Embedded Architectures in the Face of ISO26262 ASIL A to ASIL D - HW/SW Co-design and New Functionalities

摘要

Functional safety is becoming a key aspect of electrical and/or electronic systems (E/E systems) in the automotive domain through the increased usage of electronic control with its associated benefits. This is true not only for new automotive systems such as advanced driver assistance systems but also for established systems, such as power steering, and even seemingly simpler systems, such as various lighting controls, to name just two examples. When looking at such systems it soon becomes evident that a malfunction of such an E/E system could be a source of harm in the form of physical injury or damage to the health of persons. ISO 26262 focuses on circumventing such harm with the means of functional safety. To facilitate a more differentiated view of functional safety the ISO 26262 standard introduces the concept of ASIL classification. ASIL classification is applied to safety goals that result from a hazard analysis and risk assessment of the E/E system.Not only the ASIL classification, but also the nature and the quantity of the safety goals that have to be addressed by a specific E/E system have a key impact on the safety architecture of this system. To be competitive in today's market space the safety architecture needs to be effective and efficient. And to add to the challenge techno-economical needs in the automotive industry are typically not limited merely to the scope of the system, but also encompass platform aspects and in some cases even cross-platform migration. Hence, a holistic view (in absence of clairvoyance) is needed for key decisions driving the safety architecture. This view needs to include not only HW aspects as well as SW aspects but also the overall impact of the safety architecture on the safety lifecycle (including aspects such as verification and safety validation) and lastly the impact on automotive platform aspects. Today the automotive industry is still in the process of gaining this holistic view. After providing an introduction to ASIL classification the paper ventures into different aspects of this holistic view from an embedded architecture perspective.