Vibration analysis and multi-state feedback control of maglev vehicle-guideway coupling system

Due to the existence of elastic modes in the track, the suspension system of maglev train is prone to vehicle-track coupling vibration, which has become an important problem restricting the further development of maglev train technology. In view of the limitation of the existing rigid track suspension model, this paper establishes an electromagnet-controller-elastic track coupling system model. And then, the nonlinear maglev system is transformed into a linear system by Hartman-Grobman theorem. Since the elastic deformation of the track is difficult to measure, a tracking differentiator is presented to filter out the interference of the displacement signal and obtain the differential signal of the gap between the electromagnet and the track. In order to suppress the vehicle-track coupling vibration, a four-state feedback control method is proposed by introducing the gap differential feedback signal. According to the Hurwitz algebraic criterion, the stability of four-state feedback control system is compared with that of three-state feedback control system. Simulation results show that, the four-state feedback control method can provide the elastic deformation information of the track, and can suppress the coupling vibration between the vehicle and the elastic track effectively.