Reduced-order modelling and parameter estimation for a quarter-car suspension system

Abstract

This paper presents a new approach to obtaining an accurate simple model for complex mechanical systems. The methodology is applied to a quarter-car suspension system with complex linkage structures. Firstly, a multi-body dynamic model which includes kinematic characteristics is developed. Using a linearization technique, a 32-state linear model for a quarter-car system is obtained. Secondly, model reduction techniques are applied to find a reasonable reduced-order model. The result of the model reduction shows the validity of the two-mass model given that the parameters are correctly identified. The paper presents both an analytical and an experimental way of identifying the parameters of the two-mass system based on the reduced-order model. The identified parameters are shown to vary significantly from component data typically used for the two-mass system depending on kinematic structures of the suspension system. The modelling procedures outlined in this paper provide a precise and efficient way of designing active suspension systems that minimizes a necessary tuning process.