Fault diagnosis in nonlinear dynamical systems based on left invertibility condition: A real-time application to three-tank system

This work deals with the fault diagnosis problem, some new properties are found using the left invertibility condition through the concept of differential output rank. Two schemes of nonlinear observers are used to estimate the fault signals for comparison purposes, one of these is a reduced order observer and the other is a sliding mode observer. The methodology is tested in a real time implementation of a three-tank system.