JPH0962354A - Traveling vehicle control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the malfunctions to prevent the fall of a traveling vehicle and to improve the traveling reliability of the vehicle by detecting the distance between the front bottom surface of the vehicle body and the traveling floor surface and stopping the deciding action of the level difference of the floor surface. SOLUTION: A main control part 18 drives the right and left drive motors 12 and 13 of a traveling vehicle to accelerate the vehicle and also to make the vehicle travel straight via the traveling operations. Then the part 18 controls the traveling of the vehicle based on the signals received from the rotary encoders 14 and 15. At the same time, an ultrasonic sensor 10 and a secondary control part 11 detect the distance between the vehicle body and the floor surface every time the vehicle travels a prescribed distance. The part 18 decides the presence or absence of level difference of the floor surface based on the detected distance data. If two continuous level differences are detected, the existence of a large level difference is decided and the vehicle is urgently stopped. When the vehicle does not reach a prescribed speed in its stop or acceleration/deceleration mode, the part 18 disregards the detected distance data received from the part 11, does not decide the presence or absence of the level difference, and furthermore does not urgently stop the vehicle even when the presence of the level difference is decided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control technology for, for example, a carrier vehicle or a cleaning machine (a traveling vehicle that may be manned or unmanned). The present invention relates to a method of controlling a traveling vehicle for improving the property.

[0002]

2. Description of the Related Art Traveling vehicles of this type (transportation vehicles and cleaning machines)
There are those that are manually operated and those that can be driven unattended without human intervention. As shown in FIG. 3, a distance sensor 2 is arranged on the bottom surface of the front portion of the traveling vehicle 1 for the purpose of preventing the vehicle from falling over or falling over.

The distance sensor 2 detects the distance to the running floor surface, and when the detected distance exceeds a predetermined value, it is determined that the front of the running vehicle 1 is a step, and the running vehicle 1 is made to be an emergency stop. Prevent the car body from falling over.

In this case, if the front of the traveling vehicle 1 is a step such as a stair (see the broken line in FIG. 3), the step can be surely determined, but the shape and material of the floor and the floor Incorrect judgment, that is, erroneous detection, may occur due to tile joints and recesses on the floor. For example, when an ultrasonic sensor is used as the distance sensor 2, it is erroneously detected due to irregular reflection on the floor surface, resulting in an emergency stop.

Therefore, in detecting the distance to the floor surface, a two-time detection system in which the distance is continuously twice can be considered. In the two-time detection method, if the traveling vehicle 1 is traveling at a normal speed, for example, even if the first time there is an erroneous detection due to tile joints or recesses on the floor, the tile will be detected at the next second time. Since the normal detection distance data is obtained because the vehicle passes through the joints and the recesses, an erroneous emergency stop does not occur.

[0006]

By the way, in the above traveling vehicle control method, it is effective if the traveling speed of the traveling vehicle 1 is a predetermined value or more, but the vehicle body stops or the vehicle body travels at a very low speed. In this case, the distance detection may be performed twice at tile joints and recesses on the same floor surface, and thus an emergency stop malfunction may occur, resulting in unreliable traveling.

The present invention has been made in view of the above problems, and an object thereof is to eliminate erroneous detection for preventing a vehicle body from falling or falling, that is, erroneous operation of an emergency stop, and improve the reliability of traveling. It is to provide a method of controlling a traveling vehicle as described above.

[0008]

In order to achieve the above object, the present invention detects a distance to a running floor surface by a detection means provided at least on a front bottom surface of a vehicle body, and based on the detected distance. A method of controlling a traveling vehicle capable of stopping the vehicle body by determining a step on the floor surface by means of a vehicle, wherein when the traveling speed of the vehicle body is a predetermined value or less, the step on the floor surface is not determined. It is characterized by not stopping.

According to the present invention, at least the detecting means provided on the bottom surface of the front portion of the vehicle body detects the distance to the running floor surface, and based on the detected distance, the step on the floor surface can be determined to stop the vehicle body. When the traveling speed of the vehicle body is equal to or lower than a predetermined value, the floor surface is not detected and the vehicle body is not stopped.

In this case, it is preferable that the traveling floor surface is detected every time the vehicle body moves a predetermined distance or every predetermined time, and continuously twice.

Further, it is preferable that the detecting means is an ultrasonic sensor or a reflection type photoelectric sensor.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
This will be described in detail with reference to FIG. 1 and 2,
The control device for a traveling vehicle includes an ultrasonic sensor unit 10 having an ultrasonic sensor (detection means) 10a for detecting at least the distance to the floor surface, and a distance to the floor surface based on a detection signal from the ultrasonic sensor 10a. Etc., a sub-control unit (CPU board) 11, drive motors 12 and 13 with rotary encoders 14 and 15 that respectively drive the left and right drive wheels 16, operation of an operation panel (not shown), and sub-control unit 11 Measurement result and rotary encoder 14,
A main control unit (CPU board) 18 that issues control instructions for traveling (including speed), stop and reverse (rotational direction), etc. based on encoder pulses from 15 and the main control unit 18 Drive motor 1 according to the control instruction
A drive wheel control circuit 19 for outputting drive signals 2 and 13;
A drive circuit 20 that drives the drive motors 12 and 13 by this drive signal is provided. Further, auxiliary wheels 22 are provided in front of the bottom surface of the vehicle body 21.

As shown in FIG. 2, the ultrasonic sensor 10a of the ultrasonic sensor unit 10 is disposed on the bottom surface of the front portion of the vehicle body 21, and when the traveling vehicle is unmanned, the ultrasonic sensor unit 10 is not present. The ultrasonic sensors 10b and 10c of the vehicle body 21
It is located on the front and both sides of the.

In the control device for a traveling vehicle, when an operation of the operating portion of the traveling vehicle, for example, a traveling operation is performed,
The main control unit 18 drives the left and right drive motors 12 and 13 to accelerate the vehicle body 21 to a predetermined speed and make the vehicle travel straight ahead.
Travel control is performed based on encoder signals from 4, 15.

At this time, the ultrasonic sensor 10a and the sub-control unit 11 detect the distance to the floor surface at every predetermined distance movement (or at constant time intervals) and continuously detect the distance twice. Output to the main control unit 18.

The main controller 18 determines whether or not there is a step on the floor based on the detected distance data, as in the conventional case.
That is, when the detection distance is larger than the distance to the horizontal floor surface, it is determined that there is a step. Moreover, when the detected distance over two consecutive times is larger than the distance to the horizontal floor surface, it is determined that there is a step (see the broken line in FIG. 2), and the vehicle body 21
Is stopped to prevent the vehicle body 21 from falling or falling due to the step.

In this case, the main controller 18 does not make an emergency stop of the vehicle body 21 when the vehicle body 21 is stopped or when the vehicle body 21 does not reach a predetermined speed during acceleration or deceleration.

In this method, when the vehicle body 21 is stopped and the predetermined speed is not reached during acceleration or deceleration of the vehicle body 21, the main control unit 18 ignores the detected distance data from the sub control unit 11, Do not judge the step on the floor, or do not make an emergency stop even if the step on the floor is judged.

Further, the sub control unit 11 may not detect the distance to the floor, that is, may not output the data to the main control unit 18. In this case, the detection process and the determination process in the sub control unit 11 and the main control unit 18 can be omitted, and the control can be simplified.

As described above, when the vehicle body 21 is stopped or does not reach the predetermined speed (for example, during acceleration or deceleration), the detection distances for two consecutive times are almost the same,
Even if the distance is larger than the horizontal floor surface, the vehicle body 21 will not be accidentally stopped in an emergency.

That is, when the vehicle body 21 is stopped, or while traveling at a very low speed (during acceleration or deceleration), when the recessed portion on the floor surface (for example, the joint of the tile) is detected, the same recessed portion is also detected the second time. This is because the detection may be performed, resulting in a malfunction of the emergency stop.
This is because there is a high possibility that the fall and fall of 1 will occur during running with inertia (a predetermined speed after acceleration).

As a concrete example, a speed servomotor is used as the driving motors 12 and 13 of the traveling vehicle, and the vehicle body 2
It is assumed that the speed of 1 is proportional to the set speed voltage value, and the normal traveling speed is set to 6.2V at high speed and 3.7V at low speed.

Further, the main controller 18 sets the acceleration of the vehicle body 21 in steps of 0.1 V / 40 msec, and raises the voltage of the speed servo motor stepwise from 0 V to the set voltage value. The drive wheel control circuit 19 drives the speed servomotor based on the voltage set by the main control unit 18, and sets the vehicle body 21 at a predetermined speed.

In this case, the threshold value for overturning and overturn detection is set to 1V, and the voltage of the speed servomotor is set to 1V.
After reaching V, the ultrasonic sensor 10a is used to start the distance detection to the concave portion of the floor surface, and the step difference of the floor surface is determined based on the distance detected by the double detection method. .

Further, the vehicle body 21 is decelerated (for example, 0.1 V /
After decelerating in 40 msec steps) and the voltage of the speed servo motor becomes 1 V or less, or when the vehicle body 21 is stopped, the distance to the recess of the floor is not detected or the step on the floor is judged. Therefore, the malfunction of the emergency stop is also eliminated.

Although the ultrasonic sensor (ultrasonic distance measuring sensor) 10a is used as the detecting means in the above embodiment, the invention is not limited to this, and a reflective optical sensor may be used, for example. In this case, since light is used, there is an advantage that it is not affected by various noises.

[0027]

As described above, according to the first aspect of the method for controlling a traveling vehicle of the present invention, when the traveling speed of the vehicle body is less than or equal to a predetermined value, the step of the traveling floor surface is not judged. Therefore, there is an effect that erroneous operation of the emergency stop for preventing the vehicle body from falling or falling can be eliminated, and the reliability of traveling can be improved.

According to the second aspect of the present invention, when the traveling speed of the vehicle body is less than or equal to a predetermined value, the floor surface is not detected and the vehicle body is not stopped. In addition, the detection process and the determination process can be omitted, and the control can be simplified.

According to the third aspect of the present invention, the distance to the running floor of the vehicle body is detected every predetermined distance movement or every fixed time and continuously twice. Therefore, there is an effect that the malfunction of the emergency stop for preventing the fall can be surely eliminated, and the reliability of traveling can be further improved.

According to a fourth aspect of the present invention, an ultrasonic sensor or a reflection type photoelectric sensor is used as the detecting means of the first to third aspects.
In addition to the effects described above, there is an advantage that the reflection type photoelectric sensor is not affected by noise.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a control device to which a traveling vehicle control method is applied according to an embodiment of the present invention.

FIG. 2 is a schematic side view of the traveling vehicle of the present invention.

FIG. 3 is a schematic side view of a conventional traveling vehicle.

[Explanation of symbols]

 10 Ultrasonic Sensor Section 10a Ultrasonic Sensor (Detecting Means) 11 Sub Control Section 12, 13 Drive Motor 14, 15 Rotary Encoder 18 Main Control Section 19 Drive Wheel Control Circuit 21 Car Body (of Running Vehicle)

Claims (4)

[Claims] 1. A detection means provided at least on a bottom surface of a front part of a vehicle body detects a distance to a running floor surface, determines a step on the floor surface based on the detected distance, and enables the vehicle body to be stopped. A method for controlling a running vehicle, wherein the running speed of the vehicle body is less than or equal to a predetermined value, the step of the floor surface is not determined, and the vehicle body is not stopped. Method. 2. A detection means provided on at least a front bottom surface of a vehicle body detects a distance to a running floor surface, a step on the floor surface is determined based on the detected distance, and the vehicle body can be stopped. A method of controlling a traveling vehicle, wherein when the traveling speed of the vehicle body is a predetermined value or less, the floor surface is not detected,
A method of controlling a traveling vehicle, characterized in that the vehicle body is not stopped. 3. The method of controlling a traveling vehicle according to claim 1, wherein the traveling floor surface is detected every time the vehicle body moves a predetermined distance or every predetermined time, and continuously twice. 4. The method for controlling a traveling vehicle according to claim 1, wherein the detection means is an ultrasonic sensor or a reflective photoelectric sensor.