JP2577095Y2 - Body guidance system for automatic guided vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle guidance system for an automatic guided vehicle or the like moving on a traveling course having an autonomous guidance section and a guidance band detection section.

[0002]

2. Description of the Related Art A conventional vehicle guidance apparatus for an automatic guided vehicle or the like uses a rolling distance detecting sensor (hereinafter referred to as a rolling sensor) for left and right driven wheels, and detects the left and right wheel rotation amounts detected by the rolling sensor. Based on the data,
The traveling amount of the vehicle body is calculated as a coordinate value, and the coordinate value is compared with the traveling course data stored in advance, and steering and driving wheels are steered and controlled so that the vehicle body is guided on the traveling course. A so-called autonomous guidance method is often employed. However, in the case of this guidance device, 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. 7, in addition to the autonomous guidance section A, a part of the traveling course 2 is formed of an electromagnetic induction band, an optical reflection tape, a magnetic tape, or the like. There is known a system provided with a guide band detection section B in which a guide band 3 is provided. In this system, in addition to the rolling sensor and the steering and driving wheel, the vehicle body 1 is provided with an induction band detection sensor for detecting the induction band 3. An error generated during the running is reset, and the running is controlled so as to correct a deviation between the vehicle body 1 and the running course 2 caused by the error.

[0004] Even in such a guidance traveling system, in an environment where the road surface condition is poor, if the autonomous guidance section is lengthened, accurate guidance traveling may be difficult. In view of this, the present applicant has previously proposed a system in which a camera is provided on a vehicle body and a mark is provided in the front of the traveling course in the traveling direction, whereby the autonomous guidance section can be lengthened. That is, in this system, as shown in FIG. 8, a guide band 3 is installed at a predetermined position on the traveling course 2 and a mark 7 indicating the center of the traveling course 2 is provided ahead of the traveling course 2 in the traveling direction of the vehicle body 1.
Is installed. In addition to the rolling sensor, the steering and driving wheel, and the guidance band detection sensor, the vehicle 1 is provided with a camera 9 for displaying the front of the vehicle body 1. According to this system configuration, the mark 9 is imaged by the camera 9 and image processing is performed, whereby a deviation of the vehicle body is obtained,
Orbit correction can be performed.

[0005]

However, in the system proposed by the present applicant, since the mark 7 is a vertically long straight line, there is a problem that even a slight movement of the vehicle body deviates from the field of view of the camera. is there. In other words, it is difficult for the camera to detect a mark in front of the traveling course when the vehicle is deviated from the center of the traveling course during traveling in the autonomous guidance section or when the road surface condition of the traveling course is poor. Furthermore, when the distance between the car body and the mark is long or short, trying to capture the mark in the camera's field of view,
When the distance is long, the size of the mark image becomes small, and there is a problem that it is difficult to distinguish the noise (an object other than the mark) from the mark on the image.

The present invention solves the above-mentioned problem by making the mark indicating the center of the traveling course difficult to deviate from the field of view of the camera by forming a V-shaped mark. Find the deviation,
By controlling the steering of the vehicle body, the position of the vehicle body does not greatly deviate from the traveling course even in the autonomous guidance section, and the installation interval of the guidance band can be expanded even in an environment with bad road conditions, and the effect of autonomous guidance Can be fully demonstrated. An object of the present invention is to provide a body guidance device for an automatic guided vehicle or the like.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a guide band detecting sensor provided on a part of a traveling course for detecting a guide band, and detecting a rotation amount of each of right and left wheels. Rolling distance detection sensor, comprising a control unit for controlling the steering traveling of the vehicle body, the control unit, when the guidance band is not detected by the guidance band detection sensor,
Assuming that the vehicle body is in the autonomous guidance section, the vehicle body position is calculated from the respective rotation amounts of the left and right wheels detected by the rolling distance detection sensor and the left and right wheel rotation amounts having in advance,
When the guidance band is detected by the guidance band detection sensor, it is determined that the vehicle body is in the guidance band detection section, and a deviation of the vehicle body position is obtained based on a detection signal of the sensor and the vehicle body position calculation value. In a vehicle guidance apparatus for an automatic guided vehicle that performs steering traveling so as to correct, a camera that captures a V-shaped mark indicating the center of the traveling course provided in front of the traveling course excluding the road surface, and an image captured by the camera And an image processing unit that processes the edge portion from the plurality of coordinate data of the edge portion of the image captured by the camera at least while the vehicle body is traveling in the autonomous guidance section. The average value of the slope of the straight line is obtained by using the least square method, and the control unit compares the slope of the straight line of the edge with the slope obtained in the above, and the difference approaches zero. And performs steering control such.

[0008]

According to the above arrangement, the mark in front of the traveling course, which is not on the road surface, is formed in a V-shape and has a lateral width, so that even if the vehicle body is displaced from the course, the mark is hardly displaced from the camera field of view. Further, the vehicle body in the autonomous guidance section calculates the vehicle body position based on the deviation between the left and right wheel rotation amounts detected by the rolling distance detection sensor and the left and right wheel rotation amounts that have been set in advance, and calculates the deviation (lateral displacement or attitude angle). Is close to zero, the V-shaped mark imaged by the camera is image-processed as a plurality of (x, y) coordinates on the x and y axes by the image processing unit. In this image processing, the inclination of the straight line at the edge of the mark is obtained from a plurality of (x, y) coordinates.
The control unit performs steering control of the vehicle body such that the inclination is equal to the inclination of the straight line at the edge of the mark when the mark is at the center.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of the present guiding device. FIG.
(A) and (b) show an example of a schematic configuration of an automatic guided vehicle (hereinafter, referred to as a vehicle body 1). In these drawings, a traveling course 2 on which a vehicle body 1 travels is determined in advance, and a guide zone 3 is provided at a predetermined position on the road surface of the traveling course 2. A V-shaped mark 10 indicating the center of the traveling course 2 is provided in front of the traveling course 2 in the traveling direction. A section B on the traveling course 2 where the guide zone 3 is located is a guide zone detection section, and a section A without a guide zone is an autonomous guide detection section.

As shown in FIGS. 2 (a) and 2 (b), the vehicle body 1 has left and right driven wheels 8L and 8R formed on the lower surface thereof in a pair outward and rearward in the advancing direction, and a pair on the inner side. The left and right driven wheels are provided with rolling distance detection sensors (hereinafter, referred to as rolling sensors) 4L and 4R, and further, an induction band detection sensor 6 is provided inside. A steering / drive wheel 5 is provided substantially at the center in front of the lower surface of the vehicle body 1. On the upper surface of the vehicle body 1, a camera 9 is provided substantially at the front center. In the present embodiment, the camera 9 uses a motor-driven zoom lens (not shown), and controls the focal length of the lens so that the line width of the mark 10 is always imaged at an appropriate size. With this configuration, it is also possible to determine whether the mark 10 is noise or not.
The reliability of the detection of the mark 10 can be improved.

Next, a configuration for steering control of the vehicle body 1 will be described with reference to FIG. Rolling sensors 4L and 4R are provided in a vehicle guidance control device (hereinafter, referred to as a control device) 11.
, A detection signal from the guidance band detection sensor 6 is input, and further, a signal captured by the camera 9 is subjected to signal processing by the image processing unit 13, and this signal is input. The control device 11 receives these signals, performs predetermined arithmetic processing, and outputs a predetermined drive signal to the steering device 12.

That is, the control device 11 determines the presence or absence of the derivative 3 based on the signal from the guidance band detection sensor 6.
When the guidance zone 3 is not detected, the vehicle body 1 is located in the autonomous guidance section A, and the vehicle body 1 is compared with the detected amounts of the left and right wheels having the respective rotation amounts of the left and right wheels detected by the rolling sensors 4L and 4R. The deviation of the position is obtained, and the vehicle performs autonomous guidance steering. When the position of the vehicle body 1 is in the guidance band detection section B and the guidance band 3 is detected, the steering traveling is corrected based on the detection signal so as to reduce the deviation (lateral displacement or posture angle).

On the other hand, an image of the front of the vehicle body 1 is taken by the camera 9. The mark 10 provided on the traveling course 2 at a predetermined position in front of the vehicle body 1 in the traveling direction is V-shaped and has a horizontal width, and since the zoom lens of the camera 9 is motor-driven controlled, the mark 10 is always constant. Since the image is captured with the line width, the mark 10 is less likely to be out of the field of view of the camera 9. The control using the data captured by the camera 9 may be performed at least while the vehicle body is traveling in the autonomous guidance section A.

The image processing of the mark 10 picked up by the camera 9 will be described with reference to FIG. Now, it is assumed that the mark 10 is imaged in the screen 13a imaged by the camera 9 as shown in FIG. The mark 10 is image-processed to (x, y) coordinates, and the straight line of the edge 14 of the mark 10 is formed by N dots d.
It is represented by a plurality of coordinates (x, y) of the dots d.
Therefore, the average value of the inclination of the straight line of the edge portion can be obtained from the plurality of (x, y) coordinates of the edge portion of the image-processed mark 10 by the following least square method.

(Equation 1)

Since the deviation of the vehicle body from the center of the traveling course can be obtained from the average value of the inclination, the control device 11 calculates the deviation as the mark 1 when the mark 10 is at the center.
A steering control signal is output to the steering device 12 so as to be equal to the inclination of the straight line at the edge portion of 0. That is, the control device 11 outputs a signal to the steering device 12 so as to minimize the sum of the squares of the inclination of the straight line obtained by the above equation and the inclination of the straight line when the mark 10 is at the reference position.

The control device 11 stores coordinate data serving as a reference for the mark 10 in advance, and sequentially receives reference data based on signals from the sensors 4 L, 4 R, 6 and the camera 9. The position of the vehicle body on the coordinate axis is calculated and obtained.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. The control device 11 detects the amount of rotation of the left and right wheels by the rolling sensors 4L and 4R (step # 1), compares the detected data with data previously held in the control device 11 (# 2), and calculates the vehicle body position. (# 3).

Next, the controller 11 controls the guidance band detection sensor 6
The presence or absence of the guide band 3 is determined based on the signal of the vehicle 1 and it is determined whether the vehicle body 1 is in the autonomous guide section A or the guide band detection section B of the traveling course 2 (# 4). Here, the guidance zone detection section B
When the control device 11 corrects the calculated vehicle body position value to the position where the guidance band 3 is located (# 5), the control device 11 outputs a signal (steering output) for correcting the deviation between the vehicle body position and the position where the guidance band 3 is located. It sends to the steering device 12 (# 6), returns to # 1, and repeats the same operation thereafter. 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 B in step # 4, that is, when the vehicle body is in the autonomous guidance section A, the camera 9 disposed on the vehicle body takes an image of the mark 10,
The imaging signal is sent to the image processing unit 13 (# 7). In the image processing unit 13, the image is formed by dividing the edge 14 into a plurality of dots d on the x and y axes.
Image processing (# 8). The inclination of the straight line of the edge 14 is calculated based on the coordinates of the dot d (# 9). And
The controller 11 compares the inclination of the straight line of the edge 14 with the inclination obtained in advance (# 10), sends a signal for correcting the deviation to the steering device 12 (# 6), and thereafter returns to # 1. The same operation is repeated.

The present invention is not limited to the configuration of the above embodiment. As shown in FIG. 6, the camera 9 is controlled so that the road surface angle with the camera 9 can be changed by motor drive control. When approaching the upper guide zone 3, the camera 9 is tilted from a horizontal state to an angle at which the derivative 3 on the road surface can be imaged, and the camera 9 detects the guide zone 3 to correct the vehicle body position detection error in autonomous guidance. It may be performed. In this case, the camera 9 also has the role of the guidance band detection sensor 6 used in the above embodiment.

In this case, the induction band 3 is the aforementioned electromagnetic induction band,
The object may not be made of an optical reflection tape, a magnetic tape, or the like, and may be any object having a predetermined shape that can be easily identified by the camera 9. Note that the camera 9 is a rolling sensor 4
When a certain amount of rotation of the wheel is detected by L and 4R, the control device 11 may output a motor drive control signal of the camera 9 so that the road surface is controlled. According to this example, the guide band detection sensor 6 can be omitted, and the mark detection and the guide band detection on the road surface can be performed by one camera, so that an inexpensive configuration can be achieved.

Further, the control device 11 may correct the deviation given to the steering and driving wheels 5 based on the fuzzy inference rules by using the calculation data based on the above-mentioned least square method. By applying this fuzzy inference to vehicle body control, it is possible to express situation judgments and operating devices with "fuzzy quantities" rather than strict numerical information, and it is also easy to add other control functions, and to design more flexibly. Property is obtained.

[0023]

As described above, according to the present invention, since the mark indicating the center of the traveling course at a predetermined position of the traveling course is formed in a V-shape, the mark is not affected by the lateral displacement (or posture angle) of the vehicle body. The mark can be reliably detected without deviating from the field of view of the camera. Further, the inclination of the edge of the V-shaped mark is obtained by image processing, and a correction value for vehicle body control is obtained based on this by calculation. As a result, accurate guidance driving control can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle guidance apparatus according to an embodiment of the present invention.

FIG. 2 shows a configuration of an automatic guided vehicle according to the present embodiment,
(A) is a plan view and (b) is a side view.

FIG. 3 is a block diagram of a control unit according to the embodiment.

FIG. 4 is a diagram illustrating a mark captured by a camera in the present embodiment, and particularly illustrating image processing.

FIG. 5 is a flowchart showing an operation of the vehicle guidance apparatus according to the embodiment.

FIG. 6 is a diagram illustrating a camera operation of the automatic guided vehicle according to a modified example of the present invention.

FIG. 7 is a schematic configuration diagram of a conventional vehicle body guidance device.

FIG. 8 is a schematic configuration diagram of a vehicle body control device for an automatic guided vehicle or the like as a premise of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Unmanned guided vehicle 2 Running course 3 Guide band 4L, 4R Left and right driven wheel rolling distance detecting sensor 6 Guide band detecting sensor 9 Camera 10 Mark 11 Body guidance control device 12 Steering device 13 Image processing unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-229311 (JP, A) JP-A-62-285115 (JP, A) JP-A-55-47508 (JP, A) JP-A-2- 81105 (JP, A) JP-A-4-175802 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05D 1/02

Claims (1)

(57) [Scope of request for utility model registration] 1. A guide band provided on a part of a traveling course.
Guidance band detection sensors to detect
Rolling distance detection sensor that detects the amount of rolling and steering of the vehicle
A control unit for controlling traveling, wherein the control unit controls the guidance by the guidance band detection sensor.
If no belt is detected, it is assumed that the vehicle is in the autonomous guidance section.
To the left detected by the rolling distance detection sensor.
The amount of rotation of each right wheel and the amount of left and right wheel rotation previously stored
The vehicle position is calculated from the
When the guidance band is detected, the vehicle body moves to the guidance band detection section.
Assuming that there is, the detection signal of the sensor and the vehicle position calculated value
And calculate the deviation of the vehicle body position based on
In a vehicle guidance apparatus for an automatic guided vehicle that performs steering traveling in a manner as described above, a camera that captures a V-shaped mark that indicates the center of the traveling course provided in front of the traveling course excluding the road surface and processes the image captured by the camera An image processing unit to be provided in the vehicle body, the image processing unit comprising:
While traveling, the inclination of the straight line of the edge portion from the plurality of coordinate data of the edge portion of the image captured by the camera
The control unit compares the inclination of the straight line of the edge with the inclination obtained in advance with the inclination obtained as described above, and controls the steering control so that the difference approaches zero. Body guidance device for an automatic guided vehicle, characterized by performing: