Symbolic Model Checking for Interlocking Systems

Abstract

Our results yield a verification tool suitable for use in industry.

Safety and Line Capacity in Railways – An Approach in Timed CSP

“…We give here only the basic idea as presented in [21]. The signalling in the double junction requires a slightly more involved approach.…”

“…Winter [21] describes how to model railway systems in Csp for proving safety. We illustrate Then, trains are modelled as processes.…”

“…Thus, rather than using Csp, we apply Timed Csp [19,17] in order to achieve an integrated view on safety and capacity. While, e.g., [20,21] model safety within Csp, to the best of our knowledge we are the first to consider railway capacity within Timed Csp or any other similar formalism. One of the benefits of using (Timed) Csp is its naturalness; it takes little effort to explain our formal models to our industrial partners who have assisted us throughout the process in ensuring that our models remain faithful to their engineering designs.…”

“…Concerning safety, we build on the work of [21]. In general, other approaches outside of the Csp world, e.g., [10,13] verify the safety of interlocking programs with logical approaches and SAT-based model checking as the underlying proof technique.…”

“…In Section 2, we discuss basic railway concepts in terms of a realistic double junction example provided as a real-world challenge by our industrial partner Invensys Rail, and use this example to motivate the question of capacity. In Section 3, we review the approach advocated by Winter [21] to modelling safety in the railway domain using Csp. In Section 4, the language Timed Csp and the idea of timed traces is introduced.…”