Novel circular interpolation algorithm for high-accuracy positioning systems

Two-stage interpolation algorithm is popular in CNC system, this method contains software rough interpolation and hardware fine interpolation. For classical method with linear approximation at rough interpolation stage, it is known that there are some potential problems, such as: approximation error and contradiction between speed and accuracy. In this paper, a novel two-stage interpolation algorithm is proposed, the first stage is rough interpolation without linear approximation and the second stage is circular arc fine interpolation, which makes an improvement than conventional interpolation algorithms. Simulation results indicate that the proposed algorithm has almost no theoretical error. With proposed method, the contradiction between speed and accuracy is eliminated, performance for feed-rate and interpolation period would be improved while accuracy can be guaranteed.