Safety monitor for Train-Centric CBTC System

Train-centric communications-based train control (TcCBTC) system is a new solution for urban transit signalling. Compared to traditional train control systems, the on-board equipment is becoming more powerful and more complex. Due to its safety-critical nature, specialised technologies must be adopted to guarantee the safety of the system. To address the safety verification difficulty of the control logic for the new system, this study presents an innovative topology-based method for guaranteeing the train control safety. First, a railway network is described as a metric space, and then, topological spaces are introduced to express the movement authority and train trajectory. On the basis of the topological description, the safety rules are checked by performing a series computation of topology theorems. Finally, a case study has been carried out on a real metro line in China. The result shows that the proposed method strictly meets the safety verification and achieves excellent performance.