Backstepping Sliding Mode Control for PMSM Position Servo System Based on Fuzzy Disturbance Observer

This paper propose a new backstepping sliding mode control(BSSMC) method for permanent magnet synchronous motor servo system. The switching control between terminal sliding surface and linear sliding surface is used to improve the speed of position tracking and reduce the influence of nonsingularity of terminal item. A fuzzy disturbance observer(FDO) is constructed to estimate the perturbation term for feedforward compensation so as to reduce the influence of system uncertainty, external disturbance and chattering phenomenon. For the problem that it is hard to determine the optimal weight vector of fuzzy parameters, an adaptive rate of weight vector is put forward. Simulations and experiments indicate that the proposed controller has good robustness and tracking effect in the case of sudden change of load torque.