Robust Design for Steering Mechanism Based on Preference Function

In order to improve robustness of vehicle dynamic performance, a steering mechanism model is proposed with alignment parameters of front wheel based on preference function method. In the steering mechanism model controllable variables include the trapezoid connection length, the base angle of steering trapezoid, the kingpin inclination angle, caster, camber and uncontrollable variables include load and initial braking velocity. Optimization objective is some vehicle dynamic performance. In the preference function method the individual performance preference and preference aggregation in designing variable space and performance variable space are analyzed. The individual performance preference includes the controllable variable preference, noise factor preference and optimization objective preference. The aggregation function is developed by aggregating all the individual performance preferences. The robustness and optimization results are solved based on mean and variance of aggregation function. The results from the preference function method and Taguchi method have been compared. The data show that the individual performance preferences of the steering mechanism model are significantly improved using the preference function method with the nearly same optimization objective value.