Architectural design and analysis of a steer-by-wire system in view of functional safety concept

Abstract

In the context of intelligent and automated vehicles, drive-by-wire (DBW) systems have aroused wide attention, both in academia and industries. Over the years, a lot of discussion has been made about the architectural design of brake-by-wire (BBW) systems. However, the architectural design of the steer-by-wire (SBW) system hasn’t been emphasized enough, especially in the context of functional safety concept. In view of this, based on the newly released version of ISO 26262:2018 as well as the technical report from National Highway Traffic Safety Administration (NHTSA), a fail-operational architecture for the SBW system is proposed in this paper, following the detailed analysis results of the concept phase as suggested in ISO 26262:2018. Further utilizing state transition diagrams and quantitative fault-tree-analysis (FTA) analysis respectively, detailed qualitative as well well as quantitative analysis results are provided, proving the safety and reliability of the proposed architecture. The aim is to provide guidance as well as some references for the SBW system design and analysis, where the essential problem is safety and reliability of the system, so that safety and reliability of automated vehicles can be guaranteed.