Abstract-The introduction of computer-controlled intelligent safety and comfort features has turned cars into complex distributed computing systems. In such a system the proper operation of the communication backbone as well as the proper interaction of components from different vendors must be ensured for all configurations and operating conditions. This system-level test goes far beyond the (isolated) test of single components and represents a substantial problem, that seems to be still largely unsolved, although its solution is crucial for maintaining the consumers' trust in modern automotive electronics.In this paper we concentrate on the test of distributed systems based on FlexRay, the protocol that is envisioned as the communication backbone for future automotive systems. The cornerstones of our approach are a decomposition of the system into layers and mechanisms, and a versatile strategy for monitoring and stimulation under various conditions. Our concept can be adapted to diverse needs ranging from an early debugging with full access to the system, over non-intrusive online testing during inter-operability tests, to maintenance testing that is restricted to a remote access only. We give detailed discussions of the requirements and present our solutions for the various issues involved. Selected use cases demonstrate the usefulness of the taken approach.Index Terms-Automotive electronics, embedded systems, FlexRay, system test, time-triggered communication.
I. MOTIVATION
DOZENS of complaints like "while overtaking another car, the engine unexpectedly went into emergency mode and dropped to a crawl" or "windows open automatically when in heavy rain" were reported to a local Austrian automotive magazine by its readers for a survey on problems with electronics in new cars [1]. The fact that virtually all brands were affected, from low-cost to luxury, clearly indicates substantial problems with the integration of electronic systems in general. Still nobody is seriously talking about returning to the "good old days." Electronics has been the key innovation driver for automotive systems throughout the last decade, and this situation is not going to change in the near future. The vehicle networks are transforming automotive components into truly dis- tributed electronic systems, e.g., with up to 72 units interconnected with various different fieldbus systems in the new Mercedes S-class (see [2]). Replacing rigid mechanical components with dynamically configurable electronic elements triggers an almost organic, system-wide level of integration. As a result, the automotive industry expects savings resulting in improved environmental tolerance and cost reduction. Sophisticated and more complex features for safety and comfort such as chassis control and smart sensors are expected to be developed faster and more reliably and will likely become mainstream. Unfortunately, all these functionalities translate into higher performance (resource usage), reliability, and maintainability requirements for future automotive sy...