JPH04257006A - Course out detecting method for unmanned vehicle - Google Patents

Abstract

PURPOSE:To obtain the course out detecting method of an unmanned vehicle which can hold the detecting sensitivity and precision of a course out to be constant by any operation, and perform a smooth operation. CONSTITUTION:A course out detector C is provided at an unmanned carrier M traveling along a guide line L. Then, a reference value Vk by timely operational information is selected by a reference value setting circuit 8 of the pertinent device C, and the presence or absence of the course out is decided by comparing the reference value Vk with a detected value VS detected from a detector 50 of the pertinent device C by a comparator 9.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention relates to unmanned vehicles such as automatic guided vehicles and unmanned forklifts, and more specifically to a course-out detection method for detecting whether an unmanned vehicle is running off a guide line.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 3, an automatic guided vehicle system is configured to run an automatic guided vehicle M along a guiding line L while detecting a guiding signal output from a guiding line L laid on the road surface. There is. This automatic guided vehicle M is provided with a course-out detection device so that the automatic guided vehicle M does not deviate from the travel path determined by the guide line L (does not go off-course) when traveling. This course-out detection device is provided with a detector 50 for detecting a guidance signal output from the guidance line L, located at the center position in the width direction of the vehicle and in front of the fixed wheels 52 (on the traveling direction side). The detector 50 always detects the guide line L from the center position of the vehicle.

The detection value VS of the detection signal in the detector 50 that detects the guide line L indicates that the guide line L is detected directly below the detector 50 (that is, the guide line L passes through the center of the vehicle). ), it reaches a maximum as shown in FIG. 4, and decreases as the distance increases. Then, the course out detection device sets a preset value of 1 to the detection value VS of the detector 50.
The detected value VS is compared with two reference values VK, and the detected value VS is the reference value VK.
When it is smaller, it is determined that the automatic guided vehicle M has gone off course. Therefore, the detection sensitivity and accuracy are determined by the value of the reference value VK.

The setting of this reference value VK is determined by the relative position of the detector 50 and the guide line L when the vehicle is traveling on a curve. That is, Figure 3
When the vehicle travels around a curve as shown in FIG. 1, the turning angle of the steering wheels 51 is kept constant in order to travel smoothly, so the detector 50 shifts to the outside of the guide line L when the vehicle travels. and,
Since running on this curve is not judged as being off course, it is necessary to set at least the reference value VK to a value smaller than the detection value VS detected by the detector 50 when running on this curve.

[0005]

[Problem to be Solved by the Invention] Therefore, as mentioned above, the reference value VK is set to a low value assuming curved driving, so when driving in a straight line at high speed or in a narrow passageway, It was not possible to obtain the necessary detection sensitivity and accuracy. On the other hand, if the reference value VK is increased more than necessary, the vehicle will be judged to have gone off course even though it is normally traveling on a curve, and smooth travel will no longer be possible.

The present invention has been made to solve the above-mentioned problems, and its purpose is to be able to maintain constant sensitivity and accuracy in detecting out-of-course conditions during any operation;
An object of the present invention is to provide a method for detecting off-course in an unmanned vehicle that allows smooth operation.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a course-out detection means for detecting the relative position of an unmanned vehicle traveling along a guide line formed on a running road surface with respect to the guide line. In a course-out detection method for an unmanned vehicle, the presence or absence of a course-out is determined by comparing the detection signal from the course-out detection means with a preset reference value. The gist of the present invention is a method for detecting off-course in an unmanned vehicle, which is changed based on operation information and compares the reference value with a detection signal to determine whether or not the off-course has occurred.

[0008]

[Operation] Therefore, for example, when the operation information indicates that the vehicle is traveling on a curve, by lowering the reference value, it is possible to judge whether or not the vehicle is off course, which is suitable for traveling on the curve, even if the vehicle is separated from the guide line. Furthermore, when the operation information indicates high-speed straight-line travel, by setting the value higher than the reference value used for curve travel, it is possible to determine whether or not the vehicle has gone off-course with detection sensitivity and accuracy suitable for high-speed straight-line travel.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a course-out detection device provided in an automatic guided vehicle will be described below with reference to FIGS. 1 and 2. Incidentally, since this embodiment is embodied in the automatic guided vehicle M shown in FIG. 3, only the off-course detection device will be described for convenience of explanation. FIG. 1 is a block diagram showing the electrical configuration of a control device mounted on an automatic guided vehicle M,
The operation controller 1 includes a storage device, and a predetermined control program is stored in the storage device. Then, the operation controller 1 controls the movement of the automatic guided vehicle M based on the control program. Further, a mark plate sensor 3 is connected to this operation controller 1. The mark plate sensor 3 detects arrangement patterns 4a and 4b made of iron plates or the like arranged on the road surface, and outputs the detection signal to the operation controller 1.

[0010]The operation controller 1 then recognizes the arrangement patterns 4a and 4b based on the detection signal, and determines what the operation information (curve driving, low speed driving, high speed driving, etc.) is for the layout patterns 4a and 4b. to judge. Then, the operation controller 1 controls the steering wheel 51 based on the detection signal from the pickup coil 2 and the operation information.
A control signal for controlling the steering angle and rotation speed of the vehicle is output to the travel controller 5.

A steering motor 6 for controlling the steering angle of the steered wheels 51, a running motor 7 for controlling the rotational drive of the steered wheels 51, and a pickup coil 2 are connected to the running controller 5. The pickup coil 2 detects the guide wire L and guides the automatic guided vehicle M to the guide wire L.
A detection signal for driving the vehicle along the route is output to the operation controller 1. The travel controller 5 drives and controls the steering motor 6 and the travel motor 7 based on control signals from the pickup coil 2 and the travel controller 1. Therefore, the automatic guided vehicle M travels along the travel route according to the operation information (curve travel, low speed travel, high speed travel, etc.) based on the arrangement patterns 4a and 4b at each time.

The operation controller 1 is connected to a course-out detection device C. This course-out detection device C includes a reference value setting circuit 8, a comparator 9, and a detector 50 provided on the bottom surface of the automatic guided vehicle M shown in FIG. The reference value setting circuit 8 is connected to the operation controller 1, and receives operation information determined by the operation controller 1. Based on the operation information, the reference value setting circuit 8 sets various reference values VK and outputs the reference values VK to the comparator 9.

In this embodiment, two types of reference values VK1 and VK2 (<VK1) are prepared for the reference value VK. When the operation information indicates high-speed driving, the reference value setting circuit 8 selects the larger reference value VK1 and outputs it to the comparator 9. Further, when the operation information is curve driving and low speed driving, the reference value setting circuit 8 selects the smaller reference value VK2 and outputs it to the comparator 9.

The comparator 9 is connected to the reference value setting circuit 8 and the detector 50, receives the reference value VK (VK1 or VK2) from the reference value setting circuit 8, and receives the detected value from the detector 50. Enter VS. Then, when the detected value VS is smaller than the reference value VK, the comparator 9 determines that the automatic guided vehicle M has gone off course, and the determination signal (
A course out signal) is output to the operation controller 1 and forced stop circuit 10. The operation controller 1 receives a course-out signal from the comparator 9, and outputs a control signal for stopping the steered wheels 51 to the travel controller 5 based on the course-out signal.

The forced stop circuit 10 is connected to a brake driving means 11, and outputs a brake activation signal to the brake driving means 11 based on the course-out signal. The brake driving means 11 is mechanically connected to a brake 12 disposed on a steered wheel 51, and operates the brake 12 based on a brake activation signal. Next, an automatic guided vehicle M equipped with a course-out detection device having the above configuration
The effect of this will be explained. For convenience of explanation, a case will be described in which the automatic guided vehicle M is driven in the direction of the arrow in FIG. 3.

Now, when the mark plate sensor 3 detects the first arrangement pattern 4a, the operation controller 1 recognizes the arrangement pattern 4a based on the detection signal,
It is determined that the operation information (in this case, high-speed travel) is for the arrangement pattern 4a. The operation controller 1 then drives the travel motor 7 via the travel controller 5 to cause the automatic guided vehicle M to travel at high speed.

On the other hand, at the same time, the operation controller 1 outputs high-speed operation information to the reference value setting circuit 8. The reference value setting circuit 8 selects the reference value VK1 from the reference values VK1 and VK2 based on the high-speed driving information and outputs it to the comparator 9. Therefore, during high-speed running, the comparator 9 compares this reference value VK1 with the detected value VS from the detector 50, as shown in FIG. During this high-speed running, the detected value VS changes to the reference value V
When it becomes smaller than K1, the comparator 9 outputs a course-out signal, immediately stops the traveling motor 7, and also operates the brake 12 to stop the automatic guided vehicle M.

[0018] Eventually, the automatic guided vehicle M reaches the next arrangement pattern 4b, and when that arrangement pattern 4b is detected,
The operation controller 1 recognizes the arrangement pattern 4b and determines that it is the operation information for the arrangement pattern 4b (in this case, curve driving). Then, the operation controller 1 controls the driving motor 7 at a low speed via the driving controller 5, and fixes the steering motor 6 to a predetermined steering angle, thereby causing the automatic guided vehicle M to travel around a curve. At this time, when driving around a curve, the steering wheels 51
Drive with a constant turning angle. Therefore, the detector 50
is shifted to the outside of the guide line L, and the detected value VS of the detector 50 becomes relatively small as shown in FIG.

At the same time, the operation controller 1 outputs operation information for traveling on a curve to the reference value setting circuit 8. The reference value setting circuit 8 selects the reference value VK2 from the reference values VK1 and VK2 based on the operation information of the curve traveling and outputs it to the comparator 9. That is, the reference value VK is relative to the detection value VS of the detector 50, which inevitably decreases as the vehicle travels around a curve.
As shown in FIG. 2, the reference value VK1 for high-speed driving is
The smaller reference value VK2 is selected and output. Therefore, when the vehicle is running on a curve, the comparator 9 compares the reference value VK2 suitable for the curve with the detected value VS from the detector 50, as shown in FIG. Then, while traveling on this curve, the detected value VS is the reference value VK2
When it becomes smaller, the comparator 9 outputs a course-out signal to immediately stop the traveling motor 7 and activate the brake 12 to stop the automatic guided vehicle M.

When the curve travel is completed, the automatic guided vehicle M reaches the next arrangement pattern 4a, and the operation controller 1 recognizes the arrangement pattern 4a based on the detection signal and provides the operation information for the arrangement pattern 4a (this case,
High speed driving). And the same operation controller 1
controls the traveling motor 7 via the traveling controller 5 to cause the automatic guided vehicle M to travel at high speed. At this time, when the vehicle is traveling at high speed, the steered wheels 51 travel along the guide line L. Therefore, the detector 50 is located directly above the guide line L, and as shown in FIG.
becomes larger.

At the same time, the operation controller 1 outputs high-speed operation information to the reference value setting circuit 8. The reference value setting circuit 8 sets the reference value V based on the high-speed driving information.
A reference value VK1 having a large value is selected in place of K2 and outputted to the comparator 9. That is, the reference value VK is relative to the detection value VS of the detector 50, which inevitably increases with high-speed driving.
As shown in FIG.
The larger reference value VK1 is selected and output. Therefore, during high-speed running, the comparator 9 compares the reference value VK1 suitable for high-speed running with the detected value VS from the detector 50, as shown in FIG. During this high-speed running, when the detected value VS becomes smaller than the reference value VK1, the comparator 9 outputs a course out signal, immediately stops the running motor 7, and
The brake 12 is activated to stop the automatic guided vehicle M.

As described in detail above, according to the automatic guided vehicle M equipped with the off-course detection device of the present embodiment, the reference value VK was conventionally set to a low value assuming curve traveling, so Although it was not possible to obtain the detection sensitivity and accuracy required when driving in a straight line, in this embodiment, the reference value setting circuit 8 can select the reference values VK1 and VK2 for high-speed driving and curved driving, so it is possible to This gives you more leeway while driving, and eliminates incorrect decisions about going off course.

Furthermore, since the interval between the reference value VK and the detected value VS can be set narrower than before, it is possible to improve the sensitivity and accuracy of detecting off-course during each run. It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be configured as follows, for example, without departing from the spirit of the invention.

(1) In the above embodiment, the automatic guided vehicle M is used, but instead of this automatic guided vehicle M, various unmanned vehicles such as an unmanned forklift may be used. (2) In the above embodiment, the arrangement pattern of the mark plate was used as the operation information, but the operation information is not limited to this. For example, the steering angle of the steering wheel is detected and the steering angle is used as the operation information at the time. It may be used as information (curve driving, straight driving, etc.), or the traveling speed may be used as current operation information (curving driving, low speed driving, high speed driving, etc.). Of course, a combination of the steering angle and the traveling speed may be used as the operation information.

(3) Furthermore, in the above embodiment, the reference value VK
Although we have prepared two types, it is not limited to these.
A different number of reference values VK may be provided for each operation information.

[0026]

As described in detail above, according to the present invention, it is possible to maintain constant detection sensitivity and accuracy of off-course in any operation, and has an excellent effect that smooth operation can be carried out.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing the electrical configuration of a control device mounted on an automatic guided vehicle.

FIG. 2 is a diagram showing the relationship between detected values and reference values in the course out detection device.

FIG. 3 is a schematic configuration diagram of an unmanned transportation system.

FIG. 4 is a diagram showing the relationship between detected values and reference values in a conventional course-out detection device.

[Explanation of symbols]

C Course-out detection device M as a course-out detection means Automatic guided vehicle L as an unmanned vehicle Guide line VK Reference value VK1 Reference value VK2 Reference value VS Detection value

Claims (1)

[Claims] Claim 1: An unmanned vehicle that travels along a guide line formed on a road surface based on operation information is provided with course-out detection means for detecting its relative position with the guide line, and the off-course detection means detects A method for detecting off-course in an unmanned vehicle, wherein the presence or absence of off-course is determined by comparing a signal with a reference value set based on the operation information.