Wyniki wyszukiwania - Biblioteka Nauki

1

Perfect observers for standard linear systems

100%

Sławiński M.

Pomiary Automatyka Kontrola

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2012

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tom R. 58, nr 5

418-421

EN

Perfect observers for linear continuous-time and discrete-time systems are considered. Necessary and sufficient conditions for existence of the perfect observers are established and the procedures for computation of the perfect observer matrices are derived. Numerical examples and some simulation results are also presented. Some interesting advantages of the perfect observers are presented and illustrated by numerical examples.

PL

W pracy rozważana jest teoria obserwatorów doskonałych liniowych układów ciągłych i dyskretnych. Zostały tu przedstawione warunki konieczne i wystarczające istnienia tych obserwatorów dla układów ciągłych oraz dyskretnych. Omówiony został sposób wyznaczania obserwatorów doskonałych wraz z procedurami pozwalającymi na wyznaczanie tych obserwatorów dla standardowych układów ciągłych oraz dyskretnych. Sposób wyznaczania obserwatorów doskonałych został pokazany poprzez przykłady numeryczne wraz z wynikami symulacji. Nie zapominając o oczywistej wadzie obserwatorów doskonałych polegającej na tym, iż sygnał wyjściowy może zależeć od pochodnej wymuszenia, pokazano kilka niewątpliwie ważnych zalet tych obserwatorów. Zamieszczone wnioski zostały poparte przykładami numerycznymi.

2

Robust Dynamic Output Feedback H[infinity] Control for Uncertain Switched Singular Systems

84%

Fu Z. , Liu L. , Gao A. , Pu J.

Przegląd Elektrotechniczny

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2012

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tom R. 88, nr 3b

34-38

EN

This paper considers the problems of dynamic output feedback H[infinity] control for uncertain switched singular system with parametric uncertainties. A switching rule and a switched dynamic output feedback controller are designed to guarantee that the closed-loop system is asymptotically stable with a prescribed H[infinity] disturbance attenuation level [gamma]. Such sufficient conditions are derived via a series of strict linear matrix inequalities (LMIs). Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

PL

W artykule analizuje się problem dynamiki system sterowania H[nieskończoność] dla systemu pojedynczego z niepewnymi przełączeniami. Badano zasady przełączania i dynamikę przełączania gwarantującą stabilną prace systemu. Przedstawiono przykład numeryczny ilustrujący skuteczność proponowanej metody.

3

A new nonlinear L-stable scheme with constant and adaptive step-size strategy

84%

Arain S. , Qureshi S. , Shaikh A. A.

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tom Vol. 20, nr 4

7--18

EN

The present study proposes a new explicit nonlinear scheme that solves stiff and nonlinear initial value problems in ordinary differential equations. One of the promising features of this scheme is its fourth-order convergence with strong stability having an unbounded region. A modern approach for relative stability growth analysis is also presented under order stars conditions. The scheme is also good in dealing with singular and stiff type of models. Comparing numerical experiments using various errors, including maximum absolute global error over the integration interval, absolute error at the endpoint, average error, norm of errors, and the CPU times (seconds), shows better performance. An adaptive step-size approach seems to increase the performance of the proposed scheme. The numerical simulations assure us of L -stability, consistency, order, and rapid convergence.

4

Finite-time stability and stabilization of singular state-delay systems using improved estimation of a lower bound on a Lyapunov-like functional

67%

Stojanovic S. B. , Debeljkovic D. L. , Antic D. S.

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tom Vol. 63, nr 2

479--487

EN

In this paper, the problems of finite-time stability and stabilization for a class of singular time-delay systems are studied. Using the Lyapunov-like functional (LLF) with (exponential or power) weighting function and a new estimation method for the lower bound on LLF, some sufficient stability conditions are introduced. It is shown that the weighting function significantly reduces the conservatism of the stability criteria in comparison to estimation of the lower bound on LLF without this function. To solve the finite-time stabilization problem, a stabilizing linear state controller is designed by exploiting the cone complementarity linearization algorithm. Two numerical examples are given to illustrate the effectiveness of the proposed method.

5

H-infinity control of discrete-time linear systems constrained in state by equality constraints

67%

Filasová A. , Krokavec D.

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2012

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tom Vol. 22, no. 3

551-560

EN

In this paper, stabilizing problems in control design are addressed for linear discrete-time systems, reflecting equality constraints tying together some state variables. Based on an enhanced representation of the bounded real lemma for discrete-time systems, the existence of a state feedback control for such conditioned stabilization is proven, and an LMI-based design procedure is provided. The control law gain computation method used circumvents generally an ill-conditioned singular design task. The principle, when compared with previously published results, indicates that the proposed method outper forms the existing approaches, guarantees feasibility, and improves the steady-state accuracy of the control. Furthermore, better performance is achieved with essentially reduced design effort. The approach is illustrated on simulation examples, where the validity of the proposed method is demonstrated using one state equality constraint.