Train braking accuracy and safe protection distance are the two main technical indexes in the system design of an automatic train protection system. They are closely related to safety and efficiency of train operation. When a train is actuated automatically to be braked by automatic train protection (ATP) system, no matter it is service braking or emergency braking, a proper safe protection distance must be considered because of limited braking accuracy. If the safe protection distance is too long, it will reduce train operation efficiency and disturb normal train operation controlled by drivers. If it is too short, trainoperation can not be ensured to be safe. Optimal safety protection distance is one of the main tasks during the system design of an ATP system. Safe protection distance is determined by braking accuracy, while braking accuracy is affected by many factors, such as initial speed of braking train, the control way, braking system dispersion, the reaction time of ATP systems, the influence on wheel-rail adhesion under different whether and so on. As long as the above factors are analyzed, the safe protection distance can be determined correctly to make ATP systems ensure train operation safety and raise train operation efficiency. Meanwhile normal train operation is not disturbed. The paper describes the analysis of train braking accuracy and safety protection distance during the development of the ATP system for Chinese Railways.
展开▼
