Design of Unkown Input Fractional-Order Observers for Fractional-Order Systems
English
Ndoye, Ibrahima[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
Darouach, Mohamed[University of Lorraine > Research Center for Automatic Control of Nancy (CRAN UMR, 7039, CNRS)]
Voos, Holger[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit > ; University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT)]
[en] Fractional calculus ; fractional-order systems ; fractional-order observers ; existence condition ; linear matrix inequality (LMI) ; unknown input ; stability
[en] This paper considers a method to design fractional-order observers for continuous-time linear fractional-order systems with unknown inputs. The conditions for the existence of these observers are given. Sufficient conditions for the asymptotical stability of the fractional-order observer errors with the fractional-order \alpha satisfying 0<\alpha<2 are derived in terms of linear matrix inequalities. Two numerical examples are given to demonstrate the applicability of the proposed approach where the fractional-order \alpha belongs to 1<\alpha<2 and 0<\alpha<1 respectively. The stability analysis of the fractional-order error system is completed and it is shown that the fractional-order observers are as stable as their integer-order counterpart and guarantee better convergence of the estimation error.