Study On The Computerized Direct Acting Electro-pneumatic Braking

From the trend of braking technical development on high speed train and urban mass transit vehicle abroad, we can see that computerized direct acting electro-pneumatic braking system is a leading developing trend. This paper does a full-scale research on the computerized direct acting electro-pneumatic braking system. First of all, the author analyses several typical braking systems on high speed EMU and new style urban mass transit vehicle abroad. And finds that in the recent few decades, with the maturity of the technology, the braking systems on high speed train and urban mass transit vehicle abroad nearly all use computer controlled technology. The application of microcomputer make it easy for dynamic brake to co-operate with air brake, so one unit, even the entire train can take full advantage of the dynamic braking capability. The using of computer makes it possible to monitor the failure of the braking system in real time, increasing the reliability of the system as well as reducing the probability of serious accident.This paper also summarily analyses the braking system on domestic mainline train and urban mass transit vehicle. The braking control system on domestic mainline train now stay at the level of air braking system, even the electro-pneumatic braking system used in speed-raising passenger train also stay at the level of electromagnetic air brake which is the level of 1950s' or 1960s' abroad. Air braking system can't meet the need of the high speed train due to the system's function limitation itself. Although Chinese Ministry of Railways tries to obtain the foreign technology of the computerized direct acting electro-pneumatic braking system by introducing, foreign companies refuse transferring kernel technology to us. So, if we want to obtain the technology we should better research and develop by ourselves.Although domestic new style metro has adopted the computerized direct acting electro-pneumatic braking system, the braking system is all furnished with foreign products. Because the price and service are controlled by foreigners, the aim of 70%'s localization of manufactures rate required by National Development and Reform Commission is difficult to realize.The paper does conceptual analysis of the computerized direct acting electro-pneumatic braking system according to the demand of 200km/h EMU. The specification of the braking system is brought forward. The author also design a computerized direct acting electro-pneumatic braking system which is suitable for 200km/h EMU. Meanwhile, the paper does research on some key technology of computerized direct acting electro-pneumatic braking system. Then the R&D is also presented for the standing test bed of the computerized direct acting electro-pneumatic braking system. It is indicated that the braking system mentioned in this paper can basically meet the design and application requirement according to the result of the system test and service test.System reliability analysis is also done about the computerized direct acting electro-pneumatic braking system mentioned in this paper. Several main reliability parameters and the approach of increasing system's reliability as well as the theory basis of it are presented in this paper too.With regard to the situation of domestic new style urban mass transit vehicle braking system being monopolized by foreign products, the paper analyses the foundation of independently R&D urban mass transit vehicle braking system. The scheme of the localization of manufactures for the metro braking system is also proposed in this paperAccording to the developing plan of low speed maglev in shanghai, the paper also does research on the scheme of adopting the computerized direct acting electro-pneumatic braking system in low speed maglev vehicle. The author also does further research on the major parameter of 300km/h EMU which will be developed in our country.