Robust sensor FDI observer for polytopic descriptor LPV systems with unmeasurable scheduling varying parameter

This paper deals with the problem of sensor fault detection for polytopic descriptor LPV (D-LPV) systems. Unlike the conventional approach, this work considers the scheduling functions as unmeasurable. Firstly, the design of the observer for the D-LPV systems with an unmeasurable scheduling parameter is proposed. Convergence and robustness conditions are established by Lyapunov stability analysis and H_∞ approach. Sufficient conditions for the existence of such observer are given in terms of linear matrix inequalities (LMIs). Secondly, a bank of observers, based on the robust observer, is used to perform sensor fault detection and isolation despite of the unmeasurable scheduling variable. The effectiveness of the proposed methodology is illustrated by means of a numerical simulation example.