JP3341490B2 - Automatic guided vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unmanned transport that travels to a target position while judging by triangular weighing using laser emitting / receiving means mounted with a plurality of reflectors provided on a wall or the like of a traveling space. About the car.

[0002]

2. Description of the Related Art Conventionally, there is an automatic guided vehicle system that travels in accordance with a layout map stored in advance, in which a navigation system monitors and corrects a deviation from a predetermined route on a map and allows the vehicle to travel completely autonomously. Proposed. In this system, since no guide line for guiding the automatic guided vehicle is laid on the floor or the like, only the reflected light returned from the reflector depends on it. Therefore, in such a system, laser light which is hardly affected by sunlight or the like is used.

[0003]

However, no matter how much laser light is used, the amount of reflected light coming back from the reflector decreases when the vehicle is driven outdoors and fog is generated. There is a possibility that accurate position recognition cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent erroneous recognition due to a change in surrounding conditions and to surely prevent runaway of an automatic guided vehicle. .

[0005]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a laser beam is projected toward a plurality of reflectors provided in a traveling space, and a laser beam is emitted from the reflectors. An automatic guided vehicle equipped with a laser light projecting / receiving means for receiving reflected light from the reflector, and receiving reflected light from the reflector.
A means for monitoring the light intensity is provided so that the amount of light received from all directions
Stops the automatic guided vehicle when it falls below the specified value
I tried to make it.

[0006]

[0007]

[0008]

According to the present invention, the above measures are taken.
The following operations are provided.

According to the first aspect, a change in the surrounding situation can be detected.

[0010] In addition, for example, when the total amount of received light decreases outdoors such as when fog is generated, the operation of the automatic guided vehicle is stopped.

[0011]

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments unless it departs from the gist of the present invention.

FIG. 3 shows an automatic guided vehicle 1 using laser light.
FIG. 2 is a schematic diagram showing a system for guiding zero. Each automatic guided vehicle 10 is equipped with a control means, and a layout map of the traveling space is stored in the control means in advance. When each of the automatic guided vehicles 10 receives a transfer command wirelessly from the controller 20 on the ground side, it steers the traveling wheels and monitors the traveling distance with an encoder that detects the number of revolutions of the traveling wheels. It runs completely autonomously. However, even though the vehicle is traveling completely autonomously, there is a possibility that the vehicle may deviate slightly from a predetermined route due to slippage of traveling wheels. Therefore, the laser beam is directed from the mounted laser emitting / receiving means 11 to a reflector A such as a reflective tape provided on a wall surface of the traveling space or the like (this installation position is also stored in the control means in advance). Based on the amount (direction to reflector A) and direction of the reflected light that returns from reflector A, it determines its own position by triangulation and corrects the deviation from the predetermined path to the target position accurately. It is designed to run.

As shown in FIGS. 1 and 2, the automatic guided vehicle 10 has a fork unit 13 having a vehicle body 12 and a fork 13a installed at a rear portion of the vehicle body 12 and capable of moving up and down and sliding back and forth. And travels when the traveling wheels 14 provided at the bottom of the vehicle body 12 are rotationally driven. On the front surface of the vehicle body 12, a pair of left and right traveling indicator lights 15 and a plurality of collision prevention sensors 16 are provided. When the automatic guided vehicle 10 is traveling, both of them flash simultaneously, when the traveling route is changed, only the direction to be changed blinks, and when the unmanned guided vehicle 10 is stopped due to some abnormality, the both are alternately turned on. Flashes. The collision prevention sensor 16 is for detecting an obstacle in front, and the detection of the obstacle causes the automatic guided vehicle 10 to decelerate / decelerate.
Stop and collision is prevented.

On the upper surface of the vehicle body 12, there is mounted a mounting frame 17 comprising a pair of left and right side frames 17a extending upward and an upper frame 17b connecting the upper ends of the side frames 17a. The laser projection / reception unit 11 is mounted at the center of the upper surface of the upper frame 17b, is further lifted from the upper surface of the vehicle body 12, and is disposed at a height of 2 m or more from the ground. As a result, it is arranged at a position sufficiently displaced in the height direction from the line of sight of the worker who moves around the automatic guided vehicle 10, so that the laser light does not enter the eyes of the worker. I have. Further, even when various articles are placed on the floor surface on which the automatic guided vehicle 10 travels, these articles interfere with the laser beam from being emitted to the reflector A. Or the reflected light from the reflector A cannot be received.

In the case where there is no obstacle on the floor, the laser light emitting / receiving means 11 is provided at a position lower than the line of sight of the worker so that the laser light does not enter the eyes of the worker. Is also good.

The laser light projecting / receiving means 11 has a light projecting section for projecting a laser beam only in one direction, and horizontally rotates the laser beam to project a laser beam toward a reflector in all directions. It has become. By rotating the light emitting part horizontally to cover all directions, if the worker goes up to the ladder and the height position of the laser emitting and receiving means and the worker's line of sight coincide, Even so, the laser light is not continuously emitted toward the worker, and the safety is further improved.

If the rotation of the light projecting unit is stopped for some reason, the laser light will be continuously emitted in one direction, and there is a problem when an operator is present in that direction.
Therefore, a means for monitoring the rotation of the light projecting unit is provided, and when the rotation is stopped, the power supply of the automatic guided vehicle itself is cut off and the operation is stopped. The operation may be stopped when the rotation of the light projecting unit becomes lower than the predetermined speed.

The laser projecting / receiving means 11 includes a light receiving section for detecting the amount of reflected light (distance to the reflector) hitting the reflector A and the direction of the reflected light. According to the relationship, the position of the user is determined by triangulation. Sometimes the laser light is reflected back to something other than the reflector A,
The installation position of the reflector A is stored in the layout map in advance, and the light reflected from a position greatly deviated from this position is ignored.

When the vehicle travels outdoors where fog is generated, the reflected light from all the reflectors A may be weak. The laser projecting / receiving means 11 constantly checks the amount of received light. If the amount of received light from all directions becomes equal to or less than a predetermined value, the unmanned transport vehicle 10 prevents the runaway of the automatic guided vehicle 10 more reliably. The operation of the car 10 is stopped. In addition, even when the amount of reflected light from a direction other than the direction in which the reflector A is installed increases, the operation of the automatic guided vehicle 10 is stopped to more reliably prevent runaway of the automatic guided vehicle 10. ing.

[0021]

As described above, according to the first aspect, a change in the surrounding situation can be detected and it is possible to respond to the change, so that erroneous recognition due to the change in the surrounding situation can be prevented. Further, runaway of the automatic guided vehicle can be reliably prevented.

Further , for example, when the total amount of received light is reduced outdoors, such as when fog is generated, the operation of the automatic guided vehicle can be stopped, and runaway of the automatic guided vehicle can be reliably prevented. .

[0023]

[Brief description of the drawings]

FIG. 1 is a front view showing an automatic guided vehicle according to the present invention.

FIG. 2 is a side view of the automatic guided vehicle shown in FIG.

FIG. 3 is a conceptual diagram showing an automatic guided vehicle guidance system of FIG. 1;

[Explanation of symbols]

 10 Automatic guided vehicle 11 Laser light emitting and receiving means A Reflector

Claims (1)

(57) [Claims] 1. An automatic guided vehicle provided with a laser projecting / receiving means for projecting laser light toward a plurality of reflectors provided in a traveling space and receiving reflected light from the reflectors. A means for monitoring the amount of light received from the body is provided , and the amount of light received from all directions is below a predetermined value.
An automatic guided vehicle, wherein the operation of the automatic guided vehicle is stopped in the case.