Title: Optimisation for suspension system of a railway vehicle with a new non-linear creep model developed by uniform design
Authors: Yung-Chang Cheng; Po-Hsien Wu
Addresses: Department of Mechanical and Automation Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, 811, Taiwan ' Department of Mechanical and Automation Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, 811, Taiwan
Abstract: This paper presents the optimal values of suspension parameters of the railway vehicle system using an integrated procedure for the optimisation. The procedure is composed of uniform design of experiments, hunting stability analysis, kriging interpolation, genetic algorithm and local search optimisation method. The vehicle's nonlinear coupled differential equations of motion with 25 degrees-of-freedom (DOF) are created using the new nonlinear creep model which is developed from the heuristic nonlinear creep model by adding creep moments and the semi-axis lengths in the saturation constant. The performance measure of vehicle systems, vehicle unstable speed, is determined by Lyapunov's indirect method with various wheel conicities. Finally, the optimal solution of suspension parameters of the railway vehicle system under the goal of minimising the combined objective function is found. The results show that this procedure can effectively enhance the robustness of vehicle unstable speed against the noise factor.
Keywords: nonlinear creep modelling; vehicle speed; unstable speed; uniform DOE; design of experiments; kriging interpolation; hunting stability analysis; genetic algorithms; nonlinear programming; optimisation; vehicle suspension; railway vehicles; heavy vehicles; local search; passenger trains; vehicle design.
International Journal of Heavy Vehicle Systems, 2015 Vol.22 No.2, pp.157 - 191
Accepted: 13 Jan 2015
Published online: 06 Jul 2015 *