Comparison of CAN, FlexRay, and Ethernet Architectures for the Design of ABS Systems 2011-01-0453

The rapid increase of networked electronic control units in airplanes (Line Replaceable Units or Modules, LRUs/LRMs) and automobiles (ECUs) requires to move from CAN buses to higher performance buses. In aircraft the number of LRUs exceeded 100 in 1990 (B777) and is now ≻5000 (A380). Today, the number of ECUs in some automobiles also exceeds 100. Aircraft industry developed solutions based on standard switched Ethernet (AFDX) and standardized ECUs, called Integrated Modular Avionic units (IMA units) and common remote data concentrators (cRDCs) that are now flying in the Airbus A380 and A400M, the Boeing B787, and are being used in the design of future civil and military aircraft. During the last decade, automotive industry has been pursuing the development of specialized FlexRay bus solutions for automotive control and specialized MOST bus solutions for comfort electronics. However, some automotive companies are now also looking at Ethernet-based solutions.

This paper describes some of the steps aircraft industry has been taking to cope with the rapid increase of the number ECUs in aircraft and the use of Ethernet, IMAs and vehicle level executable specifications for high security applications in aircraft. For an example of an ABS system it is shown how high security Avionics Full-Duplex Switched Ethernet (AFDX) buses may be used to replace CAN, FlexRay, and MOST solutions for automobiles.