| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for interpolating a curve for generating an approximate straight line for utilizing the allowable range of tolerance to the maximum and for making the number of the approximate straight lines smaller than that in a conventional curve interpolation system. SOLUTION: A curve 20 is calculated from inputted curve data, a tolerance circle 21 with tolerance as a radius is prepared within a plane with the tangential direction of the curve as a normal direction at each point on the curve from the curve 20 and the inputted tolerance and upper and lower tolerance lines 26A and 26B are calculated based on the circle. Then, the start point and the end point of the curve 20 are connected through a straight line and the end point of the straight line is made close to the end point unit it enters the inside of the upper and lower tolerance lines 26A and 26B. The line is extended, and a cross point 24A between the upper and lower tolerance lines 26A and 26B is calculated to make the point the end point of the straight line and to decide an initial approximate straight line 25A as well. The end point is used as the start point of the second straight line and all approximate straight lines are decided by repeating the same way. Afterwards, an interpolation arithmetic operation is executed along the approximate straight line to make it command data. |
