JPS61243510A - Unattended carrying truck - Google Patents

Abstract

PURPOSE:To run an unattended carrying truck accurately on a guide path by providing an array type photodetector and a covered distance detector to control accurately the attitude and the extent of movement. CONSTITUTION:An array type photodetector 10 consisting of plural photodetecting elements expresses the incident state of a laser beam with an 8-bit parallel signal. When cells corresponding to the third and the fourth bits receive light, driving motors 22 and 22' are operated in a steady speed. When cells corresponding to bits other than the third and the fourth bits receive light, the number of rotations of motors 22 and 22' are so changed that the laser beam strikes these cells, and the attitude of the truck is corrected. In the covered distance control, a subtracting counter 101 or the like is used to count output pulses from an encoder 36, and the count value of the number of pulses corresponding to the extent of movement is set to this counter, and subtraction is performed by the rotation of a distance measuring wheel to run the truck for a prescribed distance. Thus, the attitude and the extent of movement of the unattended carrying truck are controlled accurately by the photodetector 10, the distance measuring wheel, and the encoder 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an automatic guided vehicle, and particularly to an automatic guided vehicle that controls the traveling of the guided vehicle unmanned along a predetermined guide path.

[Prior Art] In a factory, for example, an automatic guided vehicle is used to transport workpieces between production processes. Transported automatically.

Various devices have been proposed as such automatic guided vehicles, and for example, a one-to-one pass wire type automatic guided vehicle has been filed in Japanese Patent Application No. 59-33680.

In this Topaswie A7 type, the electric wire buried in the floor is used as a guide wire, J-, that is, Topaswire, and when an alternating current is passed through this wire, the magnetic field generated is detected by the automatic guided vehicle and the traveling route of the guided vehicle itself is determined. are doing. Therefore,
It is possible to run unmanned on a taxiway with topass wires installed.

[Problems to be solved by the invention] Problems of the prior art However, in such a towpath wire type automatic guided vehicle, construction work is required to lay the towpath wire on the road surface of the taxiway, which increases the cost of the entire device. Additionally, once the wire installation work has been carried out, there is a problem in that the guideway cannot be easily changed thereafter.

OBJECTS OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to easily and easily set and change taxiways without laying towpath wires. An object of the present invention is to provide an automatic guided vehicle that enables accurate travel control.

[Means and effects for solving the problems] In order to achieve the above object, the present invention provides a system for receiving rake light output from at least one laser light guide installed in a guideway. an array-type measurement device that detects the distance traveled by the transport vehicle; and a travel distance measuring device that detects the distance traveled by the transport vehicle, and changes the speed of the left and right drive wheels based on the output of the light receiving position of the array-type light receiver to determine the posture of the transport vehicle. The vehicle is characterized by having controllers 1 to rollers, etc., which control the travel distance using a travel distance measuring device, and perform accurate travel control by being guided by a laser beam.

According to the above configuration, one noser light outputted from the laser light guide provided in the guide path is detected by the array type light receiver. Then, the deviation of the automatic guided vehicle from the guide path is determined at the laser beam receiving position in the array type light receiver, and then attitude control is performed by adjusting the speed of the left and right drive wheels of the guided vehicle. In this case, the travel distance is detected by the travel distance measuring device, and the transport vehicle is automatically stopped after traveling a predetermined distance. Therefore, it is possible to accurately and automatically travel along the guide path guided by the laser beam according to arbitrary commands from the humidor roller.

[Example] Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an automatic guided vehicle, in which FIG. 1A shows a perspective view from the side, FIG. 1B shows a rear view, and FIG. 1C shows a bottom view.

A characteristic feature of the present invention is that the automatic guided vehicle body is guided by a laser beam and accurately travels along a guideway by controlling its posture and moving distance. It is installed at the front and rear of the car body by slightly retracting it from the surface of the car body. This array-type light receiver 10 is formed by arranging a plurality of light-receiving elements, and as shown in FIG. 2, the details will be described later. A laser oscillation tube 14a serving as a laser light guide is provided at target points A and B with respect to the guideway.

It has a structure that receives the laser beam 200 generated by the laser beam 14b.

A codon roller 16 that controls the attitude of the carrier based on the output of the array type light receiver 10 is connected to the bottom plate 1 of the carrier.
8, and the left driving wheel 20. A left wheel drive motor 22 that drives the right drive wheel 20-. It controls the right wheel drive motor 22-. Further, the left and right wheel drive motors 22.22- are provided with a left wheel drive motor driver 24 and a right wheel drive motor driver 24'. The rotation speed of ′ is controlled. Electric power for these drive motors 24 is supplied from the storage battery 20 directly or via a DC/DC converter. In addition, the left and right drive wheels 22.22'' and the left and right wheel drive motors 24.24- and 28.28- and 2-A
- The two wheels are connected by a wheel 30 and 30', and have a WJ construction that allows the rotational force of the motor to be efficiently applied to the drive wheels.

Furthermore, four casters 32-1.31-2.32-3.32-4 are provided at the lower ends of the four corners of the bottom plate 18 of the transport vehicle, thereby preventing the transport vehicle from shaking.

A distance measuring wheel 34 with a shock absorber and an encoder 36 are attached to the center bottom of the automatic guided vehicle body 12 on the same axis as the wheel as a device for measuring the moving distance, and the distance is determined by the number of pulses output by the encoder 36. Enables travel control for any required distance.

Further, in this embodiment, obstacle detection electrodes 38 (or 38') for detecting obstacles are provided protruding from the front and rear of the transport vehicle, and are differential capacitance sensors. When the distance between the and the obstacle detection electrode 38 (or 38-) becomes equal to the distance between the reference electrode attached to the obstacle detection amplifier 40 (or 40'), the output voltage is dropped to Ov to detect the obstacle. It is supposed to be done.

Displays indicating the operation and operating status of each of the above devices are provided in the operation box 4 provided at the upper side of the automatic guided vehicle main body 12.
2, which allows switching for determining the direction of travel, switching for manually operating the left and right wheel drive motors 22, 22- during teaching to memorize the travel distance, switching for automatic driving, and switching for emergency operation. The switch operation for switching, the processing status of the conveyance vehicle control program, and the order in which the switch operations are introduced are displayed using LEDs.

Attitude Control The above is the configuration of the automatic guided vehicle according to the embodiment of the present invention, and in order to accurately control the traveling of the automatic guided vehicle, it is necessary to accurately control the attitude and travel distance of the guided vehicle. Therefore, in the present invention, the array type light receiver 10 is used to receive laser light as a guiding light beam guided to a guiding path at a plurality of light receiving positions.

That is, the array type photodetector 10 consists of a plurality of photodetecting elements 10a, as shown in FIG.
A number of light receiving elements 10a are used.

This light-receiving element 10a has, for example, eight solar cells arranged in parallel, and the state in which the laser beam enters the solar cells is represented by an 8-bit parallel signal, and each solar cell is numbered 0 to 7. It is compatible with bits up to. Therefore, when changing the speed of the left and right drive wheels 20, 20' in order to control the attitude of the automated guided vehicle, the solar cells corresponding to the third and fourth bits of the 8-bit signals 1 to 1 are used. When these two solar cells are receiving light with the cell as a dead zone, the left and right wheel drive motors 2 are operated at a steady speed.
2. Drive 22'. This transmits the signal output from the incoming horn boat 103 to the outgoing ports 1 to 1 via the bus 102.
Enter 08, left and right wheel drive motor driver 24.24
This is done by controlling -.

On the other hand, when the solar cells corresponding to bits other than the 3rd and 4th bits are receiving light, the left and right wheel drive motors 22°22 By changing the rotation speed of ', the attitude of the automated guided vehicle is corrected based on the speed difference between the left drive wheel 20'' and the right drive wheel 20''.

FIG. 4 shows a flowchart for controlling the attitude of such a transport vehicle. First, the output of the array type photoreceptor is taken in, and then the process moves to the step of determining whether or not light is being received. If no laser light is received in this step, the process moves to a subroutine for stopping the transport vehicle and is then reset. When the laser beam is being received, it is determined which light receiving element 10a of the array type light receiver 10 is receiving the laser beam, and the light receiving element 10a corresponding to the 7th and 0th bits is receiving the laser beam. If so (maximum deviation), the process moves to a high-speed attitude correction subroutine, and then outputs a motor speed command for driving the left and right drive wheels 20, 20'.

In addition, the light receiving element 1 corresponding to the 6th and 1st bits
When light 0a is being received (at the time of intermediate deviation), the process moves to a medium-speed attitude correction subroutine, and then a medium-speed motor speed command is output. Furthermore, when the laser beam is received by the light receiving element 10a corresponding to the 5th and 2nd bits (when there is a small deviation in R), the process moves to a low-speed attitude correction subroutine, and then a low-speed motor speed command is issued. Output.

If NO in any of these determination steps, the radar light is being received by the light receiving element 10a corresponding to the 3rd and 4th bits, so the process moves to the constant speed setting mode and the constant speed is set. Outputs the Tanabata speed command.

As described above, the attitude of the guided vehicle is detected by the array type light receiver 10 installed in front of the automatic guided vehicle body 12, and corrections are made to maintain the normal attitude with respect to the guideway. 1. The automatic guided vehicle can be accurately driven along the tNW path.

Note that an l-1e-Ne gas laser tube is used as the radar oscillation tube 14 as a laser light guide, and the array type receiver 10 selectively transmits only the wavelength of this laser light. An optical bandpass filter is attached to reflect the disturbance light. Therefore, when the laser beam does not hit the array type receiver 10, it is because there is an obstacle on the taxiway or when the transport vehicle has strayed from the taxiway, and in this case, the left and right wheel drive motors 22,
22' is stopped, and the array type photoreceiver 10 waits for the input of laser light for a certain period of time. If light reception is not confirmed after a certain period of time, a light reception abnormality signal is outputted on the display LED of the operation box 42 to notify the operator of the abnormality.

Movement Distance Control Next, a description will be given of control to avoid starting and stopping the automatic guided vehicle at a predetermined distance set on the guideway. As mentioned above, the distance H traveled by the automatic guided vehicle is measured by the distance measuring wheel 34 and the encoder 36 as a distance detecting device, and the distance H is determined by the controller 16 based on the signal measured by this. The object is controlled to move by the specified distance.

In the present invention, the travel distance of the automatic guided vehicle can be freely controlled using the travel distance detection device and controllers 1 to 16, but generally a device for detecting obstacles is attached, and this embodiment As mentioned above, the obstacle detection electrodes 38 and the obstacle detection amplifiers 40 are provided at the front and rear of the transport vehicle to detect obstacles. Therefore, it is necessary that the obstacle detection sensor and the travel distance detection device are linked to control the stop of the automatic guided vehicle.
(If an obstacle comes into contact with 38M, the automated guided vehicle will stop, but if the obstacle disappears, the guided vehicle will continue to travel the remaining distance of the set distance.) If there are no obstacles, the vehicle will travel a predetermined distance and then stop.

However, although it is originally possible to control the stop using only the travel distance detection device, the automatic guided vehicle may stop due to an abnormality in the encoder etc. even though there are no obstacles, so this example embodiment In order to judge whether or not the target point has been reached and to stop the automatic guided vehicle, the output of the obstacle detection sensor and the travel distance detection device are logically multiplied and the automatic guided vehicle is stopped.

That is, for example, a subtraction counter or the like is used to count the output pulses from the encoder 36, and the count value of the number of pulses corresponding to the moving distance set by teaching is set in the subtraction counter, and is subtracted by rotation of the distance measuring wheel 34. This allows the vehicle to travel a predetermined distance.
When the subtraction counter (today is CTC) 101 reaches O count, the transport vehicle is stopped. At the same time, when contact with the target point A (B) is detected by the obstacle detection electrode 38 (38'), it is determined that the target point A (B) has been reached. Therefore, if contact is not detected by the obstacle detection electrode 38 (38') even though the subtraction counter 101 has counted O, it is determined that the encoder 36 or the like is abnormal. The operator is informed of this state by the display LED of the operation box 42.

As described above, it is possible to accurately control the attitude and moving distance of the automatic guided vehicle using both the array type light receiver 10, the distance measuring wheel 34 as the traveling distance detecting device, and the encoder 36.

As mentioned above, these controls are performed by the controller 16, and the overall control of this controller 16 will be explained based on FIG.

First, the array type photodetector 10. Output signals from the obstacle detection amplifier 40, operation box 42, etc. are supplied from the input boat 103 to the port [1-516].

Further, the output of the encoder 36 is directly added to CTClol, and the CPU 100 performs down-counting from the value set by teaching, and the output of the first to third clocks is supplied to the CPU 100.

In addition, the information necessary for automatic guided vehicle travel control is provided by RO.
Information stored in M104 and given through teaching is stored in RAM 105. and,
These capo-1-103.

The ROM 104 and the RAM 105 are connected to the CPU 100 via a bus 102, and signals output from the CPU 100 are supplied from the output boats 107 and 108 to the operation box 42 and the left and right wheel drive motor drivers 24 and 24-.

Therefore, signals from various sensors etc. input to the input boat 103 are supplied to various devices via the CPU 100 and output ports 107 and 108, and the operation box 42 displays the switch operation display or the automatic guided vehicle. Displays the running status and also displays the left and right wheel drive motor driver 2.
At 4.24-, the rotational speed of the left and right wheel drive motors 22, 22'' that drive the left and right drive wheels 20, 20- is controlled.

The unmanned guided vehicle, whose travel is controlled by the controller 16, is moved back and forth between the destination points A and B shown in FIG.
The automated guided vehicle starts running by teaching a predetermined running order and selecting forward or backward movement by switching the switch on the operation box 42.

Then, the travel of the automatic guided vehicle is controlled according to the forward automatic travel subroutine or the reverse automatic travel subroutine, respectively, and if an abnormality is detected in the travel, the abnormality detection subroutine is executed and safe travel of the automatic guided vehicle is achieved. Ru.

[Effects of the Invention] As explained above, according to the present invention, an array type light receiver and a travel distance detection device are provided (J is configured to accurately control posture and travel distance, so An unmanned guided vehicle guided by laser light can be accurately driven along a guideway.

Furthermore, the device of the present invention allows the guide route to be changed simply and easily by simply changing the laser oscillation position without performing large-scale construction work, making it possible to reduce equipment costs.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a preferred embodiment of the automatic guided vehicle, in which (a) is a perspective view seen from the side, (b) is a rear view, (C) is a bottom view, and FIG. FIG. 3 is an explanatory diagram showing the output signal processing of the array-type light receiver, FIG. 4 is a flowchart diagram that does not show attitude control by the array-type light receiver, and FIG. The figure is an explanatory diagram showing the control of the controller, and FIG. 6 is a flow chart diagram showing the control program for the automatic guided vehicle. 10...Array type light receiver 12...Automated guided vehicle body 14...Laser oscillation tube 16 as a laser light guide path...Controller 34...Distance measurement wheel which is part of the travel path nt detection device 36... Encoder 38 which is part of the travel distance detection device... Obstacle detection electrode 40... Obstacle detection amplifier 42... Operation box.

Claims (2)

[Claims] (1) An array-type light receiver that receives laser light output from at least one laser light guide provided on a taxiway, a travel distance measuring device that measures the distance traveled by a transport vehicle, and the array-type light receiver It has a controller that controls the attitude of the transport vehicle by changing the speed of the left and right drive wheels based on the output of the light receiving position of the device, and also controls the travel distance using a distance measuring device. An unmanned guided vehicle that is characterized by running control. (2) In the carrier according to claim (1),
The automated guided vehicle is characterized in that the controller performs stop control of the guided vehicle using both an output signal from a distance measuring device and an output signal from an obstacle detection sensor provided on the guided vehicle.