Wyniki wyszukiwania - BazTech

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Fundamental limitations of the decay of generalized energy in controlled (discrete-time) nonlinear systems subject to state and input constraints

Selek István, Ikonen Enso

International Journal of Applied Mathematics and Computer Science

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2019

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Vol. 29, no. 4

629--639

EN

This paper is devoted to the analysis of fundamental limitations regarding closed-loop control performance of discrete-time nonlinear systems subject to hard constraints (which are nonlinear in state and manipulated input variables). The control performance for the problem of interest is quantified by the decline (decay) of the generalized energy of the controlled system. The paper develops (upper and lower) barriers bounding the decay of the system’s generalized energy, which can be achieved over a set of asymptotically stabilizing feedback laws. The corresponding problem is treated without the loss of generality, resulting in a theoretical framework that provides a solid basis for practical implementations. To enhance understanding, the main results are illustrated in a simple example.

2

Analiza nieliniowych metod sterowania przekształtnikiem sieciowym AC/DC

Knapczyk M., Pieńkowski K.

Maszyny Elektryczne : zeszyty problemowe

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2005

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Nr 72

241-246

EN

The paper presents a comparative study of nonlinear control techniques for AC/DC line-side converter. Virtual Flux Based Direct Power Control for AC/DC converter has been modified by adding nonlinear DC-link controllers. In particular, design methods of robust control has been presented and used to design robust controllers: sliding-mode controller, fuzzy-logic controller and sliding-mode fuzzy controller. The sliding-mode method uses the concept of a sliding line which divides the state space into two semi-planes and defines the distance to the sliding line. Since the system trajectory reaches the sliding line, it cannot leave it. This is achieved despite parameters fluctuation and disturbances, being the main characteristic of robustness. Fuzzy logic controllers are designed by using the phase plane determined by error e and change of error e . The phase plane is next parted into two semi-planes by means of sliding line. This makes diagonal form of fuzzy logic control similar to sliding-mode with boundary layers. The goal of the control systems presented in the paper is to maintain the output dc-link voltage at the required level, while line currents should be ideally sinusoidal and in phase with respective phase voltages to satisfy the unity power factor (UPF) condition.

3

Lokalna obserwowalność układów z czasem ciągłym i z czasem dyskretnym

Bartosiewicz Z.

Zeszyty Naukowe Politechniki Białostockiej. Matematyka, Fizyka, Chemia

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1999

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Z. 19

7-19

PL

Praca zawiera charakteryzacje lokalnej obserwowalności i stabilnej lokalnej obserwowalności dla analitycznych układów sterowania. Podano wyniki zarówno dla układów z czasem ciągłym , jak i dla układów z czasem dyskretnym. Wyniki mają charakter algebraiczny. Wyrażone sa w języku rzeczywistej geometrii analitycznej.

EN

Necessary and sufficient conditions of local observability for analytic systems are given. The results hold for both continuous-time and discrete-time systems. They have algebraic from and are expressed with the language of real analytic geometry.