IMPROVING CONTOUR MACHINING PRECISION BY THE LINEAR SERVO ROBUST TRACKING CONTROL

ZHAO Ximei1 GUO Qingding1 CHEN Donglan2

(1. School of Electrical Engineering, Shenyang University of Technology, Shenyang 110023;
2. Tuning Machine Institute, Shenyang First Machining Tool Company, Shenyang 110025)

Abstract: To reduce the contour error of the part machine, for the linear servo drive system, a robust tracking control strategy based on combining zero phase error tracking control (ZPETC) with the disturbance observer (DOB) is proposed. The zero phase error tracking controller is designed to ensure that the system has fast tracking performance and implements exactly tracking; while the DOB can overcome the influences of the uncertainties of the parameters perturbation, the external load disturbances, unmodelled dynamic and mechanical nonlinearity etc. DOB can compensate for each axis according to predicted disturbance information to eliminate the influences of the disturbance to the system, thus the stability and robustness of the system are obtained. The simulation results show that the control scheme not only can enhance the fast tracking performance in the linear servo system, but also has a strong robustness to parametric variations and resistance disturbances. Therefore the contour error is reduced effectively, and the precision of the contour machining is improved greatly.

Key words: Disturbance observer Linear servo Zero phase error tracking control Tracking control Contouring control

CLC No:  TP273  TM383.42

国家自然科学基金资助项目(50075057). Received 20050613, received in revised form 20051220收到修改稿