ADACS: Advanced Diagnosis for Time-Triggered Automotive Communication Systems

Automotive electronics are complex distributed embedded systems. The tight interconnection of the different functionalities (e.g. ABS, ESP) makes the network resource the backbone of the system. Time-triggered architectures and time-triggered communication systems such as FlexRay have been introduced in this context to support the development and integration of safety-relevant systems. An important enhancement to this approach is online monitoring and transparent diagnosis to ensure better assessment of the system status (faster fault detection) during operation. This is required for preventive maintenance in order to improve system availability. We propose a non-intrusive two steps method for the analysis of the communication architecture. In the first step, the system behavior is monitored at different abstraction levels by a dedicated tester node. The traces are analyzed online and the current system behavior is compared to the specification (e.g. FlexRay protocol or electrical physical layer specification) and configuration (e.g. FIBEX). In the second step, the dedicated tester node is used to stress the FlexRay clock synchronization algorithm and remotely measure the quartz frequency of the distributed nodes. Additionally we evaluate the remote quartz measurement approach with respect to measurement accuracy and illustrate the approach for quartz surveillance in a context of temperature changes.