Dual-Loop Model Predictive Control of Permanent Magnet Linear Synchronous Motor for Active Suspension

To enhance the dynamic performance of the linear motor active suspension (LMAS) and the thrust characteristics of the permanent magnet linear synchronous motor (PMLSM), this study proposes a dual-loop model predictive control (MPC) framework for the LMAS. The outer loop MPC for active suspension is initially formulated, incorporating an optimization objective function that amalgamates body acceleration, suspension deflection, tire dynamic load, and suspension control force. Subsequently, a one-step delay compensation technique is introduced to address the intrinsic delay issue in the motor control system. To mitigate the degradation in performance due to motor parameter discrepancies, a disturbance sliding mode observer (DSMO) is devised. Advanced modified three-vector model predictive current control (MTMPCC) is also introduced to bolster the thrust performance of the PMLSM while minimizing the controller computational load. Accordingly, an inner loop control amalgamating DSMO and MTMPCC (DSMO+MTMPCC) is conceptualized. Experimental validation is performed using a dSPACE-based bench test. The deviation between the experimental and simulated results concerning suspension dynamic performance was confined to 8%, corroborating the simulation's accuracy. Furthermore, the DSMO+MTMPCC scheme effectively minimizes fluctuation in stator current and thrust of the PMLSM, thereby confirming the efficacy of the dual-loop MPC framework.