JP2943733B2 - Position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device,
In particular, when graphic information is known from a captured image,
The present invention relates to a position detection device that detects position information such as a position and a rotation angle of a target graphic.

[0002]

2. Description of the Related Art Conventionally, a method of detecting the position of a target work from an image input from a camera or the like in an assembling apparatus or an inspection apparatus has been widely used. It is often assumed that figures are clearly recognized, and poor proof conditions or figures that must be used for position detection cannot be clearly distinguished from surrounding noise by shading and size. Not suitable in case.

[0003] When there are several marks for position detection, which can be easily distinguished from the surroundings by size and shading, high-speed processing is possible and very effective. If the shading is mixed with the surrounding noise and cannot be distinguished at a glance, an optimum combination must be obtained from a number of candidate points or figures. When all combinations are evaluated, it takes a very long time and may not be practical.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made in order to solve the above-mentioned problems inherent in the conventional technology. It is an object of the present invention to provide a new position detection method and a new position detection device capable of quickly and accurately detecting a position when a figure to be detected is mixed with surrounding noise.

[0005]

In order to achieve the above object, a position detecting apparatus according to the present invention comprises a polygonal object to be imaged, a photoelectric conversion scanner for imaging the object and converting it into an analog signal. An A / D conversion circuit for converting the converted analog signal into a digital signal, a first memory circuit for storing the converted digital signal as a captured image,
A binarizing circuit for binarizing the captured image and outputting a binary image in which candidate points are narrowed down as small figures, and a second memory circuit for storing the binary image and outputting a stored candidate area creation drive signal A candidate area creating circuit for creating a candidate area as a group of circles (a binary image having a circle of “1” and a background of “0”) as a reference image and calculating a reference angle; A candidate area scanning circuit for moving a pixel by pixel to convert it into a moving image for raster scanning, a comparing circuit for comparing the moving image with the binary image and outputting a small figure of an AND portion as a comparative image, A circular scanning circuit that outputs the position information and the number of small figures from the comparison image, a small figure presence / absence confirmation circuit that checks whether or not the required number of small figures exists in each circle, Small figure on each circle when small figure exists A figure evaluation circuit that calculates the distance between the positions and detects a target figure when an optimal combination exists, and a target figure presence / absence confirmation circuit that checks the presence / absence of a figure from the presence / absence of a figure as a result of the figure evaluation circuit. An angle calculation circuit for detecting position information (rotational angle, center of gravity) from the figure and the reference image when the figure exists, a display circuit for displaying the position information, and whether full scanning by the moving image has been completed. And a full scan completion confirmation circuit for outputting information of no figure when it is confirmed that all the scans have been completed.

A position detecting device according to the present invention is a method for detecting a position.
In other words, a reference image and a reference angle are generated by performing photoelectric conversion, A / D conversion, binarization processing, and candidate area creation processing on a first object to be a reference, and then position detection is performed. A second binary image is generated by performing the same photoelectric conversion, A / D conversion, and binarization processing on the second object to be captured as described above, and the reference image and the second image to be captured are obtained. Comparing and evaluating the second binary image of the object,
A deviation value of the second imaged object from the first imaged object is obtained.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of the present invention;

FIG. 1 is a diagram showing a block configuration and an operation flow showing an embodiment of the present invention.

Referring to FIG. 1, a position detecting device according to the present invention includes a polygonal object to be imaged a, a photoelectric conversion scanner 1 for imaging the object to be imaged a and converting it into an analog signal b, and an analog signal b. An A / D conversion circuit 2 for converting the digital signal c into a digital signal c, a memory circuit 3 for storing the digital signal c as a captured image d, and a binary image e obtained by binarizing the captured image d and narrowing down candidate points to small figures. A binarizing circuit 4 for outputting,
A memory circuit 5 for storing a binary image e and outputting a stored candidate area creation drive signal f; and a candidate area as a group of circles receiving the drive signal f (a circle having a circle of “1” and a background of “0”). Value image)
A candidate area creating circuit 6 for creating a reference image g and calculating a reference angle, a candidate area scanning circuit 7 for moving the reference image g one pixel at a time and converting it into a moving image i, Compare i with binary image e and AND
A comparison circuit 8 for outputting a small figure of a part as a comparison image k
A circular scanning circuit 9 for outputting position information and the number of small figures from the comparison image k, a small figure presence / absence confirmation circuit 10 for confirming whether there are more small figures than necessary in each circle,
When there are more small figures than necessary in each circle, the distance between the positions of the small figures on each circle is calculated, and when there is an optimal combination, the figure evaluation circuit 11 determines that the target figure is detected.
A target graphic presence / absence confirmation circuit 12 for confirming the presence / absence of a graphic from the presence / absence m of the graphic as a result of the graphic evaluation circuit 11;
(Angle calculation circuit 13 for detecting (rotation angle, center of gravity)), display circuit 15 for displaying position information n, and whether or not all scanning by moving image i has been completed. And a full scan completion confirmation circuit 14 for outputting the no-graphic information o.

FIGS. 2A to 2D show a candidate area creation circuit 6
FIG. 4 is a diagram for explaining the operation of FIG.

Referring to FIGS. 2A to 2D, first,
A point which is relatively easy to detect from the detected object a as shown in FIG. 2A is selected in advance as a feature point, that is, a vertex (FIG. 2B). Next, the center of gravity of the feature point (vertex) and a circle centered on the center of gravity and passing through each vertex are calculated (FIG. 2C). Calculate all circles through which all vertices pass. In the case of the present embodiment, the number of circles serving as candidate areas is three. These circle groups become candidate areas (candidate area 1, candidate area 2, candidate area 3) (FIG. 2).
(C)). The candidate areas 1 to 3 composed of these circle groups are shown in FIG.
The reference image g shown in FIG. Furthermore, a reference vertex is determined, and the angle between the center of gravity and a straight line to this vertex is set as a reference angle. The reference vertex can be arbitrarily determined. For example, if the reference vertex is an upper vertex s in FIG. 2D, the reference angle h is an angle between the y axis and the straight line t. Distances between vertices (L1, L2, L
3, L4, L5)) (FIG. 2 (d)).

FIG. 3 is a diagram for explaining the operation of the candidate area scanning circuit 7.

In FIG. 3, the whole circle group is moved one pixel at a time so as to perform raster scanning. Thus, the candidate area scanning circuit 7 generates the moving image i and the center of gravity j based on the reference image g.

Next, in the same manner as in the processing for generating the reference image g, a binary image e is obtained for the object whose position is to be detected, ie, the object a, and stored in the memory circuit 5.

4A to 4E show a comparison circuit 8, a circular scanning circuit 9, a graphic evaluation circuit 11, and an angle calculation circuit 13.
FIG. 4 is a diagram for explaining the operation of FIG.

Referring to FIGS. 4A to 4E, the reference image g shown in FIG.
The binary image e shown in (b) is compared by the comparing circuit 8, and the small figure (dotted circle) shown in FIG.
Only the comparison image k is detected. Next, the distance of the small figure on the circle is evaluated between the circles, and if there is a combination that matches the distance between the characteristic points (vertexes), that combination is the detected figure (FIG. 4D).

Next, the rotation angle θ is obtained by calculating the inclination angle from the detected figure and comparing it with the reference angle h calculated in advance. The position is the coordinates at which the candidate area has been moved by the candidate area scanning circuit 7. The position information n thus obtained is output to the display circuit 15.

Next, another embodiment of the present invention will be described.

FIGS. 5A to 5E are diagrams showing the operation sequence of another embodiment of the present invention, and FIG. 6 is an operation flowchart thereof.

Referring to FIGS. 5 and 6, in this embodiment, a rectangle is used as an example of a figure to be detected (see FIG. 5).
(A)). First, considering a rectangular area containing a figure, the coordinates of the center of gravity of the figure are calculated using the upper left coordinates as the origin. Calculate the distance from the barycentric coordinates to the vertex of the figure. Next, circles having the center of gravity as the center and the distance as the radius are calculated by the number of vertices. This circle group is a candidate area. In the present embodiment, since the figure is a rectangle, all the circles coincide and become one (b).

Next, these circles are applied to the detected image, and the image is raster-scanned from the origin (c). If points exist in all the circles (d), the distance between the points is obtained, and it is evaluated whether or not the vertices of the figure. When all the distances between the points on the circle match and the areas match, the combination of the points is the vertex of the detected graphic. The center of gravity here is the position of the figure. By calculating the rotation angle θ from the positions of the points on the circle group and the reference figure, the inclination of the figure can be obtained. This indicates that the object to be detected is shifted by an angle θ from the reference angle h of the reference object.

As described above, the calculation time can be shortened by limiting the combinations of points or figures to be evaluated in advance from among many points or figures. In addition, by using a circle group as a candidate area, detection can be performed without being affected by the detected point or the inclination of the figure, and after the detection, the inclination can be easily calculated by comparing with the reference figure. There are advantages.

(A) to (e) of the detection operation flow of FIG. 6 correspond to (a) to (e) of FIG.

[0024]

As described above, according to the present invention,
By limiting the combinations of points or figures to be evaluated in advance from a large number of points or figures and finding the optimum combination from the point group or figure group, the target figure can be detected quickly and accurately. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIGS. 2A to 2D are explanatory diagrams of a candidate area creation circuit 6. FIGS.

FIG. 3 is an explanatory diagram of a candidate area scanning circuit 7;

4A to 4E are explanatory diagrams of a comparison circuit 8, a circular scanning circuit 9, a figure evaluation circuit 11, and an angle calculation circuit 13.

FIGS. 5A to 5E are diagrams showing the operation order of another embodiment according to the present invention.

FIG. 6 is a flowchart showing an operation flow of another embodiment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photoelectric conversion scanner 2 ... A / D conversion circuit 3 ... Memory circuit 4 ... Binarization circuit 5 ... Memory circuit 6 ... Candidate area creation circuit 7 ... Candidate area scanning circuit 8 ... Comparison circuit 9 ... Circular scanning circuit 10 ... Point Presence check circuit 11 ... Graph evaluation circuit 12 ... Graph presence check circuit 13 ... Angle calculation circuit 14 ... Full scan completion check circuit 15 ... Display circuit a ... Image object b ... Analog signal c ... Digital signal d ... Pictured image e ... 2 Value image f ... Drive signal g ... Reference image h ... Reference angle i ... Moving image j ... Center of gravity k ... Comparative image l ... Number of detected points m ... Presence or absence of figure n ... Rotation angle, position information such as center of gravity o ... No figure information s ... Vertex t ... straight line

Continuation of the front page (51) Int.Cl. ⁶ identification code FI G06F 15/70 400 (58) Investigated field (Int.Cl. ⁶ , DB name) G01B 11/00-11/30 102 G06T 1/00- 9/20

Claims (2)

(57) [Claims] 1. A polygonal object to be imaged, a photoelectric conversion scanner which images the object and converts it into an analog signal, and an A / D which converts the converted analog signal into a digital signal
A conversion circuit; a first memory circuit for storing the converted digital signal as a captured image; and a binary image for binarizing the captured image and narrowing down candidate points as small figures.
A binarizing circuit, a second memory circuit for storing the binary image and outputting a stored candidate area creation drive signal, and a candidate area as a group of circles (the circle is “1” and the background is “0”
A candidate area creating circuit that creates a binary image) as a reference image and calculates a reference angle, a candidate area scanning circuit that moves the reference image one pixel at a time to perform raster scanning, and converts the image into a moving image, A comparison circuit that compares an image with the binary image output from the second memory circuit and outputs a small figure in an AND part as a comparison image, and outputs position information and the number of small figures from the comparison image A circular scanning circuit, a small figure presence / absence check circuit for checking whether or not the required number of small figures are present in each circle, and a position of the small figure on each circle when the required number of small figures is present in each circle A graphic evaluation circuit that calculates the distance between the target patterns and determines that the target graphic is detected when an optimal combination exists; But An angle calculation circuit for detecting position information (rotational angle, center of gravity) from the figure and the reference image when present, a display circuit for displaying the position information, and confirming whether full scanning by the moving image has been completed And a full-scan completion confirmation circuit for outputting figureless information when it is confirmed that the full-scan has been completed. 2. The angle calculation circuit inputs the reference angle information output from the candidate area creation circuit and the center of gravity information output from the candidate area scanning circuit together with the output of the target graphic presence / absence confirmation circuit, The position detecting device according to claim 1 , further comprising calculating information.