Adaptive Fixed-Time Antilock Control of Levitation System of High-Speed Maglev Train

Due to electromagnet uncertainties, rail irregularities and other external disturbances, an excessively small levitation gap of electromagnetic levitation system (EMLS) may lead to serious deadlock, which would severely endanger the operational safety of high-speed maglev trains. A highly reliable levitation controller must be designed with the inherent antilock capability to prevent such fatal deadlock. In this work, an adaptive fixed-time levitation control scheme is established by directly introducing antilock limits of EMLS into an output-constrained controller, by which not only the desired levitation distance is achieved with a fixed-time convergence rate, but also the EMLS never exceeds the predefined levitation boundaries. Therefore, the antilock levitation operation is naturally ensured. Both theoretical analysis and numerical simulations verify the effectiveness of the proposed control method.