JP2002218504A - Method for adjusting compound eye camera and adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound-eye camera adjustment method that accurately keeps the position relation between a compound-eye camera and a target so as to enhance the performance of the compound-eye camera. SOLUTION: Two or more light sources 3A, 3B placed at a mount position of the compound-eye camera 1 emit two or more, rays 4A, 4B, a target 5 is placed at a cross point 7A between the two or more rays, and the compound-eye camera photographs the target for the adjustment of the compound-eye camera. A distance L from the compound-eye camera to the cross point of the rays depends on a distance (a) between the light sources and relative angles θ1, θ2 between the light sources. Placing the target at the cross point can accurately set the distance between the compound-eye camera and the target. Thus, the optical axis and the focus of the compound-eye camera can accurately be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustment method for adjusting the focus, the optical axis, and the like of a compound-eye camera, and an adjustment apparatus for performing the adjustment.

[0002]

2. Description of the Related Art In a compound-eye camera, for example, a stereo camera in which two cameras are arranged horizontally, it is necessary to adjust the optical axes of the two cameras. A conventional method of adjusting a compound eye camera will be described with reference to FIG. FIG. 1 shows a compound-eye camera device and a target viewed from above.

The left and right cameras 8A, 8B of the compound eye camera 1
Are arranged so that the respective optical axes 12A and 12B are parallel to each other. The distance between the optical axes 12A and 12B is the base length b. One target (target) 5 is arranged in front of the left and right cameras 8A, 8B with a predetermined distance L therebetween. The target 5 is photographed by the left and right cameras 8A and 8B. From the position of the target 5 shown in the images 9A and 9B of the left and right cameras 8A and 8B, the deviation amounts of the optical axes 12A and 12B are grasped and adjusted for each of the left and right cameras 8A and 8B.

[0004]

In the adjustment of the conventional compound-eye camera 1, it has been difficult to accurately match the positional relationship between the target 5 set in front and the compound-eye camera 1. This is because the distance between the compound-eye camera 1 and the target 5 is often as long as, for example, 30 m. If the positional accuracy is low, the accuracy of the optical axis of the compound-eye camera 1 cannot be increased.

A typical application using the compound eye camera 1 is distance measurement. In such a case,
The low accuracy of the optical axis directly affects the distance measurement performance, and cannot perform accurate distance measurement. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of adjusting a compound-eye camera capable of accurately maintaining a positional relationship between a compound-eye camera and a target, thereby improving the performance of the compound-eye camera.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. According to the method of the present invention, two or more light sources are emitted from two or more light sources provided at a mounting position of a compound-eye camera, a target is set at an intersection of the two or more light beams, and the target is photographed by the compound-eye camera. Thus, the compound eye camera is adjusted.

The distance between the compound eye camera and the intersection of the light beam is determined by the distance between the light sources and the relative angle between the light sources. By arranging the target at this intersection, the distance between the compound-eye camera and the target can be set accurately. Therefore, the optical axis adjustment and the focus adjustment of the compound-eye camera can be accurately performed. In the present invention, four or more light sources are provided, and the intersection of light beams can be two or more. Thereby, the plane of the target can be defined. If each intersection is aligned with the optical axis of the two cameras, the optical axis can be easily adjusted. In addition, it is also possible to detect and adjust the deviation in the rotation direction of each camera.

In the present invention, the plane of the target can be defined by providing three or more intersections of light rays. In the present invention, the distance from the compound-eye camera to the intersection and the distance between the intersections can be arbitrarily set by freely changing the firing angle of at least one of the light beams.

By installing a reflecting plate for reflecting a light beam having a wavelength of a light source as the above-mentioned target, an efficient adjusting operation can be performed. An apparatus for carrying out the compound-eye camera adjustment method of the present invention includes a jig for attaching the compound-eye camera, and two or more light sources attached to the jig and emitting light rays in front of the compound-eye camera. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method and an apparatus for adjusting a compound-eye camera according to the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 2A shows the configuration of a compound-eye camera adjusting device and a method of adjusting a compound-eye camera using this device, showing a state in which the adjusting device and the target are viewed from above. FIGS. 2B and 2C show light spots on the target.

A compound eye camera 1 such as a stereo camera is fixed to a jig 2. The compound-eye camera 1 is accurately mounted on the reference surface of the jig 2. At both left and right ends of the jig 2, two light sources 3A and 3B that emit light rays forward are arranged. Light source 3
A and 3B are composed of, for example, He-Ne lasers having a small light beam diameter, a high output, and a wavelength that is visible or can be received by a compound-eye camera. The number of light source devices such as lasers may be plural, or may be divided into two light beams using an optical component such as a half mirror.

The two light sources 3A and 3B are arranged at a distance a from each other, and emit light rays 4A and 4B at angles θ1 and θ2 inward with respect to the front. Two light beams 4A, 4
B intersects distance a with distance L determined by angles θ1 and θ2. When the target (target) 5 is arranged in front of the compound eye camera 1, as shown in FIG.
Light spots 6A and 6B due to B appear. When the target 5 is at a distance L from the compound-eye camera 1, the two light spots 6A and 6B overlap and become one point as shown in FIG.
Hereinafter, this point is referred to as intersection 7A. Target 5 is distance L
, Two light spots 6A and 6B appear separately. Therefore, by arranging the target 5 at a position where the light spots 6A and 6B overlap and one intersection 7A is formed, the target 5 can be accurately arranged at a position at a distance L from the compound-eye camera 1.

As described above, since the light is used for setting the distance L, it is not affected by the road surface condition between the jig 2 and the target 5. In order to accurately measure the positional relationship with the target 5, generally, a measure or the like must be used,
It is difficult to measure an accurate straight line distance when the road surface is uneven. Although there is a method using a surveying instrument to improve the measurement accuracy, a large-scale measurement must be performed every time a new instrument is introduced or the measurement environment is changed. Furthermore, it is difficult to perform high-precision measurement with such measurement in order to obtain even height information. These problems are easily solved by this example.

After placing the target 5, the target 5 is photographed by the left and right cameras 8A and 8B. First, focus adjustment is performed for each of the left and right cameras 8A and 8B, and an image 9A and
The target 5 is projected on 9B. Thus, the focus adjustment of the left and right cameras 8A and 8B is performed in a state where the target 5 at the predetermined distance L is in focus. This focus adjustment can be performed in a state where the target 5 is placed at an accurate distance L, so that it becomes accurate.

Next, the target 5 on the images 9A and 9B
From the position, the deviation of the optical axis is detected. The optical axes of the left and right cameras 8A and 8B are adjusted based on this deviation.
Also in this case, since the adjustment is performed by accurately arranging the target 5 at a position separated by the distance L, the optical axis adjustment becomes accurate.
FIG. 3 shows a specific adjustment method for the left and right cameras 8A and 8B.

In each of the cameras 8A and 8B, the lens 1
The image pickup device 11 is arranged behind 0. The axis connecting the center of the lens 10 and the center of the image sensor 11 is the optical axis 12. Focus adjustment is performed by moving the lens 10 in the direction c of the optical axis 12. The adjustment of the optical axis 12 is performed by the imaging device 1.
1 is moved in the left-right direction d or the up-down direction e. Although the details will be described later, the adjustment of the rotation direction is performed by rotating the imaging device 11 around the optical axis 12 in the rotation direction f.
This is done by rotating

Instead of performing various adjustments using the target 5 shown on the images 9A and 9B, the adjustment can be made from the position of the intersection 7A appearing on the target 5. In this case, as the target 5, a reflector that can confirm the intersection 7A is used. When laser light other than visible light is used as the light sources 3A and 3B, the reflection of light is reduced with a normal reflector. In this case, it is preferable to use a plate that reflects the wavelengths unique to the light sources 3A and 3B, for example, a detect board.

As described above, when the reflector 5 is used as the target 5 and the intersection 7A is used as a reference, a dedicated target is not required, and a small-sized reflector can be used. Therefore, the degree of freedom of the place where the compound eye camera 1 is adjusted is increased. Furthermore, even without a reflector, it is also possible to use a wall of a building or the like as a target. (Embodiment 2) In the example described above, the distance L is fixed, but it can be variable. By changing one or both of the emission angles θ1 and θ2 from the light source, the position where the intersection 7A of the two light beams 4A and 4B is formed is changed. Thereby, the distance L between the compound-eye camera 1 and the target 5 can be changed.

As concrete means for changing the firing angles θ1 and θ2, there are a method of adjusting optical components such as a half mirror and a prism, and a method of changing the mounting angle of the light source devices of the light sources 3A and 3B. (Embodiment 3) In a case where three or more rays intersect at one point, the positional relationship between the jig and the target is set to three.
Can be specified dimensionally.

FIG. 4 shows the structure of a compound-eye camera adjusting apparatus provided with three light sources. FIG. 4A is a view of the apparatus as viewed from the front, and FIG. 4B is a view showing a light spot on the target. As shown in FIG.
Of light sources 3C are provided. The light source 3C is disposed at an intermediate position between the left and right light sources 3A and 3B and above.
When the target 5 deviates from the distance L, FIG.
As shown in FIG. 4B, when three light spots 6A, 6B and 6C appear and are arranged at a distance L, one intersection 7A appears as shown in FIG. 4C.

(Embodiment 4) Using four or more light beams,
When the target 5 is configured to have an intersection point or more, the positional relationship of the target 5 with respect to the plane can be defined. FIG.
Shows an example in which four rays have two points of intersection. Here, only the points different from FIG. 2 will be described.

As shown in FIG. 5A, two light sources 3A, 3B, 3C, and 3D are arranged on both right and left ends of the jig 2, respectively. The light sources 3A, 3B are arranged at a distance a to form a set of light sources. The light sources 3C and 3D are also arranged at a distance a to form a set of light sources. The set of light sources 3A and 3B is
One intersection 7A is formed, and the light sources 3C and 3D form one intersection 7C.

FIG. 5B shows the relationship between the light spots 6A to 6D on the target 5 and the intersections 7A and 7C when the target 5 deviates from the distance L and FIG. Intersection 7 by each light source 3A and 3B, 3C and 3D
The principle of forming A and 7C is the same as in the first to third embodiments. When two intersections 7A and 7C are formed on the target 5, the plane of the target 5 becomes two intersections 7A and 7C.
A and 7C define the positional relationship.

In the illustrated example, the distance b between the two intersections 7A and 7C on the target 5 is the same as the base length b. Thereby, the left camera 8A uses the intersection 7A and the right camera 13 performs the optical axis adjustment using the intersection 7C. In this case, each camera 8A, 8B
In A and 9B, the optical axis adjustment can be performed at the same coordinate position. The distance between the intersections 7A and 7C can be different from the base line length b.

The example shown in FIG. 6 shows an example in which six rays have three intersections. FIG. 6A is a diagram of the compound-eye camera adjustment device as viewed from the front. Here, only the points different from FIG. 5 will be described. The jig 2 is provided with a third set of light sources 3E and 3F. The light sources 3E and 3F are arranged above the compound-eye camera 1, and the light sources 3E and 3F are arranged at a distance a like the other sets of light sources. The three intersections 7A, 7C and 7E are located on the target 5 in FIG.
It is formed as shown in FIG. Thus, the positional relationship of the plane of the target 5 is defined by the three intersections 7A, 7C, and 7E.

(Modification) In the first to fourth embodiments described above, the cameras 8A and 8B are arranged in the left-right direction, but they can be arranged in any direction such as the up-down direction. As in Embodiment 4, the intersection 7A on the target 5,
When two or more 7C and the like are formed, the compound eye camera 1 and the intersection 7A
It is also possible to make the distance L1 to the distance from the intersection L7 different from the distance L2 to the intersection 7C. In this case, focus adjustment can be performed for a plurality of distances by a single setting process.

[0027]

According to the present invention, the positional relationship between the compound-eye camera and the target can be accurately maintained, thereby obtaining a compound-eye camera adjusting method for improving the performance of the compound-eye camera.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional method of adjusting a compound-eye camera.

FIG. 2 is a diagram showing an adjustment method according to the first embodiment of the compound eye camera of the present invention.

FIG. 3 is a diagram showing a specific adjustment method for each camera in the present invention.

FIG. 4 is a front view of an apparatus according to a third embodiment of the compound eye camera of the present invention.

FIG. 5 is a diagram illustrating an adjustment method according to a fourth embodiment of the compound eye camera of the present invention.

FIG. 6 is a view showing a modification of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 compound eye camera 2 jig 3A, 3B, 3C, 3D, 3E, 3F light source 4A, 4B, 3C, 4D, 4E, 4F light ray 5 target 6A, 6B, 6C, 6D, 6E, 6F light Point 7A, 7C, 7E ... Intersection 8A, 8B ... Camera 9A, 9B ... Camera image 10 ... Lens 11 ... Image sensor 12 ... Optical axis a ... Distance between light sources b ... Base line length L ... Distance from compound eye camera to target θ1, θ2 ... firing angle

Claims (11)

[Claims] 1. A method according to claim 1, wherein two or more light rays are emitted from two or more light sources provided at a mounting position of the compound eye camera, a target is set at an intersection of the two or more light rays, and the target is photographed by the compound eye camera. A compound-eye camera adjustment method for adjusting the compound-eye camera based on a captured image. 2. The method according to claim 1, wherein the number of the light beams is two. 3. Four rays are emitted from four light sources provided at a mounting position of a compound-eye camera, and an intersection of two sets of two rays is set at an arbitrary constant distance among the four rays. A method of adjusting a compound-eye camera, comprising: setting a target on a plane having the two sets of intersections as common points; photographing the target with the compound-eye camera; and adjusting the compound-eye camera based on the captured image. 4. Six rays are emitted from six light sources provided at a mounting position of a compound-eye camera, and an intersection of three sets of two rays is set at an arbitrary constant distance among the six rays. A method for adjusting a compound-eye camera, comprising: setting a target on a plane having the three sets of intersections as common points; photographing the target with the compound-eye camera; and adjusting the compound-eye camera based on the captured image. 5. The method according to claim 3, wherein the intersections are set at different distances. 6. The method for adjusting a compound-eye camera according to claim 1, wherein the adjustment of the compound-eye camera is an optical axis adjustment. 7. The method of adjusting a compound-eye camera according to claim 1, wherein the adjustment of the compound-eye camera is a focus adjustment. 8. The method for adjusting a compound-eye camera according to claim 3, wherein the adjustment of the compound-eye camera is an adjustment of rotation based on an optical axis. 9. The distance from the compound-eye camera to the intersection by freely changing the emission angle of at least one of the two or more light beams. 2. The method for adjusting a compound-eye camera according to claim 1. 10. The method for adjusting a compound-eye camera according to claim 1, wherein a reflector that reflects a wavelength of the light source is provided as the target. 11. An apparatus for adjusting a compound-eye camera, comprising: a jig for mounting the compound-eye camera; and two or more light sources attached to the jig and emitting light rays in front of the compound-eye camera.