JP3197813B2 - Unmanned 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 guided vehicle equipped with a collision prevention device for judging from a reception level of an electromagnetic wave oscillated from another vehicle existing in a traveling direction to prevent a collision from a preceding vehicle. About.

[0002]

2. Description of the Related Art Conventionally, this type of unmanned guided vehicle has been
As shown in Japanese Patent Application Laid-Open No. 7-18197 (B60R21 / 00), it is necessary to mount a sensor that emits ultrasonic waves on the front of the vehicle body, detect the reflection time of the emitted ultrasonic waves, detect the distance to an obstacle, and stop. There is known one that stops a vehicle when a distance is reached. At the time of this stop, in order to change the stopping distance depending on the type of obstacle, for example, the person and the vehicle, the rear part of the vehicle is inclined with respect to the front-rear direction, and even if the distance is equal, the ultrasonic wave between the person and the guided vehicle is The type of obstacle ahead is determined by making the reflection time different.

However, in the above-described configuration, the vehicle body is set to stop at a predetermined distance, so that the braking distance increases as the speed increases, and a collision may occur if the speed is too high. It was dangerous because it came.

Further, in the above-described unmanned guided vehicle, the type of obstacle between the person and the vehicle body is determined and only the stopping distance is changed. For example, as shown in FIG. When the vehicle body 92 is traveling in the direction of the arrow and another vehicle 93 is stopped immediately after turning the curve, the vehicle is stopped from the so-called curved position (the vehicle body indicated by the broken line in the figure) and stops. When the interval exceeds the braking distance, the vehicle body 92 is within the braking distance range of the vehicle body 92 when the vehicle body 92 detects the preceding stopped vehicle 93 with the obstacle sensor 94,
There is a problem that the vehicle cannot be stopped and the vehicle main body 92 collides with the preceding stopped vehicle 93. The problem is that the smaller the radius of the curve, the greater the possibility of suddenly detecting an obstacle, so that the braking distance from detection to stop is insufficient. As a countermeasure, it is conceivable to increase the set reception level at which the braking device starts operating from the beginning, but in this case, it is not possible to stop at the optimum distance or mistakenly pick up noise. It may stop or cause inconvenience in the running operation.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a safe unmanned guided vehicle that prevents a collision even if the traveling speed or the steering angle changes during traveling. I do.

[0006]

According to a first aspect of the present invention, there is provided a receiver for detecting an electromagnetic wave from another vehicle existing in a traveling direction of a vehicle main body traveling on an installed track, and the receiver for detecting the electromagnetic wave. An unmanned guided vehicle provided with a braking device that stops a vehicle body based on detection sensitivity of a steering device, wherein a steering angle detection unit that detects a steering angle of a steered wheel of the vehicle body is provided, A control circuit for operating the braking device with a small detection signal from the device.

The main vehicle traveling on the track travels while detecting the reception sensitivity of the electromagnetic wave transmitted from the preceding vehicle existing in the traveling direction. When the detection sensitivity reaches a predetermined level, that is, when the distance from the preceding vehicle has reached a predetermined distance, the braking device is operated and stopped. At this time, the steering angle of the steered wheels is detected, and the control is performed so that the larger the steering angle, the smaller the detected signal is. In other words, control is performed such that the smaller the radius of the curve, the longer the distance to stop.

[0008]

[0009]

Further, according to a second aspect of the present invention, there is provided a receiver for detecting an electromagnetic wave from another vehicle existing in a traveling direction of a vehicle body traveling on an installed track, and a vehicle based on the detection sensitivity of the receiver. An unmanned guided vehicle equipped with a braking device for stopping the main body, provided with steering angle detecting means for detecting a steering angle of a steering wheel of the vehicle main body, and speed detecting means for detecting a traveling speed of the vehicle main body, A control circuit is provided in which the braking device operates with a smaller detection signal from the receiver as the steering angle increases and the traveling speed increases.

A vehicle body traveling on a track travels while detecting the reception sensitivity of an electromagnetic wave oscillated from a preceding vehicle existing in the traveling direction. When the detection sensitivity reaches a predetermined level, that is, when the distance from the preceding vehicle has reached a predetermined distance, the braking device is operated and stopped. At this time, the steering angle and the traveling speed of the steered wheels are detected, and control is performed so that the braking device operates with a smaller reception signal as the steering angle increases, and with a smaller reception signal as the traveling speed increases. In other words, control is performed such that the shorter the radius of the curve, the longer the distance, and the higher the speed at that time, the longer the distance.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, a block diagram of the control circuit will be described with reference to FIG.

A motor 1 drives a vehicle body 2 which is an unmanned guided vehicle. The motor 1 is driven by a battery 3 as a power supply. The battery 3 includes, for example, a 24 volt lead storage battery.

Reference numeral 4 denotes a flywheel diode connected in parallel to the motor 1, and is provided for PWM control.

Reference numeral 5 denotes a constant voltage circuit for lowering the voltage of the battery 3 and supplying power to a control circuit, that is, a microcomputer 6, which outputs a starting voltage of the microcomputer 6, for example, 5 volts. I do.

Reference numeral 7 denotes a drive circuit for controlling the PWM of the motor 1 by sending a PWM signal to a switching element 8 connected in series with the motor 1 and turning the switching element 8 on and off. 1 is driven.

Reference numeral 9 denotes a speed detection circuit for detecting the number of revolutions of wheels (not shown) of the vehicle body 2, and the speed detection circuit 9 is composed of, for example, an encoder. 6 is input.

Reference numeral 10 denotes a braking device such as an electromagnetic brake for stopping the rotation of the wheels. The braking device 10 operates via a braking drive circuit 11 based on a braking signal from the microcomputer 6. Then, a deceleration and a stop operation are performed.

Reference numeral 12 denotes a guide line buried along a predetermined traveling path. The guiding line 12 connects the traveling path with a single line, and generates a magnetic field by flowing an electric current through the guide line.

Reference numeral 13 denotes a pickup coil which is provided so as to move in conjunction with the steered wheels of the vehicle body 2 and detects a magnetic field from the guide wire 12.
The vehicle body 2 travels while detecting a magnetic field from the guide wire 12. In addition, each pickup up coil 13 has an amplification circuit
The amplified signal is input to the microcomputer 6, and by inputting the signal, it is possible to determine how much the steered wheels are shifted left and right with respect to the guide line 12.

Reference numeral 15 denotes a steering motor for moving the steering wheel to the left and right. The steering motor 15 moves the steering wheel to the left and right to travel along the guide line 12 based on the input of the pickup coil 13. The microcomputer 6 determines how much to move, and outputs a signal to the steering motor drive circuit 16 to move the steering motor 15.

Numeral 17 is a steering angle detecting means for detecting how many times the steered wheels bend in the straight running direction.
Reference numeral 17 indicates that the steering angle can be detected by a change in resistance value of a potentiometer or the like attached to the steered wheels.

Reference numeral 18 denotes a magnet detection circuit for detecting a magnetic field of a magnet embedded near the guide wire 12 on the road surface. The S and N poles of the magnet are embedded in the road surface to control the speed.
For example, commands such as deceleration, acceleration, and stop can be given to the vehicle body 2, and the operation of the commands is performed whenever the vehicle passes through the location. The magnet can also be used to issue a command to attenuate the reception sensitivity of the obstacle sensor 19, which will be described later. That is, it is possible to give an instruction so as not to stop unless the distance between the obstacle sensor 19 and the obstacle is reduced to half of the normal value.

Reference numeral 19 denotes an obstacle sensor for detecting an obstacle ahead in the traveling direction. The obstacle sensor 19 oscillates ultrasonic waves and detects the intensity of reflected ultrasonic waves or the time of reflection to detect obstacles. The distance to the object is detected, and when this signal is input to the microcomputer 6, the braking device 10 is operated by a signal output from the microcomputer 6 when the dangerous distance has to be stopped. 2 is stopped.

Reference numeral 20 denotes a transmitter provided at the rear of the vehicle main body 2 and constantly transmitting radio waves toward the rear. Reference numeral 21 denotes a receiver provided in front of the vehicle body 2 to receive a radio wave from the vehicle body ahead. When the receiver 21 receives a radio wave transmitted from the vehicle body traveling in front at a predetermined level or more, that is, when the distance from the vehicle body traveling in front becomes a predetermined distance, the microcomputer 6 determines. The brake device 10 is operated to stop.

Reference numeral 22 denotes the obstacle sensor 10 and the receiver 21
The buzzer notifies the user when the obstacle or the distance to the vehicle body in front is within a range where the vehicle must stop, and the buzzer 22 notifies the user when this is detected. It has become.

The receiver 21 and the receiver of the obstacle sensor 19 are provided with a volume for adjusting the sensitivity, and this volume is used for fine adjustment of the stopping distance at the time of shipment from the factory. For example, the vehicle body 2 and the transmitter or the pseudo obstacle are installed at a distance where they must be stopped, and the buzzer is adjusted by adjusting the sensitivity adjustment volume of the obstacle sensor 19.
The stop distance can be set to a predetermined sensitivity by ringing 22 and fixing the volume at the position where the sound starts.

Reference numeral 24 denotes remote control signal input means for inputting a remote control signal from a remote control transmitter possessed by the user. The remote control signal input means 24 can receive start and stop instruction signals from the remote control transmitter. . The remote control signal input means 24 inputs the received signal to the microcomputer 6 to perform start and stop operations.

Next, a first embodiment will be described with reference to FIGS.

When the vehicle body 2 starts running (S
1) The receiver 21 detects the distance from the preceding guided vehicle at the signal level s (S2). Then, the steering angle is detected by the steering angle detecting means 17 (S3), and the magnitude of the angle is determined based on the set value shown in FIG.
10 Set the reception level S at which operation starts (S
4). Then, the received signal level s is compared with the set received level S at which the braking device 10 starts operating (S5), and if not, the process is repeated from S2. If it has reached, the brake device 10 is operated, and the operation shifts to a stop operation (S6).

In this way, as shown in FIG. 2, as the steering angle is larger, the receiver 21 is controlled so that the braking device is operated even if the reception level is lower. Since the distance to the running vehicle is increased, the unmanned guided vehicle can be stopped just before the vehicle turns, even if there is a preceding vehicle immediately after the vehicle turns at the corner, and safety can be improved.

Next, a second embodiment will be described with reference to FIGS.

This embodiment is different from the first embodiment in that the distance from the preceding vehicle in which the braking device is operated in accordance with the steering angle is set in accordance with the speed signal from the speed detection circuit 9. The setting values shown in FIG. 6 are set, and the values are determined accordingly.

This will be described with reference to the flowchart of FIG.

When the traveling operation is started (S1), the receiver 21 detects the distance from the guidance vehicle ahead at the signal level s (S1).
2). Then, the traveling speed is detected by the speed detection circuit 9 (S3), and the set reception level S at which the braking device 10 starts operating based on the set value shown in FIG.
Is set (S4). Then, the reception signal level s is compared with the set reception level S at which the braking device 10 starts operating (S
5) If not, repeat from S2. If it has reached, the brake device 10 is operated, and the operation shifts to a stop operation (S6).

In this way, as shown in FIG. 6, the braking device is controlled to operate as the traveling speed increases, even if the reception level of the receiver 21 is low. That is, the braking device operates as the traveling speed increases. Since the distance to the preceding vehicle is lengthened, the vehicle can be stopped without hitting the vehicle even if the speed is increased and the braking distance is increased, thereby improving safety.

Next, a third embodiment will be described with reference to FIGS.

In the present embodiment, control is performed by combining the first embodiment and the second embodiment, and the set reception level of the receiver 21 is set to a distance for operating the braking device according to the steering angle. At the same time, the set value is changed depending on the running speed at that time.

When the traveling operation is started (S1), the receiver 21 detects the distance to the preceding guided vehicle at the signal level s (S1).
2). Then, the steering angle is detected by the steering angle detecting means 17 (S3), and the traveling speed at this time is detected (S4). Based on the angle and the speed, the set reception level S of the receiver 21 when the braking device 10 operates is set based on FIG. 8 (S5). Then, the received signal level s is compared with the operation level S of the braking device 10 (S6), and if not, the process is repeated from S2. If it has also reached the braking device
10 is operated, and the operation proceeds to the stop operation (S7).

As described above, based on the detected values of both the steering angle of the first embodiment and the traveling speed of the second embodiment, the distance to the vehicle body in front of which the braking device operates, that is, the receiver 21 Is changed, the stopping distance can be changed according to the size of the turning angle and the traveling speed, thereby improving the safety.

In the embodiment of the present invention, the driving source is a motor. However, if the vehicle is a guided vehicle, the driving source may be irrelevant and the engine may be used as the driving source.

Further, in this embodiment, the stopping distance is changed by changing the sensitivity of the receiver 21 based on the steering angle of the steered wheels, the traveling speed, and both signals. Control may be performed so as to detect an uphill and change the reception sensitivity. In this case, in the case of a downhill, the set receiving level at which the braking device starts to operate is reduced to increase the braking distance, and in the case of an uphill, the set receiving level at which the braking device starts operating is increased to increase the braking. Shorten the distance.

Further, in this embodiment, as shown in FIGS. 2, 6, and 8, the set reception level at which the braking device of the receiver 21 starts operating is set to linearly change. The value may be set in advance and digitally changed.

Further, in the present embodiment, the set reception level of the receiver 21 is changed according to the steering angle and the traveling speed. However, the same applies to the obstacle sensor 19. In that case,
In particular, it is necessary to remove trees and other obstacles in curves and the like.

[0046]

According to the first aspect of the present invention, the braking device is controlled to operate as the steering angle increases, even if the reception level of the receiver is low. Since the distance from the running vehicle is increased, even if there is an obstacle immediately after the vehicle turns at the corner, the vehicle body can be stopped just before the vehicle turns and the safety can be improved.

[0047]

Further, according to the present invention, the steering angle and the traveling speed of the steered wheels of the vehicle body are detected, and the braking is performed with a small reception signal at a place where the steering angle is large, and with a small reception signal as the traveling speed at that time is fast. Since the device is controlled to operate, even if an obstacle is detected immediately after the vehicle body turns, it can be stopped in front of the vehicle, and the faster the traveling speed at that time, the faster the vehicle stops, so the safety is improved. be able to.

[Brief description of the drawings]

FIG. 1 is a flowchart of a control circuit for an unmanned guided vehicle according to a first embodiment of the present invention.

FIG. 2 is a graph showing a setting reception level of a receiver with respect to the steering angle.

FIG. 3 is a schematic diagram showing the traveling state.

FIG. 4 is a block diagram of the control circuit.

FIG. 5 is a flowchart of a control circuit for an unmanned guided vehicle according to a second embodiment of the present invention.

FIG. 6 is a graph showing a set reception level of the receiver with respect to the traveling speed.

FIG. 7 is a flowchart of a control circuit for an unmanned guided vehicle according to a third embodiment of the present invention.

FIG. 8 is a graph showing a setting reception level of the receiver with respect to the steering angle and the traveling speed.

FIG. 9 is a schematic diagram showing a running state of a conventional unmanned guided vehicle.

[Explanation of symbols]

 21 Receiver 10 Braking device 17 Steering angle detecting means 6 Control circuit 9 Speed detecting means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Naohiro Shigeta 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-47-36310 (JP, A) JP-A-4-170605 (JP, A) JP-A-50-5791 (JP, A) JP-A-51-112078 (JP, A) JP-A-3-17712 (JP, A) JP-B-37-5609 (JP, A) , B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) G05D 1/02 G08G 1/16

Claims (2)

(57) [Claims] 1. A receiver for detecting an electromagnetic wave from another vehicle existing in a traveling direction of a vehicle body traveling on an installed track, and a braking device for stopping the vehicle body based on the detection sensitivity of the receiver. An unmanned guided vehicle equipped with a steering angle detecting means for detecting a steering angle of a steered wheel of the vehicle body,
An unmanned guided vehicle provided with a control circuit for operating a braking device with a smaller detection signal of the receiver as the steering angle increases. 2. A receiver for detecting an electromagnetic wave from another vehicle existing in a traveling direction of a vehicle body traveling on an installed track, and a braking device for stopping the vehicle body based on the detection sensitivity of the receiver. An unmanned guided vehicle provided with: a steering angle detecting means for detecting a steering angle of a steered wheel of the vehicle body; and a speed detecting means for detecting a traveling speed of the vehicle body, wherein the steering angle is large and An unmanned guided vehicle, comprising: a control circuit that operates a braking device with a smaller detection signal of the receiver as the speed increases.