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

Authors: L.V.V. Gopala Rao, S. Narayanan

Addresses: Machine Design Section, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036, India. ' Machine Design Section, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036, India

Abstract: 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.

Keywords: LQR; quarter-car models; random vibration; skyhook damper; stochastic optimal control; zero-lag covariance; linear quadratic regulator; vehicle suspension; vehicle performance; mean square acceleration; suspension stroke; road holding; control force; feedback control.

DOI: 10.1504/IJVAS.2008.023594

International Journal of Vehicle Autonomous Systems, 2008 Vol.6 No.3/4, pp.396 - 418

Published online: 02 Mar 2009 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article