Safety-Critical Failure Analysis of Industrial Automotive Airbag System using FMEA and FTA Techniques

Abstract

Modern cars are equipped with safety systems that protect the occupants of the vehicle. Airbags are one example of an occupant protection system. Although airbags save lives in crash situations, they may cause fatal behaviour if they are inadvertently deployed. This is because the driver may lose control of the car when this deployment occurs. In developing safety airbag systems for the automotive industry, potential hazard analysis techniques have to be applied to identify potential failure modes. The commonly used safety analysis techniques are FMEA (Failure Mode Effect Analysis) and FTA (Fault Tree Analysis). In this paper, by applying FMEA safety analysis technique we identify various failure modes of airbag system. These are sensor failures, FET failure, microcontroller failure, Firing Application Specific Integrated Circuit (FASIC) failure. Likewise FTA analysis is performed on the airbag system to identify the various faults that can lead to a top level undesired event, leading to an accident. By employing these two safety analysis techniques the weaknesses in the airbag design can be identified early and necessary interventions taken.

Keywords: safety-critical system, hazard analysis, failure modes, FMEA, FTA.