Non-fragile H ∞ control for half-vehicle active suspension systems with actuator uncertainties

In this paper we investigate the problem of non-fragile H_∞ controller design for active suspension systems with actuator uncertainty constraints. A half-vehicle model with active suspension system is considered in this paper, the vehicle dynamic system is established with a focus on handling the trade-off of constraints on the heave and pitch acceleration, suspension deflections and tyre strokes. Actuator uncertainties are formulated within the controller design process and the fact of the actuator uncertainties existing in the system is modelled as a continuous-time homogeneous Markov process. A state feedback controller is designed for the purpose of ensuring that the resulting active suspension system is asymptotically stable with a prescribed H_∞ disturbance attenuation level while simultaneously satisfying the constraint performance. The designed non-fragile H_∞ controller is constructed via convex optimization by guaranteeing its sufficient condition in terms of feasible linear matrix inequalities. A half-vehicle case study is intensively exploited to reveal the effectiveness of the proposed controller design method.