Sensitivity Analysis And Adjust Of McPherson Suspension Based On DOE

Suspension is one of the most important assemblies of modern vehicle.The suspension is a complex mechanical system. It is very difficult to define the optimization function.In practice the engineers attempt to adjust the design variables so that the front bump steering characteristics are similar with the desired front bump steering characteristics.To modify the design variables more effectively, we need to perform the sensitivity analysis. This paper presents a method for the sensitivity analysis of the McPherson suspension. This method enables us to solve the problem efficiently. Firstly, the McPherson suspension is modeled using the theory of multi-body dynamic.Effects of elastic deformations for rubber bushings on suspension are investigated. Secondly, a sensitivity analysis of the suspension is performed using fractional factorial design. The McPherson suspension is a complex mechanical system. There are so many design variables that we must perform the sensitivity analysis to find the highly important factors. Thirdly,the object function is estimated using the central composite design. Through regression analysis, the regression model function is obtained. The ANOVA table is used to verify the exactness between the obtained second order regression model function and the real system. The design variables having the optimized object function are obtained using the optimum design program. Finally, the full vehicle model is developed.The results of lane change simulation show that the full vehicle model with the optimized suspension has been improved compared with the initial full vehicle model.