Maglev vehicles, which can be regarded as large vehicle models, have tens of thousands of electronic components. The security problem of large systems has always been a challenge. If partial actuator failures occur in these components, it will lead to critical safety problems for vehicles traveling at high speed. In this paper, a fault-tolerant control strategy is developed to solve the problem of partial actuator failures in the levitation module control system of maglev vehicles based on multi-models. First, a dynamic model for the multiple-point levitation module of a maglev vehicle is established. Considering the actuator drive redundancy, the mode matrix is given for each possible fault. Next, based on each fault mode, the corresponding control signal is designed to ensure the stability and asymptotic tracking performance of the system, and the multi-controller set is formed. Then, the control switching mechanism is designed to select the most appropriate controller to generate control signals. Through simulations and experiments, the effectiveness of the proposed method with actuator fault compensation technology for multiple-point levitation modules of maglev vehicles was verified.

Maglev vehicles apply the entire vehicle load uniformly onto bridges through levitation forces. In assessing the dynamic characteristics of the maglev train–bridge coupling system, it is reasonable to simplify the distributed levitation force as a concentrated force. This article theoretically derives the analytical response of bridge dynamics under the action of a single constant force and conducts numerical simulations for a moving single constant force and a series of equally spaced constant forces passing over simply supported beams and two-span continuous beams, respectively. The topic of discussion is the response of bridge dynamics when different degrees of force concentration are involved. High-precision displacement and acceleration sensors were utilized to conduct tests on the Shanghai maglev line to verify the accuracy of the simulation results. The results indicate that when simplifying the distributed levitation force into a concentrated force model, a frequency ratio can be used to analyze the conditions for resonance between the train and the bridge and to calculate the critical speed of the train; the levitation distribution force of a high-speed maglev vehicle can be simplified into four groups of concentrated forces based on the number of levitation frames to achieve sufficient accuracy, with the dynamic response of the bridge being close to that under distributed loads.

In order to improve the current situation of poor traction ability of medium-low speed maglev train, a variable slip frequency control (VSFC) strategy is proposed based on the constant slip frequency control (CSFC) of linear induction motor (LIM). The control frequency of the starting stage of the vehicle is selected low on the premise of no obvious influence on the levitation performance. After reaching the maximum power point, the traction of the motor is always the maximum that can be exerted under the corresponding speed. Firstly, the mathematical model of linear induction motor is established, and the analytical expressions of traction and normal force are listed; Then the influence of slip frequency on vehicle tractive performance is analyzed by traction calculation, the VSFC strategy is proposed and its advantages are analyzed. The results show that the VSFC strategy can fully suppress the influence of normal force on levitation stability at low speed, and can give full play to the tractive performance of the motor in the whole process.