Adaptive sliding friction compensation method based on modified LuGre model

In order to establish an open-servo system with good dynamic performance, this paper proposes a adaptive sliding mode compensation method based on modified viscous friction LuGre model. It is applied to solve the problem of adaptive friction compensation in unknown modeling errors and disturbance rejection. Firstly, a dynamic equation of an open-servo system is given and a servo system equation of state based on modified LuGre friction model is established. Secondly, according to the inversion design, an adaptive sliding friction controller, the corresponding adaptive laws and switching functions are given. Besides, its global asymptotic stability is analyzed by this method. In the last, a programmable multi-axis controller is utilized to realize the compensation applied to the open-servo platform and demonstrate the validity of the method. Results show that the tracking error of servo system is reduced from ±6.9 μm to ±4.1 μm compared with the conventional adaptive friction compensation, when the input signal is a sinusoidal signal. The proposed method effectively suppresses the adverse effects of friction and other uncertainties on the servo system and improves the tracking performance of the servo system. ©, 2015, Tianjin University. All right reserved.