| 摘要 |
PURPOSE:To prevent occurrence of error even though a body to be checked is moved, by providing recognizing points which determine the length of a reference segment at least at two points of the body to be checked, and continuously obtaining the position of the body to be checked based on the distance between the recognizing point on a screen and the length of the reference segment. CONSTITUTION:Recongizing point 3 and 4 are provided on a body to be checked 1. The distance between the points is made to be the length L of a reference segment. The image of the body to be checked 1 is picked up by a measuring device 2 and displayed on a screen. The corrdinates X and Y of the points 3 and 4 on the screen when the body to be checked 1 is located at the position of solid lines are made to Xa0, Xb0, Ya0 and Yb0. The coordinates when the body is located at the position of dotted lines are made to be Xa1, Xb1, Ya1 and Yb1. Then by using the expression K1{(Xa0-Xb0)<2>+ (Ya0-Yb0)<2>}<1/2>=K2 {(Xa1-Xb1)<2>+(Ya1-Yb1)<2>}<1/2>= L, coefficients K1 and K2, which convert the unit distance on the screen into the actual unit distance of the position of the body to be checked 1, are continuously obtained. Thus the displacement of the actual position can be accurately obtained based on the position of the image of the body to be checked 1 and the screen. |
