Optimizing Design of Tool Interpolating Algorithm in NC System

摘要

The line and arc is approached by broken line in point by point comparison interpolating algorithm. If the pulse (the distance of one step) is short enough, the precision is high enough. If the pulse is 0.01 and the feed speed is no more than 3000mm/min, the precision of point by point comparison interpolating algorithm is well enough to meet the needs. But if the pulse is 0.005mm to 0.001mm and the feed speed is more than 3000mm/min, the number of interpolating point is more and more. The CPU is busy with the value of moving coordinate calculate and the pulse of feed set and occupy more resource, so the problem of lag, out of step and creep by low speed in Multi-axis. Then speed of response and interpolating precision about the system is effect. In this paper, In view of the principle of point by point comparison method, advance the foundation deciding whether the middle point interpolation is the control forth step error of NC system, establish math model of inserting and compensation method, change and improve the function that judge error by interpolating method. According to the result of the example, the middle interpolation method make interpolation precision raise from 1 pulse equivalent to 0.5 pulse equivalent, and interpolation points are greatly reduced, respond velocity quicken and interpolation precision heighten.