Research on functional safety design for passenger vehicles based on STPA at the vehicle level

Amidst the intelligent revolution reshaping the transportation industry, safety remains the top priority in vehicle manufacturing. International standards ISO 26262 (Road vehicles – Functional safety), ISO 21448 (Road vehicles – Safety of the intended functionality), and national standard GB/T 34590 (Road vehicles – Functional safety) define functional safety design and development processes for individual electronic/electrical systems. However, from an industry-wide perspective, the practice of treating passenger vehicles as complex integrated systems for functional safety analysis remains relatively limited. In particular, the collaborative application of ISO 26262 and SOTIF is still in the exploratory and refining stage. To a certain extent, this situation not only escalates the difficulty of identifying cross-system risks but also poses challenges to the development of a vehicle-level functional safety protection framework. This study focuses on the application of System-Theoretic Process Analysis (STPA) in vehicle-level functional safety analysis. By mapping its application pathways, we define a safety analysis methodology that integrates STPA with Hazard Analysis and Risk Assessment (HARA), enabling a shift from traditional single-system safety analysis to a system-engineering-aligned vehicle-level safety analysis. The proposed methodology effectively identifies vehicle-level functional safety risks, addressing a critical gap in industry practices. This research provides theoretical support and practical pathways for safety design in the era of intelligent vehicles.