FKFS Veranstaltungen

2025 Stuttgart International Symposium
on Automotive and Engine Technology

3. - 4. Juli 2025

Session: E/E Architecture | | 17:05 - 17:35

The Relay Race in the Control Unit - Time Deterministic Aspects in Automotive Control Units

Wolf-Hendrik Kaps, Robert Bosch GmbH

The complexity of today's software systems in modern vehicles is not only defined by a variety of functionalities, but is also determined by highly critical time constraints. So what does this have to do with a “relay race”? This analogy impressively illustrates the temporal connections in current and future software systems in the automotive sector and serves to motivate this interesting topic in this paper story line.Information processing in modern vehicles is implemented using so-called end-to-end event chains. Sensors provide data that is processed by various electronic control units (ECUs) and, at the end of this chain, adjust actuators. Just like in a relay race: A starting runner transfers the baton (signal) to the next runner and the last runner brings this baton to the finish, which results in the adjustment of the actuator. All of this must be precisely defined in time and in the correct sequence so that the requirements of the system are met.The temporal determinacy in increasingly complex overall software systems is a major challenge for design and implementation and must be an integral part of system development from the start. By defining the time requirements at an early stage, such as the sequences of the functionalities to be carried out and their latencies, it is possible to make optimal use of the usually limited resources as early as the design phase. Bosch has a profound system integration know-how built up over many years, which is based on methodical procedures e.g. timing extensions using the AUTOSAR standard. This important development aspect has been successfully implemented in a variety of control devices.This paper illustrates the requirements, the underlying methodological aspects and their implementation of time-critical functionalities using concrete examples. In this context data-flow determinism is discussed based on the Logical Execution Time (LET) paradigm. Topics such as the budgeting of functionalities, parameters and their definition in event chains, simulation (based on AMATHEA) and collaboration models are described. Teamwork is a crucial success factor - just like in a relay race. Bosch also uses e.g. the AUTomotive Open System Architecture Standard (AUTOSAR), specifically the timing extensions when defining and implementing the time-determined functionalities. AUTOSAR is generally available and can therefore be used by a variety of automotive projects. Our experiences are conveyed from a “sports” perspective and invite a stimulating discussion.