JPH0219483B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle control device, and particularly to one configured to automatically stop a vehicle at a predetermined position.

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In Figure 1, automatic guided vehicle 1 is carrying cargo 2.
2 is loaded and approaching the transfer device 3 such as a conveyor device in the direction of the arrow.
FIG. In the figure, reference numeral 4 denotes a guideway, which is provided on the floor surface in order to define the traveling route of the automatic guided vehicle 1. 5 is a mark detector;
A deceleration point mark 6 and a stop point mark 7 provided near the guideway 4 are detected. In addition, Figures 1 and 2
The chain line in the figure indicates the stopping position of the car 1.

Next, the operation will be explained. In order to transport and deliver the loaded cargo 2 to and from the transfer device 3, the automatic guided vehicle 1 uses electromagnetic or optical means (not shown) to transfer the loaded cargo 2 to the transfer device 3 while following a guideway 4 provided on the floor. 3 at a predetermined speed. At this time, the mark detector 5 attached to the bottom of the automatic guided vehicle 1 starts detecting electromagnetic or optical marks installed on the floor near the target point from the start of approach movement. .

When the mark detector 5 detects the deceleration point mark 6, the running speed of the automatic guided vehicle 1 is shifted to a low-speed run that can be stopped immediately by a built-in drive control device (not shown). While the automatic guided vehicle 1 continues to travel at a lower speed, when the mark detector 5 detects the stop point mark 7, the drive control device (not shown) immediately applies braking to stop the automatic guided vehicle 1.
Through these series of operations, the distance between the automatic guided vehicle 1 and the transfer device 3 becomes approximately a predetermined value, and the loaded cargo 2 can be delivered between the guided vehicle 1 and the transfer device 3.

Conventional vehicle control devices used for automated guided vehicles, etc. are configured as described above, so it is necessary to provide a guideway on the running floor and bury special marks (magnetic pieces, metal pieces, etc.). However, when changing the installation location of transfer equipment, etc., it is necessary to remove and install new taxiways and marks, and even for the same transfer equipment, approaches may be required depending on the shape and size of the transferred cargo. There were drawbacks such as the fact that it was not easy to change the distance intervals.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and it obtains a signal according to the distance between the target object and the vehicle from the amount of reflected light of the optical signal emitted from the vehicle to an object. The braking signal obtained by comparing this signal with a reference signal at a level that can be set in advance is output to the vehicle's drive source to brake the vehicle, eliminating the need to set marks on the floor and reducing the approach distance interval. The purpose of the present invention is to provide a vehicle control device that can freely change the

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 3 to 5, 8 is a light emitting element as a light emitting means, and 9 is a light receiving element as a light receiving means, both of which are provided on the side wall of the automatic guided vehicle 1 as a vehicle. Reference numeral 10 denotes a reflecting plate, which is installed on the side of the target transfer device 3 facing the automatic guided vehicle 1. The light emitting element 8 and the light receiving element 9 provided on the automatic guided vehicle 1 are the reflector 1 provided on the transfer device 1.
They are arranged so that the optical axes of the rays reflected at zero coincide with each other. Next, inside the automatic guided vehicle 1,
A power source 11 for the light emitting element, a distance detecting means 12 that outputs a signal according to the distance to the transfer device based on changes in the amount of light received by the light receiving element 9, and a light amount level setting means 1.
3. The control circuit 14 and the brake drive circuit 15 that constitutes the drive source 19, the braking brake 16, the running wheel motor drive circuit, and the running wheel motor 18.
etc. are built-in.

In the above configuration, the unmanned guided vehicle 1 travels in the direction of the arrow in FIG. 3 at a preset speed toward the transfer device 3 such as a conveyor device as a target object in order to transport and deliver the loaded cargo 2. When approaching the automatic guided vehicle 1, the light receiving element 9 provided on the traveling direction side of the automatic guided vehicle 1 receives the light emitted from the light emitting element 8 provided in the automatic guided vehicle 1 in parallel. Transfer device 3 which is the target object
The light beam reflected by the reflection plate 10 provided at the front is received. This amount of received light continuously increases as the distance between the automatic guided vehicle 1 and the transfer device 3 decreases, so in order to accurately detect the distance from the amount of received light, The traveling speed control and approach distance detection in the approach operation of the vehicle are performed as follows.

That is, the light emitting element power supply 1 always keeps the amount of light emitted from the light emitting element 8 constant, and modulates the emitted light at a specific frequency. The distance detecting means 12 demodulates an electrical signal corresponding to the light beam incident from the light receiving element 9 using the above-mentioned specific frequency, and detects the light beam emitted from the light emitting element 8 from the reflecting plate of the transfer device 3. Only the amount of light reflected by the transfer device 10 is detected without being affected by external light, and a signal corresponding to the distance from the transfer device 3 is output. This detection power is guided to the control circuit 14 together with the output of the light amount level setting means 13 which outputs a signal with an adjustable level in advance. In normal running conditions, the control circuit 14 outputs a control signal to the motor drive circuit 17 of the drive motor 18 of the drive source 19 coupled to the drive wheels of the automatic guided vehicle 1 so that the automatic guided vehicle 1 runs at a predetermined speed. It is configured as follows.

When the automatic guided vehicle 1 approaches the transfer device 3, it controls the motor drive circuit 17 and brake drive circuit 15 of the drive source 19 while comparing the detection output of the distance detection means 12 and the output of the light level setting device 13. Output a signal. That is, as shown in FIG. 5, in the process in which the detection output of the distance detection means 12 increases as the distance to the approaching object decreases, the detection output reaches the first setting level V of the light level setting device 13. ₁ (deceleration start level), a deceleration control signal is output to the motor drive circuit 17 according to a predetermined deceleration pattern.
In the process of continuing to drive, the distance detection means 1
When the detection output of V 2 reaches the second set level V ₂ (braking start level), the control circuit 14 stops outputting the travel control signal to the motor drive circuit 17 and also stops outputting the drive control signal to the brake drive circuit 15 of the drive source 19. A control signal for braking operation is output to the motor.

Note that D in FIG. 5 is the approach distance at the time of stopping.

By providing the control circuit 14 with the control function described above, it becomes possible to decelerate and brake the automatic guided vehicle 1 in accordance with the approach distance to the transfer device 3, which is an approaching object, Ultimately, it is possible to accurately stop the vehicle at a point within a predetermined approach distance. Note that the approach distance can be varied by changing the setting level of the light amount level setting means 13.

Further, even if the light amount level setting means 13 has a plurality of setting levels as described above,
Alternatively, only one setting level may be provided, and the other levels may be detected by the control circuit 14. Further, the control circuit 14 may not only perform analog signal processing, but may also be digitally controlled, for example, by a microcomputer or the like.

In the above embodiment, only the case where the approach distance to a specific approaching object is constant is shown, but the approaching distance may be changed depending on the structure of the approaching object or the shape of the load loaded on the automatic guided vehicle. may change frequently. In this case, as described above, as a method other than changing the setting of the light intensity level, a specific interval distance point from the reflector 10 provided on the approaching object is recognized from the reflected light intensity level, and further It may be moved forward or backward by a certain correction distance and then stopped.
The correction distance may be measured by controlling the time delay from when the specific point is recognized to the start of deceleration and braking, and as another embodiment of the present invention, as shown in FIG. , drive motor 1
The rotation amount of the wheel may be detected and controlled by an encoder 20 and a rotation amount detection circuit 21 coupled to the wheel. Note that the control circuit 14 in the figure is the control circuit shown in FIG. 4 with additional control functions including wheel rotation amount detection.

In the embodiments described above, marks for deceleration points and stopping points, which were essential to be installed on the traveling road surface in conventional automatic guided vehicles, are completely unnecessary.
These installation works will no longer be necessary. Further, even if the installation position of objects to be approached, such as a transfer device, is changed due to a layout change in the factory, no inconvenience will occur. In addition, it is extremely easy to change the approach distance, and the accuracy of the stopping position can be improved because the reflected light amount detection output for the approach distance is continuous, making it suitable for various types of driving, not just automatic guided vehicles. It can also be applied to control of moving objects.

As described above, according to the present invention, in a vehicle braking device, the reflected light of an optical signal emitted from a vehicle to an object is received, and a signal corresponding to the distance to the object is obtained from the amount of reflected light. The control circuit is configured to brake the vehicle by providing a control circuit that outputs a braking signal obtained by comparing the signal with a reference signal at a level that can be set in advance to the drive source of the vehicle. This has the effect of allowing the distance between the vehicle and the target object to be freely set when stopping the vehicle. Furthermore, since the distance between the vehicle and the object is continuously detected by changing the amount of reflected light, the accuracy of the actual stopping position of the vehicle can be improved.

[Brief explanation of drawings]

Figure 1 is a side view showing the movement of an automated guided vehicle approaching a transfer device using a conventional example;
1 is a plan view of FIG. 1, FIG. 3 is a side view showing the approaching operation when an embodiment of the present invention is used, and FIG. 4 is a block diagram of the structure of an embodiment of the present invention. FIG. 5 is a time chart showing the operation of the apparatus shown in FIG. 4, and FIG. 6 is a block diagram of another embodiment of the present invention. In the figure, 1 is a vehicle, 3 is an object, 8 is a light emitting means, 9 is a light receiving means, 12 is a distance detecting means, 13 is a level setting means, and 14 is a control circuit. In addition,
The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A light emitting means provided on a vehicle having a drive source for traveling in the direction of an object and emitting a light signal to a reflective surface of the object; a light receiving means provided on the vehicle receiving the light signal reflected by the reflective surface; distance detecting means for outputting a signal of a magnitude corresponding to the distance between the object and the vehicle based on the amount of reflected light received by the light receiving means; level setting means for outputting a reference signal of a presettable level; A vehicle braking device comprising a control circuit that compares a signal from the distance detection means with a signal from the level setting means and outputs a braking signal to the drive source.