JPS63246604A - Method for measuring posture angle of polygonal object - Google Patents

Abstract

PURPOSE:To accurately measure a posture angle in a real time by a simple means, on the assumption that the posture angle of a simple polygonal object based on a rectangle is measured. CONSTITUTION:The two-dimensional figure pattern of a polygonal object being an object to be confirmed is taken in by a pattern input apparatus and binarized to obtain a matrix pattern. After the figure pattern is converted to a projection drawing with respect to a vertical or horizontal reference axis in an image processor, said projection drawing is further converted to the second projection drawing with respect to the second reference axis crossing the reference axis at a right angle. The gradient of the oblique side in the second projection drawing is measured to measure the posture angle of the polygonal object from said gradient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for automatically measuring the attitude angle of a polygonal object with high precision, and more specifically to bonding of electronic components such as IC chips.

The present invention relates to a method for accurately and automatically measuring the attitude angle of polygonal parts when assembling mechanical parts.

[Prior Art] In production lines where electronic components such as IC chips are bonded, mechanical components are assembled, etc., it is often necessary to recognize the shape, position, orientation, etc. of objects using automatic crystals.
Usually, the shape of the recognition target is often a simple polygon, mainly a rectangle, and conventional posture angle detection techniques are known.

It is customary to be able to recognize the pose of an object regardless of its shape, but this makes the device extremely complex and requires a long time for recognition, which ultimately impairs its practicality. ing.

However, if the target object is limited to a polygon as described above, it is expected that the posture of the object can be measured accurately and in real time using a simple device.

[Problems to be Solved by the Invention] The present invention seeks to provide a method for measuring the attitude angle of a polygonal object that satisfies such requirements, and in particular, by specifying the recognition target as a polygon, The purpose of the present invention is to provide an attitude angle measurement method that allows accurate measurement using extremely simple means and in real time.

[Means for Solving the Problems] The attitude angle measuring method of the present invention to achieve the above object is to
A dimensional graphic pattern is taken in, converted into a binary matrix pattern, and then processed by an image processing device.
After converting the above figure pattern into a projection diagram with respect to a vertical or horizontal reference axis, the projection diagram is further converted into a second projection diagram with respect to a second reference axis orthogonal to the above reference axis, and this second projection diagram The method is characterized in that the slope of the hypotenuse is measured, and the attitude angle of the polygonal object is determined from the slope.

[Example] The present invention is based on the premise that the recognition target object whose attitude angle is to be measured is a polygon.

FIG. 1 shows a flowchart of the image processing process in the present invention. Here, to explain a rectangle as an example with reference to the same figure, when measuring the attitude angle,
First, the image data to be recognized is captured as a two-dimensional graphic pattern using a pattern input device such as an ITV camera, and the output for each sample point on the scanning line is A.
The D conversion converts the sample points into binary codes corresponding to the brightness and darkness of the sample points, thereby converting the graphic pattern into a binary matrix pattern.

In the image processing device to which the above matrix Φ pattern is input, first, based on the data,
, C, or two-time projections as shown in A, D, and H of the same figure. That is, the graphic pattern has a vertical or horizontal reference axis as shown in FIG. 2B or the same figure.

For example, it is converted into a projection view with respect to the Y axis, and then, as shown in C or E in the figure, the projection view is further converted into a second projection view with respect to a second reference axis orthogonal to the reference axis.

When the projection is performed twice in this way, the attitude angle θ can be accurately determined by measuring the slope a1 of the hypotenuse in the second projection, that is, the straight line represented by Y = a lX + b l Can be done.

More specifically, now, the slope of the hypotenuse in the second projection view of FIG. 2C, al.

When al=jan(α), the attitude angle θ is given by geometric calculation.

Therefore, if the gradient a1 of the hypotenuse in FIG. 2C is determined by some means, the attitude angle θ of the rectangle can be determined.

Note that the slope a1 of the oblique side can be measured extremely easily using a known technique.

On the other hand, the slope a2 of the hypotenuse in the second projection view of Fig. 2E
Similarly, if a2=jan(β), then the attitude angle θ is.

given by.

Therefore, the posture angle θ of the rectangle can also be determined by determining the gradient a2 of the hypotenuse by some means.

When measuring the attitude angle of an object using this method,
As can be seen from Figure 2 A-E, the attitude angle θ of a rectangular object is
is measured by α or β, which is essentially twice that value. Therefore, assuming that these measurements are performed using measurement means with the same resolution, the accuracy will be lower than when directly measuring the attitude angle θ. can be increased.

Next, to consider the measurement accuracy of the above method, the second
From the relationship between Figure A and Figure 2C, the relationship between the slope α of the hypotenuse in Figure 2C and the attitude angle θ of the rectangle shown in Figure 2A is expressed by the following equation.

5in2θ=　tanα Partially differentiating the above equation and summarizing it, we get Δθ=□・Δα 2 a cos20# C0fi2 (X, 1+tan2α=□ co! 12α Because of the relationship, the above formula is becomes.

That is, the relationship between the error Δα when measuring the slope α of the hypotenuse in FIG. As can be seen from the figure, the accuracy is considerably improved. In addition, in Fig. 3, the value of Δθ/Δα is 1
A smaller value means that the measurement error becomes smaller by measuring α.

Moreover, FIG. 4 shows the attitude angle measurement error amount when a rectangular object assumes various attitude angles.

W = 25. hm, H=20.0!11 rectangle, and shows the maximum error, average error, and minimum error of the results measured using a 40×40 matrix pattern.

Note that the experimental results shown in the same figure show that the figure pattern essentially falls within a 30x30 matrix pattern, and the amount of error is relatively large because the measurements were taken under extremely poor conditions. , it can be expected that the amount of error can be significantly reduced by increasing the amount of information by increasing the number of divisions of the matrix bone pattern.

[Effects of the Invention] As detailed above, according to the attitude angle measurement method of the present invention, the attitude angle measurement method of the present invention is based on the premise of measuring the attitude angle of a simple polygonal object mainly consisting of a rectangle, so that the attitude angle measurement method of the present invention can be achieved using extremely simple means. Measurements can be made accurately and in real time.

[Brief explanation of drawings]

Fig. 1 is a flowchart of the image processing process in the measurement method of the present invention, Fig. 2 is an explanatory diagram regarding two-time projection of graphic data, and Fig. 3 is a flowchart of the image processing process in the measurement method of the present invention.
4 and 4 are graphs for explaining measurement errors when using the method of the present invention. 2nd success

Claims (1)

[Claims] 1. A two-dimensional graphic pattern of a polygonal object to be recognized is captured by a pattern input device, converted into a binary matrix pattern, and an image processing device converts the graphic pattern into a vertical or horizontal reference axis. After converting into a projection diagram for
A method for measuring an attitude angle of a polygonal object, characterized in that the attitude angle of the polygonal object is measured from the gradient thereof.