High-speed Train Adaptive Braking Control Based On Time-delay Model

At present,high-speed trains play an increasingly important role in the global railway transportation system and become the first choice for passengers.High speed and superior safety make them occupy an important position in the world,and further promote the national economies.The increased speed of high-speed trains has brought great convenience to people,but also caused many railway accidents which have caused irreparable losses to the country and people.The frequent occurrence of accidents provides experts and scholars with new technical research thoughts,that is,it’s more important to research into the braking performance in the process of improving the running speed of high-speed trains.Therefore,further research on the braking technology of high-speed trains is the vital requirement to ensure the safety and reliability.In this paper,the author takes the high-speed train braking system as the research object,analyzes its dynamic characteristics and braking process based on the working principle of the system,and creates a high-speed train braking model with delay part,which increases the accuracy of the model.Considering the influence of bounded disturbances during train braking,a different time-delay model with disturbances is established on the basis of the time-delay model.Basing on the two models established above,adaptive speed tracking controllers are designed for them to ensure the stability of the system and asymptotically track the given speed curve,so as to overcome the influence of input time delay and external disturbances on the braking system.Simulation experiments verify the practicability of the control algorithm proposed under this paper.The main work of this paper is as follows:(1)After analyzing the working principle of the high-speed train braking system and fully understanding the dynamic characteristics of the actual braking process of the train,the author establishes a time-delay model of the high-speed train braking system considering the delayed receipt of the braking control command.And uses the state prediction method to deal with the delays in the system,which improves the accuracy of the braking model.(2)To overcome the delay phenomenon of high-speed train braking,The author designs a direct model reference adaptive controller based on the established time-delay model by using the advantages of the adaptive control algorithm and combining with the state prediction method.On the premise of ensuring the stability of the system,taking the CRH380 AL high-speed train braking system as the research object,the author uses the simulation software to conduct experimental simulation,controlling the actual braking speed of the train and asymptotically tracking the speed curve given in the simulation to ensure its safe braking.(3)Considering that the bounded disturbance can adversely affect the braking system based on the time-delay model,the author establishes a system model with disturbances and time-delay links.And designs a new model-referenced adaptive control mechanism,and further proves their stability.The simulation results show that in the presence of unknown disturbances and input delays,the system can achieve asymptotic tracking of a given speed curve and overcome the influence of unknown parameters and bounded disturbances,with good robustness.