A CNC Interpolation Algorithm for Parametric Curves Based on Feedback Compensation

In order to maintain a high machining accuracy and a constant speed feedrate in CNC machining and to improve the capability of CNC machining in handling complex parts, the complicated interpolation algorithms need to be used in CNC interpolator, which is time-consuming for large amount of computation, thus influencing the machining speed. To solve this problem, a simple and efficient CNC interpolation algorithm based on feedback interpolation action is presented, which corrects repeatedly the interpolation errors to meet the interpolation requirements. The simulation results demonstrate the proposed algorithm can satisfy the machining of a variety of different parametric curves. Compared with the conventional interpolation algorithm, it features high universality, small computational amount small feedrate error and high computational accuracy, thereby greatly shortening the processing time and improving the processing efficiency. The feedback interpolation compensation algorithm implements on PMC32-600 DSP motion control card. The real cutting experiment proves that the algorithm can effectively guarantee the constancy of feedrate and the smoothness of parametric curves, thus improving the processing quality.