A Novel Robust Adaptive Nonsingular Fast Integral Terminal Sliding Mode Controller for Permanent Magnet Linear Synchronous Motors

Abstract

To realize the high-precision tracking control of permanent magnet linear synchronous motor (PMLSM) in complex working conditions, a control system with strong robustness must be equipped for PMLSM, so this article proposes a novel robust adaptive nonsingular fast integral terminal sliding mode control (ANFITSMC) strategy. First, a dynamical mathematical model of PMLSM is established to describe the thrust and unknown uncertainty in the motion process. Second, considering that the uncertain factors, such as external disturbances and high-frequency noises in the system, may cause the degradation of position tracking accuracy, a nonsingular fast integral terminal sliding mode control (NFITSMC) method that only requires position and velocity information to estimate the lumped uncertainty of the system is designed. Meanwhile, the adaptive control algorithm is used to estimate the lumped uncertainty dynamically in real time, thus weakening the chattering and improving the tracking accuracy. Also, the stability of this control system is proven by utilizing the Lyapunov stability theory. Finally, the high-precision positioning experimental platform is used to carry out experimental tests with different position trajectory commands. The experimental results show that the proposed ANFITSMC method not only enables the system to have higher control accuracy but also ensures a more robust performance.