Topology Based Optimization of Suspension and Steering Mechanisms of Automobiles

Abstract

This thesis proposes a kinematic based optimization of the characteristics of suspension and steering systems by focusing on their dynamics interaction. Two of the most important suspension mechanisms are modeled. A new approach based on combining transformation matrix and vector analysis is used resulting in less time and memory consumption during optimization. Modelling is verified by comparing the results with multi-body dynamics software. Further, the steering importance and its effects on the suspension are discussed, along with modelling and analysis of the rack and pinion steering mechanism. The optimization aims at the road holding and vehicle stability considering the effects of steering mechanism on the suspension. Therefore, the cost function is defined based on both steering and wheel travel. Moreover, the effect of wheel travel in different steering angles is shown to be important and has been considered in the cost function. In regards to some behaviors of the suspension, static constraints are defined and their importance is discussed. Lastly, case studies are presented to provide analysis and optimization of the suspension characteristics including steering error and track alterations. Optimization is performed to design suspensions for particular vehicle classification, such as, family cars and SUVs. The results show that optimization can be used to arrive at desired behaviors when the steering and suspension interaction is considered in the optimization.