Experimental validation of a new model-based control strategy for a semi-active suspension system

Aiming at the control of a continuously variable hydraulic semi-active damper, in this paper a dynamic feedforward control approach is combined with a feedback component. In order to track reference forces from higher level suspension controllers, in practice, the damper current inputs are mainly calculated by means of static damper characteristics. Thereby, dynamic effects of the damper force generation are neglected. By taking the dynamic damper behavior into account, the model used in the proposed feedforward control component describes the damper behavior considerably better than the state of the art. Moreover, the additional feedback element further improves the precision of the actual provided damping force. The new concept is validated in real-time experiments on a quarter-car test rig for a semi-active suspension system. Using a skyhook law, its performance is analyzed in comparison to the static characteristic-based control. As better force tracking is provided, the proposed model-based strategy is able to improve ride comfort and ride safety simultaneously.