JP2847673B2 - Body guidance method for automatic guided vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for guiding a vehicle body of an automatic guided vehicle or the like by autonomous guidance and guidance band detection.

[Prior Art] In a conventional vehicle guidance method for an automatic guided vehicle or the like, a so-called autonomous guidance that calculates a vehicle body position by detecting a rolling distance between left and right wheels and guides the vehicle body on a traveling course is employed as the guidance method. However, in the case of this guidance method, there is a possibility that the deviation between the vehicle body position and the traveling course becomes large due to accumulation of errors included in the calculation result.

In order to prevent such a deviation from occurring, as shown in FIG. 6, an induction band 3 such as an electromagnetic induction band, an optical reflection tape, or a magnetic tape is provided on a part of the traveling course 2 of the vehicle body 1. It is arranged in the upper part and detects the guide band 3 by the guide band detection sensor 9 provided on the vehicle body 1 side.
The position of the vehicle body is obtained, the error included in the calculated value during the autonomous guidance section up to that time is reset, and the deviation between the vehicle body 1 and the traveling course 2 due to the error is corrected. In addition, in FIG. 6, A is an autonomous guidance section,
B indicates a guidance band detection section.

[Problems to be Solved by the Invention] However, in the above vehicle body guidance method, when the vehicle body reaches the guidance band detection section, the vehicle body must be within a range where the guidance band can be detected, and unevenness of the road surface is present. In an environment where the vehicle body position detection accuracy in the autonomous guidance section is deteriorated due to reasons such as doing so, the autonomous guidance section, which is the installation interval of the guidance band, can not be lengthened, and it is necessary to provide many guidance band detection sections, which is expensive. There was a problem that it became a system.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and calculates a vehicle body position based on a shift amount of a mark position on an image detected by a camera installed on a vehicle in a autonomous guidance section. Corrects the deviation between the vehicle body and the running course obtained from the value and guides the vehicle body onto the running course.There is no large deviation from the running course even in sections without guidance zones, and the road surface condition is poor It is an object of the present invention to provide a vehicle guidance method in which a guidance band installation interval can be widened even in an environment and the effect of autonomous guidance can be sufficiently exhibited.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a guide band detection section for detecting a guide band installed at intervals on a planned traveling course, and an autonomous guide zone at the installation interval of the guide band. There is an autonomous guidance section that runs by guidance.In the autonomous guidance section, the vehicle position is calculated by the data of the planned traveling course stored in the vehicle body and the rolling distance detection sensor of the left and right wheels, and in the guidance band detection section, A vehicle body guidance method for an automatic guided vehicle or the like that performs correction of the vehicle body position calculation value obtained as described above, obtains a deviation between the vehicle body and a scheduled traveling course from the vehicle body position calculation value, and performs steering control so that the deviation approaches zero. In, a mark indicating the center of the traveling course is provided in front of the scheduled traveling course, a camera for detecting the mark is provided on the vehicle body, and after correcting the vehicle body position calculation value in the guidance band detection section, If the position of the mark detected by the camera on the image is shifted to the left or right, the shift is attributed to the lateral displacement of the deviation (lateral displacement and attitude angle) between the vehicle body and the planned traveling course, A correction amount for correcting the lateral displacement of the deviation is obtained based on the deviation amount, and the steering is performed based on the correction amount.

Further, according to the second aspect of the present invention, in the above, the left and right positional deviation on the image is not based on the lateral displacement, but on the basis of the amount of the deviation based on the attitude angle. Find the amount of correction to correct the attitude angle of
The steering is performed based on this.

[Operation] According to the above method, when the vehicle body is in the autonomous guidance section, the vehicle body position is calculated from the detected rolling distance of the left and right driven wheels and the like,
When the guidance zone is detected in the guidance zone detection section, the vehicle body position calculation value obtained in the autonomous guidance section is corrected, and in the subsequent autonomous guidance section, the deviation between the vehicle body and the traveling course obtained from the body position calculation value described above. (Lateral displacement and attitude angle), and a camera installed on the vehicle body detects a mark installed in front of the traveling course so as to indicate the center of the course. The amount of positional deviation of the mark detected by the camera on the image is represented by a lateral displacement or a deviation of the attitude angle, and any correction amount is obtained. It is guided to.

Hereinafter, an embodiment of the vehicle body guidance method according to the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration example of a vehicle guidance system according to the present embodiment. A traveling course 2 on which the automatic guided vehicle 1 (hereinafter, referred to as a vehicle body 1) travels is predetermined, and a guide zone 3 is provided on a part of the road surface of the traveling course 2. A mark 4 indicating the center of the traveling course 2 is provided in front of the traveling course 2, and a camera 5 for detecting the mark 4 is provided on the vehicle body 1.

2A and 2B show an example of a schematic configuration of the vehicle body 1. FIG. The vehicle body 1 includes, in addition to the camera 5, left and right driven wheels 6
L, 6R, a steering and driving wheel 7, rolling distance detection sensors 8L, 8R for driven wheels 6L, 6R, and an induction band detection sensor 9.

FIG. 3 shows a block configuration provided in the vehicle body 1 for vehicle body position detection and guidance control.

The vehicle body guidance control device 10 receives the detection signals from the left and right driven wheel rolling distance detection sensors 8L and 8R and the detection signal from the guidance band detection sensor 9 and calculates and corrects the vehicle body position. 2 and a signal for reducing the deviation is output to the steering device 12. When the vehicle body is in the autonomous guidance section, if it is determined that the deviation (lateral displacement and attitude angle) between the vehicle body 1 and the traveling course 2 obtained from the vehicle body position calculation value is close to zero, the vehicle is installed on the vehicle. The camera 5 detects the mark position. The vehicle body guidance control device 10 inputs the detection signal of the mark position via the image processing device 11, and calculates the deviation (horizontal width) between the vehicle body 1 and the traveling course 2 calculated at that time based on the amount of lateral deviation between the vehicle center axis and the mark. (Displacement or attitude angle).

The data of the traveling course on the reference coordinate axis is stored in the vehicle guidance control device 10 in advance, and the vehicle guidance control device 10 is configured based on the input signals from the sensors 8L, 8R, and 9, The position of the vehicle body on the reference coordinate axis is sequentially calculated and obtained.

FIG. 4 shows the position of the mark detected by the camera on the image 13, and the shift L of the mark 4a on the image 13 is shown in FIG.
Is caused by the lateral displacement 1 and the attitude angle ψ. In this embodiment, it is assumed that the deviation L is caused by either the lateral displacement 1 or the attitude angle ψ, and the deviation is corrected based on the following fuzzy inference rules. That is, when the mark on the image is slightly shifted to the [+ side] with respect to the center of the vehicle body, the lateral displacement (or the posture angle) is slightly corrected to the [+ side].

When the mark on the image is greatly shifted to the [+ side] with respect to the center of the vehicle, set the lateral displacement (or attitude angle)
Make a big correction.

The same applies to [-side].

If the mark on the straight line is not displaced from the center of the vehicle body, the lateral displacement and attitude angle are not corrected.

In this way, by applying fuzzy inference to control, the situation judgment and operation method can be represented by “fuzzy quantities” instead of strict numerical information, and it is also easy to add other control functions, Flexibility.

FIG. 5 shows a flowchart of the operation of the method. Hereinafter, the operation will be described with reference to the above-mentioned drawings. The vehicle guidance control device 10 detects the rolling distance of the left and right wheels based on the signals from the rolling distance detection sensors 8L and 8R (step #).
1), the vehicle position is calculated based on the detected value (# 2).

Next, based on the calculated vehicle body position, it is checked whether or not the vehicle body 1 is in the guidance zone detection section (# 3). When the guidance band 3 is detected by the sensor 9 (# 4), the vehicle body guidance control device 10 corrects the vehicle body position calculation value (# 5),
The deviations l and の between the vehicle body 1 and the traveling course 2 are calculated (# 6), a signal (steering output) for correcting the deviation is sent to the steering device 12 (# 7), and the process returns to # 1. repeat. Thereby, the vehicle body 1 is guided onto the traveling course 2.

When the vehicle body 1 is not in the guidance zone detection section in the above # 3, that is, when the vehicle body is in the autonomous guidance section, the body guidance control device 10 determines the deviation l,. Is calculated (# 8), and it is determined whether or not the deviations l and ψ are close to zero (# 9). This deviation l, ψ
Is a value close to zero, the amount of deviation of the position of the mark 4 detected by the camera 5 mounted on the vehicle body on the image to the left and right is detected (# 10). The vehicle guidance control device 10
The correction amount Δl or Δψ of the deviation is determined based on the deviation amount (# 11), the correction of the deviations l and ψ is performed (# 12), the process proceeds to # 7, and the same operation is repeated thereafter. If the deviations l and ψ are not close to zero in step # 9, the process proceeds to step # 7, and the same operation is repeated.

It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and may be control other than control using fuzzy inference.
Further, it is also possible to add another control function, for example, a function of changing the correction amount according to the traveling speed or the change speed of the deviation amount. Further, in the above embodiment, the correction of the lateral displacement or the correction of the attitude angle is described, but both may be used in combination.

In addition, the mark 4 may be a cylindrical mark, and may be provided in front of the straight course at each corner where the running course 1 changes from straight running to turning.

[Effects of the Invention] As described above, according to the present invention, the mark on the front of the traveling course is detected by the camera on the vehicle, and the deviation calculation value between the vehicle body and the traveling course is corrected based on the detected value. Even in an autonomous guidance section without a guidance zone, there is no significant deviation from the running course, and even in an environment with poor road surface conditions, the installation intervals of the guidance zone can be widened and the effect of autonomous guidance can be exhibited. In addition, labor saving in the construction of the guide band can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle body guidance method according to an embodiment of the present invention,
2 is a schematic diagram of a configuration for detecting a vehicle body position, FIG. 3 is a functional block diagram for detecting a vehicle body position, FIG. 4 is a diagram showing a position of a mark detected by a camera on an image,
FIG. 5 is a flowchart of the operation of the present method, and FIG. 6 is a schematic explanatory view of a conventional vehicle guidance method. 3: Guidance band, 4: Mark, 5: Camera, 6L, 6R ...
… Driven wheels, 7… steering and driving wheels, 8L, 8R… wheels rolling distance detection sensor, 9… induction band detection sensor,
10 ... body guidance control device, 11 ... image processing device, 12 ...
Steering gear.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G05D 1/02

Claims (2)

(57) [Claims] 1. A guide zone detection section for detecting a guide zone set at an interval on a scheduled traveling course and an autonomous guide section for traveling by an autonomous guide at an installation interval of the guide zone. The vehicle position is calculated by the data of the planned traveling course stored in the vehicle in advance and the rolling distance detection sensor of the left and right wheels, and in the guidance zone detection section, the calculated vehicle position calculated value is corrected, A deviation between the vehicle body and the planned traveling course is calculated based on the calculated vehicle body position, and a mark indicating the center of the traveling course is provided in front of the planned traveling course in a vehicle guidance method for an automatic guided vehicle that performs steering control so that the deviation approaches zero. A camera for detecting the mark is provided on the vehicle body, and after correcting the vehicle body position calculation value in the guidance band detection section,
If the position of the mark detected by the camera on the image is shifted to the left or right, the shift is attributed to the lateral displacement of the deviation (lateral displacement and attitude angle) between the vehicle body and the planned traveling course, A vehicle guidance method for an automatic guided vehicle or the like, wherein a correction amount for correcting a lateral displacement of a deviation is obtained based on the deviation amount, and steering is performed based on the correction amount. 2. The method according to claim 1, wherein the lateral displacement of the mark on the image is caused by lateral displacement.
A vehicle body guidance method for an automatic guided vehicle or the like, wherein a correction amount for correcting a deviation posture angle is determined based on the deviation amount as being caused by the posture angle, and steering is performed based on the correction amount.