Adaptive backstepping sliding mode control for linear induction motor drive

An adaptive backstepping sliding mode controller, which combines both the merits of adaptive backstepping control and sliding mode control, is proposed to control the mover position of a linear induction motor (LIM) drive to compensate for the uncertainties including the friction force. First, the dynamic model of an indirect field-oriented LIM drive is derived. Then, a backstepping sliding mode approach is proposed to compensate the uncertainties which occur in the motion control system. The uncertainties are lumped, and the bound of the lumped uncertainty is necessary in the design of the backstepping sliding mode controller. However, the bound of the lumped uncertainty is difficult to obtain in advance in practical applications. Therefore, an adaptive law is derived to adapt the value of the lumped uncertainty in real-time, and an adaptive backstepping sliding mode control law is proposed. With the adaptive backstepping sliding mode controller, the mover position of the LIM drive possesses the advantages of good transient control performance and robustness to uncertainties for the tracking of periodic reference trajectories. The effectiveness of the proposed control scheme is verified by both the simulated and experimental results.