Adaptive fuzzy sliding mode control of linear induction motors with unknown end effect consideration

In this paper, an adaptive fuzzy sliding mode controller (AFSMC) is proposed for a linear induction motor (LIM) taking into account the longitudinal end effect and uncertainties including the friction force. The dynamic mathematical model of an indirect field-oriented LIM drive is firstly derived for controlling the LIM. On the basis of a backstepping control law, a sliding mode controller (SMC) embedded with fuzzy boundary layer is designed to compensate lumped uncertainties during the tracking control of periodic reference trajectories. Since the bound of lumped uncertainties is difficult to obtain advance in practical applications, an adaptive tuner based on the sense of Lyapunov stability theorem is derived to adjust the controller parameter in real-time, and also for further confronting the increasing disturbance and uncertainties. The indirect field-oriented LIM with the proposed AFSMC assures the system stability, asymptotic output tracking, and the robust control performance. The effectiveness of the proposed control scheme is verified through experimental results, and its advantages of control performance and robustness are exhibited in comparison with SMC and FSMC approaches.