Objective With the rapid development of cities, the growing passenger flow and the efficient train operation demands have both put forward higher requirements for urban rail transit signaling systems. As the prerequisite and foundation for signaling system design, operating scenarios play a crucial role. To ensure the forward-looking nature of the design and the stability of the signaling system, it is necessary to analyze the key operating scenario of the CBTC (communication-based train control) system, i.e. the MA (mobile authorization) generation function under the ZC (zone controller) handover scenario.

Method The information interaction process of different systems and the generation process of mobile authorization under the ZC handover scenario are constructed. A modeling method combining UML (unified modeling language) and CPN (colored Petri net) is proposed. Based on the conversion rules between the two models, the introduction of a hierarchical structure and the concept of time stamps, the HTCPN (hierarchical timed colored Petri net) model is obtained. Then, this model is verified and analyzed by utilizing the state space report in the simulation modeling tool CPN Tools and applying the ASK-CTL (ask-based computation tree logic) logical formulas.

Result & Conclusion  All dynamic attributes of the system function model are normal, with no deadlocks or livelocks. The constructed MA generation process under the ZC handover scenario is logical, conforms to the signal system requirement specifications, and meets the functional requirements of CBTC operation scenarios.