Observer synthesis for linear discrete-time systems with different fractional orders
Abstract
The paper is devoted to observer synthesis for linear discrete-time positive fractional systems with different fractional orders. The problem of finding a nonnegative gain matrix of the observer such that the observer is positive and asymptotically stable is formulated and solved by the use of linear programming (LP) and linear matrix inequality (LMI) methods. The proposed approach to the observer synthesis is illustrated by theoretical example. Numerical calculations and simulations have been performed in the MATLAB/Simulink program environment.
Keywords
discrete-time, fractional order, linear matrix inequality, linear programming, observer, positive, system
Synteza obserwatora układów dyskretnych o różnych niecałkowitych rzędach
Streszczenie
W pracy rozpatrzono problem syntezy obserwatorów dla dodatnich układów dyskretnych różnych niecałkowitych rzędów w równaniu stanu. Wykorzystując podejście oparte na typowym zadaniu programowania liniowego (LP) oraz zadaniu sformułowanym w ramach liniowych nierówności macierzowych (LMI) pokazano, że jest możliwe uzyskanie dodatniego asymptotycznie stabilnego obserwatora. Są to warunki dostateczne, alternatywne w stosunku do podanych w [5, 18] dla układów niedodatnich. Zaprojektowany obserwator poprawnie estymuje (odtwarza) zmienne stanu przyjętego do rozważań dyskretnego układu niecałkowitego rzędu. Wyniki obliczeniowe uzyskano w środowisku programowym MATLAB z wykorzystaniem biblioteki Optimization oraz pakietów SeDuMi [20] i YALMIP [14]. Rezultaty symulacyjne uzyskano przy wykorzystaniu dodatkowej biblioteki Fractional States Space Toolkit [18].
Słowa kluczowe
dodatni, liniowa nierówność macierzowa, obserwator, programowanie liniowe, rząd niecałkowity, układ dyskretny
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