JPS62254007A - Apparatus for detecting position of moving body - Google Patents

Abstract

PURPOSE:To accurately detect a position, by a method wherein the angles of the left and right sides of a corner cube are detected and represented by the average value thereof to correct an angle measuring error due to the distance difference of the corner cube from a moving body. CONSTITUTION:The laser beam emitted from the laser oscillator 1 mounted on a moving body while revolved is reflected from the corner cubes CC arranged at three reference positions so as to be separated from the moving body. The reflected beam advances along a route reverse to that at the time of emission and are reflected by a mirror 4 to be outputted 12 as a beam receiving signal (a). The oscillation means and the beam receiving means are mounted on the pulley 8 fixed to the rotary shaft of the rotary encoder 7 mounted on the moving body. The pulley 8 is rotated by an AC motor 9, and an angle signal (b) increasing in proportion to an angle of rotation and a zero reference signal (c) once per one revolution at the reference position are outputted from the encoder 7. An average angle signal is operated on the basis of left and right end angle signal of the corner cubes CC by a computer unit and, from said average angle signal and the positions of the corner cubes CC, the position and azimuth of the moving body are operated instantaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a position detection device for a moving object that corrects angle measurement errors due to distance differences from the moving object to a corner cube.

(Prior art) As a device for detecting the position of a moving object such as an unmanned vehicle in a factory or a tunnel excavator, there is a device that reflects light in the direction of incidence and is placed at a distance from the moving object. a corner cube, a laser oscillator that is mounted on the movable body and rotates to emit a laser beam to the corner cube, a light receiving element that receives reflected light from the corner cube, and a rotor that detects the angle of the laser beam. Various position detection devices for a moving object have been proposed, each of which includes a laser scanner equipped with a clear encoder and a computer unit that calculates the position and orientation of the moving object from the position of the corner cube and the detected angle from the rotary encoder. ing.

(Problems to be Solved by the Invention) FIG. 3 is a diagram for explaining a corner cube and its angle measurement error.

Corner cube CC refers to a prism used to reflect light in that direction regardless of the direction in which the light is incident. The corner cube CC is, as shown in Fig. 3 (A),
Its tip has the shape of a tetrahedron defined by one vertex of the cube and three adjacent vertices.

In the above-described position detection device for a moving object, it is important to measure the angle between the corner cubes CC (hereinafter referred to as angle measurement).

The angle to be determined is the angle θ21 as shown in FIG. 3(B).
, and the reference position of the low reencoder (mobile object direction)
Angle θ1. to corner cube CCI, CC2. θ
2 and calculated θ21-θ2-θ1...■.

When the corner cubes CCI and CC2 are equidistant from the center position 0 of the low reencoder, Δθ1゛=Δθ
2, the above formula 0 holds, but for example, when the corner cube CCI is close to the center position O (corner cube CCI°), θ21'I - θ2 - θ1゛
...■, and the measurement jlt
There was a problem that an error occurred.

SUMMARY OF THE INVENTION An object of the present invention is to provide a position detection device for a moving body that can correct a side angle error due to a distance difference between corner cubes and perform accurate position detection.

(Means for Solving the Problems) In order to achieve the above object, a position detecting device for a moving body according to the present invention includes a light reflecting means that reflects light in the incident direction and is disposed at a position away from the moving body; Nine rotatable units mounted on the moving body include a laser oscillation unit that oscillates a laser beam to the light reflection unit, a light reception unit that receives reflected light from the light reflection unit, and a rotation angle of the laser beam. a laser rotating means for detecting a left end angle signal and a right end angle signal by the angle detecting means from the light reflected at the left end and right end of the light reflecting means; and calculation means for calculating an average angle signal from the right end angle signal and the left end angle signal of the means, and instantaneously calculating the position and orientation of the moving body from the average angle signal and the position of the light reflecting means. .

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings and the like.

FIG. 1 is a block diagram showing an embodiment of a moving object position detection device according to the present invention, and FIG. 2 is a flowchart for explaining the operation of the CPU of a computer unit used in the embodiment device. .

In FIG. 1, ■ is a laser scanner, ■ is a counter box, and ■ is a computer unit.

Laser scanner I includes laser oscillator 1. Beam expander 2. Right angle prism 3. Perforated mirror 4, right angle prism 52, cylindrical lens 6, rotary encoder 7, pulley 8
．． Motor 9. Lens 10° Photodiode 11. It is composed of an amplifier 12 and the like.

The laser oscillator 1 is an oscillator that continuously oscillates laser light, and uses, for example, a helium-neon laser.

Laser light emitted from a laser oscillator 1 is incident on a beam expander 2.

The beam expander 2 is for converting incident light into parallel light, and the emitted light from the beam expander 2 is directed downward by a right-angle prism 3, passes through a perforated mirror 4, and then passes through a right-angle prism 5. re-orients it horizontally. The laser beam directed in the horizontal direction is expanded in the vertical direction by the cylindrical lens 6, and is emitted from the laser scanner (2).

The right angle prism 5 and the cylindrical lens 6 are connected to a pulley 8 fixed to the rotation axis of an incremental rotary encoder 7.
This boo IJ 8 is rotated by an AC motor 9, and the laser beam is continuously emitted in the radial direction on a horizontal plane. The rotary encoder 7 outputs an angle signal (bl) that increases in proportion to the rotation angle.
A zero reference signal fe) is output at the reference position once per rotation.

The corner cubes CC are placed at three reference positions, and the laser light reflected by each corner cube CC passes through the opposite path to the exit, that is, the first cylindrical lens 6 and the right angle prism 5, and then passes through the perforated laser beam. It is reflected by mirror 4. The laser beam reflected by the perforated mirror 4 is transmitted to the photodiode 11
After the light is focused on the top and converted into an electrical signal, the amplifier 12
is amplified by the laser scanner I as a received light signal (a).
is output from.

The output from this laser scanner I, that is, the received light signal (
a), the angle signal (b) and the zero reference signal te) are output to the counter box ■.

The counter box ■ is a 22-bit pinary count 13. First in first out (F I F
O) Consists of memory 14 and the like.

The counter 13 receives the angle signal (b
) and is reset by the zero reference signal (C1. When the light reception signal [a) from the amplifier 12 is added to the FIFO memory 14, this FIFO memory 14 receives the angle signal Cb of the counter 13 at that time. ) and memorize it.

Conbibu. -Taunisoto■ is interface 15,
CPU1G, memory 17. Keyboard 18°CRTI9
．． It is composed of a printer 20 and the like.

Next, with reference to FIG. 2, the operation of the CPU 16 will be further explained.

After the CPUI6 is initialized (101),
Corner cube CCI~C of 31 prisoners from keyboard 1B
The coordinates of the CU are input as position data (102).

This position data is output from CPU16 (103)
, displayed in CRTI 9.

The data displayed on CRTI9 is decoded and <10
4) If normal (105), record f, α in the memory 17
(106).

When the CPU 16 outputs the read signal to the FIFO memory 14 via the interface 15 (107), the
A total of six angle signals, two on the left and right sides of the three corner cubes CC stored in the IFO memory 14, are input (10B), that is, taking the corner cube CCI shown in FIG. 3 as an example, , the angle signal θj detected on the left side,
An angle signal θl' detected on the right side is input.

Based on the angle signals (θl, 01'', θ2. Calculate from the formula (l O9).

e1=(θ1 +i ”) /2 =-@θ
2-(θ2+θ2″)/2...■θ3=(
θ3×03″)/2 ...■This calculated value e1
~θ3 is checked internally by the CPU 16 (11
0”).

If it is determined to be normal (111), CPU16:
3f[i! input in step 102! Using the positions of the corner cubes CCI to CC3 of if and the three angular positions calculated in step 109, the positions and orientations are calculated (112) and output (113). The output of the CPU 6 is as follows: It is displayed on CRTI9 and printer 2
It is also possible to print 0.

Thereafter, the angle data is taken in as many times as necessary, and the above-mentioned operations (108 to 113) are repeated, and when the predetermined work etc. are completed, all operations are completed (114).

Note that the present invention is not limited to the apparatus described in the above embodiments,
It can be widely applied to devices using (-) corner cubes.The explanation was given using the case where the corner cube is 3+1i, but it can also be applied to represent the angle of one case.
Further, the same applies to the case of two cases or the case of four or more cases.

(Effects of the Invention) As explained in detail above, according to the present invention, the angle on the left side and the angle on the right side of the corner cube are detected, and the average value thereof is used to represent the angle of the corner cube. The advantage of this method is that it is possible to correct the angle measurement error due to the distance difference between the corner cube and the moving body, and to perform accurate position detection.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a position detection device for a moving body according to the present invention, and FIG. 2 explains the operation of the CPU of a computer unit used in the device of the embodiment. This is a flowchart for FIG. 3 is a diagram for explaining a corner cube and its angle measurement error. ■...Laser scanner...Laser oscillator 2...Beam expander 3...Right angle prism 4...Perforated mirror 5...
...Right angle prism 6...Cylindrical lens 7...Low reencoder 8...7'-IJ9...Mode 10...Lens 11...Photodiode 12...Amplifier 12■...・Counter box 13... Counter 14... FIFO memory ■... Computer 1 unit 15... Interface 16... CPU 17
...Memory 18...Keyboard 19...
・ORT 20...Printer CB)

Claims (1)

[Claims] a light reflecting means that reflects light in the incident direction and is disposed at a position away from the moving body; a laser oscillation means that is mounted on the moving body and rotates and oscillates a laser beam to the light reflecting means; and the light reflecting means. A light receiving means receives reflected light from the means, and an angle detecting means detects a rotation angle of the laser beam, and the angle detecting means detects a left end angle signal and a right end angle signal from the reflected light at the left and right ends of the light reflecting means. calculating an average angle signal from a laser rotating means for detecting an angle signal and a right end angle signal and a left end angle signal of the light reflecting means from the angle detecting means;
A position detecting device for a moving body, comprising calculation means for instantaneously calculating the position and orientation of the moving body from the average angle signal and the position of the light reflecting means.