Vertical vibration of hub motor driven electric vehicle based on EMPC

Here, aiming at deterioration of ride comfort and handling stability caused due to increase in unsprung mass of hub driven electric vehicle, an active suspension control method based on the explicit model predictive control (EMPC) theory was proposed. A 4-DOF system model composed of rigid ring tire model and air suspension model was established, and the function of multi-objective including vehicle ride comfort, stability and motor performance and constraint conditions were determined. Based on the multi-parameter quadratic programming theory, the implicit model predictive control system was converted into the corresponding explicit polyhedral piece-wise affine (PPWA) system, the optimal control law of state variables was solved off-line, and the optimal active forces were obtained by using the explicit control law on parametric partitions. The simulation results showed that compared with the passive suspension and the active suspension using sky-hook control strategy, the active suspension based on EMPC theory has an obvious effect on improving RMS values of vehicle body vertical acceleration, tire dynamic load and hub motor eccentricity; it improves the ride comfort, handling stability and motor performance of hub motor driven electric vehicles. © 2022, Editorial Office of Journal of Vibration and Shock. All right reserved.