Vehicle height control based on active suspension with permanent magnet synchronous linear motor

Adjustments in vehicle height and attitude under high-speed steering, emergency obstacle avoidance, and obstacle crossing can significantly improve the safety, mobility, and passing ability of a vehicle. At present, air and hydraulic suspensions are generally used for vehicle body height adjustment, both of which have problems of slow response and complex structures. In this study, a novel method of vehicle body height adjustment based on active suspension with a permanent magnet synchronous linear motor (PMSLM) is proposed. First, active suspension and PMSLM models are established. Then, the vehicle body height controller is designed by hierarchical control, where the upper layer uses PI control to make the vehicle body height track the desired vehicle body height and calculate the desired control force, whereas the lower layer uses the finite control set model predictive current control to make the linear motor track the desired suspension control force. For motor control, the cost function is constructed based on the minimum tracking error between the reference and predicted currents. The forward Euler discrete method is used to deduce the current prediction model for the linear motor. The simulation tests under different road classes and vehicle speeds prove that the active suspension with the PMSLM can effectively adjust the vehicle body height and has a fast response, simple structure, and does not affect ride comfort. The proposed method provides a new concept for short-term vehicle body height adjustments under specific working conditions.