JPH06226561A - Circular position recognizing device - Google Patents

Abstract

PURPOSE:To recognize a circular position from photographed images even in the condition in which a working means and the like are arranged directly over a circular objective to be recognized. CONSTITUTION:A circular objective such as screw hole 10 is photographed by photographing means 1a, 1b in oblique and mutually different directions, they are stored in first and second image, memories 3a, 3b through first and second image input parts 2a, 2b, the center positions of circular territotries in the horizontal direction of respective image planes are detected by means of first and second image processing parts 5a, 5b, and finally the positions in the horizontal direction and the vertical position in the actual plane is detected by means of a main control part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circular position recognizing device, and for example, it is possible to recognize the position of a screw hole from an image picked up with the screw tightening means arranged immediately above the screw hole, and to pick up an image of the screw hole The present invention relates to a circular position recognition device that can be used as a visual recognition device or the like in a screw tightening device that can perform screw tightening work without performing unnecessary movement.

[0002]

2. Description of the Related Art In recent years, as a screw fastening device in a production facility, a device provided with a visual recognition device for recognizing a screw hole position has been widely used.

A visual recognition device in a conventional screw tightening device is constructed as shown in FIG. In FIG.
Reference numeral 31 is an image pickup unit, 32 is an image input unit for digitally converting a video signal input from the image pickup unit 31, 33 is an image memory for storing the data converted by the image input unit 32, and 34 is an image memory 33. An image display unit for displaying the generated image data as an image, and an image processing unit 35 for performing circular position recognition processing on the image data stored in the image memory 33. The image processing unit 35
A circular area detecting means 36 for detecting a target circular area, and a centroid detecting means 37 for detecting the centroid position of the circular area detected by the circular area detecting means 36.
It is composed of. Reference numeral 38 is a monitor for displaying the video signal output from the image display unit 34. Reference numeral 39 denotes a screw tightening means, which is mounted on a movable head (not shown) together with the image pickup means 31, and a gravity center position detecting means 37.
The position of the screw tightening means 39 is corrected according to the position of the center of gravity detected at. 40 is a work having a screw hole 41.

Next, the operation will be described. First, the image pickup means 3
The image of the screw hole 41 of the work 40 is taken from directly above by 1.
FIG. 5 is a conceptual diagram of an image of the screw hole 41 picked up by the image pickup means 31. By obtaining the center of gravity position 43 of the circular area 42 corresponding to the screw hole 41, the accurate position of the screw hole 41 can be recognized. You can Thus, after recognizing the position of the screw hole 41, the movable head moves the screw tightening means 39 to a position directly above the position where the screw hole 41 should be, and the screw tightening means 39 is adjusted in accordance with the actual position of the screw hole 41. The position is corrected, and the screw tightening means 39 performs screw tightening work.

[0005]

However, since the positions of the image pickup means 31 and the screw tightening means 39 are different in the above configuration, the image pickup means 31 is first screwed into the screw hole 41 in order to image the screw hole 41 of the work 40. It is necessary to move the screw tightening means 39 above the position where the screw hole 41 should be, because the screw tightening work is performed on the screw hole 41 next time. It is necessary to correct and move according to the position of the screw hole 41, the operation setting of the movable head becomes complicated, the time of one working process becomes long, and there is a problem that working efficiency is poor.
In addition, since the movable head needs to move a large distance between the image pickup means 31 and the screw tightening means 39, there is a problem that the work environment is likely to be affected by the surrounding environment and the working accuracy is lowered.

In view of the above conventional problems, the present invention makes it possible to recognize the position of a circular object from a captured image even when the working means or the like is arranged directly above the circular object to be recognized. An object is to provide a shape position recognition device.

[0007]

A circular position recognition apparatus of the present invention comprises means for picking up an image of a circular object from an oblique direction and directions different from each other, and means for storing each picked-up image signal. , A means for detecting a circular area from the stored image, detecting a point having the longest horizontal distance in the image plane of the circular area, and detecting a center position of the longest distance, and a detected longest distance And means for calculating the ratio of the reference longest distance based on the circular object at the reference position, means for calculating the horizontal distance in the image plane between the center position and the center position of the reference longest distance, A means for determining the center position of the circular object based on the ratio of the longest distance to the reference longest distance and the distance between the central positions is provided.

[0008]

According to the above configuration of the present invention, since the circular object is imaged obliquely and the center position of the circular object is recognized, the center of the circular object can be recognized without arranging the imaging means directly above the object. The position can be recognized, and therefore the position can be recognized even when the working means and the like are arranged directly above the circular object, and the working time of the working device with the recognition means can be shortened and the working space can be made more efficient. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a circular position recognizing device of the present invention is applied to a screw tightening device with a recognizing device will be described with reference to FIGS.
This will be described with reference to FIG.

In FIG. 1, reference numerals 1a and 1b are image pickup means for picking up an image of a screw hole 10 of a work 9. The screw fastening device 8 is provided in a side portion of the screw fastening device 8 in vertical planes passing through the axes thereof and orthogonal to each other. It is obliquely attached so that the screw hole 10 directly below 8 can be imaged. 2a and 2b are image pickup means 1
The first and second image input units 3a and 3b, which convert the video signals input from a and 1b into digital signals, are the image input units 2a,
First and second image memories for storing image data digitally converted by 2b, 4 is an image display unit for displaying the image data stored in the image memories 3a, 3b on the monitor 7 as an image, 5a. 5b are image memories 3a and 3b
The screw hole 10 shown in FIG. 2 for the image data stored in
The first and second image processing units 6 for detecting the center position 13 in the horizontal direction on the image plane of the circular area 11 corresponding to the control unit 6 control each unit of the apparatus and the image processing unit 5
The center coordinates of the screw hole 10 are calculated from the center position 13 detected at a and 5b.

Next, a method of recognizing the position of the screw hole 10 will be described with reference to FIGS. FIG. 2 shows the image pickup means 1.
It is a conceptual diagram of the method of calculating the position of the screw hole 10 of an imaging direction from the image of the screw hole 10 imaged by a or 1b. Reference numeral 21 is a reference circular area, and the image of the screw hole 10 which is properly positioned immediately below the screw tightening device 8 is imaged by the imaging means 1a and 1b, and the reference circular area 2 is formed.
Data 1 is registered in the first and second image processing units 5a and 5b, respectively, and since the image pickup means 1a and 1b are obliquely attached, it has an elliptical shape like the circular area 11. Screw hole 1 that is the work target of the screw tightening device 8
The circular area 11 in which 0 is imaged is the normal reference circular area 2
However, since the image pickup means 1a and 1b are obliquely attached, a large image is taken when the image is located in front of the reference circular region 21, and a small image is taken when it is provided behind the reference circular region 21. By detecting the center position 13 of the longest distance 12 in the horizontal direction on the image plane of the circular region 11 for each image, the accurate center coordinates of the screw hole 10 can be obtained. The center coordinates of the screw hole 10 can be detected by performing the processing shown in FIG.

First, in step # 1, the image is scanned and a region darker than the background is detected as a circular region 11. Next, in step # 2, the longest horizontal distance 12 in the image plane of the circular area 11 detected in step # 1 is detected, and the center position 13 thereof is calculated. Next, step # 3
Then, the ratio of the reference longest distance 22 which is the longest distance in the horizontal direction in the image plane of the reference circular area 21 and the longest distance 12 of the circular area 11 is calculated. Next, in step # 4, the distance 14 between the center position 23 of the reference longest distance 22 and the center position 13 of the longest distance 12 of the circular region 11 is calculated. Then, in step # 5, the ratio of the longest distances calculated in step # 3 is 22:12.
Is the ratio (1 of the true center distance 15 between the reference circular region 21 and the circular region 11 and the distance 14 calculated in step # 4 (1
5:14), the true center-to-center distance is 15
Can be calculated by 14 × (22/12). After that, the horizontal center position X of the true screw hole 10 on the image plane can be obtained by the following equation.

X = Xb ± (L × R) where L: center-to-center distance 14 R: longest distance ratio 22/12 Xb: center position 23 of the screw hole at the reference position. By obtaining the true center position of each circular region 11 with respect to the two images captured obliquely by 1b, it is possible to detect the accurate horizontal and vertical positions of the screw hole 10 in the real plane.

In the above embodiment, the screw hole position is detected, but the center position of other circular objects can be detected in the same manner.

[0015]

As described above, according to the present invention, the circular object is imaged from the oblique direction and the position thereof is detected as described above, so that the circular object is not placed directly above the circular object. Since the center position can be recognized, the position of the circular object can be recognized in a state in which the working means and the like are arranged directly above the circular object, and unnecessary work for imaging is omitted in the working device with a recognition device. Therefore, the recognition time can be shortened, the working time can be shortened, and the working space can be made efficient.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a screw hole position recognition device in an embodiment of a screw tightening device to which a circular position recognition device of the present invention is applied.

FIG. 2 is an explanatory diagram of a method of detecting a positional deviation of a screw hole with respect to a reference position in the embodiment.

FIG. 3 is a flowchart of a method for detecting the center position of the screw hole according to the embodiment.

FIG. 4 is a block diagram of a conventional circular position recognition device.

FIG. 5 is an explanatory diagram of a conventional circular position detecting method.

[Explanation of symbols]

 1a Image pickup means 1b Image pickup means 2a First image input section 2b Second image input section 3a First image memory 3b Second image memory 5a First image processing section 5b Second image processing section 6 Main control section 8 Screw tightening means 10 Screw Hole 11 Circular area corresponding to the screw hole 12 Longest distance of the circular area 11 13 Center position of the longest distance 21 Reference circular shape area 22 corresponding to the screw hole at the reference position Reference maximum distance of the reference circular area 21 23 Longest Center position of distance 22

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // B23Q 17/24 Z 8612-3C

Claims (1)

[Claims] 1. A means for imaging a circular object from an oblique direction and directions different from each other, a means for storing each image signal of the imaged, and a circular area detected from the stored image. A means for detecting the point with the longest horizontal distance in the image plane of the circular area and detecting the center position of the longest distance, and the reference longest distance based on the detected longest distance and the circular object at the reference position. And a means for calculating a horizontal distance in the image plane between the center position and a center position of the reference longest distance, a ratio of the longest distance and the reference longest distance, and the center position. A circular position recognizing device, comprising: means for determining a center position of a circular object based on a distance.