Development of Robust Constrained Control Strategy for Active Suspension System of Electric Vehicle with In-Wheel-Motor

In order to suppress the vibration of the active suspension system for electric vehicle with in-wheel-motor, the robust constrained H ∞ control strategy is developed, the influences of the sprung mass variation and control constraint of the in-wheel active suspension system are considered in the control strategy. The oriented uncertain active suspension dynamic model is established through the linear fraction transformation method, in which in-wheel motor is suspended as dynamic vibration absorber. Under the unified framework of the generalized H ∞ synthesis system, the robust constrained H ∞ controller about the active suspension augmentation system is designed according to the theory of reachable sets and ellipsoids with considerations of the dynamic tire displacements and the suspension working spaces constraints. The simulation results show that the designed robust constrained H ∞ controller can effectively improve the ride comfort and road-holding ability even if external interference and parameter perturbation exist.