JPH01163612A - Position detector for unmanned vehicle - Google Patents

Abstract

PURPOSE:To measure the position and speed of the unmanned body with high accuracy by providing a forming device which forms a random pattern on a road surface and an optical system which picks up an image of the road surface pattern. CONSTITUTION:The forming device which forms the random pattern on the surface of a traveling path is provided at an end part of the vehicle body 10 in a traveling direction, and a recovery device which collects formed pattern generating particles is arranged at the rear end part of the vehicle body 10. The optical system 20 is so constituted that an image is formed on a line sensor through a cylinder lens in a direction parallel to the line sensor and the sensor is at the focus in a vertical direction. The pattern of the road surface is detected by a video detection part 30 through the optical system 20 and inputted to a spatial filter 40. The filter 40 detects a specific spatial frequency component from the optically random pattern of the road surface and checks the behavior with time to measure the relative movement distance and speed of the vehicle body 10 to the road surface. The filter 40 calculates the sum of products by using an input value and a set pattern and an arithmetic processing part performs arithmetic processing. Consequently, the position and speed are measured with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a position detection device for an unmanned vehicle, and more particularly to a position detection device for an unmanned vehicle that is effective for detecting the moving distance and traveling speed of the unmanned vehicle.

B4 Summary of the Invention The present invention provides a position detection device for an unmanned vehicle that detects various driving conditions by installing a detector for detecting driving conditions on the body of the unmanned vehicle. By providing a random pattern generator and an optical sensor to form a random pattern, processing the detection signal of the optical sensor with a one-dimensional spatial filter means, and detecting the two-dimensional position and speed of the vehicle body from the output, The present invention provides an unmanned vehicle position detection device with excellent detection accuracy.

C1 Conventional technology Conventionally, in the automatic operation of unmanned vehicles such as automatic guided vehicles, methods have been used in which electromagnetic induction wires and optical reflective tape are laid down on the travel path to form travel guides, and encoders are installed on axles and measurement wheels. There is a method of measuring the speed and travel distance of an unmanned vehicle from pulses or analog voltages corresponding to the rotation of the wheels by attaching a driver, an octopus, or a nerator.

1) Problems to be Solved by the Invention In various conventional position detection devices, it is necessary to process the running path by laying guide wires, reflective tape, etc. on the road surface, which is a troublesome process and also causes damage to the road surface. Due to unevenness, slippage of the li wheel due to external forces, etc., and 19 mm of the wheel, accurate body side could not be achieved.

In order to solve this problem, is it possible to use optical detection means and perform calculation processing based on the detection signal to measure the traveling position, speed, and traveling distance of the unmanned vehicle? If the pattern is not properly random, for example, if the floor is almost a mirror surface, accurate measurements cannot be made.

E. Means for Solving the Problems The present invention has been made in view of the above-mentioned problems, and includes a random pattern forming device for forming a random pattern on the road surface when the vehicle body is running. an optical system disposed on the bottom portion for photographing a pattern of a running road surface; a video detection section that samples the video pattern photographed by the optical system at a predetermined period to obtain a video pattern signal; and the video detection section. filter means for multiplying a video pattern signal by a preset trigonometric function setting signal and performing an integral operation on the multiplied signal to obtain a trigonometric function pattern signal; The moving distance and speed of the unmanned vehicle are detected by an arithmetic processing unit that calculates a moving distance signal of the vehicle body.

F Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a position detection device for an unmanned vehicle according to an embodiment of the present invention, in which 10 is the vehicle body of the unmanned vehicle, 12 is a running wheel, and 20 is an optical device disposed on the bottom surface 11 of the vehicle body 10. It is a system. Reference numeral 30 denotes a video detection unit that receives the video signal from the optical system 20; 40 represents a spatial filter that receives the video detection signal from the video detection unit 30; and 50 represents an arithmetic processing unit that uses the filter output signal of the spatial filter 40 as an input. Arithmetic processing is performed to calculate the distance traveled, speed, and current position of the unmanned vehicle. These optical systems 20. Video detection section 30. The spatial filter 40 and the arithmetic processing section 50 constitute a detection processing section 60 .

The most distinctive feature of the present invention is that a random pattern forming device 100 is provided at the front end of the vehicle body 10 in the traveling direction to form a random pattern on the road surface. Further, a random pattern collector 80 is disposed at the rear end of the vehicle body 10 to collect pattern generation particles formed by the pattern former 100.

The random pattern former +00 is configured as (1'4) as shown in FIG.
Reference numeral 1 denotes an axle that connects the front wheels +2.1.2 of the vehicle body 10, and a drive boule 102 is provided on this axle 101.

103 is a rotating shaft rotatably supported on a fixed part (not shown) of the vehicle body 10; 104 is a driven pulley pulled on the rotating shaft 103; , 05. 106 is a cylindrical sieve attached to the rotating shaft 103.

Particles of different colors are placed in a sieve 106, and the particles fall onto the road surface from the eyes of the sieve, which rotates in conjunction with the axle 101, drawing a random pattern on the road surface. The eye shape of the sieve is a random shape, and particles with a random pattern are collected using a suction type or other random pattern collector 80.
Recover by.

As shown in FIG. 3, the video detection section 30 includes a line sensor 3
1. Readout circuit 32 and analog/digital converter (
A/D converter) 33. The spatial filter 40 is a multiplication unit 41a.

41b, pattern setting sections 42a, 42b, integral calculation section 4
3a and 43b.

The arithmetic processing unit 50 includes a low-pass filter 51 . a, 51b,
Trigonometric function calculation unit 525 phase calculation unit 53. Wasa calculation section 54. Multiplication section 55. It is composed of a differential calculation section 56 and a rotation locus calculation section (m calculation section) 70. The m calculation unit 70 is
As shown in FIG. 4, sine wave signal calculation units 71a, 7],
b, multiplication section 72a;

72b, data holding units 73a to 73 which are previous value holding units;
G, and summation units 74a and 74b.

FIG. 6 shows a specific example of the configuration of the optical system 20. In FIG. 6, 21 is a cylinder lens that receives reflected light from the road surface 80, and 22 is a collimator lens. Further, FIG. 7 shows another example of the optical system, in which the reflected light from the road surface 80 is reflected by the collimating lens 22 and the cylinder lens 23.
It is something that focuses on.

Next, the operation of the position detection device having the above configuration will be explained.

As shown in FIGS. 6 and 7, the optical system 20 forms an image on the line sensor 31 in a direction parallel to the line sensor 31 using a cylinder lens 21.24, and focuses an image on the line sensor 31 in a direction perpendicular to the line sensor 31. The lens system is constructed so that point 31 is the focal point. The video signals of the optical system 20 are detected by video detection sections 8 to 30, respectively, and input to the spatial filter 40.

The spatial filter 40 detects a specific spatial frequency component from an optically random pattern on the road surface, and measures the moving distance and speed of the vehicle body relative to the road surface by examining its temporal behavior.

Generally speaking, as shown in FIG. 3, a pattern on a road surface 80 is detected by an image detection section 30 via an optical system 20,
The output is input to the spatial filter 40. The spatial filter 40 performs a sum-of-products operation using the input value and a setting pattern calculated and set in advance. here,
It uses a sine wave pattern. The setting pattern has data for a period determined by the number of elements and pitch of the line sensor 31 of the video detection section 30. The output of the spatial filter is processed by the arithmetic processing unit 50 to calculate the moving distance R11 of the car, and this moving distance is differentiated with respect to time to find the speed. Also,
When detecting the position at a cycle that is sufficiently small compared to the movement of the car, the change in the direction of the car is calculated from the difference between the measured distances traveled in one cycle by the two detection processing units, and the average value of the changes is used to calculate the change in the direction of the car. The position of the vehicle body is determined based on the assumption that the vehicle has traveled during the period.

More specifically, as shown in FIG. 3, a video signal of the road surface 80 is input to the video detection section 30 via the optical system 20.

In the video detection unit 30, the line sensor 31 detects the video, the video detection signal is read out by the output circuit 32, and the video detection signal is A/D converted and sent to the spatial filter 40.
Enter.

In the spatial filter 40, the video detection signal from the video detection section 30 and the sine wave pattern setting signal from the pattern setting section 42a are multiplied by the multiplication section 41a, and the multiplication section 4
．． ], b, the video detection signal and the cosine wave pattern setting signal of the pattern setting section 42b are multiplied together. Further, the first multiplication section 4] integrates the multiplication signal of a in an integral calculation section 438 and outputs the integrated signal a, and integrates the sliding/multiplication signal of the multiplication section 41b in a second integral calculation section 431]. , outputs its integral signal.

In the arithmetic processing unit 50, the integral signal is passed through a low-pass filter 51a to obtain a signal Sa, and an integral signal S2 is obtained.
A low pass filter 51. b to obtain signal sb. The signals Sa and sb are input to the trigonometric function calculation section 52 and the rotation locus calculation section (m calculation section) 70, respectively. The trigonometric function calculation unit 52 performs calculations based on the signals Sa and sb, and outputs p −
Arctan (S b/Sa) is calculated. The phase calculation unit 53 calculates (ρ−φ)/2π based on the input ρ and the initial phase φ.
Calculate it.

In the m calculation unit 70, as shown in FIG. 4, the signal Sa is input to the sine wave signal calculation unit 71. a to the multiplication unit 72a and the data holding unit 73a, and the signal sb is guided to the sine wave signal calculation unit 7
1b, it is guided to the summation section 74b and the data holding section 73b. The multiplication unit 72b multiplies the previous sampling value from the data holding unit 73a by the current sampling value. The summation unit 74 stores the current sampling value and the data holding unit 73b.
The previous sampled values of are summed. The multiplication unit 72b multiplies the multiplication value of the multiplication unit 72a and the summation value of the summation unit 74b, and the summation unit 74a adds the current multiplication value of the multiplication unit 72b and the previous value obtained by the data holding unit 73c to obtain m. Output a signal.

Furthermore, in the arithmetic processing section 50, as shown in FIG.
The m signal of the summation unit 54 or the m calculation unit 70 and the phase signal of the phase calculation unit 53 are summed, and the added value of the summation unit 54 is multiplied by the pitch (period) P of the spatial filter to calculate the moving distance. At the same time, this moving distance signal is input to the differential calculation section 56 to calculate the speed.

The output of the spatial filter rotates on the phase plane according to a small movement, as shown in FIG. Therefore, the traveling distance is calculated by the following formula.

Xo-(2πm+ρ-P)/nK=mxP+(ρ-φ)
/2πP - (5) where m is the number of rotations of the trajectory around the origin (counterclockwise is positive), Xo is the distance traveled,
P is the pitch (period) of the spatial filter, ρ-arctan
(S b/Sa), 0≦p<2π, P=
ρ1. = O (initial value).

Figure 8 and Figure 9 show the above-mentioned operation flow.
The figure shows the calculation flow of the spatial filter 40, and FIG. 9 shows the calculation flow of the calculation processing section 50.

As shown in FIG. 8, in step S1, the line sensor (C
CD) is A/D converted and input to the spatial filter. In the spatial filter, as shown in step S2,
A sine 2/& (sin) pattern is read as window function data 1, and a product-sum operation of this sine wave pattern and the CCD output is executed (step S3). Next, as shown in step S4, a cosine wave (cO8) pattern is read as window function data 2, and a product-sum operation of this cosine wave pattern and the CCD output is performed (step S5). And step S6
As shown in the figure, the operations of steps 81 to S5 are repeated 1.8 times per the number of CCD elements, for example, 20.

As shown in FIG. 9, in the arithmetic processing section, the output signals a and b of the spatial filter are passed through a one-dimensional low-pass filter at step S7. S8), as shown in step S9, count the number of times the phase plane moves between the first and fourth quadrants, taking the direction of movement from the fourth quadrant to the first quadrant as positive, and calculate m. Execute. Next, step S ],
As shown in O, ρ= arctan (S b/S
a) in the range of 0≦ρ<2π to perform phase calculation, and as shown in step Sll, m-P+(ρ-P
)/2π·P and executes a distance calculation, and at the same time, as shown in step S12, the distance is differentiated and a speed calculation is executed.

FIG. 10 shows another embodiment of the present invention, in which a microcomputer 90 is used as the arithmetic processing section. The microcomputer 90 includes a central processing unit (CPU) 91.
Random access memory 92° read only memory (
ROM) 93 and a bus 94.

As mentioned above, the road surface pattern is detected by the CCD via the optical system, and its output is inputted to the microcomputer 90 through the A/D converter, and its value and settings previously calculated and stored in the ROM 93 are Based on the pattern, the arithmetic processing described above is executed.

G9 Effects of the Invention As described above, the present invention provides a vehicle body with a random pattern former and an optical system sensor that form a random pattern on the road surface when the vehicle body runs, and detects the detection signal of the optical system sensor in one dimension. Since the traveling distance and speed of the vehicle body are detected from the output of the filter means, there is no need to process the travel path such as using reflective tape on the guide line 1, and measurement can be performed without contact with the road surface. It is possible to measure position and speed with high accuracy without being affected by slippage caused by unevenness or external force, or wheel wear.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a position detection device according to the present invention, FIG. 2 is a perspective view of a random pattern generator, and FIG. 3 is a block diagram showing details of a detection processing section according to an embodiment of the present invention.
Fig. 4 is a block diagram of the rotation trajectory calculation section, Fig. 5 is a rotation trajectory diagram of the rotation trajectory calculation section, Figs. 6 and 7 are configuration diagrams of the optical system, respectively, and Fig. 8 is a calculation flow diagram of the spatial filter. , FIG. 9 is a calculation flow diagram of the calculation processing section, and FIG. 10 is a block diagram showing another embodiment of the detection processing section. DESCRIPTION OF SYMBOLS 10.. Vehicle body, 11. Bottom surface part of vehicle body, 20.. Optical system, 30. Image detection section, 40. Spatial filter, 50. Arithmetic processing section, 60.. Detection processing section, 100.. Random pattern former.

Claims (1)

[Claims] (1) an optical system disposed on the bottom of the vehicle body that captures the pattern of the road surface; an image detection section that samples the image pattern captured by the optical system at a predetermined period to obtain an image pattern signal; filter means for multiplying the video pattern signal of the video detection section by a preset trigonometric function setting signal and performing an integral operation on the multiplied signal to obtain a trigonometric function pattern signal; an arithmetic processing unit that calculates a moving distance signal of the vehicle body by performing multiplication and addition processing; and a random pattern forming device that is provided on the vehicle body and forms a random pattern on the traveling road surface in accordance with the travel of the vehicle body. An unmanned vehicle position detection device featuring: