Applicability of Standard Formulation Parametric Fault Detection Methods

This paper presents a new way to test the applicability of a class of parametric fault detection and estimation methods. Those methods use linear fractional transformations to represent parameter variations and rely on H_infin filtering for the estimation of certain signals that may allow the computation of those variations. A first version of the method for parametric fault detection is briefly presented. Although previous results indicated the method could perform well it is shown this is not always the case. It is shown how one can anticipate the quality of the parametric fault estimation results that can be obtained for each system. The test procedure is general. Two simple examples illustrate the shortages of the fault detection method and help showing how to test its applicability. It is argued that the applicability of a perhaps more general version of the fault detection and estimation method can be done in the same way reported here