Research On Semi-active Control Of Lateral Suspension Systems For High Speed Railway Vehicle

Increasing train speed and operation density is an important transport strategy to ensure the rapid and sustainable development of China’s economy.In developed countries, trains run at a maximum speed of about350km/h. Technologies core to ensuring the safety of high-speed railways have been kept confidential to China, which has not developed such technologies independently. On the other hand, in light of the needs of rapid national economic development, China is now deliberating over plans of a railway with an operating speed of up to500km/h. This, for sure, would revolutionize the future development of transportation.One indicator of the properties of the train is the smoothness during operation. It guarantees both the safety of the train, and the comfort of passengers. But traditional passive suspension system is not capable of real-time adjustment of the damping force during train operation, and therefore can hardly ensure the smooth operation of a high speed train. Semi-active suspension system guarantees the safe operation of trains with low energy consumption and no external power source, the in-depth study of which will help improve the safety of China’s railway system. Hence the studies of dynamic behavior of train vehicle systems, semi-active suspension system, vibration suppression control strategy, and dampers are fundamental to ameliorating vehicle lateral vibration of the train.This thesis probes into the features of semi-active suspension dynamics, and the control method of lateral semi-active suspension vibration suppression, by means of vehicle suspension systems, vibration suppression control methods and train modeling and simulation methods. Detailed tasks will be divided into the following aspects:1. Retrospective studies of the history and development of the train vehicles. Detailed introduction of the vehicle suspension system. Analysis of the features of passive suspension systems, active suspension systems and semi-active suspension system. Elaboration on the reasons and necessity of China’s choice of semi-active suspension system. Analysis of the research and application of semi-active suspension system here and abroad. Analysis of the evaluation criteria for high-speed train comfort.2. Analyses and researches of various control strategies and their basic principles and applications; comparisons between control strategies and analyses of their advantages and disadvantages led to the choice of the lateral semi-active vibration suppression control strategy.3. Studying the cause of train vibrations when it operates, analyzing the features of model trains of different freedom degrees, and building lateral semi-active suspension system dynamics model all prepare for the simulation model in the next chapter.4. Choosing respectively the linear quadratic optimal control, H∞control and neural network predictive control strategy for lateral semi-active suspension vibration suppression control simulation, then further analyzing the efficacy of each of the three strategies in improving operation smoothness.5. The simulation demonstrates that semi-active suspension system can effectively improve the performance of train vibration suppression, reduce lateral vibration of the train, and enhance passenger comfort as well as operation smoothness.