Adaptive Failure-Tolerant Control Study For CRH380A Type High-Speed Trains With Actuator Failures

With the development of high-speed railway in our country,high-speed trains have played a significant role in transportation for people traveling today.However,the operation environment of high-speed trains is complex and variable,the operation conditions change frequently,the nonlinearity is strong,and the actuator is under the high temperature and vibration environment for a long time.Some actuators may fail easily during the operation,and the conventional control schemes will have difficulty in assuring the safe and reliable operation for the train under the actuator failures.Therefore,it is significant to study a reliable control scheme to realize the reliable operation of trains.Adaptive control can effectively deal with the uncertainties,and multiple-model adaptive control can effectively improve the transient performance of the system,which is very suitable for complex system such as high-speed trains.In this thesis,in view of the advantages of adaptive control,it is applied to the high-speed train system to achieve the tracking of a given speed curve and ensure the stability of the system even in the presence of unknown failures.The mainly works of this thesis are as follows:1.The longitudinal dynamics model of high-speed trains is established based on Newton’s second law by analyzing the force conditions of the train operation.This thesis takes CRH380 A type high-speed train as the research object,and establishes a high-speed train longitudinal dynamics model based on the marshalling structure and power distribution of the train,as well as analyzing the control force,the basic resistance,the additional resistance and the inter-train force during operation,which can accurately describe the dynamic characteristics of the train during operation.2.In order to deal with the uncertainties caused by different operation conditions and unknown actuator failures of high-speed trains,an adaptive failures compensation control scheme is designed based on the piecewise model.A piecewise constant model is introduced to describe the variable system parameters caused by the variable operation environments,and a multiple-particle piecewise model of high-speed trains,with unknown actuator failures,is then established.An adaptive failure compensation controller is developed for the multiple-particle piecewise constant model,by using a direct model reference adaptive control method.Such an adaptive controller can not only compensate the uncertainties from unknown actuator failures,but also effectively deal with the uncertainties caused by different operating conditions.Simulation results show that the proposed scheme is able to ensure the expected system performance.3.In order to improve the transient performance of the train fault-tolerant control system,an adaptive failures compensation control scheme is designed based on multiple reference models.Corresponding to different system dynamic matrices,the reference models and adaptive controllers are designed to form a bank of reference models and a bank of controllers,and the most suitable controller is selected by using the control switching mechanism based on estimation errors.Such a scheme improves the transient performance of the system on the basis of compensating the unknown actuator failures effectively.Simulation results verify the effectiveness of the proposed method.