H∞ vibration control of active suspension for automotive application

This paper deals with simultaneous control of acceleration transmission, wheel load fluctuation, suspension deflection and sprung mass displacement. The control theory is based on the robust H_∞ control theory with the consideration of the modeling errors lumped into an unstructured uncertainty acting on the unperturbed plant. The design method is new and powerful for electronic car suspension´s control systems, as it presents a new approach to the designers for the computation of a controller maintaining robust stability while guaranteeing the performance in a wide frequency range, even in the case of the controller is applied to the actual plant. Additionally, the paper emphasizes that the assumptions in the modeling step may lead to unrealistic control designs and, as an example, the effect of the rigidity assumption on the behavior of the open loop system is discussed