JPH075242A - Position measuring apparatus for moving object - Google Patents

Abstract

PURPOSE:To enable the efficient detecting of an obstacle or the like near a moving object with a simplified apparatus by using a light source (light beam) of a light wave distance measuring means together with the light source of a video camera. CONSTITUTION:A reflection mirror composing an optical scanner 100 is rotated by 360 deg. to irradiate a reflection plate (marker) with a main projection beam in the circumferential direction. An angle between a moving object and the marker is determined from an angle of rotation of the scanner 100 receiving the reflected wave at this moment to obtain a distance between the marker and the moving object from a phase difference between a light wave transmitted and a light wave received. On the other hand. the reflection mirror is turned askew downward by a mirror tilting command from a control section 400 to project a horizontal light beam. The reflected light from an obstacle is inputted into a photodetector and also into a video camera 200 to make light source thereof. Thus, an image processing of a slit light image by the infrared rays is performed to determine a distance between the obstacle and the moving object, the breadth and the height of the obstacle and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the position of a moving body, and more particularly to a device for measuring the distance and azimuth from a mark position having a reflecting means to the device by using a light beam and image processing. .

[0002]

2. Description of the Related Art Generally, it is necessary for a moving body to recognize its position in order to allow the moving body to travel independently. A marker having a reflecting means is provided in the moving area of the moving body in order to recognize the self-position of the moving body, a rotating light beam mounted on the moving body is projected toward the sign, and the reflected wave is received. Then, the angle between the sign and the moving body is obtained from the projection angle of the rotating beam at that time, and the distance between the sign and the moving body is obtained from the phase difference between the phase of the transmitted beam light and the phase of the received light.

In this method, if the number of markers having the reflecting means is three, the self-position from a certain reference position can be measured by the triangulation method. One or more signs are provided in the moving area.

As described above, an object using only the principle of the optical distance measuring method cannot identify obstacles in the vicinity of the moving body, moving objects, field ridges having complicated shapes in the field.

[0005]

In the above-mentioned conventional method (light wave distance measuring method), there is no problem if the boundary line of the moving area is a straight line, but if the boundary shape is complicated, in order to identify it. , Will need many signs. In such a case, it may be difficult to select the three markers necessary for measuring one's own position.

Further, when there is an obstacle such as a person in the moving area, an infrared sensor, an ultrasonic sensor or the like which is independent of the light wave range finder is required. In the present invention, an infrared light emitting diode is used as a light source of a light wave range finder, which is safe even if it is directly irradiated on the human body, and the device is simplified by using the infrared light emitting diode as an infrared sensor and a light source of a video camera. It is an object of the present invention to provide a position measuring device for a moving object, which aims to efficiently detect the vicinity of the moving object using a video camera.

[0007]

The present invention employs the following means in order to achieve the above-mentioned features. That is,
The presence or absence of an object is detected by using an optical sensor, which detects the position of the moving body with respect to the sign based on the angle between the main projection light and the reference direction and the phase difference between the reflected light from the sign and the projected light. The object detection means for checking and the image processing means for detecting the distance between the object and the moving body and the shape of the object from the image of the object are provided.

By tilting the light source of the light wave distance measuring means with the reflection mirror for the scanner of the distance measuring means, a plateau having an object detecting function using the light receiving means of the distance measuring means as an optical sensor of the object detecting means is provided. In addition, it can be used as a light source of a video camera.

The output of the optical sensor can be used to detect the presence or absence of an obstacle, and the image processing means can be operated only when there is an obstacle. The light source of the light wave distance measuring means may be used as a light source of a video camera, and the image processing means for obtaining an optical image may be provided.

[0010]

By using an infrared light emitting diode as a light source of the light wave distance measuring means, an optical scanner is constructed in which the light source of the light wave distance measuring means and the light source for obtaining an infrared image for detecting an obstacle are the same. An obstacle can be detected by an infrared sensor using the light source, and by similarly illuminating the object with the light source, an infrared image by a video camera that is not affected by ambient brightness can be obtained.

The direction in which the obstacle exists is known from the sensor output waveform received by the infrared sensor, and when the infrared image by the video camera at that time is processed using the data relating to this direction, the cut-out position of the image is estimated. Since it is possible, image processing becomes easy. Further, when the output of the infrared sensor is lower than the reference level, the image processing sequence is skipped to enable high-speed position measurement.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an arrangement state of a self-supporting moving body equipped with a position measuring device of the present invention and four reflecting plates installed in an area where the self-supporting moving body operates.

FIG. 2 shows the concept of a moving body A equipped with the measuring device, FIGS. 10 and 11 show a more detailed embodiment thereof, and FIG. 3 is a circuit diagram thereof. The moving body A is an optical scanner 100, a video camera 200,
Vertical slit light generator 300, position measurement main controller 400
Etc.

The reflection mirror 1 for scanning which constitutes the optical scanner 100 is rotated 360 degrees, and the main projection beam in the circumferential direction is reflected by the reflection plate (marker) 21 arranged in the work area.
Irradiate toward ~ 24. The light reflected from the reflection plates 21 to 24 is received by the light receiver 12 in the optical scanner. The angle formed by the moving body A and the markers 21 to 24 having the reflecting means is obtained from the rotation angle of the optical scanner 100 which receives the reflected wave at this time, and the markers 21 to 24 are determined from the phase difference between the transmitted wave and the received wave. And the moving body A are obtained.

The light-transmitting wave and the light-receiving wave enter the phase difference detecting section 401 to generate a phase difference signal, which is detected by the distance detecting section 402.
To generate distance data using the reference clock. On the other hand, at this timing, the content of the counter 403 that counts the output pulses of the encoder 7 connected to the rotary shaft of the optical scanner is read and input to the angle detection unit 404 together with the received light wave to generate angle data. This pair of signals is input to the traveling direction of the microcomputer control unit 500 and the position calculation unit 501 to obtain the current position and traveling direction of the moving body A.

On the other hand, the microcomputer controller 500
In response to a scanner reflection mirror tilt command output from the scanner, the reflection mirror 1 is obliquely directed downward at an angle θ and a light beam is projected. The rotating beam at this time is a lateral slit light. Illuminate the periphery of the moving body A with the lateral slit light,
The object is to detect an obstacle existing near the moving body A, a pillar, a wall, or the like.

The reflected light from the obstacle is input to the light receiver 12, and when the rotating scanner reflection mirror 1 is within the viewing angle range of the video camera, the reflected light is also input to the video camera 200. To be done. The received light wave output, which is the output from the light receiver 12, is input to the angle detection unit 404 together with the contents of the counter 403 and compared with the reference level. If the peak value of the output wave exceeds the reference level, the obstacle is detected. The output of the detection unit 405 is the A / D of the microcomputer control unit.
It is digitized through the converter unit 502 and stored in the RAM 510 together with the angle data at this time. Further, at this timing, the infrared image is also stored in the RAM 511 through the A / D converter 503 of the control unit by the slit light of the obstacle or the like taken into the video camera. Then, digitized crest values stored in the RAMs 510 and 511 indicating the presence of an obstacle and the angle data at this time are used to form slit light images by infrared light stored in the RAM 511. Image processing is then performed to obtain the distance between the obstacle and the moving body A, the width of the obstacle, the height, and the like.

At this time, a change point of the slit light image (often corresponding to the edge of a pillar or the like) is stored by using the crest value stored in the RAM 511 indicating the presence of an obstacle and the angle data.
To shorten the image processing time.

For a work area having a protrusion as shown in FIG. 5, the initial measurement position of the moving body A is near the protrusion and the protrusion is within the visual field of the video camera. Initial data is measured as a position to enter, and signs 21, 2
The coordinates of the protrusion (Xe, Y
e) is determined and the shape of the protrusion is grasped.

The projections are detected by image processing using horizontal slit light and vertical slit light. In the case of a protrusion that is difficult to reflect infrared rays, such as a ridge in a rice field, a marker having a reflecting means as shown in FIG. 6, for example, and a marker having a different shape and reflectance (the reflectance is kept small). Put. After the coordinates (Xe, Ye) of the protrusion are read and before the work by the moving body A is started, the marker is removed.

The above series of measuring operations will be described with reference to FIG. In steps S10 and S11, the optical scanner is moved to the initial measurement point while being rotated at a low speed. After the moving body A stops, in step S13, the number of markers arranged in the work area is counted, and the angle formed by the corner marker and the moving body A is measured.

When the number and the angle of the markers 21 to 24 are obtained, the distance between each of the markers 21 to 24 and the moving body A is determined in step S14, and if there is a protrusion, the position thereof is measured (S1).
6). When this is finished, for example, the marker 21 is set as the origin, and the marker 21 and the position of the protrusion are obtained by using the line connecting the markers 21 and 22 as the reference line (X axis) and centered on the moving body A.
Convert to coordinates with the origin as.

In steps S18 and S19, the optical scanner is rotated at a high speed, moved to the start point and stopped. When the work starts, in step S31, the angle formed by the three moving objects A and the three markers necessary for position measurement is obtained (the distance from the sign to the moving object is not measured), and the current position and moving direction of the moving object A are calculated. Calculate using the principle of triangulation.

In step S32, it is checked whether or not this operation is the Nth time. If it is not the Nth time, this measurement operation is repeated. If it is the Nth time, the process proceeds to step S33, and the scanner reflection mirror 1 is tilted at the angle θ to generate one rotation lateral slit light.

In step S34, delta θ is added to θ as the angle of deviation of the next horizontal slit light. In step S35, S
At 33, the output received by the light receiver 12 is checked as to whether or not there is an obstacle, as described above. If there is no obstacle, the process proceeds to step S36, and it is checked whether the occurrence of the lateral slit is the Kth time. If it is the Kth time, the corner angle θ is set to the initial check, and the lateral slits can be sequentially generated from the upper side to the lower side (S38). If there is an obstacle, one rotation of the horizontal slit light and the vertical slit light are generated at the same time. Then, the process proceeds to S38, and if the work is not completed, the measurement operation from S31 is repeated.

FIG. 8 shows the horizontal slit light, the received light waveform of the reflected wave,
The relationship of slit light image capture is illustrated. In the state where the lateral slit light is sequentially generated as 1, 2, ..., I, ... k, the received light waveform does not exceed the reference level until the i-th time, and then the first-time reference level is set. When it exceeds (), the peak value of the received light waveform, the angle data at that time, and the slit light image at that time are loaded into the RAM 511.

Then, in order to efficiently extract an object having a lateral characteristic, for example, a boundary between a wall and a corridor at the time of the next (i + 1) th horizontal slit light generation, vertical slit light is simultaneously generated and the received light waveform of The angle data and the slit light image are stored in the RAM 511. A composite of the above slit image is a slit light image, and image processing is performed by referring to this and the received light waveform of the reflected wave stored in the RAM, and the distance to the obstacle and the general shape of the obstacle. , Determine the size. (In the actual image processing, each slit light image will be analyzed without being combined.) In this example, when the presence of an obstacle is detected, the shape of the obstacle is determined by two horizontal slit lights. However, if the shape of the obstacle is to be obtained in more detail, the number of times the lateral slit is generated after the presence of the obstacle is detected may be increased.

In order to efficiently extract an object having a lateral characteristic by image processing, vertical slit light may be used instead of horizontal slit light. In addition, the lateral slit is θ,
Interlaced scanning may be performed until an obstacle is detected, such as θ + 2 * Δθ, θ + Δθ, ....

FIG. 9 shows a conceptual diagram of the measurement of the distance between the video camera and the object by the above-mentioned lateral slit light. Assuming that the height of the image of the lateral slit light projected on the video camera at the height h is Δh (not shown), h / 1 = Δh / f ∴ h = (1 * Δh) / f On the other hand, 1 = (d−h) * cotθ Therefore, the distance 1 to the object surface is obtained by 1 = d * cotθ / (1 + Δh * cotθ / f).

D is the distance between the lateral slit light source and the camera, which is a value determined mechanically, and the angle θ is the angle at which the scanning reflection mirror is tilted.

[0031]

[Optical Scanner] The upper half of FIG.
Is a more detailed embodiment of the present invention. A part of the output beam from the infrared light emitting diode 11 is a half mirror 13.
Is reflected on the scanning reflection mirror 1 through the central hole of the central axis 35 of the rotating unit 30. Further, the reflected light from the sign or the obstacle is incident on the photo sensor 12 via the rotating cylinder 3, the fixed mirror 9 and the condenser lens 10 which are opened around the central axis 35 of the rotating portion 30.

Further, the transmitted light of the half mirror 13 is
It is incident on the condenser lens 10 through two mirrors,
The reference phase of the phase difference detection unit 401 is given. However, the incident light for the reference phase is normally scattered by the shutter 14, and is incident on the photosensor 12 only when the shutter 14 is rotated to pass through the transmission hole formed in the shutter 14. . In addition, the shutter 14
Prevents the beam from entering the scanning reflection mirror 1 only when the incident light enters the photosensor.

During normal measurement, the rotation mechanism section 30 driven by the motor 31 is rotating at high speed. At this time, the light beam of the infrared light emitting diode (light emitter) 11 is reflected by the mirror 13 and the scanning reflection mirror 1 fixed on the rotating unit 30 by 90 degrees to become a horizontal beam, which is rotated by 360 degrees in the main projection. Become a beam.

When irradiating the periphery of the moving body A, the scanning reflection mirror 1 is tilted downward by the motor 32 and the screw screw 33 in response to the scanner reflection mirror tilt command sent from the position measurement control device 400. The main projection beam is used as the lateral slit light. The angle θ of the lateral slit light is determined from the angle data specified by the tilt command.

When the lateral slit light is radiated toward the surface of the earth, the reflected light from the ground surface is received by the light receiver 12 of the light wave distance measuring means.
And is input to the video camera 200. The light receiver 12 functions as an infrared sensor that detects an object, an obstacle, and the like.

According to the above structure, one infrared light emitting diode 11 can be used as the light wave distance measuring means, the infrared sensor 12, and the light source of the video camera 200.
The vertical slit for detecting the obstacle is formed by a cylindrical lens 42 for the output of the infrared light emitting diode 41. The vertical slit generating unit 16 is rotated by a motor 43, and the video camera 200 is also rotated by the motor 201. It is like this.

FIG. 11 shows another embodiment of the optical scanner. In order to obtain the lateral slit light, the light from the infrared light emitting diode 11 is changed by the tilt command signal,
The main projection beam is switched to a horizontal slit, and the beam for the horizontal slit is incident on the pyramidal polygonal mirror 2 provided on the lower side of the rotating unit 30 through a transmission hole provided at the center of the fixed mirror 9. As a result, when the rotating unit 30 rotates, the lateral slits within the predetermined angle range are obtained.

The light reflected from the object is made incident on the photosensor 12 via the pyramidal polyhedron mirror 2 and the fixed mirror 9. If you want to finish the work in the middle of the work area on the terrain as shown in FIG. 5, arrange a work end marker as shown in FIG. 7 on the line connecting the two markers and move it. Body A uses a lateral slit, which allows image processing to read and identify the code on the surface of the marker to finish the work at that point.

A marker, a sign having a reflecting means as a subgoal, and a reflecting object having a different reflectance are used (the reflectance is reduced). By forming a coded mark on the surface of the reflecting object as shown in FIGS. 6 and 7, the code can be easily read by image processing with horizontal slit light or vertical slit light. Therefore, by arranging these markers and subgoals in the work area, the moving body A
Can be given a command.

Further, in the case of a work area having a protrusion as shown in FIG. 5, since the coordinates of the protrusion are obtained for the first time, the coordinate data of the work area should be stored in, for example, an IC card at the end of the work. For example, at the time of the next work, the IC card reader of the position measurement main control unit reads the coordinates of the work area of this IC card, and marks 21, 22 and 2 at the same position as the previous time.
It is not necessary to perform initial measurement as in the beginning by only placing 3, 24.

[0041]

As described above, according to the present invention, it becomes possible for the moving body to run independently even when there are projections or the like.

[Brief description of drawings]

FIG. 1 is a conceptual diagram for recognizing an action range of a moving body according to the present invention.

FIG. 2 is a conceptual diagram of a moving body used in the present invention.

FIG. 3 is a circuit diagram of the present invention.

FIG. 4 is a flowchart showing the procedure of the present invention.

FIG. 5 is a conceptual diagram for recognition of protrusions.

FIG. 6 is a conceptual diagram of a protrusion marker.

FIG. 7 is a conceptual diagram of a work end marker.

FIG. 8 is a flowchart showing a procedure of obstacle detection.

FIG. 9 is an explanatory diagram showing a state of detecting a protrusion.

FIG. 10 is a configuration diagram of an optical scanner.

FIG. 11 is a configuration diagram of an optical scanner.

[Explanation of symbols]

 A Moving object 1 Reflective mirror for scanner 12 Optical sensor 21, 22, 23, 24 Sign 200 Video camera

Claims (4)

[Claims] 1. A light wave distance measuring means for detecting a position of a moving body with respect to a sign based on an angle of a main projected light with respect to a reference direction and a phase difference between reflected light from the sign and the projected light, and an optical sensor. A position measuring device for a moving object, comprising: an object detecting means for confirming the presence or absence of the object; and an image processing means for detecting the distance between the object and the moving object and the shape of the object from the image of the object. 2. The light source of the light wave distance measuring means is a plateau of the object detecting means using the light receiving means of the distance measuring means as an optical sensor of the object detecting means by tilting the scanner reflection mirror of the distance measuring means. The position measuring device for a moving body according to claim 1, which is also used as a light source of a video camera. 3. The position measuring device for a moving body according to claim 1, wherein the presence or absence of an obstacle is detected by the output of the optical sensor, and the image processing means is operated only when the obstacle is present. 4. The position measuring device for a moving body according to claim 1, further comprising the image processing means for obtaining an optical image by using the light source of the light wave distance measuring means as a light source of a video camera.