A Study Of Electro-hydraulic Brake System Of High-speed Trains

Braking technology plays an important role in the improvement of high-speed train’s performance. As a necessary device to guarantee the safeness when the rail is in motion, braking system must be studied creatively in order to make high-speed train a better performance. Due to the ever-increasing speed, length and weight, with inadequate braking power, old-fashioned method and unsatisfactory effect of communication, the high-speed train often stops inaccurately, being out of tracks and off hooks. Many of those accidents happen as the train is in the process of braking.Traditional braking control system cannot meet the requirement of high-speed, stopping accurately and offering comfortable conditions for passengers. A lighter-weight, higher-reliance and better performance brake is in an urgent need. Instead of adopting air brake in the early days, the braking strategy-air pushing oil is commonly used now. This paper studied hydraulic braking system in high-speed train. Three research findings are completed as following:1.Designing hydraulic brake. This paper adopted pressure reducing valve to keep pressure constantly. A mathematic model was established and later simulated by MATLAB in order to examine the dynamic characteristics of the designed hydraulic system.2.Adopting intelligent control to design hydraulic braking system. After designing PID controller, single neuron PID controller and fuzzy-PID controller were designed by analyzing advantages of both PID controller and intelligent control. The effect of simulating those designed controllers turns out acceptable.3.Establishing a dynamic characteristic of tires model by state equation. Considering the relation between slip ratio and adhesion coefficient, this paper designed anti-skid controller for high-speed train braking system by adopting nonlinear control system---sliding mode control system. Chattering problem in sliding mode control was eliminated by the improvement of reaching law.