Model-based methodology optimizes functional safety, Part 2: Challenges of integration

Jürgen Belz, Prometo GmbH, and Tapio Kramer, Ralf Münzenberger, Inchron GmbH

May 30, 2011

Jürgen Belz, Prometo GmbH, and Tapio Kramer, Ralf Münzenberger, Inchron GmbH

Part 1 of this series discussed timing as part of functional safety, and uses the example of a seat memory system for analysis of faults.

This part analyzes the seat memory system when a switch fails and how the software must respond in detecting the failure and stopping any motion. Modeling timing and "critical event" chains are introduced to determine predictable reactions in real time.

Mechanical design, electronics, and software will have a common architectural blueprint to derive critical event chains and timing budgets. The earlier (by using model based methods) this can be tested, the faster a robust architecture can be found and the safety goals achieved. The example demonstrates that even small functions aren't trivial especially when they rely on complex integrated systems. Nevertheless it is shown that the modeling of timing and performance is feasible with the right methods and tools.

For the complete second article, including integrating safety and non-safety functions into an ECU, click here, courtesy of Automotive Designline Europe.