Sliding mode control of servo systems with nonlinear friction based on a fuzzy reaching law

A fuzzy reaching law was proposed to eliminate the "crawling" and "flat top" problem of servo systems because of nonlinear friction, a sliding mode controller based on the T-S fuzzy model reaching law was designed, and the simulation and experimental tests were carried out. The results demonstrate the controller not only can effectively eliminate "crawling" and "flat top" phenomena and enhance the tracking accuracy of servo systems, but also can decrease the chattering of conventional reaching law sliding mode controllers significantly and improve control quality. Owing to the good fitness of this controller, it can be used in servo systems with high control performance.