JPH01244510A - Device for preventing erroneous detection of obstacle for unattended vehicle - Google Patents

Abstract

PURPOSE:To keep an excellent work efficiency by providing each vehicle with a detecting means which outputs a signal to a discriminating means without interfering with another detecting means and a switching means which effectively operates different detecting means and prevecting erroneous detection of an obstacle sensor to evade interruption of the work. CONSTITUTION:When one of a pair of vehicles 1 which run in opposite directions closely on both sides in a close passage area E is run in accordance with the detection result of an ultrasonic sensor 6 or a photoelectric sensor 7, the other is stopped in accordance with the detection result of the photoelectric sensor 7 or the ultrasonic sensor 6. Thus, the ultrasonic sensor 6 of one vehicle 1 is prevented from receiving the light emitted from the photoelectric sensor 7 of the other vehicle different in property to output an erroneous signal to a controller 9, and the controller 9 decelerates or stops a motor 10 only when an obstacle existing in the area where detection is required is detected. Thus, the running vehicle 1 is not unnecessarily stopped to effectively perform the work.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for preventing false detection of obstacles in unmanned vehicles.

[Conventional technology]

The automatic guided vehicle moves by detecting electrical guide wires extending on the floor using a magnetic sensor installed at the bottom of the vehicle.

That is, as shown in FIG. 5, inside a factory or the like, a guide line connects stations Stl and St2 to form a traveling path 20, and a plurality of automatic guided vehicles 2 and 1 are guided along this traveling path 20. runs.

As shown in FIG. 6, these automatic guided vehicles 21 emit pulsed ultrasonic waves to a detection area within a predetermined range from the front to the side, taking into consideration the maximum allowable load width, etc. When an obstacle exists within the area, the sensor 22 detects this and the automatic guided vehicle 21 decelerates. Further, if an obstacle comes within 1 m while the transport vehicle 21 is traveling, the transport vehicle 21 will stop traveling according to the detection result of the sensor 22, thereby preventing an accident.

[Problem to be solved by the invention]

However, in factories etc., equipment etc. need to be placed in various locations, and guide wires are installed within a limited area.
By turning in a narrow place, the hats are forced to run parallel to each other in close positions. For this reason, the running path 20
The two automatic guided vehicles 21 approach each other and run oppositely outside the detection area of the sensor 22 of the other party. However, even if it is outside the detection area of each sensor 22, if the timing of the ultrasonic waves emitted by each other matches the reception timing of the sensor 22 of the other party, this ultrasonic wave will be received by the sensor 22 of the other party in the same way as a reflected wave. Therefore, even though there is no obstacle within the detection area I, the vehicle stops and the work is interrupted, resulting in a decrease in work efficiency.

This invention was made to solve the above-mentioned problems, and its purpose is to prevent false detection of obstacle sensors, avoid interruption of work, and maintain excellent work efficiency. To provide a device for preventing false detection of obstacles in unmanned vehicles.

[Failure to solve the problem]

In order to achieve the object stated in (-), this invention detects an obstacle when it is within a detection required area necessary for safe driving in the direction of travel of a vehicle traveling on a preset travel path. A plurality of vehicles comprising a foul type detection means, a discrimination means for determining the presence of an obstacle based on the detection result of the detection means, and a travel control means for stopping the vehicle in accordance with the discrimination operation of the discrimination means. In the unmanned vehicle, each vehicle is equipped with another detection means that outputs a signal to the discrimination means without interfering with the detection means, and a detection means that outputs a signal to the discrimination means without interfering with the detection means, and a detection means that detects the other vehicle before approaching and traveling in the opposite direction. The gist of the present invention is to provide a switching means for effectively operating a different detection means from one of the detection means that operates effectively.

[Effect]

By adopting the above-mentioned means, this invention enables the switching means to operate effectively in the other vehicle before the vehicle travels within the detection area of the other vehicle. Effectively operate different detection means. This prevents the detection means of the two vehicles from interfering with each other, and erroneously detecting the other vehicle as an obstacle is avoided.

〔Example〕

Hereinafter, one embodiment of the false detection prevention device of the present invention will be described in detail with reference to FIGS. 1 to 4.

In FIGS. 2 and 3, a plurality of automatic guided vehicles detect a guide line consisting of a power line laid on the floor F using a magnetic sensor 2 installed at the bottom of the vehicle 1, and a guide line is formed along this guide line. The vehicle travels on the driving route 3. The travel path 3 described above has a ring shape with several bends, and the area surrounded by the two-dot chain line is an oncoming vehicle approach area E. and,
Mark patterns Ml and M2 drawn in two colors with significantly different reflectances, such as white and black, are provided on the bottom of the vehicle 1 between each station Stl and St2 and the approach passing area E on the floor surface F. Photoelectric pattern detection sensor 8
It is now detected in

As shown in FIG. 3, sensor mounting sections 5 are arranged at the center and both sides of the front frame 4 of the vehicle 1, respectively. Each sensor receiving portion 5 is provided with an ultrasonic sensor 6 as a detection means and a photoelectric sensor 7 as another detection means.

Both the ultrasonic sensor 6 and the photoelectric sensor 7 are of a reciprocal type, and a pulse wave emitted by a transmitting section (not shown) is received by a receiving section that is reflected by an obstacle within a predetermined period of time. As shown in Fig. 2, obstacles are detected in two stages within detection required areas x, y and within 1 m, which are set within predetermined ranges in front, right front, and left front of vehicle 1. ing.

FIG. 1 shows the electrical configuration of this embodiment. That is, the ultrasonic sensor 6 and the photoelectric sensor 7, as well as the pattern detection sensor 8 and the magnetic sensor 2, are a traveling control means,
The controller 1 is connected to a roller 9 as a determining means and a switching means. Further, connected to the controller 9 are an electric motor 10 for rotating the drive wheels and a steering device 11 for controlling the steering angle of the steered wheels.

The vehicle 1, which is sequentially departed from each station stt and st2, travels along the travel path 3'2 by operating the steering device 11 by the controller 9 in accordance with the detection signal from the magnetic sensor 2. Note that when an obstacle is detected by both sensors 6 and 7 after the vehicle 1 has passed the mark pattern M1, the controller 9 activates only the detection signal output by the ultrasonic sensor 6 and activates the signal from the photoelectric sensor 7. Disable. Further, when an obstacle is detected by both sensors 6.7 after the vehicle 1 passes the mark pattern M2,
The controller 9 validates the signal from the photoelectric sensor leaf and invalidates the signal output from the ultrasonic sensor 6.

The controller 9 of each vehicle 1 uses the rotation of the motor 10 to
Step SL in Figure 4 (hereinafter the step is simply referred to as S)
When the running operation of the vehicle 1 is confirmed at S2, the controller 9 determines whether or not the mark pattern M1 is detected by the pattern detection sensor 8, that is, the vehicle 1 passes through the mark pattern M1 and moves toward the approach passing area E. determine whether or not. If the result of this judgment is YES,
In S3, the controller 1-roller 9 effectively handles the signal from the ultrasonic sensor 6 and performs processing to invalidate the signal from the photoelectric sensor 7. Then, the controller 9 decelerates and rotates the motor 10 based on the detection output from the ultrasonic sensor 6 that has detected an obstacle existing within the detection required area X in the traveling direction of the vehicle 1 (No. When an obstacle is detected, the rotation of the motor 10 is stopped and the running of the vehicle 1 is stopped.

Further, when the determination result in S2 is NO, it is determined in S4 whether or not the pattern detection sensor 8 has detected the mark pattern M2. If the result of this determination is YES, the controllers 1 to 9 perform a process of validating the signal from the photoelectric sensor 7 and invalidating the signal output from the ultrasonic sensor 6 in S5. After that, when the photoelectric sensor 7 detects an obstacle within the detection required area Y, the controller 9 decelerates and rotates the motor 0 based on the command from the photoelectric sensor 7 to reduce the traveling speed of the vehicle 1. When an obstacle is detected within 1 m in the direction, the rotation of the motor 0 is stopped and the running of the vehicle 1 is stopped.

Now, in the above driving process, after the vehicle 1 has passed the mark pattern M1, if an obstacle enters the detection area X, the controller 9 decelerates the motor 0 based on the detection signal from the ultrasonic sensor 6, and further Motor 0 is stopped when the obstacle is within m distance. After that, when the obstacle is removed by a worker or the like and the vehicle 1 starts and passes the mark pattern M2, the controller 1-roller 9 invalidates the detection signal output from the ultrasonic sensor 6, and the photoelectric sensor 7
Activate the detection signal from. At this time, another vehicle 1 through which the mark pattern M1 has passed detects an obstacle only by the ultrasonic sensor 6.

Therefore, in the approach passing area E, if a pair of vehicles 1 are running opposite each other in close positions on the left and right, one will follow the detection result of the ultrasonic sensor 6 or the photoelectric sensor 7, while the other will follow the detection result of the ultrasonic sensor 6 or the photoelectric sensor 7. Photoelectric sensor.

7 or according to the detection result of the ultrasonic sensor 6.

For this reason, for example, the ultrasonic sensor 6 of one vehicle 1 does not receive the light emitted by the photoelectric sensor 7 of the other party, which has different properties, and outputs an erroneous signal to the controller 9, and the ultrasonic sensor 6 of one vehicle 1 does not output an erroneous signal to the controller 9. The controller 9 decelerates or stops the motor 10 only when an obstacle is detected. Thereby, the traveling vehicle 1 is not stopped unnecessarily, and the work can be carried out effectively.

Note that the above-described embodiments can also be implemented in the following embodiments.

■In place of the ultrasonic sensor 6 and the photoelectric sensor 7, two types of sensors that emit ultrasonic waves with different wavelengths or two types of sensors that emit light with different wavelengths or light amounts are installed, so that the approach area E can be The configuration is such that mutual interference between sensors of two vehicles 1 running opposite to each other is avoided.

■Pattern detection sensor 8 is for each mark pattern MI
When M2 is detected, the ultrasonic sensor 6 and the photoelectric sensor 1
The rear side of the sensor 7 is operated in the opposite direction to that of the vehicle 1 traveling in the opposite direction, so that interference between the sensors 6 and 7 is prevented.

〔effect〕

As described in detail above, according to the present invention, it is possible to prevent the erroneous detection of the obstacle sensor when entering the vehicle, thereby maintaining excellent work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of the malfunction prevention device according to the present invention, FIG. 2 is a front view showing an automatic guided vehicle, and FIG. 3 is an explanatory diagram showing a plurality of automatic guided vehicles traveling on a running path. FIG. 4 is a flowchart 1 for explaining the action of the controller 1-roller, FIG. 5 is an explanatory diagram showing a conventional example, and FIG. 6 is a plan view showing the same conventional example. A vehicle 1, a running path 3, an ultrasonic sensor 6 and a photoelectric sensor 7 as detection means, a controller 9 as a discrimination means, a travel control means, and a switching means, and areas X and Y that require detection.

Claims (1)

[Scope of Claims] 1. Reflective detection means for detecting an obstacle when it is within a detection required area necessary for safe driving in the direction of travel of a vehicle traveling on a preset travel path; In a plurality of unmanned vehicles, each vehicle is equipped with a discriminating means for discriminating the presence of an obstacle based on a detection result of the discriminating means, and a travel control means for stopping the vehicle from traveling according to the discriminating operation of the discriminating means, each vehicle having: Another detection means that outputs a signal to the discrimination means without interfering with the detection means, and one of the detection means that operates effectively in the other vehicle before approaching the other vehicle and traveling in the opposite direction. An obstacle detection prevention device for an unmanned vehicle, comprising a switching means for effectively operating a different detection means.