Diagnostic approach using Bond Graph and timed automata

The problem of fault diagnosis involves detecting, locating and identifying the considered faults occurring in the dynamical system. The aim of this paper is to explain the use of hybrid tool which combines Bond Graph (BG) and Timed Automata (TA). These tools allow us, respectively, to detect the fault and find the cause of a system dysfunction. Due to the structural and causal properties of the bond graph tool, we use it to detect the incorrect behavior and then to isolate faults which can affect the physical process. But sometimes, some failures of the system components can not be identified by the Bond Graph model. Therefore, we use, in this case, the timed model (timed automata) in order to locate and identify these faults. And subsequently, the performances of the phase of fault location will be improved (i.e. isolation of non-isolable faults) thanks to the use of these tools (Bond Graph and Timed Automata). The proposed approach is then validated through simulation tests to a level regulation system.