Sensitivity Analysis And Robust Design Of Dynamic Performance Of Railway Passenger Vehicle

Due to advantages such as big transport capacity, low energy consumption, low pollution, safety and comfort, Railway transportation is one of the key development modes of transportation in many countries. The dynamic performance has an important effect on railway vehicle’s running quality. Running condition and suspension parameters are the main influence factors of railway vehicle’s dynamic performance. With vehicle’s running condition and suspension parameters analyzed as the basic objects in this paper, sensitivity analysis and robust design of railway passenger vehicle’s dynamic performance are mainly researched.On the respect of sensitivity analysis of ride quality, general formula of sensitivity of the vehicle’s ride quality Sperling index with respect to mass parameters, running speed and suspension parameters etc. is derived by using direct derivation method. Program is compiled based on MATLAB to analyze the influence law of different parameters on the railway passenger vehicle’s ride quality, and parameters which has significant influence of running stability are found out. In order to improve the efficiency of sensitivity analysis, a four-factor and four-level orthogonal experiment table is designed to construct the polynomial response surface model between the ride quality Sperling index and suspension parameters. The sensitivity of ride quality Sperling index with respect to suspension parameters is calculated based on the response surface model. Besides, the precision of the sensitivity based on response surface model is discussed.On the respect of sensitivity analysis of running stability, using17degrees of freedom Lateral Vibration Model for Vehicle, with the combination of characteristic root analysis and binary search method, the exact solution of critical hunting speed is realized. An analysis model of sensitivity of critical hunting speed with respect to mass parameters and suspension parameters is built. According to the model, the influence law of different parameters on critical hunting speed is analyzed, parameters which have significant influence of running stability are found out. Considering global sensitivity analysis, an8-factors and2-levels orthogonal experiment table is designed, the range sensitivity of critical hunting speed with respect to suspension parameters is calculated. By comparing range sensitivity and finite difference sensitivity, characteristics and application scopes of two sensitivity methods are concluded.On the respect of dynamic performance robust design, a robust design scheme of railway passenger vehicle’s ride quality is established based on the sensitivity analysis and genetic algorithm. Using suspension parameters as controllable parameter, robust design of railway passenger vehicle’s vertical ride quality upon carbody mass, speed and longitudinal position in vehicle body are accomplished. The change trend of suspension parameters is analyzed. By comparing the changes of vertical ride quality of railway passenger vehicle which is robust designed or not, relate to vehicle body mass, running speed and longitudinal position in vehicle body, the robust design is proved to increase the robustness of vertical ride quality of railway passenger vehicle.