Improved Adaptive Terminal Sliding-Mode Reaching Law for Speed Control of TPMLSM With Disturbance Observer

This paper investigates the speed regulation issue of the tubular permanent magnet linear synchronous motor (TPMLSM) control system based on sliding-mode control (SMC) and disturbance compensation technology. By introducing the terminal attractor on the basis of exponential reaching law, an improved adaptive terminal sliding-mode reaching law (IATSMRL) is proposed to ensure the state variables of the control system to reach their equilibrium points quickly and suppress the chattering effectively. Based on the IATSMRL, the sliding-mode speed controller is designed to improve the dynamic performance of the TPMLSM control system. To further compensate the lumped disturbance in the TPMLSM control system, the paper utilizes an extended sliding-mode disturbance observer (ESMDO) to obtain the estimated lumped disturbance. Then an anti-disturbance sliding-mode speed controller is designed to strengthen the disturbance rejection capability of the TPMLSM control system and further improve the dynamic performance. The stability of the controller is proved by the Lyapunov stability theory. Comprehensive simulation and experimental results have been carried out to demonstrate the superiority of the proposed method.