Title: Non-linear observers for state and unknown inputs estimation

Authors: Fenglong Liu, Mondher Farza, Mohammed M'Saad

Addresses: GREYC, UMR 6072 CNRS, Universite de Caen, ENSICAEN 6 Bd Marechal Juin, Caen 14050, Cedex, France. ' GREYC, UMR 6072 CNRS, Universite de Caen, ENSICAEN 6 Bd Marechal Juin, Caen 14050, Cedex, France. ' GREYC, UMR 6072 CNRS, Universite de Caen, ENSICAEN 6 Bd Marechal Juin, Caen 14050, Cedex, France

Abstract: High gain observers are proposed for a class of multi-inputs multi-outputs non-linear systems with unknown inputs in order to simultaneously estimate the whole state together with the unknown inputs. The gain of these observers does not require the resolution of any dynamical system and is explicitly given. Two situations are analysed and an observer is proposed in each case. In the first situation, the dynamics of the proposed observer can be arbitrarily assigned while in the second one only a part of the observer dynamics can be freely assigned. Two simulation examples are given in order to highlight the performance of the proposed observers.

Keywords: nonlinear systems; high gain observers; unknown inputs; state estimation; simulation.

DOI: 10.1504/IJMIC.2007.014325

International Journal of Modelling, Identification and Control, 2007 Vol.2 No.1, pp.33 - 48

Published online: 01 Jul 2007 *

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