Adhesion And Lateral Attitude Control Of High-speed Trains Via Adaptive Fault-tolerant Approach

With the rapid development of High-Speed Train (HST) program in China, the safe and reliable operation of HST has become the major concern. As the train speed increases, the safety issue is becoming more and more important yet challenging to address. There are many factors that must be taken into account in control design, which include the varying and uncertain operation environment, the unknown nature of the rail surface, and unexpected geological hazards. For this reason, there still remain certain open problems in this field that are of great theoretical and practical interest from control system point of view. For instance, the slip phenomenon and the hunting oscillation phenomenon, both have significantly impact on the train’s operation, are very common in practice. In this thesis, the major objective is design control schemes to deal with these factors. More specifically, control algorithms for the adhesion control and the lateral attitude control of the High-speed Train via a robust adaptive fault-tolerant control strategy are derived. The major contributions of the work can be summarized as follows:Firstly, Lyapunov-based robust adaptive fault-tolerant control strategy for a class of nonlinear system is developed. The proposed user-friendly and cost-effective control schemes are not only robust against the modeling uncertainties and external disturbances, but also tolerant the actuator failures. Such control methods are applied to solve the adhesion control problem and the active suspension control problem of High-speed train.Secondly, based on the concept of the High-speed Train’s slip phenomenon and hunting oscillation phenomenon, two dynamic models that reflects the effects of uncertain nature of the rail surface and surrounding environment (such as the sudden change of the weather, the appearance of the foreign matter on the rail and the geological hazards), as well as the possibility of the actuator failures are individually established. Such model improves the one commonly used in the literature in that it is able to reflect the practical operation situation more effectively.Third, on the basis of the developed dynamic model of the adhesion control system and active suspension control system, robust adaptive fault-tolerant control strategy is proposed to achieve the High-speed Train’s adhesion control and lateral attitude control. The adhesion control strategy contains the adhesion force observer, the reference slip ratio generator and the controller; Both the lateral vibration and the rolling vibration of the train body are stabilized by the proposed active suspension control strategy. The control schemes are not only robust against the modeling uncertainties, the unknown time-varying of the system parameters and the uncertain nature of the rail surface and surrounding environment, but also tolerant the actuator (the brake and the damping force output) failures. The closed-loop stability issues of the control scheme are analyzed using a Lyapunov-based method. Such control schemes are with simple structure and trivial computations. Little human interference and limited system information are required here. The stability and the efficiency of the proposed control scheme are tested and verified via MATLAB simulations.Some remarks and conclusions are provided at the end of the thesis.