Interpolation method in automatic programming

A method for machining a workpiece having a target shape with first and second sides using a numerical control program including first and second blocks corresponding to the first and second sides, respectively, comprising the step of:

• (a) generating target movement amounts of substantially equal length, from the first block;
• (b) generating a last target movement amount from the first block;
• (c) determining whether the last target movement amount is substantially equal to one of the target movement amounts of said step (a);
• (d) determining an angle between the first and second sides of the target workpiece in response to a determination in said step (c) that the last target amount is less than one of the target movement amounts;
• (e) determining whether the angle of said step (d) is less than a predetermined angle, and whether the last target movement amount of said step (b) is less than a predetermined length;
• (f) executing an overlapping process to establish a starting position for determining target movement amounts for the second block in response to a determination in said step (e) that the angle of said step (e) is not less than the predetermined angle or that the last target movement amount is not less than the predetermined length;
• (g) determining the starting position for determining target movement amounts for the second block without executing the overlapping process of said step (f) in response to a determination in said step (e) that the angle of said step (e) is less than the predetermined angle and the last amount of movement is less than the predetermined length;
• and
• (h) machining the workpiece based on said steps (a)-(g).