Improved Systemic Hazard Analysis Integrating with Systems Engineering Approach for Vehicle Autonomous Emergency Braking System
Abstract Safety analysis is a significant step for the safety-critical system development. Compared with traditional vehicles, the system interactions for autonomous vehicles are more abundant and complex. Traditional hazard analysis methods, such as Failure Mode and Effects Analysis (FMEA) and Fault Tree Analysis (FTA) which are on the basis of the component failure and reliability theory, can not identify the system hazards related to system interactions. An emerging hazard analysis method based on systems theory, Systems Theory Process Analysis (STPA) mainly focuses on identifying the control system hazards caused by system interactions. In this study, STPA method is used to identify the potential hazards and casual factors for autonomous emergency braking system by concentrating on system interactions. To improve the consistency between system design and safety analysis, the workflow combining model-based systems engineering (MBSE) and STPA is proposed. The systems modeling language (SysML) is used to describe control structure and system interaction relationships. According to the identified casual factors, the certain constraints and requirements can be derived, which can provide the guidance for system development with respect to system design. Furthermore, the quantitative analysis of the certain unsafe control action is conducted by simulation, which shows effectiveness and feasibility of the proposed method in safety analysis and system design.