Compliance of ISO 26262 Safety Standard for Electric Power Steering System

This paper is an application of ISO 26262 functional safety standards for fail-safe design, development and validation of Electric Power Assisted Steering (EPAS) System. As part of safety feature to save lives, prevent injuries and reduce economic loss due to accidents, many research institutes are working to ensure the safety and reliability of emerging safety-critical Electronic Control Systems in automobile applications. As, Advanced Driver Assistance Systems (ADAS) and other emerging technologies are introduced in the automobile application, the overall safety of these advanced electronic systems relies on the vehicle safety systems, such as steering systems. This paper outlines the approach of performing the Hazard Analysis & Risk Assessment (HARA) and developing a Functional Safety Concept. This approach incorporates several analysis methods, including Hazard and Operability study, Functional Failure Modes and Effects Analysis. This approach is then applied to the Electric Power Assisted Steering (EPAS) system to identify vehicle-level hazards, and derive safety goals and functional safety requirements. This paper presents the vehicle-level hazards, and safety goals derived from the analysis and includes a discussion of “fail-safe” and “fail-operational” needs, which results in the derivation of functional safety requirements. The results of this study may serve as an example of how different analytical methods could be applied to develop a functional safety concept.