JPH0719868A - Position and azimuth measuring device for moving body - Google Patents

Abstract

PURPOSE:To provide a position and azimuth measuring device for moving body which is capable of simplifying the processing in a laser navigator by calculating highly reliable position and azimuth, decreasing the information amount against a light reflector and reducing the capacity of memory in an arithmetic processing circuit. CONSTITUTION:Many light reflectors are arranged in moving body area and the reflection effective angles of the reflectors are limited according to the arranged positions. Inside of the moving body area is separated into sections. An area administration part 9 calculates the number of light reflector effective for each section based on the information of the light reflector from the data input part 12 and the data of light beam reaching distance, and the light reflector number for each section and its reflection effective angle are recorded in a memory part 9a. According to the present position data of the moving body, the section is selected and light reflector information is sent to a position and azimuth calculation part 8. The position and azimuth calculation part 8 extracts information on three light reflectors from these information and calculates the present position and azimuth data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of light reflectors that reflect in the direction of incidence in the area where a moving body moves.
The light beam is rotationally scanned and emitted from the moving body, the reflected light from at least three light reflectors of the plurality of light reflectors is detected on the moving body, and the position between each reflector and the light reflector are detected. A position and orientation measuring device that measures the current position of the moving body based on the opening angle, and more specifically, a position and orientation of the moving body that has been improved to reduce the amount of information to be processed and eliminate recognition errors of the optical reflector. Regarding measuring device.

[0002]

2. Description of the Related Art As a specific example of the above-mentioned moving body position measuring apparatus, at least a laser beam is rotationally scanned and emitted from a moving body such as an automated guided vehicle, and is arranged separately from the moving body. A laser navigator that detects the reflected light from three light reflectors (corner cubes) on the moving body and measures the current position of the moving body based on the position of the light reflector and the opening angle between the light reflectors. Proposed (Japanese Patent Publication No. 2-4806)
9, JP-A-1-145517). FIG. 6 is a block diagram showing an example of a specific structure of the laser navigator. This device is provided with a cylindrical laser scanner 25 rotatably supported on the upper part of the device body.
At the bottom of 5, a cylindrical body 26 is provided so as to project downward.

A semiconductor laser 27 is installed below the cylindrical body 26. The laser light from the semiconductor laser 27 is shaped into parallel light via a lens 28, and then the cylindrical body 26.
After passing through the inside, it is reflected in the horizontal direction by the mirror 29 in the laser scanner 25. Further, it becomes a vertical surface beam via the cylindrical lens 30 and is emitted toward the corner cube 22. At least three corner cubes 22 are previously positioned and arranged on the moving plane of the moving body. Further, a DC motor 31 is installed in the main body of the apparatus, and the rotation of the DC motor 31 is controlled by the driving pulley 3
2, transmitted to the cylindrical body 26 via the timing belt 33 and the driven pulley 34. As a result, the cylindrical body 2
6 and the laser scanner 25 rotate integrally, and the laser beam emitted from the laser scanner 25 is rotationally scanned in the horizontal plane.

The reflected light from the corner cube 22 is reflected downward by the mirror 29, and enters the photodiode 38 via the mirror 35, the condenser lens 36 and the interference filter 37. The output of the photodiode 38 is sent to the light receiving circuit 39 and becomes a light receiving signal, and the arithmetic processing circuit 40
Is input to. The encoder 23 is integrally attached to the lower end of the cylindrical body 26, and the angle signal and the reference signal output from the encoder 23 are used as the arithmetic processing circuit 40.
Sent to. The arithmetic processing circuit 40 calculates the position and azimuth of the moving body based on the principle of triangulation based on the input data, and sends the result to the host computer 24. According to the laser navigator 21, the position and orientation of the moving body can be calculated with a high resolution of millimeters and milliradians.

[0005]

In the laser navigator proposed above, each light reflector arranged is capable of reflecting light from any direction. Effective angle (effective angle range that can be reflected)
have. FIG. 7 is a diagram for explaining the principle of calculating the current position of the moving body by the laser navigator.
Eleven light reflectors R1 to R11 are arranged so that at least three light reflectors exist within the laser reach distance with respect to the moving area 41 regardless of the position of the moving body. For example, if there is a moving object at point A,
Light reflectors R9, R10, R11 are included within the laser reach 42. In such a moving area, when the moving body moves to the point B, R2 is within the laser reach distance 43.
R4, R9, R10 and R11 light reflectors will be included. The light reflectors R4 and R10 are very close to each other when viewed from the moving body, and when the emitted light returns as reflected light, it cannot be determined from which light reflector the light is.

Therefore, when the moving body is moved to such a position, a recognition error of the light reflector is apt to occur, and the calculated position / azimuth data lacks reliability. An object of the present invention is to divide a moving body area into a plurality of sections, and to limit the effective reflection angle of the light reflector according to the position where it is arranged, thereby calculating a highly reliable position azimuth and at the same time the light reflector. To reduce the amount of information to the laser and reduce the memory capacity in the arithmetic processing circuit.
It is an object of the present invention to provide a position / orientation measuring device for a mobile body, which can simplify the processing in the mobile unit.

[0007]

In order to achieve the above-mentioned object, a position / orientation measuring apparatus for a moving body according to the present invention has a plurality of light reflectors which reflect in the incident direction in an area where the moving body moves. A light beam is rotationally scanned and emitted from the moving body, and reflected light from at least three light reflectors of the plurality of light reflectors is detected on the moving body, and the position of each reflector and the light reflector. In a device for measuring the current position of a moving body based on an opening angle between them, an area where the moving body moves is divided to form a plurality of sections, and a part of the light reflectors of each of the light reflectors. Is configured to have a specific reflection effective angle of 0 ° to 360 ° depending on the position where it is arranged, and the position data of all the light reflectors in the area and the reflection effective angle data thereof. Data input means for inputting data , The effective light reflector number in each section is calculated based on the effective reflection angle of each light reflector, and the effective light reflector number is stored in the memory unit for each section. Area management means for selecting a section in which the mobile body is currently located based on the data, and reading the light reflector number and its position data, which is the information of the light reflector corresponding to the selected section, from the memory section, and the area management means. From the light reflectors corresponding to the selected section, three light reflectors in consideration of the effective reflection angle are extracted by receiving the light reflector information read out from the light reflector and comparing it with the data by the light beam. And a data extracting means used for calculating the current position of the moving body.

[0008]

According to the above construction, it is not necessary to register the information of the optical reflector which the laser does not reach for each section.
The amount of calculation and memory can be reduced. Further, by limiting the effective reflection angle depending on the position where the light reflector is arranged, the recognition error of the moving body is eliminated, and the highly reliable position and orientation can be calculated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. FIG. 1 is a diagram for explaining an outline of a position / orientation measuring apparatus for a moving body according to the present invention. An unmanned guided vehicle 2 as a moving body is provided with a wheel 2a for moving, a laser navigator 3 for measuring the position and orientation, a laser scanner 4 for emitting and receiving laser light, and a host computer for controlling the unmanned guided vehicle 2. It is equipped with 1.
The light reflectors 6 are arranged within the range in which the automated guided vehicle 2 moves, and the number thereof is at least three or more. The laser scanner 4 emits laser light to each light reflector 6 around the automated guided vehicle 2 by rotational scanning, and the light reflector 6 that received the laser light reflects the light in the incident direction. The laser scanner 4 has the same structure as the conventional one shown in FIG. Some of the light reflectors 6 are configured so as not to reflect incident light from a specific direction depending on the position where they are arranged. That is, the effective reflection angle is limited.

FIG. 2 is a diagram for explaining how to make a light reflector used in the present invention and its structure. In FIG. 2A, the reflection sheet 10b is attached to the entire circumference of the cylindrical pipe 10a, and the effective reflection angle is 360 °. The principle is the same as that in which six concaves having an effective reflection angle of 60 ° shown in (c) are combined in the respective directions as shown in (b). FIG. 2 (d) shows the light reflector 1 of (a) above.
It is a light reflector 11 (effective reflection angle: 180 °) provided with a non-reflecting surface 11b on half of the outer peripheral surface of 0. (E) is the figure which looked at the light reflector 11 from the upper surface. Non-reflective surface 11
b can be constructed by not attaching a reflection sheet to this portion or by covering the reflection sheet. The principle is the same as the case where three concaves having an effective reflection angle of 60 ° are provided as shown in (f) and (g).
In this way, a light reflector having an arbitrary effective reflection angle can be produced.

FIG. 3 is a block diagram showing an embodiment of the arithmetic processing circuit of the laser navigator of FIG. The laser navigator 3 is composed of a laser scanner 4 and an arithmetic processing circuit 7. The arithmetic processing circuit 7 includes a position / azimuth calculation unit 8, an area management unit 9 including a memory unit 9a, and a data input unit 12.
Made of. From the data input section 12 to the automatic guided vehicle 2
All the position data of the light reflector 6 arranged in the area where the object moves and the data of its effective reflection angle are input. Also, data is input as to how many sections the area is divided into. The area management unit 9 divides the area based on the data and the laser reach distance to calculate the number of the light reflector that can be used for each section, and the calculated light reflector number and the number thereof. The effective reflection angle is stored in the memory unit 9a for each section.

The area management unit 9 selects the section where the automatic guided vehicle 2 is currently located based on the current position of the automatic guided vehicle 2 (the position calculated immediately before), and obtains the effective light reflector data of the section. The data is sent from the memory unit 9a to the read position / azimuth calculation unit 8. When calculating the current position and orientation of the moving body, the position and orientation calculating unit 8 extracts the position data of the light reflector from the area managing unit 9 and uses the position of the required light reflector to move the position and orientation of the moving body. To calculate. That is, the position / azimuth calculation unit 8 calculates using only the information on the light reflector required at the current position of the moving body. The calculated measurement data is sent to the host computer 1.

FIG. 4 is a diagram showing an example of the arrangement of the light reflectors in the area where the device of the present invention moves. Moving area 14
Light reflectors R1 to R9, R10 'and R11' are provided therein. It is an area having the same shape as the moving area 41 shown in FIG. 7, and the arrangement position of the light reflector is also the same.
The difference is that the effective reflection angles of the light reflectors 10 'and R11' are limited to a certain direction (in the example, R10 'reflects only from the fourth quadrant, and reflection R11' reflects only from the third phenomenon). ing. FIG. 4B shows details of the light reflector 17 (R10 '). The light reflector 17 is set at a reflection effective angle of 90 °. Similarly, the effective reflection angle of the light reflector 18 is also set to 90 °.

When the automatic guided vehicle is at the point A, the light reflectors within the laser reach distance 15 are R10 ', R11' and R.
9 light reflectors, and the information of these light reflectors is used. When the automatic guided vehicle is at the point B, the light reflectors within the laser reach distance 16 are R2, R9, R10 'and R1.
1'and R4 light reflectors. In such a case, the structure of the conventional light reflector could not recognize which of R4 and R10 the reflected light was, but in the present invention, the reflection from R10 'can be eliminated and it can be discriminated as R4. Therefore, the effective reflection angle of R10 'is invalid for the point B, so that the memory section has an R corresponding to the section including the point B.
2, R4, R9 and R11 'are registered. In the position / azimuth calculation unit (extracting means) 8, the necessary three light reflectors are extracted from these.

FIG. 5 is a flowchart for explaining area management and position / azimuth calculation for measuring the position / azimuth of a mobile unit.
It is In the area management, the position data of all the light reflectors in the area and the effective reflection angle data are the data input section 1
Input from 2 (Step (hereinafter referred to as "S")
1). Next, the area division number is input (S2), and the area management unit 9 divides the area into a plurality of sections. Then, the light reflector number in each section is calculated based on the input effective reflection angle of each light reflector and the previously known laser reach distance (S3), and is registered in the memory unit 9a for each section. (S4). When calculating the position and orientation, the area management unit 9 inputs the current position data (the current position obtained immediately before) from the position and orientation calculation unit 8 (S5) and selects the section where the automatic guided vehicle 2 is currently located (S6). . Then, the information (number and position data) of the light reflector registered in the memory section 9a corresponding to the section is output (S7).

On the other hand, the position / orientation calculation unit 8 receives the light reflector information from the area management unit 9 (S9), compares it with the data from the laser scanner, and selects the required light reflector (S10). Based on the position data of the light reflector and the opening angle between the light reflectors, the current position azimuth of the automatic guided vehicle 2 is calculated (S11).

[0017]

As described above, according to the present invention, the moving area is divided into a plurality of sections, the effective reflection angle of the light reflector is limited by the position of the moving area, and the area management unit controls the effective reflection angle. By registering only effective light reflectors for each section, when a light beam is projected from a moving body, there are two light reflectors in the same direction, and it is not possible to recognize which light reflector has reflected light. Even at such a specific position in the moving body area, it is possible to specify from which light reflector the reflected light is, the recognition error of the light reflector is eliminated, and the position azimuth with higher reliability can be calculated. Also,
It is possible to reduce the amount of information on the light reflectors that the optical beam does not reach, and to reduce the number of light reflectors registered for each section.
This has the effect of reducing the memory capacity and the amount of calculation.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an outline of a position and direction measuring device for a moving body according to the present invention.

FIG. 2 is a diagram for explaining the structure of a light reflector used in the present invention.

FIG. 3 is a block diagram showing an embodiment of an arithmetic processing circuit of the laser navigator of FIG.

FIG. 4 is a diagram showing an example of arrangement of light reflectors in an area where the device of the present invention moves.

FIG. 5 is a flowchart for explaining area management and position / azimuth calculation for measuring the position / azimuth of a mobile body.

FIG. 6 is a view for explaining the outline of a conventional laser navigator.

FIG. 7 is a diagram for explaining a measuring method of a conventional moving body measuring apparatus.

[Explanation of symbols]

 1, 24 ... Host computer 2 ... Automated guided vehicle (moving body) 3, 21 ... Laser navigator 4, 25 ... Laser scanner 5 ... Laser light 6, 10, 11 ... Optical reflector 7, 40 ... Arithmetic processing circuit 8 ... Position / azimuth calculation unit 9 ... Area management unit 9a ... Memory unit 12 ... Data input unit 22 ... Concave 23 ... Encoder 27 ... Semiconductor laser 28 ... Lens 29, 35 ... Miller 30 ... Cylindrical lens 31 ... DC motor 32 ... Driving pulley 33 ... Timing belt 34 ... Driven pulley 36 ... Condenser lens 37 ... Interference filter 38 ... Photodiode 39 ... Photodetector circuit

Claims (1)

[Claims] 1. A plurality of light reflectors that reflect light in an incident direction are arranged in an area where a moving body moves, and a light beam is rotatively scanned and emitted from above the moving body. In a device that detects reflected light from at least three light reflectors on a moving body and measures the current position of the moving body based on the position of each reflector and the opening angle between the light reflectors, The moving area is divided to form a plurality of sections, and some of the light reflectors have a specific reflection effective angle of 0 ° to 360 ° depending on the position where they are arranged. And data input means for inputting the position data of all the light reflectors in the area and the reflection effective angle data thereof, and the reflection effective angles of the respective light reflectors. Effective light reflection in each section based on The number is calculated, the effective light reflector number is stored in the memory section for each section, the section in which the moving body is present is selected based on the current position data, and the optical reflector corresponding to the selected section is selected. Area management means for reading the light reflector number, which is information, and its position data from the memory section, and receiving the light reflector information read from the area management means, and comparing it with the data by the optical beam. According to the above, data extraction means for extracting three light reflectors in consideration of the reflection effective angle from the light reflectors corresponding to the selected section, and providing the data for calculating the current position of the moving body, are provided. Position and orientation measuring device for moving objects.