Adaptive Integral-Type Sliding Mode Control for Magnetic Levitation Linear Guide Suspension Altitude

This paper investigates the constant position suspension altitude control problem for a novel magnetic levitation linear guide. The magnetic levitation linear guide is comprised of a magnetic suspension processing platform and a linear motor direct-drive system. The magnetic suspension system has several characteristics of complicated nonlinearity, parameter perturbation and strong disturbance. In view of these characteristics, an adaptive integral-type sliding mode control (AISMC) technique is used to design magnetic suspension system constant position suspension altitude controller. The AISMC can alleviate chattering and reduce steady error by estimating the boundary of uncertain perturbation. The adaptive tuning algorithm is derived in the sense of the Lyapunov stability theorem, thus the stability of the system can be guaranteed. Simulation results indicate that the proposed AISMC has a better stability, transient and robustness compared with PID control.