55. Functional Safety System Design on EPS

This paper aims to present the safety design and analysis method complied with ISO 26262 based on EPS (Electric Power Steering) application. There are six sections included in this paper. At the first section, it introduces the functional safety basic idea for risk reduction and the work principle of pinion-EPS. Then the hazard analysis and risk assessment of EPS system is carried out which is significant for the concept stage of functional safety. With HARA (Hazard Analysis and Risk Assessment) result, safety goal and safety requirement are derived, and also the safety mechanism is designed. To verify the plausibility of safety mechanism design, a failure analysis is conducted to perform as evidence for safety case report. The failure analysis is finished by means of FMEDA and PMHF. And as innovative part of this paper, a Markov model for safety path is created and the qualitative analysis is applied. Last but not the least, a conclusion of the paper is finished on the sixth section.