Research on Interpolation Algorithm for NC Machining Trace Control Based on Midpoint Interpolation

摘要

Point-by-point comparison interpolation algorithm is often applied to NC (Numerical Control) system, however, there are some problems such as lag in phase, out of step and low-speed crawl for higher feed velocity(F≥3000mm/min )in multi-axes synchronous machining system, which influences response velocity and interpolation precision of NC system. In view of this, based on the point-by-point comparison principle , the midpoint interpolation algorithm for deviation judgment in NC machining trace control was proposed, mathmatical model of interpolation established, the deviation judgement function of the interpolation algorithm improved and optimized. It is shown from comparative analysis and practical application of midpoint interpolation algorithm that the interpolation precision raises from 1 to 0.5 pulse equivalent, interpolation points reduce greatly, response velocity quickens and interpolation precision heightens as well.