Robust Fault Detection and Isolation with Unstructured Uncertainty Using Eigenstructure Assignment

Abstract

A numerical implementation is presented for the eigenstructure assignment approach to the design of a robust fault detection and isolation observer. By formulating the problem of multiple fault isolation in an eigenstructure, wedevelopaparametriccharacterizationofallallowableeigenspaces,whichprovidesadiagnosticobservercapable ofmultiplefaultisolation.Inaddition,awell-conditioneddesignoftheallowableeigenvectorsisshowntoreducethe effectofthesystem unstructured uncertainty.Theresulting diagnosticobserverisrobustto unstructuredmodeling errorswithoutlosingfaultdetectionsensitivity.Aprocedureforthesynthesisofareduced-orderdiagnosticobserver is also presented to increase the computational efe ciency of the proposed observer.