A Time-Triggered Constraint-Based Calculus for Avionic Systems

The Integrated Modular Avionics (IMA) architecture and the Time-Triggered Ethernet (TTEthernet) network have emerged as the key components of a typical architecture model for recent civil aircrafts. We propose a real-time constraint-based calculus targeted at the analysis of such concepts of avionic embedded systems. We show our framework at work on the modelisation of both the (IMA) architecture and the TTEthernet network, illustrating their behavior by the well-known Flight Management System (FMS).

I. Introduction

The growing complexity of avionic embedded systems led to the definition of a new standard of architecture called Integrated Modular Avionics (IMA) [1]. This type of architecture is characterized essentially by the sharing of distributed computing resources, called modules. Sharing these resources requires to guarantee some safety properties such as the collision- free. In order to achieve this objective, the Avionic Full Duplex Switched Ethernet (AFDX) [2] has been adopted as a networking standard for the avionic systems. IMA and AFDX became the components of a typical architecture model for the recent civil aircrafts such as the Boeing B787 and the Airbus A380. However, AFDX underuses the physical capacities of the network. Recently, the Time-Triggered Ethernet (TTEthernet) has emerged as a new standard of the avionic network [3]. This standard enables to achieve a best usage of the network and is more deterministic since the schedule is established offline.