JPH0578243B2 - - Google Patents

Description

A travel control device for an automatic guided vehicle, comprising a travel control circuit 9 for controlling travel.

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a travel control device for an automatic guided vehicle that stops traveling by detecting patterns for each station provided on a travel route using a detector provided on the vehicle body. This is related to improving the reliability of

(Prior art) As a conventional travel control device for an automatic guided vehicle, a magnet for detection is provided at each station on the travel path, and a reed switch is provided on the vehicle body at a position corresponding to the magnet. There was one that detected a predetermined pattern made of magnets and eventually stopped the vehicle from running.
With such a detection means consisting of a combination of a reed switch and a magnet, a large number of detection means can be installed in a direction perpendicular to the direction of movement of the car body, and a relatively large number of patterns can be obtained, but there is a limit to the width of the car body. Therefore, the number of patterns was limited. Additionally, those using reed switches had problems in reliability because of the contact points. Another example is a system in which a barcode is placed on the road and the automatic guided vehicle is stopped by optically detecting this barcode. The increase in the number of stations is likely to be restricted, and there are problems in that malfunctions may occur due to dirt during sorting of the stations.

Furthermore, it is conceivable to use an oscillation-type proximity switch instead of the reed switch and install a detection plate such as an iron plate on the running path, but when using this proximity switch, in order to eliminate mutual interference between the proximity switches, The detection plates installed on the road must be installed at a certain distance, and as mentioned above, in the case of those installed perpendicular to the direction of travel of the vehicle, in the case of vehicles with limited vehicle width such as automatic guided vehicles, It is difficult to provide a large number of sensing plates, which limits the number of patterns that can be formed.

(Object of the Invention) The present invention provides a travel control device for an automatic guided vehicle that effectively provides a large number of detection means in a limited space, can generate a large number of patterns, and has high reliability in detection and selection. With the goal.

(Structure of the Invention) The present invention provides a travel control device for an automatic guided vehicle that detects a pattern for each station provided on a travel path using a detector installed in the vehicle body to control travel. A detection plate array F consisting of a predetermined pattern provided at appropriate intervals in the direction
Proximity switches S1 to S4 are provided on the vehicle body to face the sensors 1 to F4 and detect the patterns, and a strobe detection plate F0 is provided on the running path at a position offset from the above detection plate array in the running direction. a strobe proximity switch S0 provided on the vehicle body to obtain the strobe signal; and a destination instruction memory 6 based on the above detections after the vehicle has traveled a predetermined distance or after a predetermined time has elapsed after detecting the strobe signal. The pattern discriminating circuit 8 includes a pattern discriminating circuit 8 having arithmetic means for discriminating between patterns according to the above, and a traveling control circuit 9 that controls the traveling of the vehicle body using the output of the pattern discriminating circuit 8.

According to this configuration, compared to the conventional configuration in which the detection plate is provided in a direction perpendicular to the direction of travel, the proximity switch can be provided with a margin in the longitudinal direction of the relatively long vehicle body, and the strobe signal can be Since pattern discrimination is performed with a predetermined delay after detection, it is possible to read the pattern reliably.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an automatic guided vehicle and its traveling path, 1 is the vehicle body of the automatic guided vehicle, 2 is the traveling path, and on this traveling path 2, there are
A large number of stations A and B are provided with arrays of detection plates arranged in a predetermined pattern. That is,
Station A has a detection plate row consisting of detection plates F1 and F3, and station B has a detection plate row consisting of detection plates F2, F3, and F4. The pattern of the detection plate rows of these stations may be set as appropriate, and the detection plates F1 and F4 may be iron plates or the like buried in the running path. Further, on the running path, a strobe (timing) detection plate F0 is provided for each station at a position shifted in the running direction from the above-mentioned detection plate array.

The vehicle body 1 includes a proximity switch S for detecting the pattern of the detection plate array at a position opposite to the detection plate array.
1, S2, S3, and S4, and a strobe proximity switch S0 for obtaining a strobe signal is provided at a position facing the strobe detection plate F0 in each station. In this example, the detection plates F1 to F4 in each station are arranged in one row, and this and the strobe detection plate F0 are provided on both sides of the travel path 2, but this is not limited to this example. For example, if there are two rows of detection plates,
Furthermore, the number of types of patterns can be further increased. Further, in each of the stations A and B, the corresponding detection plate is not provided at the position indicated by the two-dot chain line.

Although details of the proximity switches S1 to S4 and S0 are not shown, high frequency induction type or capacitance type may be used. A high-frequency induction type proximity switch has an LC oscillation circuit in its detection part, which generates a high-frequency magnetic field. Eddy current loss occurs within the body, and the oscillation circuit becomes equivalent to a hanging load, lowering the Q of the oscillation circuit and stopping oscillation.
This stopping of oscillation of the oscillator is used to control the switching element of the output section.

In addition, a capacitance type proximity switch has an R-
The detection surface has the function of a capacitor electrode, so when a nearby object approaches and the capacitance value between the nearby object reaches a certain value, the oscillation circuit oscillates. People are starting to do this. Switching operation is obtained by utilizing the oscillation stop of this oscillator, and this capacitance type oscillation circuit is stopped during normal operation and oscillates when a nearby object approaches. is the opposite situation.

FIG. 2 shows the specific configuration of the travel control device for an automatic guided vehicle, in which signals are transmitted from the ground control panel 3 via the ground optical data transmission device 4 to the vehicle body optical data transmission device 5 provided on the vehicle body 1 by optical transmission. The vehicle body 1 can be driven to travel by this optical transmission, and the vehicle body 1 can be stopped at a predetermined station based on a predetermined instruction signal. That is, the vehicle body 1 includes a destination instruction memory 6 that receives signals from the on-board optical data transmission device 5, a ground pattern memory 7 that is compared with the instruction memory of the destination instruction memory 6, and a ground pattern memory 7 that receives signals from the destination instruction memory 6. a pattern discrimination circuit 8 which receives signals from pattern detection proximity switches S1 to S4 and strobe proximity switch S0; A motor M and the like that drive the steering of the vehicle body 1 driven by the control circuit 9 are provided.

FIG. 3 shows a specific example of the pattern discrimination circuit 8. This pattern discrimination circuit 8 receives a detection signal from a rotation speed detector 10 for detecting the rotation speed of the motor M and a detection signal from the strobe proximity switch S0. It has a distance calculation circuit 11, and AND circuits 12 to 15 that take the logical product of the output of the vehicle body mileage calculation circuit 11, the signal from the destination instruction memory 6, and the detection signals of the pattern detection proximity switches S1 to S4, and An AND circuit 16 is provided to take the logical product of logical product outputs, and the output terminal 1 of this AND circuit 16
7, a pattern discrimination signal can be obtained.

That is, the pattern discrimination circuit 8 is configured to operate for discrimination after the vehicle has traveled a predetermined distance (for example, lmm) after detecting the strobe signal.

Next, the operation of the above configuration will be explained. When the vehicle body 1 travels along the running path 2 in the direction of the arrow in FIG. 1, the proximity switch S for pattern detection provided on the vehicle body 1
1 to S4, detection signals corresponding to the detection plate rows provided on the station are obtained at the station positions. FIG. 4 shows the detection signal when the vehicle body 1 is moving onto the station A. In FIG. 4, a, b, c, d, and e indicate detection signals of the proximity switches S1, S2, S3, and S4, and the strobe proximity switch S0, respectively. Further, f indicates the AND output of the inverted signal of the proximity switch S1, the signal of the proximity switch S2, the inverted signal of the proximity switch S3, and the signal of the proximity switch S4 after a time t has elapsed since the detection of the strobe signal of the proximity switch S2 for strobe. This AND output is obtained by the pattern discrimination circuit 8 shown in FIG. 3 when the signal from the destination instruction memory 6 based on the command from the ground control panel 3 shown in FIG. 2 matches the pattern detected at the station. It's starting to become easier.

That is, after detecting the signal from the destination instruction memory 6, the signals from the pattern detection proximity switches S1 to S4, and the strobe signal from the strobe proximity switch S0, the vehicle body moves a predetermined distance (lmm in this embodiment).
The logical product output is obtained after the vehicle has been driven for . In FIG. 4e, time t corresponds to the time during which the vehicle body 1 travels by lmm in FIG. 1.

Although the above-mentioned pattern discrimination circuit 8 uses the vehicle mileage calculation circuit 11, the pattern discrimination circuit 11 is used instead of the vehicle mileage calculation circuit 11 after a predetermined period of time has elapsed since the strobe signal was detected. It may be provided with a calculation means that performs a discrimination operation.

Furthermore, after the vehicle body 1 has stopped at station A based on the instructions from the ground control panel 3, a travel command is issued from the ground control panel 3 again, and the vehicle body 1 is made to travel toward the station according to the pattern according to the next command. It's summery. Further, the vehicle body 1 is guided and controlled unmanned along the traveling path 2. Although details are not shown, an energized guide wire is provided on the traveling path 2, and the guide wire is attached to the vehicle body 1. A pair of pick-up coils are provided on the left and right sides of the vehicle, and driving control of the motor of the vehicle body 1 is made possible by detecting the difference in detection signals from the pick-up coils.

(Effects of the Invention) As described above, according to the present invention, the vehicle body is provided with the detection plate array and the strobe detection plate arranged in a predetermined pattern at appropriate intervals in the traveling direction of the vehicle body, which are provided on the traveling path. A proximity switch for pattern detection and a proximity switch for strobe are installed in the 3D display, and the pattern discrimination operation is performed after a predetermined time delay after the detection of the strobe signal. , it can be provided by utilizing the longitudinal direction of a relatively long vehicle body. Therefore, it is possible to effectively utilize limited space to install stations with a large number of patterns, and it is possible to fully accommodate the expansion and development of equipment. Furthermore, since the proximity switches can be provided at appropriate predetermined intervals, mutual interference between the proximity switches can be reduced.
The detection and selection of patterns becomes accurate and has great effects, such as contributing to improved reliability.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a travel control device for an automatic guided vehicle according to the present invention, FIG. 2 is a specific configuration diagram of the travel control device for an automatic guided vehicle, and FIG. 3 is a specific diagram of a pattern discrimination circuit in the travel control device. Circuit diagram showing an example, 4th
The figure is a signal waveform diagram for explaining the operation of the device. 1...Vehicle body, 2...Runway, A, B...Station, F1-F4...Detection plate, F0...Detection plate for strobe, S1-S4...Proximity switch, S
0...Proximity switch for strobe, 6...Destination instruction memory, 7...Ground pattern memory, 8...Pattern discrimination circuit, 9...Travel control circuit, 11...
Vehicle mileage calculation circuit.

Claims (1)

[Scope of Claims] 1. In a travel control device for an automatic guided vehicle that performs travel control by detecting a pattern for each station provided on a travel path using a detector provided on the vehicle body, Detection plate rows F1 to F formed in a predetermined pattern provided at appropriate intervals
Proximity switches S1 to S4 are provided on the vehicle body to face the strobe and detect the patterns; A strobe proximity switch S0 is provided on the vehicle body and obtains the strobe signal, and after the vehicle has traveled a predetermined distance or a predetermined time has elapsed after detecting the strobe signal, a pattern is created by the destination instruction memory 6 based on each of the above detections. A pattern discrimination circuit 8 has a calculation means for discriminating the vehicle body.