Fault-tolerant Control Of High-speed Trains

The high-speed railway network, marked by "Gao-Tie", has been con-structed through "speed boost" and "high-speed railway construction" in the past ten years. In specific, much more concerns are given to the train controller design in high-speed trains (HST), since any fault of HST at a speed of300km/h will harm property and passengers more than traditional trains.In this dissertation, the multi-point dynamic models of HST are built firstly, under the parameter uncertainty and the nonlinear rolling resistance, and a set of probable actu-ator failures in traction/breaking system of HST. Based on the dynamic models of HST, the fault-tolerant controllers, under different working conditions of HST, are designed. Finally, the widely applicable fault-tolerant controller, for the general working condition of HST, is designed.The main contents and contributions of this dissertation are listed as follows:First of all, a passive fault-tolerant controller is designed to compensate constant-bias or proportional-bias actuator failure for HST linear model. A robust fault-tolerant controller is designed, against constant-bias or proportional-bias actuator failure for HST linear model with uncertain parameters. The stability analysis is given for the both fault-tolerant control systems.Secondly, a robust adaptive fault-tolerant controller is designed to compensate un-known actuator failure with disturbance for HST linear model with unknown parameters. In order to diagnose actuator failures, the information-based fault detection module and smooth switching module, for switching the robust adaptive fault-tolerant controller of HST, are introduced. And then, by adding the guaranteed tracking performance function, the robust adaptive fault-tolerant controller is designed, and the simulations show that position and velocity tracking errors of HST converge to an arbitrarily predefined small residual set. The stability analysis of fault-tolerant control system is given.Thirdly, an immersion and invariance robust adaptive fault-tolerant controller is de-signed to compensate unknown actuator failure with disturbance in HST nonlinear model with the nonlinear rolling resistance and the unknown parameters. The maximum po-sition and velocity tracking errors, using as criterion for detecting actuator failures, are presented by using state observer for HST without actuator failures. Base on immersion and invariance theory, a class of adaptive parameter estimators is designed, and then, the immersion and invariance fault-tolerant controller is obtained by switching the adaptive parameter estimators according to the actuator failures. The simulations show that posi-tion and velocity tracking errors of HST converge to a small set. The stability analysis of fault-tolerant control system is given.Finally, a direct adaptive fault-tolerant controller is designed to compensate the un-known hopping actuator failure in HST nonlinear model with the unknown parameters. The adaptive controller designed in this paragraph also can handle the fault-tolerant con-trol problem of HST issued in the last three paragraphs. The framework to obtainβ(x) is simplified by adding a P(x)-monotone, and a fault detection and diagnosis module is designed by usingβ(x). A direct adaptive controller is designed to handle unknown hopping actuator failure and control input saturation of traction/breaking system in HST simultaneously, and the simulations show that position and velocity tracking errors of HST converge to a small set. The stability analysis of fault-tolerant control system is given.