Application of diagnostic bond graph to fault diagnosis for liquid-propellant rocket engine

The liquid-propellant rocket engine's fault isolation method using analytical redundancy relations (ARRs) generating from diagnostic bond graph (DBG) has been studied. The DBG model of LRE has been constructed by introducing observed signal and virtual sensors into bond graph model of the system. Then the ARRs for LRE can be established using the DBG model. The method to build fault signature matrix by incorporating with the causality of DBG and the tendency analysis with the residuals of ARRs has been proposed. The fault eigenvalue obtained from this fault signature matrix can represent fault signature in a better and more precise way. By using the simulation data, the fault diagnosis results have been analyzed and verified. It is shown that the fault diagnosis method is simple, fast and with high veracity.