Control of response of a quarter-car vehicle model with optimal skyhook damper

In this paper, the control of the stationary random response of a two degree of freedom (DOF) quarter car vehicle model traversing a homogenous rough road with skyhook damper control strategy is considered. The parameters of the skyhook damper, namely the damping coefficient and the constant which determines the extent of the skyhook damper participation are optimally determined. The skyhook damper control strategy is realised through a feedback control scheme. The optimal parameters of the skyhook damper are determined by equating the control force of the feedback system to that obtained by linear quadratic regulator (LQR) stochastic optimal control in a mean square equivalence sense. The random road profile is modelled as the output of a second-order linear spatial filter to white noise, which takes into account the effect of the rolling contact of the tyre with the road. The average behaviour of the system is described by the zero-lag covariance matrix of the response state vector. In the LQR control the vehicle suspension is optimised to improve the vehicle performance given by a performance index which is a weighted integral of the mean square acceleration, suspension stroke, road holding and control force. Copyright © 2008 Inderscience Enterprises Ltd.