Characterisation of interval-observer fault detection and isolation properties using the set-invariance approach

Abstract

The aim of this paper is to provide a robust Fault Detection and Isolation (FDI) approach that combines the set-invariance approach with a zonotopic interval observer. The effect of the uncertainty is taken into account considering zonotopic-set representations in both the transient and steady states. The set-invariance approach is used to characterize the fault detectability and isolability properties in the steady-state operation of the system. In particular, the Minimum Detectable Fault (MDF) and the Minimum Isolable Fault (MIF) are characterized for several type of faults in separate formulations utilizing the integration of classical sensitivity analysis and set-invariance approaches. Finally, a simulation example based on a two-tanks system is employed to both illustrate and discuss the effectiveness of the proposed approach.