Transmission of Safety-Relevant Sensor Data in Intra-Car Communication Systems

Project Description

Currently used airbag systems work independently, consisting of only few external and internal sensors and several firing units. To fulfill the demands of safety in an automotive environment, sensors and controllers are designed redundantly, plausibility tests are performed and activation of actuators is proved against misuse by so-called safing-concepts.
The connection of different electronic systems within the car – e.g. electronic stability program (ESP) or anticipatory sensors with the airbag control unit (ACU) – leads to new architectures with sensors, actuators and several controllers. As a consequence of the connection, more signals and sensor data are available to the single control units and self-test functions can be integrated in software, increasing the reliability, availability and safety of the system while costs can be reduced as redundant components may become unnecessary.
Nevertheless, the complexity of the overall system grows with such a distributed design of the intra-car network, especially in terms of predicting performance measures such as latencies, firing times or failure probabilities.
To overcome this, a method is to be developed to analyze existing design layouts as well as new architecture patterns, taking into account key characteristics of network components (bus system and topology, controller, sensor), investigated scenarios (crash, roll-over, pre-crash phase, pedestrian protection) and common reliability engineering methods (SIL, FMEA, FTA, FEM, discrete and/or continuous simulation, Markov Chains). The method shall be validated by measurements for an actual system configuration on the one hand, while its basic applicability to arbitrary design patterns is to be assured on the other hand. The results are intended to give a sound basis for predicting the system behavior, especially when discussing new layout decisions in industrial committees (VDA) or boards of directors.

Project Period

    2006-12-01 – 2009-11-30

Project Members

Sponsered by

  • AUDI AG (Ingolstadt)

Involved Institutions

  • Safety-Electronics / Airbag-Control-Systems
  • INI.FAU
  1. Ulrich Klehmet, Thomas Herpel, Kai-Steffen Jens Hielscher und Reinhard German, “Real-Time Guarantees for CAN Traffic,” 2008 IEEE 67th Vehicular Technology Conference, Piscataway, N.J., Marina Bay, Singapore, pp. 3037-3041, Mai 2008
  2. Ulrich Klehmet, Thomas Herpel, Kai-Steffen Jens Hielscher und Reinhard German, “Delay Bounds for CAN Communication in Automotive Applications,” Proc. 14th GI/ITG Conference Measurement, Modelling and Evaluation of Computer and Communication Systems, Berlin, Dortmund, Germany, pp. 157-171, März 2008
  3. Ulrich Klehmet, Thomas Herpel, Kai-Steffen Jens Hielscher und Reinhard German, “Worst Case Analysis for Multiple Priorities in Bitwise Arbitration,” GI/ITG-Workshop MMBnet: Leistungs-, Zuverlässigkeits- und Verlässlichkeitsbewertung von Kommunikationsnetzen und verteilten Systemen, Hamburg, Germany, pp. 27-35, September 2007