Method of measuring the position of a hole

摘要

The position of a hole is measured by image-sensing a holed portion formed in a workpiece and then measuring the central position of the holed portion based on an image of the holed portion on a screen of an image sensing apparatus. A plurality of hole edge points which coincide with a hole edge of the image of the holed portion are picked up. A regression ellipse which represents the image of the holed portion from coordinates of the hole edge points is calculated. The central position of the holed portion is obtained from coordinates of the center of the regression ellipse.