General provisions of the substantiation of functional safety of intelligent systems in railway transportation

Abstract

Aim. The paper aims to solve the problem of objective and confident functional safety (FS) evaluation of intelligent control systems (ICS). As regards ICS, the conventional methods, due to their particular features, do not allow for a sufficiently confident estimation of the actual state of FS. The above features include primarily the nondistinct architecture of ICS and the changing connections between the system elements.Methods. Substantiating ICS FS requires using the complete arsenal of known methods and means recommended in GOST 33432-2015 [1], including managerial measures defined by the requirements for the safety policy, program and case. The authors have analysed the capability to prove ICS FS using experimental, expert, analytical, technological, and simulation-based methods. The limitations of some methods as regards ICS FS substantiation have been established.Results. The authors suggest a heuristic graph-based semi-Markov (Markov) method of proving system FS. For the purpose of substantiating ICS FS, it is recommended using the heuristic graph-based method combined with the technological method defined in GOST R IEC 61508 [2–4]. They don’t only allow confidently evaluating the FS of intelligent systems, but developing recommendations for achieving acceptable safety levels of such systems.