LMI-based design of robust fault isolation filters for linear systems

In this paper we employ general linear dynamic filters to robustly isolate faults in linear systems. The concept can be regarded as a generalization of observer based approaches and offers more degrees of freedom and less structural constraints than fault isolation observers (FIOs). We propose an LMI-based design approach for fault isolation filters (FIFs), where the existence of a solution for exactly known system matrices is guaranteed by the constructive design of an attainable reference model. The approach can readily be applied to systems with disturbances and/or parametric uncertainties, which is a main advantage over observer-based approaches. Its applicability is demonstrated by means of both simulations and lab experiments with a gantry crane system.