Ontology-Based STPA Safety Analysis Method for the Train Control System in Western China

To address the challenges posed by the complex natural environment and sparse station layout in western regions, the train control system in western China has undergone a systematic architectural restructuring, aiming to reduce reliance on trackside equipment and shift toward an “onboard intelligence–centered” design paradigm. Given the potential risks introduced by structural and control logic updates, there is an urgent need to conduct systematic safety analysis early in the system lifecycle. In response, this paper proposes an ontology-based STPA safety analysis method (Ontology-STPA), which incorporates ontology modeling and semantic reasoning into the traditional STPA framework. An Ontology-STPA meta-model is constructed, and SWRL rules are employed to automatically infer unsafe control actions and their causal factors. Taking the restructured train integrity monitoring scenario as a representative case, the model is instantiated with domain-specific knowledge. A total of 23 reasoning rules are formulated, from which 31 key safety requirements are successfully derived and subsequently verified under complex constraints using the UPPAAL tool.