Qualitative fault propagation in complex systems

The fault propagation aspects of an overall real-time control system are examined. A novel method is introduced that extends previous work done in the context of fault models and qualitative behavioral modeling for addressing the problem of fault propagation through a complex system. The goal of the proposed approach is to provide a tractable solution to the multiple failure problem within a reasonable time frame to permit some preventive or corrective action to be instituted before a catastrophic event occurs. Two basic approaches are being studied. The first involves the use of qualitative fault models and behavioral states to determine the impact of a failed component in a complex system. The second approach involves energy-based stability analysis and qualitative simulation. A space station thermal subsystem and a jet engine have been chosen as the basis for model and simulation work