Semi-Active Augmented H(subscript ∞) Control of Vehicle Suspension Systems with MR Dampers

In this work, we extend and study the implementation of H(subscript ∞) output feedback controller to a vehicle suspension system with magnetorheological fluid (MRF) damper. In the closed-loop suspension system, the H(subscript ∞) controller serves as a system controller to provide the necessary robustness, however, in most of the cases, the controller gain is high. This makes the damper controller, which issues input currents to control the MR damper, hard to track the desired damping force. To this end, an augmented filter is proposed to remedy this issue. Although in the augmented filter, full system states are required in one of the term, while through numerical experiments, we found that this term can be ignored without sacrificing noticeable performance