Robust Detection and Estimation of Faults by Exact Fault Decoupling and H /spl infin/ Disturbance Attenuation in Linear Dynamical Systems.

In this paper a useful combination of the idea of inversion-based direct input (fault) reconstruction and H_infin optimal filtering for robust estimation, detection and separation of multiple simultaneous faults in the presence of persistent, non-decouplable disturbances in linear dynamical systems is presented. In particular, it is shown how in a specific filtering structure, relying on the inverse representation of the system, an H_infin detection filter can be designed providing detection residuals by exact fault decoupling where the estimation of the inverse dynamics is obtained by means of the optimal filter thus ensuring H_infin disturbance attenuation on the residual output. The applicability of the method is demonstrated based on the aircraft monitoring problem that was originally considered in the papers by Douglas and Speyer (1995) and Chung and Speyer (1998)