JPS62197806A - Optical bumper for automatically governed vehicle - Google Patents

Abstract

PURPOSE:To confirm automatically and completely the safety of an automatically governed vehicle AGV over the approximately entire length of its body and to make the vehicle excellent in durability, by providing optical sensors on the same side face of the vehicle body and opposite to the all-direction reflecting screens fixed at the end part opposite to those optical sensors. CONSTITUTION:If no obstacle exists between the reflecting optical sensors 21-24 and all-direction reflecting screens 11-14 opposite those sensors in a drive or stop mode of an AGV, the beams emitted from the light emitting elements of sensors 21-24 are made incident on the screens 11-14 respectively. These incident beams are reflected by those screens and received by the light receiving elements of the sensors 21-24. Thus the output circuit levels of sensors 21-24 have the normal value showing absence of faults. Thus, it is possible to confirm the safety of the AGV automatically and completely over the approximately entire length of the AGV body. In addition, an optical bumper for AGV can be attached with no change of specifications.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical bumper for an automatic guided vehicle for safe operation of an automatic guided vehicle.

Conventional technology Unmanned factories equipped with processing cells, assembly cells, etc., and unmanned J-construction lines with various types of work machines are equipped with automated guided vehicles (hereinafter referred to as AGVs) to transport workpieces,
It is well known that receiving and delivering goods, etc. The AGV uses electromagnetic pickup coils installed on both sides of the AGV to detect the magnetic field generated around the induction wire installed in the travel route and through which a low-frequency current flows, and generates a voltage of 80 V depending on the difference in induced voltage between the two coils. Both drive wheels are controlled to drive the AGV along the guide line, and workpieces and parts loaded onto the AGV are transferred. It is also known that flexible bumpers equipped with collision detection switches are installed on the front and rear surfaces of the AGV to detect when the AGV collides with an obstacle and to perform safe driving. For example, this flexible bumper is deformably fixed to the AGV body via wires, and when an obstacle collides with the bumper while the AGV is operating, the bumper deforms and the wires loosen, and the wires in tension normally The collision detection switch, which is in the OFF position, is switched to the ON position, detecting a collision with an obstacle, and managing the safety of the 8GV in the longitudinal direction. However, conventional collision detection flexible bumpers for AGVs cannot confirm safety on the sides of the AGV, and therefore, for example, in an unmanned production line, workers approaching the AGV for bodywork may be injured before they leave the AGV. There is a risk of inconveniences such as the GV starting.

Problems to be Solved by the Invention The present invention recognizes the need for safety confirmation on the side of the AGV, which has not been done in the past, and automatically checks the safety on the side of the AGV for almost all aspects of the AGV. To provide an optical bumper for an AGV which can be confirmed reliably, can be installed without changing the 80V specifications, and has excellent durability.

Means for Solving the Problems The optical bumper for an AGV of the present invention is used in an 80V vehicle in which a flexible bumper having a projecting portion projecting to the side of the vehicle body is attached to the front and rear of the vehicle body. and a reflective optical sensor housed in a housing provided on the side surfaces of the front and rear ends of the vehicle body. The screen is disposed on the same side of the vehicle body and facing an omnidirectional reflective screen fixed to the opposite end of the vehicle body.

If there is no obstacle between the action-reflective optical sensor and the omnidirectional reflective screen that is fixed on the same side of the vehicle body of the AGV and at the opposite end of the vehicle body, the optical sensor The light emitted from the light emitting element of the sensor reaches the omnidirectional reflective screen, is reflected by the screen towards the light sensor, and is then received by the light receiving element of the sensor.
The optical sensor output is maintained at a level representative of no faults. On the other hand, if there is an obstacle between the two, the light from the optical sensor will not reach the screen, and the output from the optical sensor will be at a level indicating that there is an obstruction.

Embodiment FIGS. 1 and 2 show an AG equipped with an optical bumper according to an embodiment of the present invention and installed, for example, in an unmanned Ve line.
V (automated guided vehicle), and this AG is, for example, a conventionally known magnetic induction type, which operates the drive wheels according to the difference in induced voltage between electromagnetic pickup coils (not shown) provided on both sides of the vehicle body 1. It is configured to drive and control. and,
Flexible bumpers 2 are attached to the front and rear of the vehicle body 1 of the AGV, and each bumper 2 is made of plastic, for example.
Both ends are fixed to the frontmost or rearmost side of the vehicle body 1,
The intermediate portion is deformably held on the vehicle body 1 of the AGV via a wire 3, and is arranged along the front or rear surface of the vehicle body 1. Both ends of each flexible bumper 2 are connected to the vehicle body 1.
, respectively, to form overhanging portions 2a. A collision detection switch (not shown) is connected to each wire 3, and the switch is normally biased in the off direction by the wire 3, which is in tension due to the elastic force of the bumper 2.
The wire 3 is switched to a slackened cut-on position.

In the figure, reference numeral 4 indicates drive wheels arranged on both sides of the central portion of the vehicle body 1 and driven by a servo motor (not shown), and reference numeral 5 indicates wheels arranged at the front and rear of the vehicle body 1, respectively.

The optical bumper installed on AGV is Flexible Bumper 2.
Omnidirectional reflective screens 11 to 14 are fixed to the facing surfaces of the overhanging parts 2a, and reflective optical sensors 21 are housed in housing parts 7 provided on the sides of the front and rear ends of the vehicle body 1 and protected from external forces. - 24, and each optical sensor 21-24 has a corresponding omnidirectional reflective screen 1 fixed on the same side of the vehicle body 1 as the optical sensor and on the opposite end of the vehicle body.
They are arranged towards numbers 1 to 14. The omnidirectional reflective screens 11 to 14 are conventionally known mirrors that reflect incident light rays back to the original direction (path), and are made of, for example, lenticular plates with a diffusing surface provided on the surface. Further, the reflective optical sensors 1 21 to 24 are conventionally known sensors that detect changes in light reflected by the detection object, that is, the screens 11 to 14, and are, for example, sensors in which a light emitting element and a light receiving element are set in a case. , the output side is preferably connected to a control device (both not shown) mounted on the AGV via an operational amplifier.

Hereinafter, the operation of the AGV optical bumper configured as described above will be explained. Travel control of the AGV itself is performed in a conventionally known manner, and the AGV travels, for example, along a guide line laid on a travel route of an unmanned manufacturing line, and various parts, workpieces, etc. are mounted on the AGV. When an obstacle collides with the flexible bumper 2 while the AGV is operating, the collision detection switch is switched to the on position as the bumper deforms, and the operation of the AGV is stopped, for example.

Roughly speaking, if there are no obstacles between the reflective optical sensors 21 to 24 and the omnidirectional reflective screens 11 to 14 corresponding to the optical sensors while the AGV is running or stopped, each The light emitted from the light emitting elements of the optical sensors 21 to 24 enters the corresponding omnidirectional reflective screens 11 to 14, and this incident light is reflected by the screens 11 to 14 and is then received by the light receiving elements of the sensors. , the output current level of each optical sensor 21-24 shows a normal value indicating that there is no fault. Therefore, there is no need to set any restrictions on AGV operation.

On the other hand, if there is an obstacle between the optical sensors 21 to 24 and the corresponding screens 11 to 14, for example, if there is a worker, the light from the optical sensor will be blocked by the obstruction. No reflected light reaches the corresponding screen, no reflected light enters the light receiving element of the optical sensor, and the output current level of this sensor drops to a level indicating a fault.

As a result, it is detected that there is a driving problem in the AGV, and based on this detection result, for example, an alarm is issued when the AGV starts. 11vJ works etc. will be performed. Note that the alarm operation and the like are conventionally known, so the explanation will be omitted.

Effects of the Invention As described above, according to the present invention, omnidirectional reflective screens are fixed to the projecting parts of flexible bumpers attached to the front and rear of the vehicle body of the AGV, and reflective screens are installed on the sides of the front and rear ends of the vehicle body. An optical sensor is provided, and the optical sensor is placed facing an omnidirectional reflective screen fixedly installed on the same side of the vehicle body as the sensor and at the opposite end of the vehicle body, and there is no obstacle between the two. When there is no problem, the light emitted from the light emitting element of the optical sensor and reflected by the screen is received by the light receiving element of the optical sensor, and the optical sensor outputs an output at a level indicating that there is no interference, but there is no interference between the two. If there is an object, the light from the optical sensor will be blocked and the output of the optical sensor will be at a level that indicates an obstruction or harm, so safety checks on the sides of the AGV, which were not done in the past, are now possible. This can be done automatically and reliably for almost all of the eight GVs, and furthermore, the AGV optical bumper can be installed without changing the specifications of the AGV.

Further, since the reflective optical sensor is housed in the housing provided in the vehicle body, the AGV optical bumper is not subjected to external force and has excellent durability.

In addition, since the incident light from the optical sensor is reflected by the omnidirectional reflective screen, even if the direction of the screen changes due to the deformation of the flexible bumper to which the screen is fixed, the reflected light from the screen will not change. Reliably reaches the optical sensor and does not cause malfunction.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing an AGV equipped with an optical bumper for an AGV according to an embodiment of the present invention, and FIG.
This is a schematic side view of V. 1...Vehicle body, 2...Flexible bumper, 2a...
・Protruding portion, 3...Wire, 7...Accommodating part, 11~
14... Omnidirectional reflective screen, 21-24...
Reflective optical sensor.

Claims (1)

[Claims] In an automatic guided vehicle equipped with a flexible bumper having a projecting portion projecting to the side of the vehicle body, which is mounted on the front and rear of the vehicle body, an omnidirectional reflective screen fixedly installed on opposing surfaces of the projecting portions of the flexible bumper; a reflective optical sensor housed in a housing provided on a side surface of the front and rear ends of the vehicle body; An optical bumper for automated guided vehicles that faces an omnidirectional reflective screen.