Adaptive Backstepping-Based Non-singular Finite-Time Sliding Mode Controller for Suspension of Maglev Platforms

In this paper, an adaptive backstepping-based sliding mode controller is proposed for a magnetic levitation (maglev) platform. A novel non-singular finite-time sliding surface is proposed to reduce the steady-state error. The proposed controller is tested using numerical simulation in MATLAB/Simulink, and the results are compared with an adaptive backstepping-based sliding mode controller having a conventional non-singular terminal sliding surface. Backstepping is used to derive the sliding surface, and two adaptively tuned gains are included in the controller. The control law is obtained at the final step of backstepping where a power rate reaching law is used to obtain a faster convergence. Detailed stability analysis of the entire controller, including the smaller subsystems obtained via backstepping is also presented, and conditions based on the stability criteria are derived which can be used to design the controller parameters.