Self-organized Message Scheduling for Asynchronous Distributed Embedded Systems

  • Tobias Ziermann
  • Zoran Salcic
  • Jürgen Teich
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6906)

Abstract

A growing number of control systems are distributed and based on the use of a communication bus. The distributed nodes execute periodic tasks, which access the bus by releasing the messages using a priority-based mechanism with the goal of minimal message response times. Instead of randomly accessing the bus, a dynamic scheduling of messages technique based on adaptation of time offsets between message releases is used. The presented algorithm, called DynOAA, is executing on each node of the distributed system. It takes into account the current traffic on the bus and tries to avoid simultaneous release of messages by different nodes, hence reduces the likelihood of conflicts and need for repeated release. In this paper, we first address single bus (segment) systems and then extend the model and the offset adaptation algorithm to systems that use multiple buses (segments) connected by a communication gateway. A rating function based on the average of maximum response times is used to analyze DynOAA for the case of CAN-bus systems based on bit-accurate simulations. Experiments show the robustness of the algorithm (1) in case of fully asynchronous systems, (2) ability to deal with systems that change their configuration (add or remove message release nodes) dynamically and (3) model systems containing multiple bus segments connected by a gateway. The approach is also applicable to other priority-based bus systems.

Keywords

Time Slot Controller Area Network Data Link Layer Maximum Response Time Message Stream 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    CAN Specification 2.0 B. Robert Bosch GmbH, Stuttgart, Germany (1991)Google Scholar
  2. 2.
    Bai, T., Hu, L., Wu, Z., Yang, G.: Flexible fuzzy priority scheduling of the CAN bus. Asian Journal of Control 7(4), 401–413 (2005)CrossRefGoogle Scholar
  3. 3.
    Braun, C., Havet, L., Navet, N.: NETCARBENCH: A benchmark for techniques and tools used in the design of automotive communication systems. In: 7th IFAC International Conference on Fieldbuses and Networks in Industrial and Embedded Systems. Citeseer (2007)Google Scholar
  4. 4.
    Di Natale, M.: Scheduling the can bus with earliest deadline techniques. In: Proceedings of the 21st IEEE Real-Time Systems Symposium, pp. 259–268 (2000)Google Scholar
  5. 5.
    Felser, M.: Real-time ethernet - industry prospective. Proceedings of the IEEE 93(6), 1118–1129 (2005)CrossRefGoogle Scholar
  6. 6.
    FlexRay Consortium. FlexRay Communications Systems - Protocol Specification v3.0 (2009), http://www.flexray.com
  7. 7.
    Goossens, J.: Scheduling of offset free systems. Real-Time Systems 24(2), 239–258 (2003)CrossRefMATHGoogle Scholar
  8. 8.
    Grenier, M., Havet, L., Navet, N.: Pushing the limits of CAN-scheduling frames with offsets provides a major performance boost. In: Proc. of the 4th European Congress Embedded Real Time Software (ERTS 2008). Citeseer, Toulouse (2008)Google Scholar
  9. 9.
    Pfeiffer, O., Ayre, A., Keydel, C.: Embedded networking with CAN and CANopen. Copperhill Media (2008)Google Scholar
  10. 10.
    Racu, R.: The role of timing analysis in automotive network design. In: Talk, 4th Symtavision News Conference on Timing Analysis, Braunschweig, Germany (2010)Google Scholar
  11. 11.
    RTaW-Sim. Real-time at Work CAN Simulator, http://www.realtimeatwork.com/
  12. 12.
    Ziermann, T., Salcic, Z., Teich, J.: DynOAA - Dynamic Offset Adaptation Algorithm for Improving Response Times of CAN Systems. In: Proceedings of Design, Automation and Test in Europe (DATE 2011), March 14-18, IEEE Computer Society, Grenoble (2011)Google Scholar
  13. 13.
    Zuberi, K.M., Shin, K.G.: Non-preemptive scheduling of messages on controller area network for real-time control applications. In: rtas, p. 240. IEEE Computer Society, Los Alamitos (1995)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Tobias Ziermann
    • 1
  • Zoran Salcic
    • 2
  • Jürgen Teich
    • 1
  1. 1.University of Erlangen-NurembergGermany
  2. 2.The University of AucklandNew Zealand

Personalised recommendations