Fault diagnosis based on directed factor graph for mode switching spacecraft power system

Spacecraft power system is a complex, highly interconnected hybrid system that exhibit nonlinear and mode switching behaviors. Directed factor graph is an inference model for fault diagnosis using probabilistic reasoning techniques. A novel approach for constructing the directed factor graph structure based on hybrid bond graph model for fault diagnosis in spacecraft power system is proposed. The cause-effect relations between system components status and fault symptoms are identified and concluded through causal path analysis on hybrid bond graph model. A power supply module of a spacecraft power system is provided as case study to show the feasibility and validity of the proposed method.