Observability of linear discrete-time systems with different fractional orders
Abstract
In the paper the observability problem for the linear discrete-time positive systems with different fractional orders is presented. Necessary and sufficient conditions for observability of this class of dynamical systems are given. A method for computing the initial state is proposed. Considerations are illustrated by theoretical example. Numerical calculations have been performed in the MATLAB program environment.
Keywords
discrete-time, fractional order, observability, positive, system
Obserwowalność liniowych układów dyskretnych różnych niecałkowitych rzędów
Streszczenie
W pracy rozpatrzono problem obserwowalności układów dyskretnych dodatnich przy różnych niecałkowitych rzędach w równaniu stanu. Podano warunki konieczne i wystarczające obserwowalności rozpatrywanej klasy układów dynamicznych. Zaproponowano prostą metodę wyznaczania nieujemnego stanu początkowego takiego układu. Rozważania zilustrowano przykładem teoretycznym, zaś niezbędne obliczenia wykonano w środowisku programowym MATLAB.
Słowa kluczowe
dodatni, obserwowalność, rząd niecałkowity, układ dyskretny
Bibliography
- Kalman R.E., On the general theory of control system., Proc. Of the 1st IFAC Congr., Butterworth, London 1960.
- Kaczorek T., Control theory and systems, PWN, Warsaw 1996.
- Kaczorek T., Positive 1D and 2D systems, Springerverlag, London 2002.
- Debnath L., Recent applications of fractional calculus to science and engineering, “Int. Journal of Mathematics and Mathematical Sciences”, Vol. 54, 2003, 3413-3442 [on-line: www.ijmms.hindawi.com].
- Dzieliński A., Sierociuk D., Sarwas G., Some applications of fractional order calculus, “Bull. of the Polish Acad. Of Sciences, Technical Sciences”, Vol. 58, No. 4, 2010, 583-592.
- Kilbas A.A., Srivastava H. M., Trujillo J. J., Theory and applications of fractional differential equations. Elsevier, Amsterdam 2006.
- Lino P., Maione G., Loop-shaping annd easy tuning of fractional-order proportional integral controllers for position servo systems, “Asian Journal of Control”, 2012.
- Podlubny I., Fractional differential equations, Acad. Press, San Diego 1999.
- Sabatier J., Agraval O. P., Machado, Advances in fractional calculus. Theoretical developments and applications in physics and engineering, Springer, London 2007.
- Sierociuk D., Estimation and control of discrete-time dybnamical fractional systems described in state space, Ph.D. thesis. Warsaw University of Technology, Warsaw 2007.
- Kaczorek T., Selected problems of fractional systems theory, Springer, Berlin 2011.
- Kaczorek T., Vectors and matrices in automatics and electrotechnics, WNT, Warsaw 1998.
- Bettayeb M., Djennoune S., A note on the controllability and the observability of fractional dynamical systems, [in:] Proc. of the 2nd IFAC Workshop on Fractional Differentation and its Applications, Porto, Portugal 2006, 506-511.
- Mantignon D., d’Andrea-Novel B., Some results on controllability and observability of finite-dimensional fractional differential systems, [in:] Proc. of the IMACS. IEEE SMC Conf., France 1996, 952-956.
- Mozyrska D., Pawłuszewicz E., Observability of linear q-difference fractional order systems with finite initial memory, “Bull. of the Polish Acad. of Sci.”, Vol. 58, No. 4, 2010, 601-605.
- Kociszewski R., Controllability and observability of linear time-invariant positive discrete-time systems with delays, Ph.D. thesis, Białystok University of Technology, Białystok 2008.
- Busłowicz M., Simple analytic conditions for stability of fractional discrete-time linear systems with diagonal state matrix, “Bull. of the Polish Acad. of Sciences, Technical Sciences” (in press).