A novel fractional-order boundary layer fast terminal sliding mode controller for permanent magnet linear synchronous motor

This paper presents a novel fractional-order boundary layer fast terminal sliding mode (FBLFTSM) control method for high-precision tracking tasks of the permanent magnet linear synchronous motor (PMLSM). Specifically, a dynamic model of PMLSM with lumped uncertainty is established by considering the tracking task involving parameter variations, disturbance load, etc. Then, based on the dynamic model, a FBLFTSM control law is designed to guarantee higher tracking accuracy of the surface motion than the classical terminal sliding mode control even if the system suffers from unknown disturbance. Meanwhile, the fractional-order boundary layer control has the feature of “large error turns into large gain, small error turns into small gain,” which solves the contradiction between weak chattering and fast convergence in the integer-order boundary layer control and improves the dynamic performance of the system. Finally, the effectiveness of the control approach is verified by conducting tracking experiments on the cSPACE-based motor platform.