Prediction of part machining cycle times via virtual CNC

This paper presents the virtual prediction of part machining cycle times within 95% accuracy by considering the trajectory generation and corner smoothing models of commercial CNCs. The key functions of the CNC which control the machine motions are the real time interpolation, trajectory generation and feed drive control modules. It is shown that only the trajectory generation and the interpolation of tool path geometry are crucial in predicting the part machining cycle times, and the servo control loops contribute negligible time delay. The proposed model is experimentally validated in machining 3 and 5-axis parts on commercial CNC machine tools.