Single-Input Multiple-Output Perturbation Rejection in Automotive Semi-Active Suspension Systems

In the automotive industry, the main indicators taken into account to evaluate the performance of a vehicle are the riding comfort and maneuverability (evaluated as the road holding). In this paper, an analysis of a semi-active suspension system is carried out to assess the effect of the implementation of a single control loop on the perturbation rejection characteristics of both comfort and road holding. By using the ‘individual channel analysis and design’ tool adapted for single-input multiple-output systems, a fundamental quantification of the coupling between the comfort and road holding is obtained to establish control strategies providing the best trade-off between them. The quarter of vehicle model (commonly used for the analysis of this kind of systems) is used to model the plant, leaving the actuator's non-linearity out of the scope of the analysis and focusing exclusively on the comfort and road holding relationship.