Parameters optimisation of vehicle suspension system for better ride comfort

Abstract

The performance of a vehicle suspension system affects ride comfort and stability of the vehicle which are the two conflicting requirements. A passive vehicle suspension uses a spring and viscous damper to control the performance. In this paper, an efficient method is proposed for determining optimal stiffness and damping coefficient of a vehicle suspension system. A two degree-of-freedom quarter car vehicle model using linear quadratic regulator (LQR) control is established and the response of the model is obtained. The vehicle is considered to travel on the random road with constant velocity and the road roughness profile is modelled as the output of first-order linear filter under white noise excitation. The optimal parameters are obtained for the vehicle by correlating the performance of passive suspension with the fully active suspension using LQR. Results show that the performance of passive suspension using optimal parameters is very close to that of active suspension.