Nonlinear H∞ identity observers for sensor FDI: An application example

In this paper the problem of detecting and isolating sensor faults on a certain class of nonlinear systems is considered. A procedure to design a bank of extended H∞ observers for sensor FDI is carried out: each observer is composed of an open loop nonlinear part replying the system dynamics and a linear feedback action. Sufficient conditions for the synthesis of the feedback action are provided in terms of LMI feasibility problems. Constraints on the position of the observer poles are added to fasten the residual generation dynamics and to avoid low damped or high frequency modes. Numerical results on the attitude control demonstrator Twin Rotor MMO System built by Feedback™ are provided to show the application of the proposed technique.