Title: Safety requirement verification of train-centric CBTC by integrating STPA with coloured Petri net
Authors: Qian Xu; Jun-ting Lin
Addresses: School of Automation and Electrical Engineering, Lanzhou Jiaotong Universiy, Lanzhou 730070, China ' School of Automation and Electrical Engineering, Lanzhou Jiaotong Universiy, Lanzhou 730070, China
Abstract: Train-centric communication-based train control (TcCBTC) system is characterised by core functions centralised into on-board facilities with simplified trackside equipment. Coloured Petri net (CPN) is one of the classical model checking methods and system-theoretic process analysis (STPA) is a relatively new hazard identification method based on system thinking and control theory. STPA and CPN are mutually complementary because STPA provides the verification basis for CPN while CPN makes STPA's results written by natural language verifiable. The functional requirements of TcCBTC are analysed first. Secondly, via the assistant analysis tool XSTAMPP 2.0, the hierarchical control structure is built and the refined unsafe control actions are obtained to generate the safety requirements. Thirdly, CPN models are constructed for verifying the basic properties and the safety. Results show that the potential unsafe control paths can be identified by the proposed method on the system level and the dependence severity on the manual analysis is considerably reduced.
Keywords: train-centric CBTC; system-theoretic process analysis; STPA; coloured Petri net; CPN; safety requirements verification; unsafe control actions.
DOI: 10.1504/IJISE.2023.128667
International Journal of Industrial and Systems Engineering, 2023 Vol.43 No.2, pp.168 - 189
Received: 24 Apr 2020
Accepted: 15 Jan 2021
Published online: 01 Feb 2023 *