Improved sliding mode control for permanent magnet synchronous motor servo system

In this study, an improved sliding mode control (ISMC) method combining continuous non-singular terminal sliding mode (CNTSM) and linear active disturbance rejection control (LADRC) for permanent magnet synchronous motor (PMSM) servo system is proposed to improve the performance of PMSM. Based on the mathematical model of PMSM, combined with SMC theory and LADRC theory, CNTSM controller based on continuous function is proposed to solve the singularity of terminal sliding mode (TSM) control. In order to solve the contradiction between the convergence performance of sliding mode control and the ability of chattering suppression, fuzzy control is introduced to adjust the gain of sliding mode controller in real time. LADRC is developed to ensure the current starting conditions of the motor and improve the robustness. Moreover, the asymptotic stability of the system is guaranteed by the Lyapunov theorem and it is verified by the AISim MBD servo motor experimental platform. Experiments show that the algorithm has good tracking performance and robustness.