Multi-objective optimization of quarter car models with passive and semi-active suspensions

Abstract

A methodology is presented for optimising the suspension damping and stiffness parameters of quarter car models, subjected to road excitation. First, models involving passive damping with constant or dual rate characteristics are considered. Then, models where the damping coefficient of the suspension is selected so that the resulting system approximates the performance of an active suspension system with sky-hook damping are also examined. For all these models, appropriate methodologies are first employed for obtaining the second moment characteristics of motions resulting from roads with random profile. This information is next utilized in the definition of a composite vehicle performance index, which is optimised to yield representative numerical results for the most important suspension parameters. Finally, results obtained by applying a suitable multi-objective optimization methodology are also presented in the form of classical Pareto fronts.