Robust fault detection observer design for LTI systems based on GKYP lemma

This paper addresses the robust fault detection observer design issue for linear time invariant (LTI) systems with parameter uncertainties in a polytope and subjected to unknown inputs. The observer design is investigated under the H ∞ /H - index framework in the finite frequency domain where the generalized KYP lemma is utilized. The threshold design and the worst undetectable fault size estimation are discussed. An example is given to illustrate the results obtained in this paper.