A model-based framework for the safety analysis of computer-based railway signalling systems

Abstract

This paper on the safety analysis of computer-based railway signaling systems is from the proceedings of the 12th International Conference on Computer System Design and Operation in Railways and Other Transit Systems, held in Beijing, China, in 2010. The authors note that the crucial safety analysis of railway signaling systems with distributed computer techniques is becoming extraordinarily difficult, because of the frequent and complex interaction between components and the various backup modes. They propose a hierarchical methodology for safety analysis based on the failure propagation model and state-transition model. Unlike traditional safety analyses, the proposed approach demonstrates more accurate representation of practical failure behavior in a computer-based signaling system. Dynamic properties, system structure and failures at the component level are separately modeled in different layers, and connected with synthesis laws. The analysis can be easily refined as the system design progresses and automatically produces safety-related information to help the engineer in making design decisions. The authors use the preliminary design of the Communication Based Train Control (CBTC) system for the Yizhuang Line in Beijing to demonstrate this approach.