA of the cylindrical structure Yλ, as explained in Figure 47.
As shown in Figures 55 to 57, the unmanned aerial vehicle 1 is placed (landed) on the bottom surface YA of the cylindrical structure Yλ inside the cylindrical structure Yλ with the center line e of the airframe 11 (airframe section 21) coinciding (positioning) with the center line a of the cylindrical structure Yλ (center line b of the flight indicator 31). The unmanned aerial vehicle 1 is placed (landed) on the bottom surface YA of the cylindrical structure Yλ with the camera optical axis σ1 of the inspection camera 3 directed toward the inner surface Ya of the cylindrical structure Yλ and the camera optical axes σ2 and σ3 of the first and second reference cameras 51 and 52 directed toward the bottom surface YA of the cylindrical structure Yλ (the flight indicator 31 and each light-emitting body 32 to 35). The unmanned aerial vehicle 1 is placed (landed) on the bottom surface YA of the cylindrical structure Yλ with the camera optical axes σ2, σ2 of the first and second reference cameras 51, 52 parallel to the center line a of the cylindrical structure Yλ and each support leg 23 abutting against the bottom surface YA of the cylindrical structure Yλ. The unmanned aerial vehicle 1 is placed (installed) on the bottom surface YA of the cylindrical structure Yλ at a distance from the inner side surface Ya of the cylindrical structure Yλ in the radial direction of the cylindrical structure Yλ.

As shown in FIG. 28, the inspector operates the light emission pattern input unit 71 on the control device 6 to output a lighting command (inspection signal) to the signal transmission unit 72. When the signal transmission unit 72 receives the lighting command, it outputs the lighting command to the signal receiving unit 96 (light-emitting device 22).

In the light-emitting device 22, when a light-on command is input from the signal transmission unit 72 (control device 6), the signal receiving unit 96 outputs the light-on command to the display control unit 98, as shown in FIG.
49, when a lighting command (lighting signal) is input, the display control unit 98 causes, for example, each light-emitting element 42 of the first light-emitting body 32 to emit green light (light up in green) and each light-emitting element 42 of the second and third light-emitting bodies 33, 34 to emit red light (light up in red). The first light-emitting body 32 causes each light-emitting element 42 to emit green light (light up) and emit green light inside the cylindrical structure Yλ. The second and third light-emitting bodies 33, 34 cause each light-emitting element 42 to emit red light (light up) and emit red light inside the cylindrical structure Yλ.

As shown in FIG. 49, when the display control unit 98 causes the first to third light emitters 32 to 34 to emit light (light up), it outputs a light start command (light start signal) to the lighting transmission unit 37. When the lighting transmission unit 37 receives the light start command from the display control unit 98, it transmits the light start command to the lighting reception unit 15 (unmanned aerial vehicle 1).

In the unmanned aerial vehicle 1, when the lighting receiver 15 receives a lighting start command from the lighting transmitter 15 (light-emitting device 2), as shown in FIG. 46, it outputs a lighting start command (lighting start signal) to the aircraft control unit 86.

As shown in FIG. 28, the inspector operates the control unit 73 (control lever) to output an ascent command (ascent signal) to the wireless communication unit 75 (transmitter). When the wireless communication unit 75 receives an ascent command from the control unit 73, it transmits the ascent command to the wireless communication unit 13 (unmanned aerial vehicle 1).

In the unmanned aerial vehicle 1, when the wireless communication unit 13 (receiving side) receives an ascent flight command from the wireless communication unit 75 (control device 6), as shown in FIG. 46, it outputs the ascent flight command to the aircraft control unit 86.

As shown in FIG. 46, when the aircraft control unit 86 inputs a lighting start command from the lighting receiving unit 15 and an ascending flight command from the wireless communication unit 74 (FIG. 64: ST31, Yes, FIG. 64: ST32, Yes), it outputs a reference camera shooting command (reference camera start signal) to the camera control unit 105 (FIG. 64: ST33).
As shown in Fig. 46, when the aircraft control unit 86 receives a lighting start command from the lighting receiving unit 15 (Fig. 64: ST31, Yes) and an ascent command from the wireless communication unit 74 (Fig. 64: ST32, Yes), it rotates the rotor motors 26 (propellers 25) of each rotor unit 12 (Fig. 64: ST34), causing the unmanned aerial vehicle 1 to take off from the bottom surface YA of the cylindrical structure Yλ and fly upward. The aircraft control unit 86 controls the flight of the unmanned aerial vehicle 1 so that the center line e of the aircraft 11 (aircraft unit 21) coincides with (is located at) the center line a of the cylindrical structure Yλ.

As shown in FIG. 46, when the camera control unit 105 receives a reference camera shooting command from the aircraft control unit 86 (FIG. 66: ST751, Yes), it starts shooting with the first reference camera 51 (reference camera) (FIG. 66: ST72). The camera control unit 105 starts shooting with the first reference camera 51 (reference camera) from the start of takeoff of the unmanned aerial vehicle 1. The first reference camera 51 starts shooting from the start of takeoff of the unmanned aerial vehicle 1 and outputs the captured image to the camera control unit 105.

As shown in FIG. 46, the camera control unit 105 inputs an image including each light-emitting body 32 to 34 captured by the first reference camera 51 (reference camera) from the first reference camera 51, detects (calculates) the image resolution of the image including each light-emitting body 32 to 35, and if the image resolution is lower than a predetermined resolution (FIG. 66: ST74, No; FIG. 66: ST75, Yes), switches from capturing images with the first reference camera 51 (reference camera) to capturing images with the second reference camera 52 (reference camera) (FIG. 66: ST76).
The camera control unit 105 switches from taking pictures with the first reference camera 51 (reference camera) to taking pictures with the second reference camera (reference camera) during the ascending flight of the unmanned aerial vehicle 1, causes the second reference camera 52 to take pictures including each of the light-emitting bodies 32 to 34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ, and inputs the images taken by the second reference camera 52 (reference camera) including each of the light-emitting bodies 32 to 34. The second reference camera 52 takes images including each of the light-emitting bodies 32 to 34 arranged (installed) on the bottom surface YA of the cylindrical structure Yλ during the ascending flight of the unmanned aerial vehicle 1 (during flight in the center line direction Z of the cylindrical structure Y).

As shown in FIG. 46, the camera control unit 105 inputs images including each light-emitting element 32 to 34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the first or second reference camera 51, 52, and outputs the images captured by the first or second reference camera 51, 52 to the image transmission unit 14.
The camera control unit 105 outputs images captured by the first reference camera 51 (reference camera) to the image transmission unit 14 from the start of takeoff of the unmanned aerial vehicle 1 until the shooting switch, and outputs images including each light-emitting element 32 to 34 captured by the second reference camera 52 to the image transmission unit 14 upon shooting switch.

As shown in FIG. 46, when the image transmission unit 14 receives an image captured by the first or second reference camera 51, 52 from the camera control unit 55, it transmits the image to the image receiving unit 76 (control device 6).
28, when the image receiving unit 76 receives an image captured by the first or second reference camera 51, 52 from the image transmitting unit 14 (unmanned aerial vehicle 1), the image receiving unit 76 outputs the image to the display unit 77. The display unit 77 displays the image captured by the first or second reference camera 51, 52.

As shown in FIG. 28, while the unmanned aerial vehicle 1 is in an ascending flight, the inspector operates the control unit 73 (control lever) to input a stop flight command (stop flight signal) and output a stop display command to the wireless communication unit 74. The wireless communication unit 74 transmits the stop flight command (stop flight signal) to the wireless communication unit 13 (unmanned aerial vehicle 1).

As shown in FIG. 46, in the unmanned aerial vehicle 1, when a stop flight command is sent from the wireless communication unit 75 (FIG. 64: ST35, Yes), the wireless communication unit 13 outputs the stop flight command to the aircraft control unit 86.

As shown in Figure 46, when the aircraft control unit 86 inputs a stop flight command (stop flight signal) from the wireless communication unit 13, it controls the rotation (rotation speed, rotation direction) of the rotor motors 26 (propellers 25) of each rotor unit 12 to cause the unmanned aerial vehicle 1 to stop flying (hovering flight/hovering) in the air inside the cylindrical structure Yλ (Figure 64: ST36).
As shown in Fig. 58, the unmanned aerial vehicle 1 flies (hovering flight/hovers) in the air inside the cylindrical structure Yλ with the first and second reference cameras 51, 52 (camera optical axes σ2, σ3) directed toward the flight indicator 31 and each light-emitting body 32-35 (bottom surface YA of the cylindrical structure Yλ) and the inspection camera 3 directed toward the inner surface Ya of the cylindrical structure Yλ. As shown in Fig. 58, the unmanned aerial vehicle 1 flies (hovering flight/hovers) in the air at an altitude Z1 from the bottom surface YA of the cylindrical structure Yλ (chimney) in the center line direction Z of the cylindrical structure Yλ.

As shown in Figure 46, when the aircraft control unit 86 causes the unmanned aerial vehicle 1 to fly in a stopped state (hovering flight/hovering) (Figure 64: ST36), it controls the rotation and stopping of the rotation of the unmanned aerial vehicle 1 by causing the unmanned aerial vehicle 1 to fly in a rotational motion while the unmanned aerial vehicle 1 is in a stopped flight.
The aircraft control unit 86, for example, while maintaining the unmanned aerial vehicle 1 in a stopped flight (while the unmanned aerial vehicle 1 is in a stopped flight), rotates the unmanned aerial vehicle 1 around the center line a (center line e of the unmanned aerial vehicle 1) of the cylindrical structure Yλ by a predetermined angle (rotation angle) in the circumferential direction of the cylindrical structure Yλ, and repeats the rotation stopping of the unmanned aerial vehicle 1 after rotating by the predetermined angle, thereby causing the unmanned aerial vehicle 1 to fly in a rotational flight (Figure 65: ST37).
As shown in Figures 59(a), 60(a), 61(a) and 62(a), while the unmanned aerial vehicle 1 is stopped in flight, the aircraft control unit 86 rotates the unmanned aerial vehicle 1 by an angle (rotation angle): 90 degrees at a time, and while the unmanned aerial vehicle 1 is stopped in flight, it rotates the unmanned aerial vehicle 1 by an angle (rotation angle): 90 degrees from the start of rotation [0 degrees] and stops it [see Figure 59(a)], then rotates the unmanned aerial vehicle 1 by an angle (rotation angle): 180 degrees from the start of rotation and stops it [see Figure 60(a)], then rotates the unmanned aerial vehicle 1 by an angle (rotation angle): 270 degrees from the start of rotation and stops it [see Figure 61(a)], and further rotates the unmanned aerial vehicle 1 by an angle (rotation angle): 360 degrees from the start of rotation and stops it [see Figure 59(a)], thereby rotating the unmanned aerial vehicle 1 once.

As shown in Fig. 46, when the aircraft control unit 86 causes the unmanned aerial vehicle 1 to fly stationary (hovering flight/hovering), it outputs an inspection camera photography command (inspection camera photography signal) to the camera control unit 55. For example, while the unmanned aerial vehicle 1 is flying stationary, the aircraft control unit 86 rotates the unmanned aerial vehicle 1 at a predetermined angle, and when the unmanned aerial vehicle 1 is stopped after rotating at each predetermined angle, it outputs an inspection camera photography command (inspection camera photography signal) to the camera control unit 55 at each predetermined angle (Fig. 39: ST12).
The machine control unit 86 outputs, for example, a 0-degree inspection camera shooting command, a 90-degree inspection camera shooting command, a 180-degree inspection camera shooting command, and a 270-degree inspection camera shooting command to the camera control unit 105 in the same manner as described in ST12 of FIG. 39 (FIG. 65: ST38).

As shown in FIG. 46, when the camera control unit 105 inputs an inspection camera shooting command (inspection camera shooting signal) from the aircraft control unit 86 (FIG. 67: ST77, Yes), it starts shooting with the inspection camera 3, inputs an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3 from the inspection camera 3, and simultaneously with the shooting by the inspection camera 3, inputs an image including each light-emitting body 32 to 34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the first or second reference camera 51, 52 (FIG. 67: ST78).
When the camera control unit 105 receives an inspection camera shooting command for each angle (inspection camera shooting command for each angle) from the machine control unit 86 (FIG. 67: ST77, Yes), it starts shooting with the inspection camera 3 for each inspection camera shooting command, inputs an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3 from the inspection camera 3, and simultaneously with the shooting of the inspection camera 3 (synchronized with the shooting of the inspection camera 3), inputs an image including each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) from the first or second reference camera 51, 52 (FIG. 67: ST78). Before switching the shooting of the reference camera (FIG. 66: ST74, No), the camera control unit 105 inputs an image including each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) from the first reference camera 51 simultaneously with the shooting of the inspection camera 3. After switching the reference camera's shooting (Figure 66: ST74, Yes, Figure 66: ST76), the camera control unit 105 inputs from the second reference camera 52 an image including each light-emitting element 32 to 34 captured by the second reference camera 52 (reference camera) at the same time as capturing images by the inspection camera 3.

As shown in Figure 46, when the camera control unit 105 inputs an inspection camera shooting command of 0 degrees from the aircraft control unit 86, it starts shooting with the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ captured by the inspection camera 3, and simultaneously with the shooting by the inspection camera 3 (at the time of shooting by the inspection camera 3), inputs an image GP5 including each light-emitting element 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see Figure 59 (b)]. When the camera control unit 105 receives a 90-degree inspection camera shooting instruction from the aircraft control unit 86, it starts shooting the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ captured by the inspection camera 3, and simultaneously with the shooting of the inspection camera 3 (when the inspection camera 3 is shooting), it inputs an image GP6 of each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see FIG. 60(b)]. When the camera control unit 105 receives a 180-degree inspection camera shooting instruction from the aircraft control unit 86, it starts shooting the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ captured by the inspection camera 3, and simultaneously with the shooting of the inspection camera 3 (when the inspection camera 3 is shooting), it inputs an image GP7 including each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see FIG. 61(b)]. When the camera control unit 105 inputs a 270-degree inspection camera shooting command from the aircraft control unit 86, it starts shooting with the inspection camera 3, inputs an image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ captured by the inspection camera 3, and simultaneously with the shooting by the inspection camera 3 (when shooting with the inspection camera 3), inputs an image GP8 including each light-emitting element 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) [see Figure 62 (b)].
The inspection camera 3 captures images of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ (chimney) at predetermined angles by the rotational flight of the unmanned aerial vehicle 1, and captures images of the entire circumference of the inner surface YA of the cylindrical structure Yλ in multiple installments.
The first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) captures images including each of the light-emitting bodies 32-34 while the unmanned aerial vehicle 1 is in stopped flight (during hovering flight/hovering) (capturing images including each of the light-emitting bodies 32-34 simultaneously with the inspection camera 3).

As shown in FIG. 46, while the unmanned aerial vehicle 1 is stopped in flight, the camera control unit 105 outputs to the position calculation device 5 an image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3, and an image including each light-emitting body 32-34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the image is captured by the inspection camera 3 (FIG. 67: ST79).

The camera control unit 105, for example, for each specified angle (for each inspection camera shooting command), associates an image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3 with an image including each light-emitting body 32 to 34 photographed by the first reference camera (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, and outputs the images to the position calculation device 65 (Figure 67: ST79).
The camera control unit 105 corresponds the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera input based on the inspection camera shooting specification of 0 degrees, and the image GP5 [see FIG. 59(b)] including each light-emitting body 32-34 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3, and outputs it to the position calculation device 65. The camera control unit 105 corresponds the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3 input based on the inspection camera shooting command of 90 degrees, and the image GP6 [see FIG. 60(b)] including each light-emitting body 32-34 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3, and outputs it to the position calculation device 65. The camera control unit 105 corresponds the image of the inner surface YA (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera 3, which was input based on the 180-degree inspection camera shooting command, and the image GP7 [see FIG. 61(b)] including each light-emitting body 32-34 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, and outputs them to the position calculation device 65. The camera control unit 105 corresponds the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ photographed by the inspection camera, which was input based on the 270-degree inspection camera shooting command, and the image GP8 [see FIG. 62(b)] including each light-emitting body 32-34 photographed by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the inspection camera 3 photographs, and outputs them to the position calculation device 65 (FIG. 67: ST79).

As shown in FIG. 46, the camera control unit 105 outputs to the image transmission unit 14 an image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Yλ input from the inspection camera 3 at each predetermined angle (each inspection camera command for a predetermined angle), and an image taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the image is taken by the inspection camera 3.

As shown in FIG. 46, when the image transmission unit 14 receives from the camera control unit 105 the image taken by the inspection camera 3 and the image taken by the first or second reference camera 51, 52 at the same time as the image is taken by the inspection camera 3, the image transmission unit 14 transmits the image taken by the inspection camera 3 and the image taken by the first or second reference camera 51, 52 to the image receiving unit 76 (control device 6).

In the control device 6, as shown in FIG. 28, when the image receiving unit 76 receives from the image transmitting unit 14 (unmanned aerial vehicle 1) the images taken by the inspection camera 3 and, simultaneously with the images taken by the inspection camera 3, the images GP5 to GP8 taken by the first or second reference camera 51 [see FIG. 59(b), FIG. 60(b), FIG. 61(b) and FIG. 62(b)], it outputs the images taken by the inspection camera 3 and the images taken by the first or second reference camera 51, 52 to the display unit 77 and displays them on the display unit 77.

As shown in FIG. 46, when the position calculation device 65 inputs from the camera control unit 105 an image captured by the inspection camera 3 and an image including each of the light-emitting bodies 32 to 34 captured by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) at the same time as the image captured by the inspection camera 3 (FIG. 68: ST121, Yes, FIG. 68: ST122, Yes), it calculates the focal lengths f1, f2 and the center intervals ψ in the same manner as described in FIGS. 19 to 24, 50 and 51. 1, ψ2 and area S2 are read from the memory unit 17, and simultaneously with the photographing by the inspection camera 3, the area S1 (area of an equilateral triangle) formed (configured) by the first to third light emitters 32-34 in the image (within the image) photographed by the first reference camera 51 (reference camera) or the second reference camera 52) is calculated, and the photographing altitude H of the inspection camera 3 is calculated from equations (5) and (6) using the focal lengths f1, f2, center intervals ψ1, ψ2 and areas S1, S2 (Figure 68: S124).

As shown in Figure 59 (b), based on an inspection camera shooting command of 0 degrees, the position calculation device 65 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-34 of the image GP5 (in the image) captured by the first or second reference camera 51, 52 at the same time as shooting with the inspection camera 3, and calculates the shooting altitude H5 of the inspection camera 3 from equations (5) and (6) using the respective focal lengths f1, f2, the respective center intervals ψ1, ψ2 and the respective areas S1, S2. As shown in Figure 60 (b), based on a 90-degree inspection camera shooting command, the position calculation device 65 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-34 of the image GP6 (in the image) captured by the first or second reference camera 51, 52 simultaneously with the inspection camera 3, and calculates the shooting altitude H6 of the inspection camera 3 from equations (5) and (6) using the respective focal lengths f1, f2, center spacing ψ1, ψ2 and respective areas S1, S2. As shown in Figure 61 (b), based on a 180-degree inspection camera shooting command, the position calculation device 65 calculates the area S1 formed (composed) by the first to third light-emitting elements 32-34 of the image GP7 (in the image) captured by the first or second reference camera 51, 52, at the same time as the shooting by the inspection camera 3, and calculates the shooting altitude H7 of the inspection camera 3 from equations (5) and (6) using the respective focal lengths f1, f2, respective center intervals ψ1, ψ2 and respective areas S1, S2. As shown in FIG. 62(b), the position calculation device 65 calculates the area S1 formed (composed) by the first to third light emitters 32-34 of the image GP8 (in the image) captured by the first or second reference camera 51, 52 at the same time as the inspection camera 3 captures the image based on a 270-degree inspection camera 3 capture command, and calculates the capture altitude H8 of the inspection camera 3 from equations (5) and (6) using the focal lengths f1, f2, the center intervals ψ1, ψ2, and the areas S1, S2 (FIG. 68: ST123).

As explained in Figures 52 to 54, the position calculation device 65, at the same time as the inspection camera 3 takes an image, determines the shooting direction V of the inspection camera 3 using the image including each light-emitting body 32 to 34 taken by the first reference camera 51 (reference camera) or the second reference camera 52 (reference camera) and the direction correspondence data (diagonal direction WL) (Figure 68: ST124).

As shown in Fig. 59, the position calculation device 65 calculates the angle θe between the first light emitter 32 (center line c of the first light emitter 32) of the image GP5 captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data at the same time as the inspection camera 3 captures the image based on the inspection camera capture command of 0 degrees, and obtains the capture direction V5 of the inspection camera 3. As shown in Fig. 59, the capture direction V5 of the inspection camera 3 is the direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θe in the circumferential direction of the cylindrical structure Yλ based on the first light emitter 32 (center line c of the first light emitter 32). 60, based on a 90-degree inspection camera shooting command, the position calculation device 65 calculates the angle θf between the first light emitter 32 (center line c of the first light emitter 32) of the image GP6 captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data at the same time as shooting with the inspection camera 3, and obtains the shooting direction V6 of the inspection camera 3. As shown in FIG. 60, the shooting direction V6 of the inspection camera 3 is a direction in which the inspection camera 3 (camera optical axis σ1) is rotated by angle θf in the circumferential direction of the cylindrical structure Yλ with the first light emitter 32 (center line c of the first light emitter 32) as a reference. As shown in Fig. 61, based on a 180-degree inspection camera shooting command, the position calculation device 65 calculates the angle θg between the first light emitter 32 (center line c of the first light emitter 32) of the image GP7 (in the image) captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data at the same time as shooting with the inspection camera 3, and obtains the shooting direction V7 of the inspection camera 3. As shown in Fig. 61, the shooting direction V7 of the inspection camera 3 is a direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θg in the circumferential direction of the cylindrical structure Yλ with the first light emitter 32 (center line c of the first light emitter 32) as a reference. As shown in FIG. 62, the position calculation device 65 calculates the angle θh between the first light emitter 32 (center line c of the first light emitter 32) of the image GP8 (in the image) captured by the first or second reference camera 51, 52 and the diagonal direction WL of the direction correspondence data at the same time as the inspection camera 3 captures the image based on the 270-degree inspection camera capture command, and determines the capture direction V8 of the inspection camera 3. As shown in FIG. 62, the capture direction V8 of the inspection camera 3 is the direction in which the inspection camera 3 (camera optical axis σ1) is rotated by an angle θh in the circumferential direction of the cylindrical structure Yλ based on the first light emitter 32 (center line c of the first light emitter 32) (FIG. 68: ST124).

When the position calculation device 65 determines the shooting altitude H and shooting direction V of the inspection camera 3, it associates the shooting altitude H and shooting direction V of the inspection camera 3 determined based on the image captured by the first or second reference camera 51, 52 at the same time as the inspection camera 3 captures the image (capturing the image of the inspection camera 3), with the inner surface Ya of the cylindrical structure Yλ (chimney) captured by the inspection camera 3 at the same time as the first or second reference camera 51, 52 captures the image (capturing the image of the first or second reference camera 51, 52), and stores this as position image data GF in the memory unit 17 (Figure 68: ST125, ST126).

The position calculation device 65 corresponds the shooting altitude H5 and shooting direction V5 of the inspection camera 3 obtained based on the image GP5 taken by the first or second reference camera 51, 52 at the same time as the inspection camera 3 takes the image, and stores the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 as position image data GF5 in the storage unit 17 at the same time as the image GP5 of the first or second reference camera 51, 52 is taken. The position calculation device 65 corresponds the shooting altitude H6 and shooting direction V6 of the inspection camera 3 obtained based on the image GP6 taken by the first or second reference camera 51, 52 at the same time as the inspection camera 3 takes the image, and stores the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 as position image data GF6 in the storage unit 17 at the same time as the image GP6 of the first or second reference camera 51, 52 is taken. The position calculation device 65 associates the shooting altitude H7 and shooting direction V7 of the inspection camera 3 obtained based on the image GP7 taken by the first or second reference camera 51, 52 with the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 at the same time as the image GP7 of the first or second reference camera 51, 52, and stores the associated image data GF7 in the storage unit 17. The position calculation device 65 associates the shooting altitude H8 and shooting direction V8 of the inspection camera 3 obtained based on the image GP8 taken by the first or second reference camera 51, 52 at the same time as the image GP8 of the inspection camera 3, with the image of the inner surface Ya (part of the inner surface Ya) of the cylindrical structure Y taken by the inspection camera 3 at the same time as the image GP8 of the first or second reference camera 51, 52, and stores the associated image data GF8 in the storage unit 17 (FIG. 68: ST125, ST126).

As shown in FIG. 46, when the unmanned aerial vehicle 1 rotates once (360 degrees) during the stationary flight of the unmanned aerial vehicle 1, the aircraft control unit 86 outputs an inspection camera photography stop command (inspection camera photography stop signal) to the camera control unit 105 (FIG. 65: ST39, Yes) to maintain the stationary flight of the unmanned aerial vehicle 1 (FIG. 65: ST40).

As shown in FIG. 46, when the camera control unit 105 receives an inspection camera image capture stop command from the aircraft control unit 86 (FIG. 67: ST80, Yes), it stops (pauses) image capture by the inspection camera 3.

As shown in FIG. 28, the inspector looks at the image captured by the inspection camera 3 displayed on the display unit 77, and when he confirms that the inspection camera 3 has stopped capturing images, he operates the control unit 73 (control lever) to output an ascent command (ascent signal) to the wireless communication unit 75 (transmitter). When the wireless communication unit 75 receives an ascent command from the control unit 73, it transmits the ascent command to the wireless communication unit 13 (unmanned aerial vehicle 1).

In the unmanned aerial vehicle 1, when the wireless communication unit 13 (receiving side) receives an ascent flight command from the wireless communication unit 75 (control device 6), as shown in FIG. 28, it outputs the ascent flight command to the aircraft control unit 86.

As shown in FIG. 46, when the aircraft control unit 86 inputs an ascending flight command from the wireless communication unit 13 (FIG. 65: ST41, Yes), it causes the unmanned aerial vehicle 1 (see FIG. 58 and FIG. 63), which is flying stationary at altitude Z1, to ascend.

As shown in FIG. 28, while the unmanned aerial vehicle 1 is in an ascending flight, the inspector operates the operation unit 73 (control lever) to input a stop flight command (stop flight signal) and output a stop display command to the wireless communication unit 75. The wireless communication unit 75 transmits the stop flight command (stop flight signal) to the wireless communication unit 13 (unmanned aerial vehicle 1).

As shown in FIG. 46, in the unmanned aerial vehicle 1, when a stop flight command is sent from the wireless communication unit 75, the wireless communication unit 13 outputs the stop flight command to the aircraft control unit 86.

As shown in Figure 46, when the aircraft control unit 86 inputs a stop flight command (stop flight signal) from the wireless communication unit 13, it controls the rotation (rotation speed, rotation direction) of the rotor motors 26 (propellers 25) of each rotor unit 12 to cause the unmanned aerial vehicle 1 to stop flying (hovering flight/hovering) in the air inside the cylindrical structure Yλ (Figure 64: ST36).
As shown in Fig. 56, the unmanned aerial vehicle 1 flies (hovering flight/hovers) in the air inside the cylindrical structure Yλ with the first and second reference cameras 51, 52 (camera optical axes σ2, σ3) directed toward the flight indicator 31 and each light-emitting body 32-35 (bottom surface YA of the cylindrical structure Yλ) and the inspection camera 3 directed toward the inner surface Ya of the cylindrical structure Yλ. As shown in Fig. 56, the unmanned aerial vehicle 1 flies (hovering flight/hovers) in the air inside the cylindrical structure Yλ from altitude Z1 to altitude Z2 in the center line direction Z of the cylindrical structure Yλ (chimney).

When the aircraft control unit 86 stops the unmanned aerial vehicle 1 in flight (ST36 in Figure 64), it executes ST37 to ST39 shown in Figure 64, and the camera control unit 105 executes ST77 to ST80 shown in Figure 67 to output an image of the inner surface Ya of the cylindrical structure Yλ photographed by the inspection camera 3, and an image including each light-emitting element 32 to 34 photographed by the first or second reference camera 51, 52 to the position calculation device 65, and the position calculation device 65 executes ST121 to ST136 shown in Figure 68 to store the position image data GF (the shooting altitude H of the inspection camera 3, the shooting direction V of the inspection camera 3, and the image photographed by the inspection camera 3) in the memory unit 17.
In this way, the inspector operates the control unit 73 to input multiple ascent display commands and stop display commands, the aircraft control unit 86 executes ST34 to ST39 shown in Figures 64 and 65 multiple times, the camera control unit 105 executes ST77 to ST80 shown in Figure 67 multiple times, and the position calculation device 65 executes ST121 to ST126 shown in Figure 68 multiple times, thereby storing position image data GF at multiple altitudes inside the cylindrical structure Yλ in the memory unit 17.

As shown in FIG. 28, the inspector operates the control unit 73 (control lever) to output a descent flight command (descent flight signal) to the wireless communication unit 75 (transmitter). When the wireless communication unit 75 inputs a descent flight command from the control unit 73, it transmits the descent flight command to the wireless communication unit 13 (unmanned aerial vehicle 1). The wireless communication unit 13 outputs the descent flight command to the aircraft control unit 86.

As shown in Figure 47, when the aircraft control unit 86 inputs a descent flight command (descent flight signal) from the wireless communication unit 13 (Figures 64 and 65: ST42, Yes), it controls the rotation (rotation speed, rotation direction) of the rotor motors 26 (propellers 25) of each rotor unit 12 to cause the unmanned aerial vehicle 1 to descend from the air inside the cylindrical structure Yλ toward the bottom surface YA.
As shown in Figures 55 and 56, the unmanned aerial vehicle 1 descends from the air inside the cylindrical structure Yλ (chimney) in the center line direction Z of the cylindrical structure Yλ and lands on the bottom surface YA of the cylindrical structure Yλ.

When the aircraft control unit 86 receives a descent flight command from the wireless communication unit 13 (FIGS. 64 and 65: ST42, Yes), it outputs a shooting end command (shooting end signal) to the camera control unit 105 (FIG. 65: ST43).

As shown in FIG. 46, when the camera control unit 105 receives a command to end image capture from the aircraft control unit 86 (FIGS. 66 and 67: ST81, Yes), it causes the inspection camera 3 to end image capture.

In the cylindrical structure inspection system Xβ, while the unmanned aerial vehicle 1 is in stopped flight, the shooting altitude of the inspection camera 3 can be determined based on an image taken by the first or second reference camera 51, 52 (reference camera), or an image taken by the first or second reference camera 51, 52 (reference camera) simultaneously with shooting by the inspection camera 3, and the shooting direction V of the inspection camera 3 can be determined based on an image taken by the first or second reference camera 51, 52 (reference camera) simultaneously with shooting by the inspection camera 3.
An inspector can obtain position image data GF (the shooting altitude H and shooting direction V of the inspection camera 3, and the image captured by the inspection camera 3) from the memory unit 17 of the unmanned aerial vehicle 1 that has landed on the bottom surface YA of the cylindrical structure Yλ, and can inspect the condition of the inner surface Ya of the cylindrical structure Yλ by referring to the position image data GF. If the inspector notices an abnormality (cracks, defects in the inner surface coating material (lining material, etc.)) in the image captured by the inspection camera 3, the inspector can identify the position of the abnormality that has occurred on the inner surface Ya of the cylindrical structure Yλ by referring to the shooting altitude H and shooting direction V of the inspection camera 3 that are associated with the image of the inner surface Ya of the cylindrical structure Yλ captured by the inspection camera 3.

This invention is ideal for inspecting cylindrical structures (chimneys).

Xα Cylindrical structure inspection system (chimney inspection system)
Yλ Cylindrical structure (chimney)
YA: Bottom surface of cylindrical structure Ya: Inner surface (inner circumferential surface/inner wall surface) of cylindrical structure
1 Unmanned aerial vehicle 2 Light emitting device 3 Inspection camera 4 Photography device 5 Position calculation device 6 Control device 31 Flight indicator 32 First light emitting body 33 Second light emitting body 34 Third light emitting body 51 First reference camera (reference camera)
52 Second reference camera (reference camera)

Claims (11)

An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A flight indicator is located at the center of the cylindrical structure, arranged on the bottom surface of the cylindrical structure, and emits light inside the cylindrical structure to display the flight mode of the unmanned aerial vehicle;
A first light emitter is disposed on an inner surface of the cylindrical structure and on the bottom surface of the cylindrical structure between the flight indicators at a distance from the flight indicator, and emits light into the interior of the cylindrical structure;
a second light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in the radial direction of the cylindrical structure, and emits light into the interior of the cylindrical structure;
a third light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a second radial direction of the cylindrical structure perpendicular to the first direction, and that emits light into the interior of the cylindrical structure;
a fourth light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the second light emitter in the second direction and at a distance from the third light emitter in the first direction, and that emits light into the interior of the cylindrical structure;
The photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle,
The unmanned aerial vehicle is suspended and flies in the air inside the cylindrical structure,
The reference camera captures an image including the flight indicator and each light-emitting body during the stopped flight of the unmanned aerial vehicle ,
The inspection camera captures an image of the inner surface of the cylindrical structure during the stationary flight of the unmanned aerial vehicle,
The position calculation device is
At the same time as the image is captured by the inspection camera, a photographing altitude of the inspection camera is calculated based on the image captured by the reference camera.
A cylindrical structure inspection system comprising: a camera for inspecting a cylindrical structure, the camera being operable to detect a shooting direction of the inspection camera based on an image captured by the reference camera at the same time as the inspection camera captures an image. An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A flight indicator is located at the center of the cylindrical structure, arranged on the bottom surface of the cylindrical structure, and emits light inside the cylindrical structure to display the flight mode of the unmanned aerial vehicle;
A first light emitter is disposed on an inner surface of the cylindrical structure and on the bottom surface of the cylindrical structure between the flight indicators at a distance from the flight indicator, and emits light into the interior of the cylindrical structure;
a second light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in the radial direction of the cylindrical structure, and emits light into the interior of the cylindrical structure;
a third light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a second radial direction of the cylindrical structure perpendicular to the first direction, and that emits light into the interior of the cylindrical structure;
a fourth light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the second light emitter in the second direction and at a distance from the third light emitter in the first direction, and that emits light into the interior of the cylindrical structure;
The imaging device is
An inspection camera mounted on the unmanned aerial vehicle ;
A fixed-focus type first reference camera mounted on the unmanned aerial vehicle and configured to capture an image including the flight indicator and each light-emitting body ;
A fixed-focus type second reference camera having a focal length longer than that of the first reference camera, the second reference camera being mounted on the unmanned aerial vehicle and capturing an image including the flight indicator and each of the light emitters ;
A camera control unit,
The unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure,
The camera control unit is
The first reference camera starts taking pictures from the start of takeoff of the unmanned aerial vehicle;
When the resolution of the image including the flight indicator and each light-emitting body captured by the first reference camera becomes equal to or lower than a predetermined resolution, the image is switched from the first reference camera to the second reference camera;
The inspection camera photographs the inner surface of the cylindrical structure during the stopped flight of the unmanned aerial vehicle,
The first or second reference camera captures an image including the flight indicator and each of the light emitters during a stopped flight of the unmanned aerial vehicle,
The position calculation device is
At the same time as the image is captured by the inspection camera, a photographing altitude of the inspection camera is calculated based on the image captured by the first or second reference camera;
A cylindrical structure inspection system comprising: a camera for inspecting a cylindrical structure, the camera being operable to detect an image captured by the inspection camera; and a camera for inspecting a cylindrical structure, the camera being operable to detect an image captured by the inspection camera. The inspection camera is
The inspection camera is mounted on the unmanned aerial vehicle such that a camera optical axis passing through the center point of the camera lens of the inspection camera is oriented in a direction perpendicular to the center line of the unmanned aerial vehicle,
The reference camera is
The reference camera is mounted on the unmanned aerial vehicle such that a camera optical axis passing through a center point of the camera lens of the reference camera is parallel to a center line of the unmanned aerial vehicle;
The inspection camera is arranged at a shooting distance in the direction of the center line of the unmanned aerial vehicle,
The position calculation device is
A first area formed by the first to third light emitters in an image captured by the reference camera at the same time as the image captured by the inspection camera;
a second area formed by the first to third light emitters disposed on the bottom surface of the cylindrical structure;
A center distance between a center point of the camera lens of the reference camera and a camera optical axis of the inspection camera in a direction of a center line of the unmanned aerial vehicle;
2. The cylindrical structure inspection system according to claim 1 , wherein the shooting altitude of the inspection camera is calculated using the focal length of the reference camera . A control device for remotely controlling the unmanned aerial vehicle is provided,
The unmanned aerial vehicle is
An aircraft control unit that controls the flight of the unmanned aerial vehicle,
The aircraft control unit includes:
Based on an ascending flight command from the control device, the unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and ascends in the direction of the center line of the cylindrical structure,
The cylindrical structure inspection system described in claim 2 , characterized in that the flight of the unmanned aerial vehicle is controlled based on the flight behavior displayed on the flight indicator in the image captured by the first or second reference camera. An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A flight indicator is located at the center of the cylindrical structure, arranged on the bottom surface of the cylindrical structure, and emits light inside the cylindrical structure to display the flight mode of the unmanned aerial vehicle;
A first light emitter is disposed on an inner surface of the cylindrical structure and on the bottom surface of the cylindrical structure between the flight indicators at a distance from the flight indicator, and emits light into the interior of the cylindrical structure;
a second light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in the radial direction of the cylindrical structure, and emits light into the interior of the cylindrical structure;
a third light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a second radial direction of the cylindrical structure perpendicular to the first direction, and that emits light into the interior of the cylindrical structure;
a fourth light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the second light emitter in the second direction and at a distance from the third light emitter in the first direction, and that emits light into the interior of the cylindrical structure;
The photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle,
The unmanned aerial vehicle is suspended and flies in the air inside the cylindrical structure,
The reference camera captures an image including the flight indicator and each light-emitting element,
The inspection camera captures an image of the inner surface of the cylindrical structure during the stationary flight of the unmanned aerial vehicle,
The position calculation device is
During the stopped flight of the unmanned aerial vehicle, a shooting altitude of the inspection camera is determined based on an image captured by the reference camera;
At the same time as the image is captured by the inspection camera, the image capturing direction of the inspection camera is calculated based on the image captured by the reference camera.
An inspection system for a cylindrical structure. An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A flight indicator is located at the center of the cylindrical structure, arranged on the bottom surface of the cylindrical structure, and emits light inside the cylindrical structure to display the flight mode of the unmanned aerial vehicle;
A first light emitter is disposed on an inner surface of the cylindrical structure and on the bottom surface of the cylindrical structure between the flight indicators at a distance from the flight indicator, and emits light into the interior of the cylindrical structure;
a second light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in the radial direction of the cylindrical structure, and emits light into the interior of the cylindrical structure;
a third light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a second direction in the radial direction of the cylindrical structure perpendicular to the first direction, and that emits light into the interior of the cylindrical structure;
a fourth light emitter that is disposed between the inner surface of the cylindrical structure and the flight indicator at a distance from the flight indicator, and that is disposed on the bottom surface of the cylindrical structure at a distance from the second light emitter in the second direction and at a distance from the third light emitter in the first direction, and that emits light into the interior of the cylindrical structure;
The imaging device is
An inspection camera mounted on the unmanned aerial vehicle ;
A fixed-focus type first reference camera mounted on the unmanned aerial vehicle and configured to capture an image including the flight indicator and each light-emitting body;
A fixed-focus type second reference camera having a focal length longer than that of the first reference camera, the second reference camera being mounted on the unmanned aerial vehicle and capturing an image including the flight indicator and each of the light emitters ;
A camera control unit,
The unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure,
The camera control unit is
The first reference camera starts taking pictures from the start of takeoff of the unmanned aerial vehicle;
When the resolution of the image including the flight indicator and each light-emitting body captured by the first reference camera becomes equal to or lower than a predetermined resolution, the image is switched from the first reference camera to the second reference camera;
The inspection camera photographs the inner surface of the cylindrical structure during the stopped flight of the unmanned aerial vehicle,
The position calculation device is
During the stopped flight of the unmanned aerial vehicle, a shooting altitude of the inspection camera is determined based on an image captured by the first or second reference camera;
A cylindrical structure inspection system comprising: a camera for inspecting a cylindrical structure, the camera being operable to detect an image captured by the inspection camera; and a camera for inspecting a cylindrical structure, the camera being operable to detect an image captured by the inspection camera. The inspection camera is
The inspection camera is mounted on the unmanned aerial vehicle such that a camera optical axis passing through the center point of the camera lens of the inspection camera is oriented in a direction perpendicular to the center line of the unmanned aerial vehicle,
The reference camera is
The reference camera is mounted on the unmanned aerial vehicle such that a camera optical axis passing through a center point of the camera lens of the reference camera is parallel to a center line of the unmanned aerial vehicle;
The inspection camera is arranged at a shooting distance in the direction of the center line of the unmanned aerial vehicle,
The position calculation device is
A first area formed by the first to third light emitters in an image captured by the reference camera at the same time as the image captured by the inspection camera;
a second area formed by the first to third light emitters disposed on the bottom surface of the cylindrical structure;
A center distance between a center point of the camera lens of the reference camera and a camera optical axis of the inspection camera in a direction of a center line of the unmanned aerial vehicle;
6. The cylindrical structure inspection system according to claim 5 , wherein the shooting altitude of the inspection camera is calculated using the focal length of the reference camera . An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A first light emitter disposed on a bottom surface of the cylindrical structure and emitting light into the cylindrical structure;
a second light emitter that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in a radial direction of the cylindrical structure and emits light into the inside of the cylindrical structure;
a third light emitter that is spaced apart from the first light emitter in a second direction in a radial direction of the cylindrical structure that intersects with the first direction and that is spaced apart from the second light emitter and that is disposed on the bottom surface of the cylindrical structure, and that emits light into the interior of the cylindrical structure;
The photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle,
The unmanned aerial vehicle is suspended and flies in the air inside the cylindrical structure,
The reference camera captures an image including each light-emitting body during a stationary flight of the unmanned aerial vehicle ;
The inspection camera photographs the inner surface of the cylindrical structure during the stopped flight of the unmanned aerial vehicle,
The position calculation device is
At the same time as the image is captured by the inspection camera, a photographing altitude of the inspection camera is calculated based on the image captured by the reference camera.
A cylindrical structure inspection system comprising: a camera for inspecting a cylindrical structure, the camera being operable to detect a shooting direction of the inspection camera based on an image captured by the reference camera at the same time as the inspection camera captures an image. An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A first light emitter disposed on a bottom surface of the cylindrical structure and emitting light into the cylindrical structure;
a second light emitter that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in a radial direction of the cylindrical structure and emits light into the interior of the cylindrical structure;
a third light emitter that is spaced apart from the first light emitter in a second direction in a radial direction of the cylindrical structure that intersects with the first direction and that is spaced apart from the second light emitter and that is disposed on the bottom surface of the cylindrical structure, and that emits light into the interior of the cylindrical structure;
The imaging device is
An inspection camera mounted on the unmanned aerial vehicle;
A fixed-focus type first reference camera mounted on the unmanned aerial vehicle and configured to capture an image including each light-emitting object;
A fixed-focus type second reference camera having a focal length longer than that of the first reference camera, the second reference camera being mounted on the unmanned aerial vehicle and capturing an image including each of the light emitters;
A camera control unit,
The unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure,
The camera control unit is
The first reference camera starts taking pictures from the start of takeoff of the unmanned aerial vehicle;
when a resolution of an image including each of the light-emitting bodies captured by the first reference camera becomes equal to or lower than a predetermined resolution, switching from capturing an image by the first reference camera to capturing an image by the second reference camera;
The inspection camera photographs the inner surface of the cylindrical structure during the stopped flight of the unmanned aerial vehicle,
The first or second reference camera captures an image including each of the light-emitting bodies during a stopped flight of the unmanned aerial vehicle,
The position calculation device is
At the same time as the image is captured by the inspection camera, a photographing altitude of the inspection camera is calculated based on the image captured by the first or second reference camera;
At the same time as the image is captured by the inspection camera, the image capturing direction of the inspection camera is calculated based on the image captured by the first or second reference camera.
An inspection system for a cylindrical structure. An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A first light emitter disposed on a bottom surface of the cylindrical structure and emitting light into the cylindrical structure;
a second light emitter that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in a radial direction of the cylindrical structure and emits light into the inside of the cylindrical structure;
a third light emitter that is spaced apart from the first light emitter in a second direction in a radial direction of the cylindrical structure that intersects with the first direction and that is spaced apart from the second light emitter and that is disposed on the bottom surface of the cylindrical structure, and that emits light into the interior of the cylindrical structure;
The photographing device has a reference camera and an inspection camera mounted on the unmanned aerial vehicle,
The unmanned aerial vehicle is suspended and flies in the air inside the cylindrical structure,
The reference camera captures an image including each light emitter;
The inspection camera captures an image of the inner surface of the cylindrical structure during the stationary flight of the unmanned aerial vehicle,
The position calculation device is
During the stopped flight of the unmanned aerial vehicle, a shooting altitude of the inspection camera is determined based on an image captured by the reference camera;
A cylindrical structure inspection system comprising: a camera for inspecting a cylindrical structure, the camera being operable to detect a shooting direction of the inspection camera based on an image captured by the reference camera at the same time as the inspection camera captures an image. An unmanned aerial vehicle that is flown inside a cylindrical structure erected on the ground;
A light emitting device disposed inside the cylindrical structure;
An imaging device mounted on the unmanned aerial vehicle;
A position calculation device,
The light emitting device comprises:
A first light emitter disposed on a bottom surface of the cylindrical structure and emitting light into the cylindrical structure;
a second light emitter that is disposed on the bottom surface of the cylindrical structure at a distance from the first light emitter in a first direction in a radial direction of the cylindrical structure and emits light into the inside of the cylindrical structure;
a third light emitter that is spaced apart from the first light emitter in a second direction in a radial direction of the cylindrical structure that intersects with the first direction and that is spaced apart from the second light emitter and that is disposed on the bottom surface of the cylindrical structure, and that emits light into the interior of the cylindrical structure;
The imaging device is
An inspection camera mounted on the unmanned aerial vehicle;
A fixed-focus type first reference camera mounted on the unmanned aerial vehicle and configured to capture an image including each light-emitting object;
A fixed-focus type second reference camera having a focal length longer than that of the first reference camera, the second reference camera being mounted on the unmanned aerial vehicle and capturing an image including each of the light emitters;
A camera control unit,
The unmanned aerial vehicle takes off from the bottom surface of the cylindrical structure and flies hovering in the air inside the cylindrical structure,
The camera control unit is
The first reference camera starts taking pictures from the start of takeoff of the unmanned aerial vehicle;
when a resolution of an image including each of the light-emitting bodies captured by the first reference camera becomes equal to or lower than a predetermined resolution, switching from capturing an image by the first reference camera to capturing an image by the second reference camera;
The inspection camera photographs the inner surface of the cylindrical structure during the stopped flight of the unmanned aerial vehicle,
The position calculation device is
During the stopped flight of the unmanned aerial vehicle, a shooting altitude of the inspection camera is determined based on an image captured by the first or second reference camera;
At the same time as the image is captured by the inspection camera, the image capturing direction of the inspection camera is calculated based on the image captured by the first or second reference camera.
An inspection system for a cylindrical structure.

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