Observer-based fault isolation for statically non-isolable linear systems

This contribution deals with the design of fault isolation observers (FIOs). Their purpose is to detect and isolate faults acting on linear systems by means of only a single observer. While parameterizations for such observers have been proposed for statically isolable systems, we generalize the existing results to linear systems without the restriction of a non-singular fault detectability matrix. To achieve fault isolation in such systems, we introduce virtual system extensions, which enable stable isolation. These virtual augmentations are then realized by dynamically extended fault isolation observers (DFIOs). Apart from that the proposed design allows to isolate both actuator and sensor faults.