Design of Constrained Robust Controller for Active Suspension of In-Wheel-Drive Electric Vehicles

This paper presents a constrained robust H? controller design of active suspension system for in-wheel-independent-drive electric vehicles considering control constraint and parameter variation. In the model, uncertainties sprung mass are analyzed via linear fraction transformation, perturbation bounds can be also limited, then uncertain quarter-vehicle model where in-wheel motor is suspended as dynamic vibration absorber built. The feedback closed-loop designed using concept reachable sets ellipsoids, in which tire displacements working spaces constrained, comprehensive solution finally derived from performance stability. Simulations on frequency responses road excitations implemented to verify evaluate controller; results show that with developed effectively achieve better ride comfort road-holding ability compared passive despite existence constraints variations.