A position servo system of permanent magnet synchronous motor based on back-stepping adaptive sliding mode control

For the position servo system of permanent magnet synchronous motor(PMSM), a back-stepping based adaptive sliding mode control(ASMC) strategy is proposed in this paper to meet the requirements of strong robustness, high control accuracy, fast and non-overshoot response. The combination of back-stepping and sliding mode control solves the problems of low-accuracy, poor system performance, and weak robustness in the conventional PID design. Meanwhile, the introduction of adaptive mechanism releases the priori knowledge of upper bounds on disturbance and parametric uncertainty. Lyapunov stability theorem is employed to provide the stability analysis of the closed-loop system. Finally, the proposed method is verified on DSP based experimental platform. The experimental results show that the proposed design performs better than conventional PID control with respect to the tracking accuracy, robustness and response speed.