JPH04145506A - Guiding device for optically guided unmanned carrier - Google Patents

Abstract

PURPOSE:To make the device to hardly receive the influence of the contamination and gloss of the paint used for guidepath wires so that the device can be used outdoors by irradiating the guidepath wires with the light emitted from a light emitting section and receiving scattered reflected light from the guidepath wires with a light receiving section. CONSTITUTION:Light emitting diodes 31 which are arranged in an array so that the diodes 31 can uniformly emit rays of light to a guidepath wires 101a in the normal direction emit pulse-modulated rays of light OPC at a fixed angle theta. The scattered reflected rays of light OPC of the rays of light OPA which are not affected by the gloss of the wire 101a are made incident to an PSD element 34 through a condenser lens 33 and the element 34 detects the position of the line 101a as far as a difference exists on the reflectivity between the line 101a and road surface even when the line 101a is contaminated. Therefore, this optical guiding device can be easily used outdoors and an unmanned carrier system can be constituted inexpensively as compared with a loop-wire induced electromotive force system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a guiding device for an optically guided automatic guided vehicle, such as a golf bag automatic guided vehicle used indoors or outdoors, for example, at a golf course.

[Prior Art] Conventionally, automatic guided vehicles have often adopted an optical guidance method for indoor use, and an induced electromotive force induction method using a loop wire for outdoor use.

FIG. 5(a) is a plan view showing the overall configuration of a conventional optical guidance type automated guided vehicle guidance device disclosed in, for example, Japanese Unexamined Patent Publication No. 55-10654, and FIG. 5(a) is a side view thereof. It is a diagram.

In both Figures 5(a) and 5(bl), 1 is a guide line made of white paint or aluminum tape applied to the traveling road surface, 2 is an automatic guided vehicle, and 3 is a guide line along the guide line 1. 4 is a steering wheel, 5 is a drive motor, 6 is a rear drive wheel, and 7 is a battery that supplies the DC1 source of the automatic guided vehicle 2.

Further, 8 is a sensor unit that detects the guide wire l, and 9
is a light-emitting element (in this case, a fluorescent lamp) that emits a light source onto the road surface
, IO are a plurality of light receiving elements arranged in an array to receive reflected light from the light emitting element 9.

FIG. 7 is a side view showing the overall configuration of a conventional guided electromotive force induction type automatic guided vehicle guidance device using a loop wire, which is disclosed in, for example, Japanese Patent Application Laid-Open No. 1983-8005. 1a is a taxiway including a guidance loop line buried in the taxiway, 2 is an automated guided vehicle (in this case, a golf cart)
, 3 is a steering motor that rotates forward and backward along the loop line on the guideway la, 4 is the steering wheel, 5 is a drive motor, 6 is a rear drive wheel, and 7 is a battery that supplies a DCt source for the automatic guided vehicle 2. It is. Note that GL is a ground.

Reference numeral 8 denotes a sensor section of an induced electromotive force type automatic guided vehicle guidance device, which is configured as shown in FIGS. 8(a) and 8(bl). In both figures (b), a low frequency current is passed through the induction loop wire buried above the guideway la, and the magnetic field generated by this is applied to two detection coils lla attached at equal intervals from the center line of the vehicle body. ,
llb, and the induced electromotive force generated in the detection coils lla and llb is amplified through an amplification δ12 to a deviation detector I3.
It is designed to be compared with.

Next, the operation will be explained. In the case of an optical guidance system for guiding an automatic guided vehicle, as shown in FIG. 6, the light emitted from the light emitting element 9 is irradiated onto the road surface zone in the width direction of the sensor section 8.

The irradiated light beam is reflected (regularly reflected) at an angle compared to the incident angle θ and enters the light receiving element 10, but since white paint or alumina is stretched on the road surface as the guide line 1, an array is arranged. Among the plurality of light receiving elements 10, there are elements that turn on and elements that turn off due to differences in light reflectance, and the position of the guide line can be detected based on the pattern.

In addition, in the case of an automatic guided vehicle guidance device using an induced electromotive force induction method using a loop line shown in FIGS. 7, 8(a), and 8(b), FIG. As shown in bl, a low frequency current is passed through the induction loop wire R buried on the guideway Ia, and the magnetic field generated by this is detected by two detection coils Ila and llb installed at equal intervals from the center line of the vehicle body. By detecting and comparing the induced electromotive force generated in the detection coils Ila and Ilb via an amplifier 12 and a deviation detector 13, it becomes possible to detect the 1st order of the induction loop line R.

Therefore, in order to travel along the detected guide line in both types, the position of the guide 1sl is detected and the steering motor 3
The automatic guided vehicle 2 is controlled by.

Note that the operations in FIGS. 8(a) and 8(b) are exactly the same except for the receiving sensitivity of the induced electromotive force.

(Problems to be Solved by the Invention) Conventional automated guided vehicles using optical guidance are configured as described above, so the configuration is simple and inexpensive, but the reflectance decreases due to dirt on the guide wire l. Due to these problems, it could only be used indoors in a good environment.

In addition, the guided electromotive force automatic guided vehicle guidance system using loop wires shown in Figures 7, 9, 8(a) and 8(b) is resistant to adverse environments and has a track record of being used outdoors. However, since the loop line is buried in the road surface, the course cannot be changed easily.

In addition, it is necessary to constantly run a low-frequency current through the loop wire, which poses problems such as system failure due to lightning strikes and high construction costs for installing a low-frequency power supply or burying the loop wire.

This invention was made to solve the above-mentioned problems, and by using an optical guidance method, the construction cost is only the cost of the guide wire construction, and the course can be easily changed, and it can be used outdoors. An object of the present invention is to obtain a guidance device for an optically guided automatic guided vehicle that can have a sensor structure that is less susceptible to the influence of dirt on the guide wire.

[Means to solve the problem]

The optical automatic guided vehicle guidance device according to the present invention is provided corresponding to a guide line, and irradiates the guide line with light from a light emitting part,
A control unit mainly consisting of a sensor unit that receives the reflected light with a light receiving unit, and a microcomputer that determines the position of the guide line from the output of this sensor unit and controls the automatic guided vehicle to travel along the guide line. It has been established that

[Function] By installing the light-receiving part of the sensor part in this invention at a position where it receives diffuse reflection corresponding to the relative position of the automatic guided vehicle, the guide wire is irradiated from the light-emitting part, and the light is diffusely reflected from there. This light-receiving section receives the reflected light, which is unaffected by the dirt and gloss of the guiding wire paint, and combines it with the absolute reflection signal corresponding to the absolute value of the automatic guided vehicle from the photo IC in the sensor section. , IIW including microcomputer
By determining the position of the guide wire in the section, it can be used outdoors.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a guidance device for an optically guided automatic guided vehicle according to the present invention will be described based on the drawings. FIG. 1(a) is a plan view showing the overall configuration of one embodiment, and FIG. 1(a) is a side view of FIG. 1(a).

In both FIG. 1(a) and FIG. 1(b), 21
is a body frame of the automatic guided vehicle 2, and a rear wheel drive motor 5 for traveling is attached to this body frame 2I, and the rear wheel drive motor 5 drives the rear drive wheels 6.

Further, a port 27 is attached to the lateral direction of the vehicle body frame 21, and joints 26 are attached to both ends of this rod 27.
One end of a pair of arms 25 is attached in a right angle direction via. That is, the pair of arms 25 are parallel to the vehicle body frame 21.

Casters 22a are attached to this pair of arms 25.

Steering wheels 4a and 4b are attached via 22b, respectively.

Furthermore, a plywood 50 is attached to the vehicle body frame 22 in the width direction of the vehicle body frame 22.

A steering motor 3 is attached to the plywood 50. The rotational driving force of the steering motor 3 is transmitted to the boot 924 via the timing belt 23.

The rotational force of the pulley 24 is transmitted to the casters 22a, 22b via the shaft 51, thereby steering the steered wheels 4a,
4b is rotatably driven.

Further, the vehicle body frame 21 has a pair of guide wires 101a, 1
The guide lines 101a and 101b have a width of 5 mm and are applied in parallel on the floor.

These guide lines 101a, 101b are applied on the asphalt in the same manner as ordinary road markings.

Optical sensor sections 28a and 28b are connected to the vehicle body frame 2 in correspondence to the pair of guide wires 101a and 101b, respectively.
It is attached to the bottom of 1.

The sensor parts 28a and 28b are the guide wires 101a.

101b is detected, a signal is transmitted to the control unit 29, and the steering wheels 4a, 4b, and ultimately the automatic guided vehicle 2 are controlled to travel along the guide lines 101a, 1o1b.

Further, a battery 7 is mounted on the vehicle body frame 21 and supplies DC power to each part of the automatic guided vehicle 2.

FIG. 2 shows the optical sensor section 28a shown in FIG.
FIG. 2A is a side view of the sensor, and FIGS. 2A and 2B are front views of the sensor.

In this Fig. 2(a) and Fig. 2(bl), the guide wire 10
1a and 101b, GaAs infrared light emitting LEDs (light emitting diodes) 31, which serve as light emitting elements in the light emitting part, are arranged in an array so as to irradiate uniform light vertically to the angle of view l of the sensor part. Irradiate pulse modulated light at θ (
OPA).

On the other hand, the photo IC 32 as a light receiving unit arranged in an array facing the light emitting LED 31 receives specularly reflected light (OPB) in synchronization with the pulse modulated light of the light emitting LED 31, and receives specularly reflected light (OPB) several times as much as the road surface such as Alfalto. The guide wire 101a has a high reflectance.

The absolute position of the photo IC 32 is detected by the on/off pattern of each photo IC 32, and the received level of the amount of reflected light is transmitted to the control unit 29.

The control section 29 is attached to a plywood board 50 shown in FIG. 1(a), and is mainly composed of a microcomputer.

The second microcomputer learns and controls environmental changes such as dirt on the guide wire.

Further, the diffusely reflected light (OPC) which is not affected by the gloss of the guide lines 101a and 101b is imaged through the condenser lens 33 and enters the PSD element 34.

FIG. 3 is an internal structural diagram of the PSD element 34. P.S.
The D element 34 includes a P-type resistance layer 35, a high-resistance Si substrate 1 layer 3
6. It consists of an N layer 37, and the photo-generated charge generated at the light incident position (in this case, the imaged diffuse reflection position) reaches the P-type resistance layer 35 as a photocurrent proportional to the incident energy of the light. Then, the photocurrent II and 12 are divided in inverse proportion to the resistance values of the respective electrodes 0UT1 and 0UT2, and are taken out from the electrodes 0UTI and 0UT2.

That is, regardless of the intensity of the incident light energy, the photocurrent +1. Since the incident position is detected by the ratio of I2, even if the guide lines 101a and 101b become dirty and the reflectance decreases, as long as there is a difference in reflectance with the road surface, the guide line 101a in FIG.
, 1o1b can be detected.

Next, the distinction from disturbance light will be explained using FIG. 4.

The microcomputer 41 passes through a flip-flop circuit 52, a synchronization circuit 42, and a constant current circuit 43, and the LEDs 31 arranged in an array emit pulsed light (pulse width approximately 15
0 μs).

That is, the frequency distribution of the light intensity of the disturbance light has a strong low frequency component and when pulse modulated light is used, the high frequency component of the target light becomes strong. Bypass filter) times W4
6a and 46b, most of the disturbance light can be removed.

In this invention, the second-order LPF C low-pass filter) circuits 47a and 47b are further passed through, and the HPF circuit 46a,
46b attenuates the disturbance light that cannot be removed, and the arithmetic circuit 4
8. The microcomputer 41 takes in the data via the sample and hold circuit 49.

As a result, it is completely synchronized with the modulated light of the light emitting LED 31, and is not affected by disturbance light.

In addition, in the above embodiment, the sensor section 28 having the same optical function
A, 28b are attached to the left and right sides of the automatic guided vehicle 2 in the explanation, but in principle, only one sensor section 28 may be used.

〔Effect of the invention〕

As described above, according to the present invention, light is irradiated from the plurality of light emitting elements of the light emitting part of the optical sensor part to the traveling road surface including the guide line, and the reflected light is received to guide the automatic guided vehicle toward the target. In addition to detecting the position, it is configured to combine detection of the absolute position of the automatic guided vehicle, output the detection result to a control unit including a microcomputer, and use this control unit to guide the automatic guided vehicle along the guide line. As a result, the optical guidance device of an automatic guided vehicle can be easily used outdoors, the system configuration of an automatic guided vehicle that runs both indoors and outdoors can be made cheaper than the loop line induced electromotive force method, and it is possible to easily change course. This has the effect of providing a high degree of freedom.

[Brief explanation of drawings]

FIG. 1(a) is a plan view showing the overall configuration of a guidance device for an optically guided automatic guided vehicle according to an embodiment of the present invention.
b) is a side view of FIG. 1(a), FIG. 2(a) is a side view of the sensor section in the same embodiment as above, FIG. 2 0:I) is an internal sectional view of the same sensor section, and FIG. A cross-sectional view showing the configuration of the PSD provided in the sensor section as above, Figure 4 is the PSD as above.
Electronic circuit diagram of a PSD amplifier that processes the output signal of
The figures (al is a plan view showing the overall configuration of the conventional optical guidance type automatic guided vehicle guidance system, Figure 5, etc.) are side views of Figure 5 (a), and Figure 6 is the optical guidance system of Figure 6. FIG. 7 is a side view of the conventional induced starting power induction system automatic guided vehicle guidance device, and FIGS. 8(a), 8, etc.) are respectively FIG. 8 is an explanatory diagram of the configuration of a sensor section of the automatic guided vehicle guidance device using the induced electromotive force induction method shown in FIG. 7; 2...Automated guided vehicle, 3...Steering motor, 4a, 4b
... Steering wheel, 5... Drive motor, 6... Drive wheel,
21... Vehicle body frame, 28a, 28b... Sensor unit, 29... Control unit, 31... Light emitting LED, 32...
... Fo) IC. 34... PSD element, 41... Microcomputer. In addition, the same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A guide line laid on a running road surface to guide automatic guided vehicles used indoors and outdoors, a light emitting unit that irradiates light from a plurality of light emitting elements onto the running road surface including this guide line, and the light from this light emitting unit as described above. an optical sensor section comprising a light receiving section that receives reflected light from the traveling road surface including the guide line and separately detects the absolute position and relative position of the automatic guided vehicle; and based on the output of this sensor section. A guidance device for an optically guided automatic guided vehicle, comprising: a control unit including a microcomputer that controls the automatic guided vehicle to travel along the guide line.