JPS62105206A - Guiding device for unmanned guided vehicle - Google Patents

Abstract

PURPOSE:To easily change paths by decomposing the relative displacement from a road surface into an orthogonal two-axial component at two different positions on a vehicle body and measuring it under non-contact state, and calculating the movement distance and direction of the vehicle body from the measurement signal. CONSTITUTION:Steering wheels 8 are fitted on the front of the unmanned guided vehicle 3 in its moving direction and driving wheels 9 are provided at the back. A displacement sensor 10 decomposes the relative displacement from the rod surface into an orthogonal two-axis (X, Y) component and measures number non-contact state, and is fixed at two different positions P and Q on the guide vehicle 3. The center point O is determined by the wheels 8 and 9, an axis I is in the moving direction and fixed at the center point O, and an axis II is fixed at the center point O at right angles to the axis I. An axis I is provided at about 45 deg. to the axis I. A movement extent arithmetic means 11 calculates the movement distance and direction of the vehicle body from the signals from the sensors 10 and outputs them to a deviation arithmetic means 12, which calculates the deviation from a position which is transmitted from a command means 12 and outputs it to a steering means 14 and a driving means 15. Thus, paths are easily changed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an unmanned guided vehicle used for cargo handling work in factories and the like, and particularly provides a guiding device that allows easy route changes.

(Technology from the past) Fig. 6 shows a conventional guidance system for an unmanned guided vehicle. In the figure, l is a passage provided in a factory or warehouse, and 2
3 is a signal cable buried in the passageway IK, 3 is an unmanned guided vehicle for loading and unloading goods, and 4 is a wheel for driving the unmanned guided vehicle 3 and determining the direction of movement, the number of which is adjusted according to the load. 5
is a magnetic sensor mounted on the unmanned guided vehicle 3.

FIG. 7 is an explanatory diagram of the operation of the device configured in this way,
7-7 sectional view of the figure is shown. A high frequency current for guiding the unmanned guided vehicle 3 is applied to the signal cable 2 .

Then, a magnetic field 6 is generated around the signal cable 2, and the unmanned guided vehicle 3 reads this signal via the magnetic sensor 5 and moves according to this command. In this way, unmanned guided lr
, 3 move on the signal cable 2.

(Problem to be Solved by the Invention) However, since the unmanned guided vehicle 3 can only move on the signal cable 2, when changing the production line and changing the movement route of the unmanned guided vehicle 3, the buried signal cable There is a problem in that it requires work to dig up and re-lay the 4-2.

The present invention solves these problems.

The purpose of the present invention is to realize a guidance device for an unmanned guided vehicle that can easily change the travel route.

(Means for solving the gap between the two axes) The present invention achieves the above object by decomposing the relative displacement with the road surface into two orthogonal axes components at two different locations on the vehicle body and measuring it in a non-contact manner. On the displacement to be performed; /su, there is a movement amount calculation means that calculates the fixed movement distance and support movement direction of the car body from the signals of these displacement sensors, and calculates the current state of the car body based on the results calculated by this movement amount calculation means. The present invention is characterized in that it is provided with a deviation calculating means for calculating the total deviation between the position of , and the commanded position, and the unit is guided to the commanded toilet lid based on the calculation of the deviation calculating means.

(Operation) Movement 1 is determined using a displacement sensor mounted on the vehicle, and the vehicle body is guided to a specified position.

(Example) The present invention will be explained below using the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, 3Fi unmanned guided vehicle % 8 is a steering wheel attached to the unmanned guided vehicle in front in the direction of travel, 9 is a drive wheel that propels the unmanned guided vehicle, and 10 is a drive wheel that propels the unmanned guided vehicle with two orthogonal axes (X,
Y) A displacement sensor that measures components in a non-contact manner, and is used for unmanned guided vehicles. Two different points P above.

It is fixed at Q.

O is the center point determined by the unmanned guided vehicle 30 wheels & 9, f
$lI is an axis that coincides with the traveling direction of the unmanned guided vehicle 3 and is fixed at the center point 0, and the n axis is! This is an axis that is perpendicular to the axis and fixed at the center point O. The X-axis is an axis used for measurement of the displacement sensor 10,
One axis means an approximately 45 degree inclination.

The Y-axis is an axis perpendicular to the X-axis and is used for measurement by the displacement sensor 1o.

1) is a movement amount calculation means 12 which calculates 1 ml for movement and movement direction ψ of the unmanned guided vehicle 3 from the signal of the displacement sensor 10;
13 is a deviation calculation means 12 for calculating the deviation between the current position of the unmanned guided vehicle 3 and the position to be reached by the unmanned guided vehicle 3 based on the result calculated by the movement amount calculation means 1);
A command means for transmitting the position to be reached can specify a series of movement positions gl'tr as necessary. Reference numeral 14 denotes a steering means for controlling the steered wheels 8 based on the direction of the deviation determined by the deviation calculation means 12, and a driving means for controlling the driven wheels 9 based on the amount of deviation of 15.

The device configured as described above operates as follows. - According to the knowledge of calibration mechanics, the motion of a rigid body in a plane is determined when the motion vectors of two points within the rigid body are determined. Therefore,
When the displacement (x, y) of the displacement sensor 10 in the two rectangular directions at the point x', <=, Q is measured, the motion vector of the two points is determined. Next, the movement distance t and the movement direction ψ of the unmanned guided vehicle 3 are calculated using the movement calculation means 1). 7 For example, assume that the displacement at PAK is (Xl, Yl), the displacement at point Q is (x2.y2), the interval between point P and point Q is 1, d, and the center point is O. The alignment of the center point 0 and the Yuu linkage are made using the displacements of points P and Q.

is given by From this, the moving distance and the moving direction ψ are given by the following formula. Here, the moving direction ψ is the inclination with respect to the 1st axis.

Since the moving distance l and the moving direction ψ are integrated every moment by the deviation calculation means 12, the current position on the route from the starting point to the destination point can be determined, and the distance and direction to the destination point can also be easily determined. Therefore, if the steering wheel 8 is controlled by the steering means 14 in this direction and the unmanned guided vehicle 3fc is directed,
, drives the drive wheel 9 by the required distance.

FIG. 2 is a configuration diagram showing a specific example of the displacement sensor IO.

In the figure, 20 is a bottom plate provided on the side of the unmanned guided vehicle 3 closer to the road surface l, and has an opening 21 formed therein. 22 is a lighting device that emits light from the opening 21 onto the road surface 1; 23 is a lens that focuses the light reflected by the road surface 1; and 24 is a half mirror that divides the reflected light into two optical paths. Convert one of the lights divided by 24 into electricity No. 43)
The optical element 26 is a grating with a pitch P17) provided in the image space of the photoelectric element 25, and serves as a space filter that emphasizes the light and shade in the X-axis direction of the plane perpendicular to the optical axis (Y:J). 27 is a comparator that converts the signal waveform of the pulsating output of the photoelectric element 25 into a pulse signal, and 28 is a comparator 2.
This is an X-axis totalizer that shows the pulse signal of 7 as a horizontal line. 29 is the other light divided by the half mirror 24 f1) Light 71 to be converted into a signal! element, 30 is a grating that emphasizes a and f in the X-axis direction perpendicular to the This is the product side of the axis.

Km was completed like this! ! In the neck, it works as follows. As the unmanned guided vehicle 3 moves, the photoelectric elements 25, 2'l
The statue above moves. On the other hand, since the grating 26.30 constitutes a spatial filter, the product S total 28.32 is integrated one by one each time one layer on the photoelectric element 25.29 moves by the pitch p. By multiplying this by the magnification of the optical system, the amount of movement of the displacement sensor 10 can be determined.

Note that although this method cannot determine whether the automatic guided vehicle is moving forward or backward, no problem will occur if the deviation calculation means 12 knows in which direction the drive wheels 9 are rotating.

FIG. 3 is a block diagram of main parts showing another specific example of the displacement sensor 10, in which a spatial filter for detecting movement in the -axis direction is shown. In the figure, 40 is a seven-photo diode array that constitutes a spatial filter.
array, hereinafter referred to as r PDA J), 41 is P
3n photoelectric sensing parts are provided in the DA 40 with a spacing of i4p/3, and are connected every second to each other to form three spatial filters with an n-stage pitch p. 42 is an amplifier a that amplifies the signals of the three spatial filters, 43 is a switch that sequentially scans the output of the amplifier 42, 44 is a summing amplifier that amplifies the signal connected by the switch 43, and 45 is a switch 4.
46 is a detection circuit that detects the frequency f of the output signal of the low-pass filter 45, calculates the difference from the reference frequency fo, and outputs it to the movement amount calculation means 1). . 47 is a switch 43 according to the clock (CLK) of frequency 3fo.
with a control circuit that switches.

Only one of the switches 43 is turned on.

The operation of the apparatus constructed in this way will be explained based on FIG. FIG. 4 shows the signal waveform of the device +1 in FIG. 3, and (A) is the input signal iB of the low-pass filter 45.
) shows the waveform of the output of the low-pass filter 45 (No. 1).Each spatial filter is shifted by 13/3 from each other. It becomes a shaped sine wave. The low second filter 45 works effectively 12, and the sine wave peak υ shown in FIG. 4(B) is obtained. If the image of PDA 40-, h is stationary, the hawk on the original switch PDA 40 moves again in 3 crooks, and if it moves 2, its direction is += the scanning direction of switch 4J. In the case of h, the balding frequency f becomes low, and in the opposite direction, it becomes high. Therefore, this Shuhan error difference (f-fo)
The amount of movement can be determined by determining this using the detection circuit 46. still,
Instead of the frequency difference, λ may be used to find the phase difference with CLK.

In this way, it is possible to determine in which direction the steering wheel 8 is moving, so even if the steering angle of the steering wheel 8 becomes large, the steering angle can be accurately followed.

FIG. 5 shows a displacement sensor that detects movement of interference fringes (speckle patterns) caused by light interference. Such a displacement sensor is disclosed, for example, in Japanese Patent Application Laid-open No. 162405/1983 proposed by the applicant of the present invention. In FIG. 5, parts having the same functions as those in FIG. 2 are designated by the same reference numerals and their explanations will be omitted.

In the figure, it is a laser light source that emits 50-order coherent laser light onto a road surface 1. Since the reflected light from the road surface 1 creates a laser speckle pattern, the speckle pattern also moves in accordance with the movement of the unmanned guided vehicle 3, so that the movement amount calculation means 1) can calculate the amount of movement.

In this way, it is possible to measure even if there is no clear pattern on the road surface l.

(Effects of the Invention) As explained above, according to the present invention, since all the movements on the road surface 1 are determined by the displacement sensor 1o mounted on the unmanned guided vehicle 3, it is very easy to command the destination position if. You can change your travel route.

[Brief explanation of drawings]

Fig. fa1 is a block diagram showing an embodiment of the present invention, Figs. 2, 3, and 5 are block diagrams showing a specific example of a displacement sensor used in the present invention, and Fig. 4 is a block diagram showing a specific example of the displacement sensor used in the present invention. Waveform diagram explaining the operation, Figure 6 is an explanatory diagram of the conventional unmanned guided vehicle. Figure 7 is the diagram 6.
FIG. 3 is an explanatory diagram of the operation of the device shown in the figure. 10...Displacement sensor, 1)...Movement/bin calculation means 2...Difference calculation means. Agent Rishi I, Nobuko Ozawa＼, J

Claims (3)

[Claims] (1) Displacement sensors that measure the relative displacement with the road surface at two different locations on the vehicle body into orthogonal two-axis components, and calculate the distance and direction of travel of the vehicle body from the signals from these displacement sensors. A movement amount calculation means, and a deviation calculation means for calculating a deviation between the current position of the vehicle body and a commanded position based on the result calculated by the movement amount calculation means, A guidance device for an unmanned guided vehicle, characterized in that the vehicle is guided to the commanded position. (2) The displacement sensor includes an optical means into which light from the road surface is incident, and an axis (Z) perpendicular to the optical axis (Z) of the incident light of this optical means.
A first spatial filter that emphasizes the shading in the axis (
Claims comprising: a second spatial filter that emphasizes the shading in the axis (Y) direction orthogonal to The guidance device for an unmanned guided vehicle according to item 1. (3) The displacement sensor includes a laser light source that emits laser light onto the road surface, and a movement of the speckle pattern in the direction of an axis (X) perpendicular to the optical axis (Z) of the reflected light of the laser light from the road surface. Claim 1, comprising: a first detection means for detecting; and a second detection means for detecting movement of the speckle pattern in the direction of the axis (Y) orthogonal to the axis (X). guidance system for unmanned guided vehicles.