Enabling Fail-Operational Power Supply Through Capacitor-Based Safety Adapter

Abstract

Modern vehicles feature an increasing number of automated driving functions. This raises formal safety requirements for systems that directly intervene with these functions, such as steering or braking systems. The state-of-the-art offers various solutions that ensure fail-operational capability of safety-relevant systems. However, many existing approaches are associated with increased material and integration effort, particularly when applied to existing automotive E/E architectures. This paper proposes a capacitor-based Safety Adapter to address this gap. It is intended to support the fulfillment of higher functional safety requirements under ISO 26262. We derive formal safety requirements based on an exemplary steering system and also present a first possible hardware layout. Initial verification results on a HiL test bench indicate that the proposed Safety Adapter can maintain steering assistance during undervoltage scenarios, even under aged conditions and very low ambient temperatures.