| 摘要 |
PURPOSE:To detect the center of a hole highly accurately, by computing the position of the center of the hole in the scanning direction based on the position of an image sensor at an instant of the start of the detection of the hole and the instant of the finish of the detection of the hole, and computing the position of the center in the direction perpendicular to the positions of both ends of a chord. CONSTITUTION:A camera 29 starts the scanning in the direction of X 6 by an encoder. The counted number of encoder corresponding to the distance from an original point 5, which is a starting point, to an initial detected position 17 of a tightening hole 10 to be detected is temporarily stored. The counted number of the encoder corresponding to the distance from the original point 5 to a last detected position 2 of the hole 10 is also temporary stored. By using these memory values, a central position 13 of the hole 10 in the directiom of X 6 is computed by a four rules, and the computed result is temporarily stored. At a position 18, which is deviated from the center 11, a central position 14 of the hole in the direction of Y 7 is computed, based on the changed output value from an image sensor 1, from positions 19 and 22 for both ends of a chord in the direction of Y of the hole 10. The positions 13 and 14 in the directions of X and Y of the central position 11 of the hole 10 are outputted in a BCD code. |
