Lazy Prescribed-Time Synchronization Control of Half Bogie for High-Speed Maglev Train Considering Track Irregularities and Input Constraints

Inevitable irregularities excite a traveling maglev train along a journey by disturbing air gaps and thus modifying levitation forces. For a half bogie which is a rigid coupled structure with a separate levitation unit at each endpoint, the effects of track irregularities hamper the synchronization of the two units. Motivated by the aforementioned, this paper establishes a newly nonlinear model for the half bogie considering irregularities, internal and external disturbances. Based on this model, a prescribed-time synchronization controller (PTSC) considering input constraints is designed while two adaptive disturbance observers (ADOs) are combined to address track irregularities and disturbances. To reduce the actuating times caused by synchronization, a lazy cooperation mode is adopted by independently introducing an event-triggered mechanism for each levitation unit. Theoretical analysis establishes the stability of the whole control scheme and demonstrates that the tracking errors and estimate errors can be arbitrarily small within a prescribed time, which can be determined by users through a parameter, and the synchronization is achieved. Numerical simulations compared with other two control schemes verify the effectiveness of the proposed control scheme, where both the ideal irregularity model and the field data measured from the Shanghai commercial line are tested.

I. Introduction

The historic patent applied by a German engineer called Hermann Kemper in 1934 marks the dawn of maglev train research. After seven decades, a commercial Electro-Magnetic Suspension (EMS) train finally came out in Shanghai. Since then, maglev trains have gained continuous attention since the maglev train enjoys the features of less friction, less wear, less noise, strong climbing capacity and low-cost maintenance compared with steel-on-steel railway systems [1].