A novel fault-tree approach for identifying potential causes of satellite reaction wheel failure

Due to unforeseen circumstances and naturally occurring faults, it is desired that an on-board fault-diagnosis system of a space vehicle be capable of detecting, isolating, identifying or classifying faults in the system. In this paper, a novel approach is proposed which strengthens existing efficient fault-detection mechanisms with an additional ability to classify different types of faults to effectively determine potential failure causes in a subsystem. This extra capability ensures a quick and efficient recovery/reconfiguration from disruptions. Our developed diagnosis/analysis procedure exploits a widely used qualitative technique called fault-tree analysis, as a diagnostic aid, for failure analysis in the attitude control subsystem (ACS) of a spacecraft. Constructed fault-trees have been able to represent combinations of events leading to different failures resulting due to artificially injected faults in a MATLAB-Simulink model of the ACS. It is important to emphasize that proposed technique has potentials for being integrated in an on-board health monitoring and diagnosis tool for space vehicles.