Adaptive Nonsingular Terminal Sliding Mode Control with Time-Delay Estimation for Linear Motor Systems

This paper presents a new adaptive nonsingualr terminal sliding mode control scheme for a class of motion platform driven by permanent-magnet linear motor. A barrier function (BF) is utilized to design the adaptive control gain law, then the overestimation of control gain that usually exists in sliding mode control (SMC) is avoided without requiring the upper boundary of system uncertainties. Moreover, this control scheme can guarantee the finite-time convergence of the system and maintain the system state within a specified zero neighborhood. In addition, the practical time-delay estimation (TDE) technology is used to estimate the system dynamics and uncertainties, such as model errors, parameters variation and external disturbances. Therefore, the proposed controller has strong robustness and disturbance rejection ability. Finally, the effectiveness of this study is proved through some comparative experiments via a linear motor driven platform.