Multiphysics modeling and vibration control optimization of the electromagnetic damper in vehicle suspension systems

The electromagnetic damper (EMD) represents a novel approach to vehicle suspension vibration control, offering fast response and precise controllability. Nevertheless, the friction and inertia within its internal structure limit further improvements in control performance. In this paper, a mathematical model of the EMD is proposed which takes into account multiphysics factors, including electromagnetic damping of the permanent magnet synchronous motor (PMSM), inertia of moving parts and nonlinear friction. The proposed model is validated through motor and damper characteristic experiments, combined with a genetic algorithm (GA) to accurately identify motor parameters and damper structure parameters. Furthermore, the role of each physical factor on the output damping force in different frequency ranges is revealed through the sine frequency sweep experiments and spectral analysis. The results reveal that friction dominates at low-frequency excitation, where both the traditional and multiphysics models can effectively describe system behavior. At high-frequency excitation, inertial effects become significantly pronounced, and the semi-active control strategy based on the multiphysics model demonstrates enhanced force-tracking capability and vibration suppression, clearly outperforming the traditional model and approaching the performance of a fully active suspension system. These findings provide theoretical support for the design and control optimization of the EMD, and thus benefit the improvement of the overall performance of the suspension systems.