Overview of End-to-End Event Chain in Advanced Driver-Assistance Software following AUTOSAR

In general, an event chain describes the casual order for a set of functionally dependent timing events. Each event chain has a well-defined stimulus and response, which describes its start and end point. In automotive software, that performs driver-assistance function, end-to-end event chain contains sensor acquisition as starting point, processing and decision in the middle, and action upon that decision in the end. Since performance and reliability of these functions have direct impact on road and driver safety, they have very strict safety requirements. To satisfy these requirements, system that performs these functions needs to have highly deterministic behavior and very low latency. End-to-End latency in this case means duration between the recognition of a sensor event and the corresponding action of an actuator. Correct description of end-to-end event chains enables accurate development of software architecture for specific driver-assistance functions and system in general. This paper presents an overview and general decomposition of event chains in automotive software developed according to AUTOSAR. It showcases major components of such event chain in layered AUTOSAR architecture, their respective time properties, and how it affects end-to-end latency.