Independent Suspension—The Equivalence of Model and Vehicle Parameters

Abstract

The vehicle suspension design starts with studies on simple models, needing few input data. The aim of the initial model simulations is to choose the suspension parameters able to ensure the a good compromise between comfort and dynamic vehicle qualities, at different travelling speeds and loads. The result of this stage is the setup on the model of the needed suspension parameters, from which the stiffness of the suspension springs and tires and the damping coefficient are the most important. After starting the design with initial layouts and dimensions of the suspension linkage, the model parameters must be “translated” to the real vehicle. This paper primarily deals with the suspension model—real vehicle suspension translation process. For the MacPherson, short-long arm and swing arm suspensions, it is emphasizing the equivalence between a displacement or a force at the wheel or ground level and its corresponding displacement/force at the suspension spring or shock absorber (motion ratio and mechanical advantage).