JP7588515B2 - Waterway tunnel inspection device, flight control method, and gas injection method - Google Patents

Description

The present invention relates to a waterway tunnel inspection device, a flight control method, and a gas injection method.

Many waterways have been constructed and are in use for water supply, irrigation and other purposes. Some waterways are constructed underground, i.e. as waterway tunnels (underground waterways).

There is a demand for inspection of such waterway tunnels. Waterway tunnels may deteriorate over time, so in order to ensure the safe and stable operation of the waterway tunnel, it is desirable to inspect the condition of the waterway tunnel periodically. In particular, in the event of a large earthquake, it is desirable to inspect the walls of the waterway tunnel to confirm its soundness.

The applicant of this application has previously filed a patent application for a waterway tunnel inspection device for inspecting the walls of waterway tunnels (see JP 2018-199915 A). JP 2018-199915 A discloses an airship-type waterway tunnel inspection device that is equipped with an observation system and a controller on a balloon and inspects the walls while flying autonomously inside the waterway tunnel.

To improve the accuracy of the inspection of the waterway tunnel, it is preferable to fly the airship-type waterway tunnel inspection device stably inside the waterway tunnel. To achieve stable flight, it is desirable for the airship-type waterway tunnel inspection device to be configured to suppress contact with the wall of the waterway tunnel, and also to be configured so that it can continue flying even if it does come into contact.

JP 2018-199915 A

Therefore, one object of the present invention is to provide a technique for improving the flight stability of a waterway tunnel inspection device. Other objects and novel features of the present invention will be apparent to those skilled in the art from the following disclosure.

In one aspect of the present invention, there is provided a waterway tunnel inspection device configured to fly inside a waterway tunnel. The waterway tunnel inspection device includes a balloon and a guide mechanism joined to the balloon. The guide mechanism includes an arm and a roller rotatably joined to the tip of the arm.

In another aspect of the present invention, a flight control method is provided for controlling flight inside a waterway tunnel of a waterway tunnel inspection device. The flight control method includes controlling wind inside the waterway tunnel when the waterway tunnel inspection device is flown inside the waterway tunnel. Controlling the wind inside the waterway tunnel includes at least one of at least partially blocking at least one of the entrances of the waterway tunnel and blowing wind into the waterway tunnel with a blower.

The present invention can improve the flight stability of a waterway tunnel inspection device.

1 is a side view showing the configuration of a waterway tunnel inspection device in one embodiment. FIG. FIG. 1 is a front view showing the configuration of a waterway tunnel inspection device in one embodiment. FIG. 2 is a side view showing the configuration of the aircraft in one embodiment. FIG. 2 is a top view showing the configuration of the aircraft in one embodiment. FIG. 13 is a perspective view showing the configuration of a guide mechanism attached to the upper portion of a balloon in one embodiment. FIG. 13 is a perspective view showing the configuration of a guide mechanism attached to the side of a balloon in one embodiment. 7 is a front view showing a configuration of a support member of the guide mechanism of FIG. 6 according to one embodiment. FIG. 7 illustrates the function of the guide mechanism of FIG. 6 in one embodiment. FIG. 4 is a bottom view showing a configuration of a guide frame in one embodiment. FIG. 2 is a perspective view showing a configuration of a guide frame according to one embodiment. 1 shows a configuration of a ballast water dropping device in one embodiment. FIG. 2 is a cross-sectional view showing a configuration of a chamber in one embodiment. FIG. 2 is a side view showing the configuration of a circumference management tape measure in one embodiment. FIG. 2 is a side view showing a configuration of a machine body fixing tape in one embodiment. 1 is a perspective view showing a configuration of an imaging module holding mechanism in one embodiment. FIG. 2 is a perspective view showing a configuration of a thruster holding mechanism in one embodiment. 1 is a side view showing the configuration of a waterway tunnel inspection device in one embodiment. FIG. 1 is a flow chart illustrating a method for inspecting a waterway tunnel in one embodiment. 1 illustrates a method of injecting gas into a balloon in one embodiment. 1 illustrates a method for controlling wind in a water tunnel in one embodiment. 1 illustrates a method for controlling wind in a water tunnel in one embodiment.

<Overall composition>
Fig. 1 is a side view showing the configuration of a waterway tunnel inspection device 100 in one embodiment, and Fig. 2 is a front view. In the following description, an XYZ orthogonal coordinate system may be used to represent directions, in which the X axis is defined in the lateral direction of the waterway tunnel inspection device 100, the Y axis is defined in the front-back direction, and the Z axis is defined in the up-down direction. In the illustrated embodiment, the waterway tunnel inspection device 100 has a configuration suitable for flying in the forward direction shown as the +Y direction in Fig. 1. However, the flight direction is not limited to the +Y direction.

The waterway tunnel inspection device 100 is configured as an airship and is configured to fly inside the waterway tunnel to inspect the wall surface. The waterway tunnel may be a waterway provided underground. In one embodiment, the waterway tunnel inspection device 100 is configured to capture an image of the wall surface of the waterway tunnel while flying inside the waterway tunnel to obtain a captured image.

In one embodiment, as shown in FIG. 1, the waterway tunnel inspection device 100 includes a balloon 1, a side thruster 2, a main thruster 3, an imaging module 4, and an aircraft 5. The side thruster 2, the main thruster 3, the imaging module 4, and the aircraft 5 are all mounted on the balloon 1.

The balloon 1 is filled with a gas lighter than air, such as helium, and generates buoyancy to float the waterway tunnel inspection device 100. The waterway tunnel inspection device 100 flies using the buoyancy obtained by the balloon 1. The balloon 1 has a generally cylindrical shape that is long in the front-to-back direction shown as the Y-axis direction in FIG. 1. In one embodiment, the balloon 1 is made of a flexible material, such as a polyvinyl chloride sheet. By using a flexible material for the balloon 1, the balloon 1 becomes foldable, and the portability of the waterway tunnel inspection device 100 can be improved. The balloon 1 is preferably made of a thin and light material, and a polyvinyl chloride sheet is one of the materials that meets such requirements.

The side thruster 2 is joined to the lower part of the balloon 1, and is configured as a first thrust generating mechanism that generates thrust in the lateral direction shown as the X-axis direction in Figures 1 and 2. In the illustrated embodiment, two side thrusters 2 are provided at different positions in the front-rear direction. The side thrusters 2 are used to generate thrust for translating the waterway tunnel inspection device 100 in the lateral direction, and for generating thrust for rotating the waterway tunnel inspection device 100 in a horizontal plane. The directions in which the two side thrusters 2 generate thrust are not necessarily the same. For example, when rotating the waterway tunnel inspection device 100 in a horizontal plane, one of the side thrusters 2 generates thrust in the +X direction, and the other generates thrust in the -X direction.

The main thruster 3 is attached to one end of the balloon 1 in the fore-and-aft direction, for example the rear end, and is configured as a second thrust generating mechanism that generates thrust in the fore-and-aft direction of the waterway tunnel inspection device 100.

The imaging module 4 is attached to the other end of the balloon 1 in the front-rear direction, for example, the front end, and is configured to capture images of the wall surface of the waterway tunnel. In one embodiment, the imaging module 4 may include a 360° camera and a lighting device.

The aircraft 5 is attached to the lower part of the balloon 1 and is equipped with various mechanisms for controlling the flight of the waterway tunnel inspection device 100. FIG. 3 is a side view showing the configuration of the aircraft 5 in one embodiment, and FIG. 4 is a top view. In the illustrated embodiment, the aircraft 5 is equipped with a mecha deck 6, a pair of vertical thrusters 7, a controller 8, and a battery 9. The mecha deck 6 is configured to be attached to the lower part of the balloon 1, and mounts and holds the vertical thrusters 7, the controller 8, and the battery 9. The vertical thrusters 7 are configured as a third thrust generating mechanism that generates thrust in the up and down directions of the waterway tunnel inspection device 100. In one embodiment, each of the vertical thrusters 7 is detachably connected to the mecha deck 6. The vertical thrusters 7 are individually detachable from the aircraft 5. In such an embodiment, the waterway tunnel inspection device 100 is configured so that the side thrusters 2, the main thrusters 3, and the vertical thrusters 7 are separable from each other. This makes it easier to transport the parts that make up the waterway tunnel inspection device 100 into the waterway tunnel, as described below. The controller 8 controls the side thruster 2, main thruster 3, and vertical thruster 7 described above to control the flight path of the waterway tunnel inspection device 100. The battery 9 stores power to operate the side thruster 2, main thruster 3, vertical thruster 7, and controller 8.

<Guide mechanism>
1 and 2 again, in one embodiment, at least one guide mechanism 10 is joined to the top of the balloon 1, and at least one guide mechanism 20 is joined to the side. In the embodiment shown in Fig. 1, two guide mechanisms 10 are joined to the top of the balloon 1, two guide mechanisms 20 are joined to the left side, and two guide mechanisms 20 (not shown in Fig. 1) are joined to the right side. The guide mechanisms 10 and 20 are provided to reduce the effect of contact when the waterway tunnel inspection device 100 comes into contact with the wall surface of the waterway tunnel, and to improve flight stability.

Figure 5 is a perspective view showing the configuration of a guide mechanism 10 joined to the upper part of a balloon 1 in one embodiment. In the illustrated embodiment, the guide mechanism 10 includes a base portion 11 attached to the surface of the balloon 1, a pair of arms 12 joined to the base portion 11, and a roller 13 connected to the tip of the arm 12. The base portion 11 is configured to support the pair of arms 12, and includes a front bar 14, a rear bar 15, and a pair of rods 16 connecting them. The base portion 11 is joined to the balloon 1 so that the front bar 14 is located further forward of the waterway tunnel inspection device 100 than the rear bar 15. The arm 12 is joined to the front bar 14. The arm 12 is joined to the front bar 14 so as to be oblique to the base portion 11. The position where the arm 12 is joined to the front bar 14 is located further forward than the roller 13. This structure contributes to absorbing the impact when the roller 13 comes into contact with the wall surface while the waterway tunnel inspection device 100 is flying forward. In one embodiment, the arm 12 is formed of an elastically deformable material, such as carbon fiber reinforced plastic or glass fiber reinforced plastic. The roller 13 is sandwiched between a pair of arms 12 and is rotatably connected to each arm 12.

The guide mechanism 10 having such a structure can suppress the effect of contact when the waterway tunnel inspection device 100 rises excessively and comes into contact with the upper wall of the waterway tunnel. When the waterway tunnel inspection device 100 rises excessively, the roller 13 of the guide mechanism 10 first comes into contact with the upper wall of the waterway tunnel. The roller 13 comes into contact with the wall and rolls, thereby mitigating the impact. This contributes to improving the flight stability of the waterway tunnel inspection device 100. In addition, if the balloon 1 is made of a flexible material, the base part 11 can bite into the balloon 1 to mitigate the impact. This also contributes to the flight stability of the waterway tunnel inspection device 100. Furthermore, if the arm 12 is made of an elastically deformable material, the impact is further absorbed by the bending of the arm 12, which can also contribute to improving the flight stability.

Figure 6 is a perspective view showing the configuration of a guide mechanism 20 joined to the side of the balloon 1 in one embodiment. In the illustrated embodiment, the guide mechanism 20 includes a base portion 21 attached to the surface of the balloon 1, an arm 22 joined to the base portion 21, a roller 23 connected to the tip of the arm 22, a support member 24 supporting the arm 22, and a connecting plate 25 joined to the support member 24. The base portion 21 is configured to support the arm 22, and includes a front end bar 26, a rear end bar 27, and a pair of rods 28 connecting them. The rollers 23 are rotatably connected to the arm 22. As shown in Figure 7, the support member 24 is configured as a truss structure, and has a connecting portion 24a connected to the arm 22 and a fitting portion 24b in which a notch 24c into which the rod 28 is fitted is formed. Returning to Figure 6, the connecting plate 25 is used to position the support member 24. One end of the connecting plate 25 is fixedly joined to the support member 24, while the connecting plate 25 has a plurality of holes 25a that are used for connecting to the front end bar 26. The connecting plate 25 is connected to the front end bar 26 using one of the plurality of holes 25a. FIG. 6 shows the state in which the hole 25a (not shown) closest to the end of the connecting plate 25 is used for connecting to the front end bar 26.

The guide mechanism 20 is configured so that the angle of the arm 22 relative to the base portion 21 is adjustable. Such a configuration makes it possible to adjust the distance of the roller 23 provided at the tip of the arm 22 from the balloon 1 according to the width of the waterway tunnel. Since the distance of the roller 23 from the balloon 1 affects the frequency with which the roller 23 comes into contact with the wall surface of the waterway tunnel, appropriately adjusting the distance of the roller 23 from the balloon 1 contributes to improving the flight stability of the waterway tunnel inspection device 100.

In order to adjust the angle of the arm 22 relative to the base 21, the arm 22 is connected to the front end bar 26 so as to be rotatable, and the support member 24 is connected to the arm 22 so that the angle it forms with the arm 22 is free. In this configuration, as shown in FIG. 8, the angle of the arm 22 relative to the base 21 can be adjusted to a desired angle by adjusting the distance between the support member 24 and the front end bar 26. The adjustment of the distance between the support member 24 and the front end bar 26 may be performed by selecting the hole 25a used to connect the connecting plate 25 to the front end bar 26. The hole 25a corresponding to the distance between the support member 24 and the front end bar 26 that makes the angle of the arm 22 relative to the base 21 a desired angle is selected, and the connecting plate 25 is connected to the front end bar 26 using the selected hole 25a.

In the embodiment described above, the guide mechanism 10 is joined to the top of the balloon 1, and the guide mechanism 20 is joined to the side of the balloon 1, but the positions at which the guide mechanisms 10, 20 are joined to the balloon 1 are not limited to these. For example, the guide mechanism 20 may be joined to the top of the balloon 1, and the guide mechanism 10 may be joined to the side of the balloon 1.

<Guide frame>
Referring again to FIG. 1, in one embodiment, a guide frame 30 for protecting the side thruster 2 is joined to the lower part of the balloon 1. FIG. 9 is a bottom view showing the configuration of the guide frame 30 in one embodiment, and FIG. 10 is a perspective view. The guide frame 30 includes two rods 31 and 32 and base parts 33, 34, 35, and 36. The rods 31 and 32 are formed so as to be elastically deformable. In one embodiment, the rods 31 and 32 are formed of an elastically deformable material. The rods 31 and 32 may be formed of, for example, carbon fiber reinforced plastic or glass fiber reinforced plastic. The rods 31 and 32 are bound to each other at a position where they intersect by a binding body 37 (for example, a cable tie). One end of the rod 31 is connected to the base part 33, and the other end is connected to the base part 34. The base parts 33 and 34 are joined to the balloon 1 and are used to hold the rod 31. Similarly, the rod 32 has one end connected to the base portion 35 and the other end connected to the base portion 36. The base portions 35 and 36 are joined to the balloon 1 and are used to hold the rod 32.

The side thruster 2 is positioned between the guide frame 30 configured in this manner and the balloon 1. In this structure, when the balloon 1 approaches the wall of the waterway tunnel, the guide frame 30 contacts the wall before the side thruster 2, protecting the side thruster 2. This contributes to improving the flight stability of the waterway tunnel inspection device 100.

<Ballast water dropping device>
The balloon 1 is filled with a gas lighter than air, such as helium gas, but the gas lighter than air has a small molecular weight and is prone to leak from the balloon 1. The gas in the balloon 1 can pass through, for example, the sheet surface or the sheet joint surface of the balloon 1. This can cause the gas to gradually escape from the balloon 1 over time, resulting in a gradual decrease in the buoyancy of the balloon 1. If the buoyancy of the balloon 1 gradually decreases, the waterway tunnel inspection device 100 may descend, and it may become necessary to generate a thrust in the vertical direction by the vertical thruster 7. This can lead to an undesirable increase in power consumption.

In order to address such problems, in one embodiment, as shown in Figures 3 and 4, a ballast water dropping device 40 is mounted on the aircraft 5. The ballast water dropping device 40 includes a container 41 for storing ballast water, and is configured to gradually drop the ballast water stored in the container 41 and release it to the outside of the waterway tunnel inspection device 100. In one embodiment, the ballast water dropping device 40 includes a water discharge valve 42 configured to be operated by a servo motor to gradually release the ballast water stored in the container 41. By gradually dropping and releasing the ballast water, the overall weight of the waterway tunnel inspection device 100 gradually decreases, and the decrease in buoyancy of the balloon 1 is compensated for. The amount of ballast water released per unit time is adjusted according to the amount of decrease in buoyancy of the balloon 1 per unit time. By compensating for the decrease in buoyancy of the balloon 1 by releasing the ballast water, the power consumption for generating thrust in the vertical direction can be reduced, and the flight stability of the waterway tunnel inspection device 100 can be improved.

In another embodiment, the ballast water dripping device 40A shown in FIG. 11 may be used to drip ballast water onto the outside of the waterway tunnel inspection device 100. The ballast water dripping device 40A is configured to drip ballast water gradually without receiving a power supply. In the illustrated embodiment, the ballast water dripping device 40A includes a container 43, a chamber 44, and a clamp 45.

The vessel 43 is configured to store ballast water. An inlet tube 46 for introducing air into the vessel 43 and an upstream tube 47 for sending ballast water from the vessel 43 to the chamber 44 are connected to the vessel 43.

The chamber 44 is configured to drip and accumulate the ballast water received from the container 43 inside the chamber 44. FIG. 12 illustrates the configuration of the chamber 44 in one embodiment. In the illustrated embodiment, the chamber 44 includes a chamber body 44a and a lid body 44b that closes the opening at the upstream end of the chamber body 44a. The chamber body 44a is formed in a substantially cylindrical shape with an inner diameter that gradually narrows in the downstream direction. A flow path is formed in the lid body 44b, and the lid body 44b is configured to drip the ballast water supplied from the upstream tube 47 into the inside of the chamber body 44a as droplets. The downstream end of the chamber body 44a is connected to the downstream tube 48, and the ballast water accumulated in the chamber 44 is sent to the downstream tube 48. As shown in FIG. 11, the clamp 45 is provided to clamp the downstream tube 48. The clamp 45 is configured so that the clamping amount of the downstream tube 48 is variable. When a roller clamp is used as the clamp 45, the clamping amount may be adjusted by adjusting the position of the roller of the roller clamp. The downstream tube 48 is arranged so that its end hangs down from the aircraft body 5, and the ballast water is dripped from the downstream tube 48 to the outside of the waterway tunnel inspection device 100.

In the ballast water dropping device 40A configured in this way, the amount of ballast water released per unit time is adjusted by adjusting the clamping amount of the clamp 45. The amount of ballast water released per unit time is adjusted according to the amount of decrease in buoyancy of the balloon 1 per unit time, thereby compensating for the decrease in buoyancy of the balloon 1. The ballast water dropping device 40A can release ballast water without using electricity, which is ideal for saving electricity stored in the battery 9.

<Balloon circumference management>
In order to reduce the power consumption for generating thrust in the vertical direction and/or to improve the flight stability of the waterway tunnel inspection device 100, it is desirable to appropriately adjust the buoyancy generated by the balloon 1. Since the buoyancy generated by the balloon 1 depends on the amount of gas sealed in the balloon 1, it is desirable to appropriately manage the amount of gas sealed in the balloon 1 in order to obtain an appropriate buoyancy.

In order to manage the amount of gas sealed in the balloon 1, in one embodiment, as shown in FIG. 1, at least one circumference management tape measure 50 is provided to wrap around the balloon 1. The circumference management tape measure 50 is used to measure and manage the circumference of the balloon 1. Since the circumference of the balloon 1 depends on the amount of gas sealed in the balloon 1, the amount of gas sealed in the balloon 1 can be appropriately managed by managing the circumference of the balloon 1. In one embodiment, two circumference management tape measures 50 are provided at different positions in the front-rear direction. In the illustrated embodiment, one of the two circumference management tape measures 50 is provided near the front side thruster 2, and the other is provided near the rear side thruster 2.

Figure 13 shows a circumference management tape measure 50 in one embodiment. The circumference management tape measure 50 is configured as a tape-shaped member with a scale formed on at least a portion. The end 50a of the circumference management tape measure 50 is joined to the surface of the balloon 1, and the circumference of the balloon 1 is read from the position on the scale of the end 50a in a state where the circumference management tape measure 50 is arranged to wrap around the balloon 1. Based on the circumference of the balloon 1 that has been read, it is determined whether the amount of gas sealed in the balloon 1 is appropriate. By constantly placing the circumference management tape measure 50 on the surface of the balloon 1, it is no longer necessary to place the circumference management tape measure 50 every time a measurement is made, and the circumference of the balloon 1 can be measured at any time. This makes it easier to manage the amount of gas sealed in the balloon 1.

<Fixing the aircraft to the balloon>
Referring again to FIG. 1, in one embodiment, the airframe 5 is fixed to the balloon 1 by a plurality of airframe fixing tapes 60. The airframe fixing tapes 60 are provided by wrapping the balloon 1 so as to be in close contact with the balloon 1, and both ends of the tapes are connected to the airframe 5. The structure of fixing the airframe 5 to the balloon 1 by the airframe fixing tapes 60 makes it possible to freely adjust the mounting position of the airframe 5. The waterway tunnel inspection device 100 may experience fluctuations in the front-to-rear weight balance each time it is assembled. By adopting a structure of fixing the airframe 5 to the balloon 1 by the airframe fixing tapes 60, it becomes easy to adjust the mounting position of the airframe 5 in response to fluctuations in the weight balance.

In one embodiment, as shown in FIG. 14, the aircraft body fixing tape 60 has an elastically expandable stretchable portion 60a. When gas gradually leaks from the balloon 1, the stretchable portion 60a shrinks in response to the decrease in the circumference of the balloon 1, preventing the aircraft body fixing tape 60 from loosening. In one embodiment, the stretchable portion 60a may be formed of a rubber band.

<Attaching equipment to the balloon>
1 and 2 again, when the imaging module 4 is attached to the front end of the flexible balloon 1, the weight of the imaging module 4 may cause the imaging module 4 to tilt downward. This may affect the quality of the image obtained by the imaging module 4. For example, if the imaging module 4 is oriented in an inappropriate manner, an image with a desired imaging range may not be obtained.

In order to attach the imaging module 4 to the balloon 1 in the correct orientation, in one embodiment, an imaging module holding mechanism 70 configured as shown in FIG. 15 is used. In the illustrated embodiment, the imaging module 4 includes a 360° camera 51, an LED (light emitting diode) module 52 for illuminating the inside of the water tunnel, and a base 53, and the imaging module holding mechanism 70 includes a plurality of fixing pieces 71 and a plurality of fixing cables 72, 73. In the illustrated embodiment, the 360° camera 51 is joined to the LED module 52, which is further joined to the base 53. The base 53 includes a hub portion 53a joined to the LED module 52, a ring-shaped rim portion 53b, and a plurality of spoke members 53c connecting the rim portion 53b to the hub portion 53a. The fixing pieces 71 are joined to the balloon 1, and each is configured to hold a fixing cable 72. The fixing cable 72 has an end connected to the fixing piece 71, and is further bound to the base 53 of the imaging module 4. The fixing pieces 71 are installed at sufficiently wide intervals, and the multiple fixing cables 72 each connected to the fixing piece 71 pull and hold the base 53 from different directions. The fixing cable 73 has an end connected to the fixing piece 71, and is further bound to the LED module 52. In the illustrated embodiment, two fixing cables 73 are respectively connected to two fixing pieces 71 located diagonally above the imaging module 4, and the fixing cables 73 pull and hold the LED module 52 from diagonally above. The imaging module holding mechanism 70 configured in this way supports the imaging module 4 by pulling it from different directions, and can hold the imaging module 4 in a proper orientation. FIG. 15 illustrates an embodiment in which the number of fixing pieces 71 and fixing cables 72 is four, and the number of fixing cables 73 is two, but the numbers of fixing pieces 71 and fixing cables 72, 73 are not limited to these.

Similarly, when the main thruster 3 is installed, the weight of the main thruster 3 may cause the main thruster 3 to tilt downward. When the main thruster 3 tilts downward, an upward thrust is generated, which may result in a loss of thrust or disturbance in the attitude of the waterway tunnel inspection device 100.

In order to join the main thruster 3 to the balloon 1 in the correct orientation, in one embodiment, a thruster holding mechanism 80 configured as shown in FIG. 16 is used. In the illustrated embodiment, the main thruster 3 includes a base 54 having a configuration similar to that of the base 53 of the imaging module 4 described above, and the thruster holding mechanism 80 includes a plurality of fixing pieces 81 and a plurality of fixing cables 82. The base 54 includes a hub portion 54a, a ring-shaped rim portion 54b, and a plurality of spoke members 54c that connect the rim portion 54b to the hub portion 54a. The fixing pieces 81 are joined to the balloon 1, and each of them is configured to hold a fixing cable 82. The fixing cables 82 have ends connected to the fixing pieces 81 and are further tied to the base 54. The fixing pieces 81 are installed at sufficiently wide intervals, and the plurality of fixing cables 82 pull and hold the base 54 from different directions. The thruster holding mechanism 80 configured in this manner can hold the main thruster 3 in the correct orientation. Although FIG. 16 illustrates an embodiment in which the number of fixing pieces 81 and fixing cables 82 is four, the number of fixing pieces 81 and fixing cables 82 is not limited to this.

<Gas detection in tunnels>
In one embodiment, the waterway tunnel inspection device 100 may be configured to perform gas detection in the waterway tunnel in addition to or instead of inspecting the wall surface of the waterway tunnel. In a long tunnel, for example, with a length of more than 1000 m, there may be a location where the composition of the gas inside the tunnel is unsuitable for work by workers. For example, in a long tunnel, there may be a location where the oxygen concentration is low, and there may be a location where toxic gas and/or flammable gas is present. In the past, in the inspection of such a tunnel, the tunnel was ventilated before entering the tunnel carrying a gas detector, and work in a tunnel with a small cross section, such as a waterway tunnel, may involve difficult work such as bending and moving inside the tunnel. Using the waterway tunnel inspection device 100 having a gas detection function as described below is useful for ensuring the safety of work while reducing the labor required for work inside the waterway tunnel.

17 illustrates an example of the configuration of the waterway tunnel inspection device 100 in one embodiment when the waterway tunnel inspection device 100 has a gas detection function. In the embodiment shown in FIG. 17, the waterway tunnel inspection device 100 is equipped with a gas detector 90. The gas detector 90 is configured to be able to detect a desired gas. In detecting a gas, the presence or absence of the gas may be detected, and/or the concentration of the gas may be measured. In one embodiment, the gas detector 90 is configured to detect the presence or absence of a desired gas and/or to measure the concentration of the desired gas. Examples of gases detected by the gas detector 90 include combustible gas, hydrogen sulfide, carbon monoxide, oxygen, etc. The gas detector 90 may be configured to detect the presence or absence of at least one of the combustible gas, hydrogen sulfide, carbon monoxide, and oxygen, and/or to measure the concentration of at least one of the combustible gas, hydrogen sulfide, carbon monoxide, and oxygen. In one embodiment, the gas detector 90 is configured to measure the concentrations of combustible gases, hydrogen sulfide, carbon monoxide, and oxygen.

The gas detector 90 may have a logging function that records the detected gas concentration at a set period (e.g., every 5 seconds). The gas concentration can be measured and recorded while flying the waterway tunnel inspection device 100, and the recording time and gas concentration data can be extracted after the measurement is completed, thereby making it possible to grasp the gas concentration distribution inside the waterway tunnel. For example, if the gas concentration is measured while flying the waterway tunnel inspection device 100 at a constant speed, the position of the waterway tunnel inspection device 100 at each time, i.e., the gas concentration measurement position, can be identified from the recording time, and the gas concentration at each position in the waterway tunnel can be identified. The gas detector 90 may be configured to record the temperature at each time in addition to the detected gas concentration.

In one embodiment, the imaging module 4 (or another imaging device provided in the waterway tunnel inspection device 100) may capture the wall of the waterway tunnel and the gas detector 90 may detect gas in a synchronized manner (or linked manner). In such an embodiment, the captured image of the wall of the waterway tunnel and the gas concentration data measured in synchronization with the capture of the captured image may be associated and recorded in an appropriate recording device (e.g., a recording device incorporated in the controller 8, or another recording device provided in the waterway tunnel inspection device 100). With this configuration, the measurement position of the gas concentration can be easily identified by referring to the corresponding captured image. In one embodiment, the waterway tunnel inspection sequence includes capturing the captured image and measuring the gas concentration. The inspection sequence may be repeated at a set period (e.g., every 5 seconds) under the control of the controller 8, or may be performed in response to a user operation. In such an embodiment, the captured image and the gas concentration captured in the same inspection sequence may be associated and recorded in a recording device incorporated in the controller 8, for example. The time at which each inspection sequence was performed may also be recorded in the recording device. In such an embodiment, by repeatedly performing the inspection sequence while flying the waterway tunnel inspection device 100 at a constant speed, it becomes easy to identify the position at which the inspection sequence was performed from the execution time and the captured image, and further to identify the gas concentration at each position in the waterway tunnel.

In FIG. 17, the gas detector 90 is shown mounted on the tip of the balloon 1, but the installation position of the gas detector 90 may be determined according to the position where gas detection is desired (e.g., the center, upper side, or lower side of the waterway tunnel) and/or the type of gas to be detected. For example, if gas detection is desired in the upper part of the waterway tunnel, the gas detector 90 may be mounted on the upper part of the balloon 1. Also, if the specific gravity of the gas to be detected is greater than that of air, the gas detector 90 may be mounted on the lower part of the balloon 1, for example, on the aircraft 5. Also, if the aircraft 5 of the waterway tunnel inspection device 100 is lightweight, such as if the aircraft 5 is not equipped with a control device for autonomous flight, the gas detector 90 may be mounted on the lower part of the balloon 1, for example, on the aircraft 5. Note that gas detection is also useful for tunnel inspection devices that inspect long tunnels other than waterway tunnels, and the configuration of the waterway tunnel inspection device 100 described above is generally applicable to tunnel inspection devices.

<Waterway tunnel inspection method>
18 is a flow chart showing a method for inspecting a waterway tunnel by the waterway tunnel inspection device 100 in one embodiment. In step S01, the parts constituting the waterway tunnel inspection device 100 are carried into the waterway tunnel. The embodiment in which the waterway tunnel inspection device 100 is configured so that the side thruster 2, the main thruster 3, and the vertical thruster 7 are separable from each other as described above is preferable for facilitating the carrying of each part constituting the waterway tunnel inspection device 100 into the waterway tunnel. For example, in an embodiment in which the side thruster 2 and the main thruster 3 can be individually attached to the balloon 1 and the vertical thruster 7 can be detached from the aircraft body 5, the side thruster 2, the main thruster 3, and the vertical thruster 7 can be separated from each other. This is preferable from the viewpoint of facilitating the carrying of the parts constituting the waterway tunnel inspection device 100 into the waterway tunnel.

In step S02, the waterway tunnel inspection device 100 is assembled inside the waterway tunnel. The assembly of the waterway tunnel inspection device 100 includes a process of injecting gas into the balloon 1. After the balloon 1 is inflated with gas, each of the parts of the waterway tunnel inspection device 100 described above is attached to the balloon 1.

In one embodiment, as shown in FIG. 19, in injecting gas into the balloon 1, a gas cylinder 91 that accumulates the gas to be injected is installed outside the waterway tunnel 200. The gas cylinder 91 is connected to the balloon 1 by a hose 92, and gas is injected from the gas cylinder 91 to the balloon 1 through the hose 92. Such a procedure contributes to reducing the work effort and increasing safety. The gas cylinder 91 is often heavy, and there may be cases where it is difficult to transport the gas cylinder 91 inside the waterway tunnel 200. For example, if the entrance of the waterway tunnel 200 is located under a vertical shaft and the gas cylinder 91 cannot be loaded onto a vehicle and transported directly to the entrance, it is difficult to transport the gas cylinder 91 inside the waterway tunnel 200. In addition, when the gas cylinder 91 is transported inside the waterway tunnel 200, if gas leaks from the gas cylinder 91 or the hose 92, oxygen deficiency may occur inside the waterway tunnel 200. By placing the gas cylinder 91 outside the waterway tunnel 200, oxygen deficiency can be prevented.

In step S03, the assembled waterway tunnel inspection device 100 is flown inside the waterway tunnel. Once flight has commenced, the waterway tunnel inspection device 100 flies autonomously under the control of the controller 8. When wind is blowing inside the waterway tunnel, in one embodiment, the waterway tunnel inspection device 100 is flown in the downwind direction. This is effective in reducing the power consumption of the waterway tunnel inspection device 100 and saving the power stored in the battery 9.

In one embodiment, the wind in the waterway tunnel may be actively controlled. As shown in FIG. 20, if the wind speed inside the waterway tunnel 200 is too high, a shield 93 may be installed to at least partially block the mouth of the waterway tunnel 200. If the wind speed inside the waterway tunnel 200 is excessively high, the flight speed of the waterway tunnel inspection device 100 may become excessively high, and the clarity of the captured image of the wall surface of the waterway tunnel 200 may decrease. By installing the shield 93, the wind speed inside the waterway tunnel 200 can be reduced. The shield 93 may be installed only at one of the mouths of the waterway tunnel 200, or the shield 93 may be installed at both mouths. If there is no wind inside the waterway tunnel 200 or if the wind speed is too low, a blower 94 may be installed at the mouth of the waterway tunnel 200 to generate a desired wind inside the waterway tunnel 200, as shown in FIG. 21. The blower 94 may be installed inside the waterway tunnel 200. By actively controlling the wind inside the waterway tunnel, the waterway tunnel inspection device 100 can fly at an optimal speed. This improves the image quality of the captured images of the wall surface of the waterway tunnel 200, and is also effective in reducing the power consumption of the waterway tunnel inspection device 100.

In step S04, while flying the waterway tunnel inspection device 100, images of the wall surface of the waterway tunnel 200 are sequentially acquired. The captured images are stored in a storage device (not shown) provided in the controller 8 and/or the imaging module 4. After the acquisition of the image pixels of the wall surface of the section of the waterway tunnel 200 to be inspected is completed, the waterway tunnel inspection device 100 is retrieved. In one embodiment, the waterway tunnel inspection device 100 may be retrieved by placing personnel at a position where the waterway tunnel inspection device 100 will reach. In addition, after flying the waterway tunnel inspection device 100 over the section of the waterway tunnel 200 to be inspected, the waterway tunnel inspection device 100 may be retrieved by reversing the thrust of the main thruster 3 and retreating the waterway tunnel inspection device 100 to a desired position (e.g., the starting point or its vicinity). In one embodiment, a sensor is installed at the tip of the waterway tunnel inspection device 100, and when the sensor detects a wall or an obstacle, the thrust of the main thruster 3 is reversed to return the waterway tunnel inspection device 100 to the desired position for recovery. In another embodiment, a timer or the like is used to measure the time from departure, and after a certain period of time has elapsed, the thrust of the main thruster 3 is reversed to return the waterway tunnel inspection device 100 to the desired position for recovery. The state of the wall of the waterway tunnel 200 can be grasped from the captured images stored in the storage device provided in the controller 8 and/or the imaging module 4. In an embodiment in which the waterway tunnel inspection device 100 is equipped with a gas detector 90, data on the gas concentration and/or temperature and the recording time recorded by the logging function of the gas detector 90 may be further extracted and used to identify the gas concentration distribution in the waterway tunnel 200.

Although various embodiments have been specifically described above, it will be obvious to those skilled in the art that the technology disclosed in this specification can be implemented with various modifications.

100: Waterway tunnel inspection device 1: Balloon 2: Side thruster 3: Main thruster 4: Imaging module 5: Airframe 6: Mecha deck 7: Vertical thruster 8: Controller 9: Battery 10: Guide mechanism 11: Base section 12: Arm 13: Roller 14: Front bar 15: Rear bar 16: Rod 20: Guide mechanism 21: Base section 22: Arm 23: Roller 24: Support member 24a: Connection section 24b: Fitting section 24c: Notch 25: Connection plate 25a: Hole 26: Front end bar 27: Rear end bar 28: Rod 30: Guide frame 31: Rod 32: Rod 33: Base section 34: Base section 35: Base section 36: Base section 37: Binding body 40: Ballast water dropping device 40A : Ballast water dropping device 41 : Container 42 : Water discharge valve 43 : Container 44 : Chamber 44a : Chamber body 44b : Lid 45 : Clamp 46 : Inlet tube 47 : Upstream tube 48 : Downstream tube 50 : Circumference management tape measure 50a : End 51 : 360° camera 52 : LED module 53 : Base 53a : Hub portion 53b : Rim portion 53c : Spoke member 54 : Base 54a : Hub portion 54b : Rim portion 54c : Spoke member 60 : Aircraft fixing tape 60a : Expandable portion 70 : Imaging module holding mechanism 71 : Fixing piece 72 : Fixing cable 73 : Fixing cable 80 : Thruster holding mechanism 81 : Fixing piece 82 : Fixing cable 90 : Gas detector 91 : Gas cylinder 92 : Hose 93 : Shield 94 : Blower 200 : Waterway tunnel

Claims (10)

1. A water tunnel inspection device configured to fly inside a water tunnel,
Balloons and
A guide mechanism attached to the balloon ;
A guide frame including a first rod and a second rod configured to be elastically deformable;
Equipped with
The guide mechanism is
An arm,
a roller rotatably joined to the tip of the arm ,
Both ends of the first rod and the second rod are joined to the balloon such that their respective intermediate portions are spaced apart from the balloon;
The first rod and the second rod are connected to each other so as to cross each other at the intermediate portion.
Water tunnel inspection equipment. The waterway tunnel inspection device according to claim 1,
the guide mechanism further comprises a first base portion joined to the balloon and supporting the arm;
The waterway tunnel inspection device, wherein the first base portion is configured such that an angle of the arm relative to the first base portion is adjustable. The waterway tunnel inspection device according to claim 1,
A waterway tunnel inspection device, wherein the arm is configured to be elastically deformable. The waterway tunnel inspection device according to any one of claims 1 to 3,
Furthermore, it has an aircraft equipped with multiple thrusters,
The aircraft is a waterway tunnel inspection device in which the multiple thrusters are configured to be individually detachable. 1. A water tunnel inspection device configured to fly inside a water tunnel ,
Balloons and
A guide mechanism attached to the balloon;
a tape-like member provided to wrap the balloon ;
Equipped with
The guide mechanism is
An arm,
A roller rotatably joined to the tip of the arm;
Equipped with
A waterway tunnel inspection device, wherein a scale is provided on at least a portion of the tape-shaped member. The waterway tunnel inspection device according to any one of claims 1 to 5 ,
Furthermore,
a vessel for storing ballast water;
A waterway tunnel inspection device comprising: a ballast water dripping device configured to drip the ballast water onto the outside of the waterway tunnel inspection device. The waterway tunnel inspection device according to any one of claims 1 to 5 ,
The water tunnel inspection apparatus further comprising a gas detector configured to detect a desired gas. The waterway tunnel inspection device according to claim 7 ,
The desired gas includes at least one of a flammable gas, hydrogen sulfide, carbon monoxide, and oxygen. Flying the waterway tunnel inspection device according to any one of claims 1 to 8 inside the waterway tunnel;
Controlling the wind inside the waterway tunnel when flying the waterway tunnel inspection device inside the waterway tunnel ;
Including,
controlling wind within the waterway tunnel,
At least partially blocking at least one portal of the waterway tunnel;
and blowing air into the waterway tunnel by a blower. Carrying the waterway tunnel inspection device according to any one of claims 1 to 8 into the waterway tunnel;
a cylinder for storing gas to be injected into the balloon is installed outside the waterway tunnel;
injecting the gas from the cylinder into the balloon through a hose connected between the cylinder and the balloon.

Images