Position Tracking Control for PMSM System Based on Continuous Sliding Mode Control and Sliding Mode Observer

In this article, a robust finite-time control strategy using continuous terminal sliding mode control (CTSMC) and sliding mode observer (SMO) is proposed to solve the problem of position tracking of permanent magnet synchronous motor (PMSM) servo system. The control performance of such a system is always affected by internal and external disturbances. For this reason, a continuous sliding mode control (CSMC) method with fast convergence and strong anti-disturbance is firstly introduced. Then, considering that the disturbance of the actual system is generally in various forms and time-varying, to further improve the disturbance rejection ability of the system, an SMO based CTSMC method is proposed, where the SMO is devised to estimate time-varying disturbances and the estimations are employed to the position controller through feedforward compensation for disturbance attenuation. The present control method can not only improve the tracking rate, but also enhance the disturbance suppression ability of the system. Compared with the PD control, CSMC, and CTSMC, simulation results demonstrate that the proposed control method can achieve the promised control performance for the studied system.