Abstract:

It is very necessary to conduct safety analysis on the safety critical avionics system by fault tree. However, fault tree is traditionally modeled in a manual way, which mainly relies on how well the analyzers understand the system. Meanwhile, the consistency between failure modes and system architectures is hard to be guaranteed due to the differences  in the understanding between the safety analyzers of the system and the system designers. Aiming at the above problems, we propose a fault tree auto-modeling method based on avionics system architecture model. The safety analysis model is constructed through adding safety properties to the system design model and embedding assertion mechanism of the advanced formal language AltaRica to describe the fault transition process. The fault tree auto-modeling is then conducted by tracing the data signal path of the model. The results of the case study on one cockpit display system indicate that the proposed method is able to conduct fault tree auto-modeling efficiently based on the avionics system architecture model, ensuring the completeness of the fault tree analysis results.

Key words: avionics system architecture, SysML, fault tree modeling, AltaRica, guarded transitions system