The Use of Uniform Design and Nelder-Mead Simplex Methods to Optimization of Suspension Parameters of a High Speed Railway Vehicle System

Abstract

This paper has proposed an optimization process with two phases to optimize suspension parameters of a high speed railway vehicle for advancing system’s robustness and performance. The vehicle’s nonlinear coupled differential equations of motion with fourteen degrees of freedom are created based on Kalker’s linear theory and the heuristic nonlinear creep model. The performance measure of the vehicle system is critical hunting speed, which is determined by Lyapunov’s indirect method. The first phase of optimization is to execute a set of experiments which is planned based on uniform design method. The second phase of optimization is to apply the Nelder-Mead Simplex method to exploit the best solution obtained in the first phase. Finally, the presented optimization process can effectively not only advance the performance of the vehicle system but also increase the performance’s robustness.