Avionics databus safety criteria and certification

摘要

The paper considers databuses used in avionics and automotive applications (ARINC 629, ARINC 429, FlexRay, CAN, TTP, SAFEbus, SpaceWire, FireWire and others) and identifies the criteria to evaluate them with respect to safety. The criteria address comprehensive aspects of databus assessment problem, combining mechanical (bus wiring, connectors, pinout, module design and dimensions, etc.), electrical (signal levels, their dynamics to carry information, electromagnetic compatibility, etc.), and logical characteristics, including the protocol of exchanging information between devices over a bus, in all three phases: bus arbitration, data transfer and fault handling. A systematic list of safety-related attributes and their relationships for evaluation of aviation databuses is presented, which would allow building the uniform evaluation criteria for certification purposes. Preliminary simulations and real experiments are aimed at protocol comparison, according to the methodology previously developed by the authors. The study is intended to allow establishing standard and objective criteria for evaluating databus technologies in safety-critical applications.