Practical Verification of Railway Signalling Programs

Abstract

SafeCap is a modern toolkit for modelling, simulation and formal verification of railway networks. This paper discusses the use of SafeCap for formal analysis and automated scalable safety verification of solid state interlocking (SSI) programs -a technology at the heart of many railway signalling solutions around the world. The main driving force behind SafeCap development was to make it easy for signalling engineers to use the technology and thus to ensure its smooth industrial deployment. The unique qualities and the novelty of SafeCap are in making the use of formal notations and proofs fully transparent for the engineers. In this paper we explain the formal foundations of the proposed method, its tool support, and their successful application by railway companies in developing industrial signalling projects.

The SafeCap Trajectory: Industry-Driven Improvement of an Interlocking Verification Tool

“…This paper discusses the SafeCap tool used for formal verification of geographical data of SSI and derived (Smartlock and Westlock) interlockings [8], [9], [6]. It provides scalable and fully-automated verification by mathematical proof.…”

“…From 2017 we have focused our work exclusively on developing a fullyreworked version of SafeCap targeting SSI verification (described in [6] 1 ). Two main decisions leading to the industrial adoption of the tool were made during this period, namely, to focus on fully-automated scalable verification by mathematical proof; to ensure that the tool inputs the data developed by signalling engineers and outputs the diagnostics reports exclusively presented in terms of these data.…”