Research on Non-Linear Parameters Identification for Servo System of CNC Machine Tools

As phenomena of friction in computer numerical control(CNC) machine tools is inevitable, accurately modeling of friction is need for precise position control and performance evaluation of CNC machine tools. This paper proposed an identification method that non-linear friction model described as Stribeck are linearized by using high order Taylor series expansion and parameters of the model are obtained by least square method (LSM). Signals of servo motor current and rotating rate which are offered in many modem CNC machine tools are needed for the identification and experiments results show that parameters of Stribeck model can be obtained accurately by identification. The method is suited for industrial condition and has its practicality.