Reliability and safety verification of the new collision avoidance strategy for Chinese train control system
Junting Lin, Xiaoming Wang, Jianwu Dang
School of Automation & Electrical Engineering, Lanzhou Jiaotong University, Anning West Road, Lanzhou, China
Although equipped with comprehensive and complex technologies on the railway to avoid collisions between trains, such as train control system extensively deployed in the infrastructure, there are still enormous amount of collision between trains. The safety of railway operation mainly depends on the correct operation of the interlocking and train control system, because only the control centre has an overall overview of the traffic situation, and a train driver could only be warned of a possible collision if the operation centre decides it. Experiences from the aviation, the maritime navigation and road transportation have shown that the probability of collisions could be significantly reduced with infrastructure-less collision avoidance system. In this paper, an enhanced safety strategy, namely, Collision Avoidance System overlay Train Control System (CASOTCS) for Chinese railway was provided, which was based on direct vehicle-to-vehicle communication and independent of the regular control mechanism. CASOTCS can receive and evaluate the information broadcasted by other neighbouring trains all the time, which will trigger collision alert and provide a solution for the collision when a potential collision is detected. The unit architecture and its key issues of CASOTCS were also discussed. After the analysis of reliability and safety of both the traditional train control system and the enhanced CASOTCS, the reliability block diagram and isomorphic Markov model were established in the paper. Through the calculation of the indexes of the reliability and safety about the two kinds of control systems, a significant conclusion has been made, that is, the reliability and safety of the train control system plus collision avoidance system are much higher than that of the traditional one and CASOTCS has the ability to increase the reliability, safety and efficiency in the future.