JPH0535884B2 - - Google Patents

Description

[Detailed Description of the Invention] Object of the Invention (Industrial Application Field) The present invention relates to an image-based control device for an unmanned vehicle, and more specifically, an imaging device in which an unmanned vehicle is provided with a travel line that indicates the travel route of the unmanned vehicle. This invention relates to a control device that causes an unmanned vehicle to travel along a traveling line based on pixel data of the photographed traveling line.

(Prior art) Conventionally, in this type of image-based unmanned vehicle, for example, an image of a white traveling line indicating a traveling route taken by an imaging device is divided into a left half and a right half, and the traveling line in the right half is divided into a left half and a right half. Find the area of and the area of the travel line on the left half, calculate the difference between the two,
Based on the difference, the vehicle was able to determine the route ahead. In other words, the determination of the forward travel route is not made solely by determining which direction the entire image of the travel line in the image is deviated from.

(Problem to be solved by the invention) As a result, it is only possible to determine whether the driving line in the imaging range is deviated to the left or right with respect to the current moment of the unmanned vehicle, and the exact trajectory of the driving line cannot be determined. I couldn't decide. Moreover, such arithmetic processing operations for the amount of deviation require a large amount of processing time, which poses a problem in increasing the speed.

An object of the present invention is to solve the above-mentioned problems by being able to determine an accurate driving route, and furthermore, to shorten the determination processing time and to increase the speed of an image-based unmanned vehicle. The present invention provides a control device for a vehicle.

Structure of the Invention (Means for Solving Problems) The image-based unmanned vehicle control device of the present invention is mounted on an unmanned vehicle, and while the vehicle is running, a traveling line indicating the traveling route of the unmanned vehicle is set in a predetermined area. an imaging device that captures an image; a first discrimination device that selects a plurality of points in the longitudinal direction of a running line in an image captured by the imaging device and encodes a pixel signal at each point to generate pixel data; a second determining means that determines in which imaging region the traveling line is present among the imaging regions obtained by dividing the area into a plurality of regions, based on the pixel data, and determines the pixel data distribution of the imaging region in which the traveling line exists; a storage means that stores a group of tables including travel control data for the steering mechanism corresponding to various pixel data distributions; and a table corresponding to the pixel data distribution based on the determination result of the second determination means from the storage means. The gist of the present invention is to provide a steering control means for selecting a table and operating a steering mechanism based on travel control data in the table.

(Function) With the above configuration, when the imaging device images a running line, the first discrimination means selects a plurality of points in the longitudinal direction of the running line in the image captured by the imaging device, and determines the pixel value of each point. The signal is encoded into pixel data. The second determining means determines in which of the plurality of divided imaging regions in the area the traveling line exists based on the pixel data, and determines the pixel data distribution of the imaging region in which the traveling line exists. . Next, the steering control means selects from the storage means a table corresponding to the pixel data distribution based on the determination result of the second determination means, and operates the steering mechanism based on the traveling control data of the table.

(Embodiment) An embodiment of an unmanned vehicle control device embodying the present invention will be described below with reference to the drawings.

In FIG. 1, a support frame 2 is erected at the upper center position on the front side of the unmanned vehicle 1, and an image pickup device is installed at the upper center position of the frame 2.
A CCD (charge coupled device) camera 3 is provided. The CCD camera 3 is set on the support frame 2 so as to photograph an area 4a on the road surface 4 in front of the unmanned vehicle 1. And in this example
The CCD camera 3 covers the area 4a shown in FIG.
This is captured in image 9 shown in the figure. Also, that area 4
Image 9 of a is composed of 256×256 pixels.

In this embodiment, illumination lamps 5 are installed below both sides of the CCD camera 3 in order to facilitate imaging by the camera 3, but the illumination lamps 5 may not be used.

As shown in FIG. 2, on the road surface 4, a traveling line 6 indicating the traveling route of the unmanned vehicle 1 has a constant line width D.
In this embodiment, the road surface 4 is painted with white paint, which is different from the color of the road surface 4. Then, the running line 6 having a constant line width D is connected to the CCD.
This will be taken with camera 3.

Note that the level of the signal (hereinafter referred to as a pixel signal) from the CCD camera 3 that photographed the white running line 6 is high, and on the contrary, the level of the pixel signal from the CCD camera 3 that photographed the dark road surface 4 is low.

Next, the electrical configuration of the control device mounted on the unmanned vehicle 1 will be explained with reference to FIG.

The microcomputer 10 has a central processing unit (hereinafter simply referred to as CPU) 11 as a second discrimination means and a steering control means, a program memory 12 as a storage means consisting of a read-only memory (ROM) storing a control program, and a CPU 11.
It is composed of a working memory 13 consisting of a readable and rewritable memory (RAM) in which arithmetic processing results, etc. are temporarily stored, a timer 14, etc.
The CPU 11 determines the locus of the travel line 6 using a control program stored in the program memory 12 and executes various arithmetic processing operations for steering control.

The CPU 11 operates and controls the CCD camera 3 via an input/output interface 15 and an A/D converter 16 as a first discrimination means at regular intervals based on the time measured by the timer 14, and also controls the CCD camera 3. A pixel signal from the camera 3 is converted into pixel data via an A/D converter 16 and a bus controller 17 and is stored in a working memory 13. When converting pixel signals from the CCD camera 3 from analog values to digital values, the A/D converter 16 determines whether each pixel signal is greater than or equal to a predetermined set value. For each pixel that is input sequentially, the pixel of the white driving line 6 is set to "1", and conversely, if the pixel signal is less than 1, the pixel of the dark road surface 4 is set to "0". The pixel signal is binarized and stored as pixel data in the working memory 1 via the bus controller 17.
3 is stored in a predetermined storage area 13a.

Therefore, the working memory 13 includes the CCD camera 3.
The image 9 taken by the user is stored as 256 x 256 image data.

Note that, as mentioned above, in this example, the CCD
The camera 3 is controlled to perform an imaging operation at predetermined intervals, and the pixel data of the image at that time is stored in the working memory 13, but the image data group of the new image is When input, the previous image data group is erased and a new image pixel data group is stored in that area.

In addition, in this embodiment, for convenience of explanation, the CCD camera 3 is
The scanning control adopts a scanning method in which scanning is performed in the horizontal direction (x-axis direction) and the scanning moves from the top of the screen to the bottom (y-axis direction), but other scanning methods may also be used. Of course.

The binarization level controller 18
Based on the control signal from the CPU 11, the A/D
The converter 16 outputs setting value data for binarization to the A/D converter 16.

The drive controller 20 also controls a driving motor (not shown) and a steering mechanism 19 using a CPU.
Control is performed based on control signals from 11. The steering mechanism 19 then controls the steering angle based on the control signal.

Next, the processing operation of the CPU 11 will be explained.

Now, based on the control signal from CPU11, the CCD
When the camera 3 is scan-controlled, the CCD camera 3 captures an image not perpendicular to the road surface 4 but tilted at a certain angle, so that the front area 4a shown in FIG. 4 is imaged as shown in FIG. 5. Take an image at 9. The image 9 captured by this CCD camera 3 is output as a pixel signal to the A/D converter 16, and the A/D converter 16 converts each pixel signal into a pixel signal for the traveling line 6 or a pixel signal for the road surface 4. It is determined whether the pixel signal is a pixel signal and stored in a predetermined storage area 13a of the working memory 13 as pixel data. The CPU 11 performs image recognition of the traveling line 6 based on the pixel data. The CPU 11 sequentially reads out each pixel data in the scanning direction (x-axis direction) from the top of the image 9, and determines whether there is a running line 6 having a constant line width D and at which position in the scanning line it is located. At the same time, the central position Cn of the range determined to be the travel line 6 is determined and stored in the work network memory 13.

As shown in Figure 8, for each pixel in image 5, the 128th vertical pixel column counting from the left is taken as the y-axis, and the 128th horizontal pixel row from the top is set as the x-axis. The position and center position Cn of the traveling line 6 are determined by the x, y coordinates, with each pixel of the image 5 being expressed by the x, y coordinates. Then, the center positions C0 to C255 of each scanning line up to the bottom of the image 9 are determined.

Next, the CPU 11 determines the center position C0~
A plurality of center positions are selected from C255 as selection points. In this embodiment, the scan lines to be selected are determined in advance, and four scan lines are selected so that when image 9 (to be described later) is projectively transformed, all adjacent selected points are equidistant with respect to the traveling direction (y-axis direction). scan column
La~Ld is determined. That is, the scan line La
~Ld is determined so that it becomes the center line of each of divided areas A1 to A4 obtained by dividing area 4a into four in the y-axis direction when image 9, which will be described later, is projectively transformed, and the divided areas A1 to A4 are The presence/absence of the running line 6 in the previous scanning line La~
It is now held at Ld. Then, the center positions Ga, Gb, Gc, found in each scanning line La to Ld,
Gd is defined as selected points Z1 to Z4 as shown in FIG.

The CPU 11 projects the selected points Z1 to Z4,
That is, calculation processing is performed to determine at which positions (hereinafter referred to as base points) Q1 to Q4 on the actual area 4a shown in FIG. 9 the selected points Z1 to Z4 found in the image 9 are located. This is a CCD as mentioned above.
This is a process to match the difference between the travel line 6 in the image 9 and the actual travel line 6 in the area 4a since the camera 3 does not image the road surface 4 vertically.

This projective transformation processing operation is based on preset standards such as focal length and magnification of the CCD camera 3, and installation conditions such as tilt and height.
That is, coordinate transformation is performed. The general formula for this projective transformation is as follows.

Let the positional coordinates of the selected point be x, y, the positional coordinates of the base point be X, Y, the height of the camera 3 be H, the inclination of the camera 3 be Θ, and the constant that determines the magnification of the corresponding position be F.

X=x・secθ/{1-(y/F)tanθ}・H
/F Y=y+F・tanθ/{1-(y/F)tanθ}
・H/F Next, the CPU 11 selects these four base points Q1 to Q4.
As shown in Figure 9, area 4a is 8
It is determined which of the divided regions B1 to B8 the object belongs to.

In this embodiment, the judgment as to which of these belongs is made in advance by dividing the partition lines that partition each area B1 to B8 and the center of each area on lines a to d of divided areas A1 to A4 corresponding to each scanning line La to Ld. Since the positions are also set in advance and divided, for example, as shown in FIG. 10, each region B on both sides of the base point Q3
3. Center position P3 of B4, distance D3 to P4,
D4 is determined, and the area B4 on the center position P4 side, which is located at a short distance D4, is determined to be the area to which the reference point Q3 belongs.

In this way, the area 4a is divided into a plurality of imaging areas An, Bn by the combinations of the divided areas A1 to A4 and the divided areas B1 to B8, and as described above, the CPU 11 determines which imaging area each base point Q1 to Q4 corresponds to. Determine whether it belongs to An or Bn.

Note that if the base points Q1 to Q4 do not exist, the imaging areas An and Bn are set as A0 and B0 by the CPU 11.
is determined, and four base points Q1 to Q including this case are determined.
There are 9 to the 4th power (=6561) combinations (number of pixel data distributions) belonging to the imaging areas An and Bn of 4.
6561 pixel data distributions are stored in advance in a predetermined storage area 12a of the program memory 12.

A group of 6561 tables corresponding to the pixel data distribution is stored in advance in a predetermined storage area 12b of the program memory 12, as shown in FIG. 12, and the CPU 11 arranges the determined base points Q1 to Q4. The CPU 11 searches for a pixel data distribution that matches , reads out a table of the matching pixel data distribution, and reads travel control data provided in the table.

The travel control data of each table is based on its pixel data distribution, that is, the travel control data for rationally and efficiently traveling from the original position to the imaged area 4a on the travel line 6 based on the arrangement of the base points Q1 to Q4. The steering mechanism 19 is actuated based on this data, which has been experimentally determined in advance from data on the steering angle at various times during the vehicle's travel.

Now, the CPU 11 searches for a pixel data distribution that matches the array of base points Q1 to Q4 based on the latest image 9 captured by the CCD camera 3, reads out a table for that pixel data distribution from the program memory 12, and runs the table. The control data is stored in a predetermined storage area 13b of the working memory 13. Then, the CPU 11 operates the steering mechanism 19 based on the latest traveling control data stored in the working memory 13. That is, at this point, the travel route of the unmanned vehicle 1 to the latest area 4a has been determined based on this travel control data.

The CPU 11 causes the unmanned vehicle 1 to travel toward the area 4a while controlling the steering angle based on the latest travel control data.

During this travel, when a predetermined period of time has elapsed, the CPU 11 controls the CCD camera 3 to store a group of pixel data of an image 9 of a new area 4a ahead of the previous imaging area 4a in the working memory 13. Based on this latest pixel data group, the CPU 11 determines base points Q1 to Q4 in the same manner as described above, searches for a matching pixel data distribution, and reads travel control data corresponding to the matching pixel data distribution. Then, the CPU 11 rewrites the contents of the working memory 13 from the previous travel control data to this new travel control data, and operates the steering mechanism 19 using this latest travel control data. That is, the travel of the unmanned vehicle 1 based on the previous travel control data is changed to travel based on the latest travel control data for the area 4a during the travel.

After that, by repeating this, CPU11
Each time the CCD camera 3 images a new area 4a, new travel control data based on the image of the area 4a is read out, the steering mechanism 19 is operated, and the unmanned vehicle 1 is driven along the travel line 6.

Note that the present invention is not limited to the embodiments described above, and although the number of selection points Z1 to Z4 is four in the embodiment, the number may be changed as appropriate. Further, in the above embodiment, the selection points Z1 to Z4 were selected at equal intervals in the y-axis direction, but this may be changed as appropriate, such as making the intervals narrower toward the top, without being limited to equal intervals. It may also be carried out by selecting selection points.

Furthermore, in the above embodiment, the selected points Z1 to Z4 are the center positions Cn of the pixel group indicating the running line 6 in the predetermined scanning column direction, but the point is that the selected points Z1 to Z4 are the center positions Cn of the pixel group indicating the running line 6 captured in the image 9. is selected, and any selection method may be used. Furthermore, in the above embodiment, after determining the center position Cn for all the scan rows, the predetermined center position was set as the selection point, but instead of determining all the center positions, only the center position of the predetermined scan row that becomes the selection point is used. It may be implemented by simply asking for. In this case, the travel route setting processing time can be further shortened.

Further, although a CCD camera was used as the imaging device in the above embodiment, it may be implemented using other imaging devices, and in the above embodiment, the CCD camera 3
Although the pixel configuration (resolution) of the image is set to 256 x 256 pixels, it is not limited to this, and may be changed to, for example, 512 x 512 pixels, 1024 x 1024 pixels, etc. as appropriate.

Effects of the Invention As detailed above, according to the present invention, an accurate driving route can be determined, and the determination processing time can be shortened, and the speed of the image-based unmanned vehicle can be increased. It has a great effect.

[Brief explanation of drawings]

Fig. 1 is a side view of an unmanned vehicle embodying this invention, Fig. 2 is a plan view of the same, Fig. 3 is an electric block circuit diagram of the control device, Fig. 4 is a diagram showing the area imaged by the CCD camera, Figure 5 is an explanatory diagram to explain the image taken by the CCD camera, and Figure 6 is
Figure 7 is a diagram to explain the relationship between the number of images taken by the CCD camera and its area, Figure 7 is a diagram to explain the contents of the working memory, Figure 8 is a diagram to explain the coordinates of images, Figure 9 is a diagram showing each base point when the selected point is projectively transformed into the actual area, Figure 10 is a diagram to explain the area to which the base point belongs, and Figures 11 and 12 are diagrams to explain the contents of the program memory. This is a diagram. In the figure, 1 is an unmanned vehicle, 3 is a CCD camera, 4 is a road surface, 4a is an area, 5 is a lighting lamp, 6 is a running line, 9 is an image, 10 is a microcomputer,
11 is a central processing unit (CPU), 12 is a program memory, 13 is a working memory, 14 is a timer, 1
6 is an A/D converter, 18 is a binary level controller, 19 is a steering mechanism, and 20 is a drive controller.

Claims (1)

[Scope of Claims] 1. An imaging device that is mounted on an unmanned vehicle and captures images in a predetermined area of a traveling line that indicates the traveling route of the unmanned vehicle while the vehicle is traveling; and the traveling line in the image captured by the imaging device. a first discriminating means that selects a plurality of points in the longitudinal direction and encodes the pixel signal of each point as pixel data; a second determining means that determines whether a travel line exists based on the pixel data and determines the pixel data distribution of the imaging area where the travel line exists; and travel control data of the steering mechanism corresponding to the various pixel data distributions. a storage means storing a group of tables comprising: a table corresponding to the pixel data distribution based on the determination result of the second determination means from the storage means; and operating the steering mechanism based on the travel control data of the table. A control device for an image-based unmanned vehicle, comprising a steering control means for controlling the vehicle.