Double Wishbone Suspension Design Based on Design for Six Sigma (DFSS)

A robust design based on DFSS is presented for double wishbone suspension system kinematic and compliance (K&C) performance. Variations in suspension K&C caused by the uncertainties of hard points and bushing stiffness coefficients are minimized. The robust design involves two steps. In the first step, suspension kinematic characteristic are optimized. The objective functions are the toe angle and camber angle, and random design variables are the hardpoints of joints. The bushing stiffness coefficients are assumed as constant design parameters. In the second step, suspension compliance characteristics are optimized, where the bushing stiffness coefficients are random design variables. The optimized hardpoints in the first step are treated as constant design parameters. The optimization result shows that the robustness of suspension K&C performance is improved.