What is specific for the modelling in fault detection and isolation

摘要

In this note some reflexions about the differences between the models used for control and for fault detection and isolation (FDI) are presented. The first part is concerning with the analysis of reidual generators based on three different approaches. As a result, the dependence of the different residual generators on the transfer function from the fault to the output of the considerd system is established. Consequences of this dependence are also ointed out. Secondly, based on three examples, it is shown that in some cased the models used for FDI are not useful for control purposes and vice versa.