Research And Simulation Of On-board ATP Of CBTC System In The Urban Mass Transit

The CBTC (Communication Based Train Control) system is an advanced train control system, and is the trend in train control systems in the urban mass transit. It is widely applied in the subway lines of many cities in our country. However, most of these CBTC systems are foreign systems, and until now China has no mature CBTC system, thus the relative department pays much attention to its research and development.The on-board ATP (Automativ Train Protection) is an important subsystem of the CBTC system. It is in charge of the safety functions cooperating with the ZC (zone controller). The on-board ATP has many functions such as converting of drive mode, measuring train speed and train distance, calculating ATP curves, monitoring train speed, protecting train speed, monitoring train and doors, reading balise, communicating with zone controller and handover of zone controllers etc. It is seen that the on-board ATP has many functions and all of them are related to the safety of the train, and because it is not well developed in China now, it is valuable to study the on-board ATP.The architecture and functions of the on-board ATP subsystem of the CBTC system in the urban mass transit are designed, and the on-board ATP subsystem is simulated using VC++6.0. The design and simulation of the on-board ATP are based on studying the functions and technology specifies of the mature CBTC systems, especially specifies of their ATP subsystems according to the real CBTC system applied in the subway lines.During the realization of the on-board ATP simulation subsystem, this paper focuses on the following several points:First, the ATP model of the CBTC system in the urban mass transit is studied, and an ATP model based on the standards of the speed monitoring of the most restrictive speed triggering curve, normal braking triggering curve, emergency braking warning curve and emergency braking triggering curve is designed. The factors of train performance, line conditions, train basic resistance, train additional resistance are considered in this ATP model. The formulas and the algorithm of the ATP curves are also given. At last the automatic train protection process is realized dynamically cooperating with other modules.Second, the resistances existing in train running are studied and their influences on emergency braking are analyzed by quantity. The main resistances during train running are the train's basic resistance, the gradient additional resistance, the line curve additional resistance and the tunnel's additional resistance. The influence of each resistance on the emergency braking is shown by comparing the differences between the emergency braking distance not considering the certain resistance and the emergency braking distance considering all the resistances. An analysis and calculation module of the emergency braking process is developed, the influence of the train basic resistance, gradient additional resistance, line curve additional resistance and tunnel additional resistance on the train emergency braking process is separately analyzed by quantity using it, and then an analysis conclusion is given.Finally, the ZC handover process of CBTC system in the urban mass transit is studied, and a ZC handover process is designed and simulated simply and dynamically cooperating with other modules.