Virtual Vehicle
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Advanced Diagnosis for time-triggered Automotive Communication Systems (ADACS)

Funded by the FWF Der Wissenschaftsfond ( contract (L652-N15)
Duration: 01.11.2009 - 31.10.2011

Project Description

Time-triggered architectures and time-triggered communication systems present a defined behavior both in the time and in the value domain. The precise interface definition provides features such as independent node development, stability of prior services at the node level and constructive integration of the communication system1. This precise interface definition also supports efficient network supervising for online assessment of the current system status (online test).


We propose a non-intrusive two steps methods. During a 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).


During a second step, the dedicated tester node is used to stress the FlexRay clock synchronization algorithm. This patented approach [1] provides further information about quartz frequency of the distributed nodes while being non-intrusive for the system [2]. Hence, normal operation of the network is not endangered and the other nodes do not take notice of this transparent online test.


1H. Kopetz, Real-Time Systems: Design Principles for Distributed Embedded Applications. Norwell, MA, USA: Kluwer Academic Publishers, 1997


Project Aim

The aim of this project is to evaluate and enhance existing methods and present new approaches for the remote test of FlexRay networks. More especially, the project goal is to remotely and automatically extract attributes that summarize the current system state. This information can be further presented concisely to the end user (the system know-how is embedded in the prototype) and / or used for advanced error detection. Example of attributes can be FlexRay related (remote measurement of system precision, nodes offset and rate correction), system related (remote quartz drift measurement) or transparent test methods for the communication system.


Application area

  • Online system monitoring --> better assessment of the system status, faster fault detection
  • Preventive maintenance --> Improvment of the system availability
  • Integrated system supervising --> longer service interval possible


[1] Remote measurement of local oscillator drifts in FlexRay networks
Armengaud, E.; Steininger, A.; Design, Automation & Test in Europe Conference & Exhibition, 2009. DATE '09. 2009 Page(s):1082 - 1087 (Austrian Patent Application A1503/2007)

[2] Safely Stimulating the Clock Synchronization Algorithm in Time-Triggered Systems - A Combined Formal and Experimental Approach
Steininger, A.; Armengaud, E.; Fugger, M.; IEEE Transactions on Industrial Informatics, Volume 5,  Issue 2,  May 2009 Page(s):132 - 146



The methods and technology have been developed at the Vienna University of Technology and are being implemented and evaluated conjointly by the Virtual Vehicle Competence Center (VIF) and the Austrian Institute of Technology (AIT) within the FWF Project ADACS (contract number L652-N15).

These two Austrian institutes present many years of experiences in the field of real-time communication systems and dependable systems.