Finite-time Control of High-speed Maglev Train Levitation System based on Terminal Sliding Mode

The levitation system of the high-speed maglev train is a complex system that must quickly adjust after disturbances to minimize their impact on the train's movements. This paper presents a type of non-singular terminal sliding mode (NTSM) finite-time control approach for the levitation gap tracking of the high-speed maglev train. First, we analyze the levitation system's dynamic characteristics with unknown disturbances. Secondly, a nonlinear observer is used to estimate disturbances in the system. Then, based on the estimated disturbance and considering the potential singularity of the sliding mode surface, a non-singular terminal sliding mode control method (NTSMC) is devised with an improved power type reaching rate. Finally, the closed-loop system is proven to be stable. The simulation results show that under disturbance conditions the proposed method can significantly reduce the convergence time and diminish the levitation gap fluctuations by more than 90%. This offers a new way to make Maglev trains more reliable and stable at high speeds.