Robustness of Observer-based Fault Diagnosis Technology

A key for the feasibility and applicability of the techniques of observer-based fault diagnosis for dynamic systems is a satisfactory robustness with respect to system uncertainties. According to the features of studying robustness of observer-based fault diagnosis systems, emphasis is put on robustness improvement of fault diagnosis in linear uncertain systems by increasing robustness of observers, and enhancement of robustness by using unknown input observers. A new design method of compound fault estimator is developed to estimate compound faults. The existence condition of a estimator is given and a related computing method is proposed.