Disturbance-observer-based nonlinear friction compensation in table drive system

Presents a disturbance-observer-based high-accuracy trajectory control algorithm for nonlinear friction compensation in table drive systems. In order to design an effective compensator, dynamic characteristics of the friction are examined and, as a result, a simple but high-accuracy disturbance observer can be designed on the basis of the analyzed friction characteristic. Using the observer-based compensation, the precise velocity/position control can be attained without the response delay which is caused by the restricted control bandwidth in conventional compensation algorithms. Experimental results show the significant performance improvement of the proposed algorithm in trajectory control with low feed rate and velocity reversal motion.