Research And Simulation On The Main Function Of Vital Computer Of CTCS-2 Train Control System

In recent years, based on the corresponding technical specifications and technical conditions of Chinese Train Control System (CTCS), China's railway construction develops rapidly and greatly meets the growing needs for rail transport. CTCS-2 train control system plays a significant and irreplaceable function not only as the main application model in 200～250km/h speed level railway, but also as the backup mode of CTCS-3. The Vital Computer (VC) is the core part of the board equipments in CTCS-2 train control system. The realization of its functions directly affects the train control system.At home and abroad, the research on the function of the Vital Computer is are many and varied. Most of these studies choose to use kinetic equations to model. However, the complex factors of kinetics make it difficult to simulate and get accurate results. Thinking that now the train braking performance parameters are provided as braking decelerations by the vehicle supplier, the study about the function of vital computer based on the vehicle braking deceleration is advanced. Meanwhile, some of the data can be verified in the lab instead of field. The simulation can also provide decision support to designers engaged in related work and operations management to improve the traffic efficiency.In the thesis, research is focused on the speed control function of the Vital Computer. This thesis introduces the development process and current situation of the domestic and international train control system firstly. Equipment, structure and function of CTCS-2 Train Control System are analyzed. The control model and the key algorithm of the Vital Computer are deeply study which is based on track circuit and balise. Then it describes the working principle and data flow of ground and onboard equipments which are working with the Vital Computer. On this basis, the Vital Computer could be analysised and modeled, and then the Vital Computer simulation system could be designed and analyzed from functional requirements. As the result of the thesis, the Vital Computer simulation system is builded by VC++. In the final of the paper, combining with the actual line condition data and control, some of the data can be verified. From the results, the simulation can achieve the goals.Research is focused on the followings in the thesis. First, finite automaton is used to analysis and model the mode of train. It can clearly express the transform conditions between each two modes. Even more, it makes mode change achieve when a fault happened. Then, during the brake curve calculated, the dynamic model and the segmented braking deceleration model are compared and optimized under the premise of ensuring safety. Furthermore, the process of temporary speed restriction orders working is simulated, and calculation methods for temporary speed restriction orders of the Vital Computer are described. Finally, in order to verify the availability of the simulation, the developed software is tested for interface and function by combining with train running environment.