Functional Safety Assessment of a Generic Accelerator Control System with Electronic Throttle Control in Electric Vehicles

2020PDFTech ReportDOT HS 812 656DOT-VNTSC-NHTSA-15-13Intra-Agency Agreement DTNH22-13-V-0011451HS7BA100Accelerators (Devices)ThrottlesElectric vehiclesHazard evaluationFailure analysisSystems analysisHazard analysisRisk assessmentSafetyAccelerator control systemelectronic throttle controlhazard and operability studyfailure modes and effects analysissystems theoretic process analysisISO 26262safety requirementsUnited StatesUnited States. Department of Transportation. National Highway Traffic Safety AdministrationBecker, ChristopherNasser, AhmadAttioui, FouadJohn A. Volpe National Transportation Systems Center (U.S.)United States. Department of Transportation. Office of the Assistant Secretary for Research and TechnologyUnited States. Department of Transportation. National Highway Traffic Safety AdministrationNHTSA-Vehicle Safety Research;Volpe National Transportation Systems Center, Technical Reference CenterThis report describes research assessing the functional safety of accelerator control systems with electronic faults such as errant electronic throttle control signals, following an industry process standard. This study focuses specifically on errant signals in motor vehicles with electric propulsion. This study follows the concept phase process in the ISO 26262 standard and applies a hazard and operability study, functional failure mode and effects analysis, and systems theoretic process analysis methods. In total, this study identifies 7 vehicle-level safety goals and 202 ACS/ETC system safety requirements (an output of the ISO 26262 and STPA processes). This study uses the results of the analysis to identify potential opportunities to improve the risk assessment approach in the ISO 26262 standard.90