Materiały konferencyjne (WEl)

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https://oa.zut.edu.pl/handle/20.500.12539/63

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Przeglądaj Materiały konferencyjne (WEl) wg Autor "Technical University of Szczecin"

Teraz wyświetlane 1 - 6 z 6
  • Miniatura
    PozycjaOpen Access
    Comparative boundary and sensitivity analysis for uncertain dynamical systems
    (Wydawnictwo Uczelniane Politechniki Szczecińskiej, 2002) Orłowski, Przemysław; Technical University of Szczecin
    The paper develops analysis for models of uncertainty for dynamical, discretetime control systems on finite time horizon. Various models of uncertainty are analysed: additive, subtractive, and multiplicative. An analysis for electrical circuit with real, perturbed parameters is carried out. It is assumed, that the uncertain parameters are bounded, and could be described by rectangular distribution. A few cases of systems are considered. In the first case system is time-invariant. In the second case, system is time variant. Output errors are estimated using discrete evolution operators. As a comparison sensitivity analysis for time-invariant sis has been carried out. The results from estimations are compared to the set of the worst-case uncertain parameters related to output error.
  • Miniatura
    PozycjaOpen Access
    Convergence of the optimal non-linear GPC method with iterative state-dependent, linear time-varying approximation
    (2005) Orłowski, Przemysław; Technical University of Szczecin
    Solution of the optimal non-linear GPC method is mostly obtained in an iterative way with 3 following steps: initialisation, transformation from non-linear system given in general form into time-varying state-dependent form, and checking whether the convergence condition is satisfied. The main aim of this paper is to analyse how the transformation method from nonlinear model into time varying state-space dependent form have effect on the convergence of the algorithm. We try to answer following questions: If chosen transformation method is suitable ? If the convergence to the optimal solution is guaranteed ? If the number of iterations can be cut down ?
  • Miniatura
    PozycjaOpen Access
    An introduction to SVD-DFT frequency analysis for time-varying systems
    (Wydawnictwo Uczelniane Politechniki Szczecińskiej, 2003) Orłowski, Przemysław; Technical University of Szczecin
    The paper develops tools and methods for linear time-varying, discrete-time sys-tems analysis. It consists of theoretical background, definitions and numerical algorithms for frequency characteristics approximation. The main method is based on Singular Value Decomposition SVD, Discrete Fourier Transform DFT and power density spectrum proper-ties. A few illustrative numerical examples are included. Three different models have been analysed: oscillatory element, low pass filter and variable structure system. For better evaluation, results for presented method are compared with classical Bode characteristics.
  • Miniatura
    PozycjaOpen Access
    Properties of the frequency SVD-DFT for discrete LTV systems based on first order examples
    (2006) Orlowski, Przemyslaw; Technical University of Szczecin
    The paper develops frequency analysis tools for linear time-varying (LTV), discrete-time systems. The main method is based on the properties of the Singular Value De-composition (SVD), Discrete Fourier Transform (DFT) and Power Spectral Density (PSD). The analysis is carried out for a system with first order dynamics. The general objective of this paper is to examine how system frequency diagrams are depend on the variability of particular parameters. Especially, it is examined how the variability of three matrices of the state space model (scalars, in the 1st order case) influence the approximated Bode diagrams. A few cases of the variability of each matrix, in particular with different frequencies and phase shifting, are considered. Moreover, the analysis is carried out for different cases of the system parameters. The results of analysis for each case are shown in four diagrams: amplitude, phase, impulse and step responses. On the basis of these examples the most important features in each example are characterized.
  • Miniatura
    PozycjaOpen Access
    Robust control design for a class of non-linear systems
    (2003) Orłowski, Przemysław; Technical University of Szczecin
    The paper develops design methods for a class of uncertain, non-linear control systems. It extends the robustness analysis techniques of linear time varying systems and in particular the associated computational methodology to a class of nonlinear systems. It can be divided into following four parts: theoretical background, identification procedure, structure of feedback control system and cost functional for control optimisation for uncertain non-linear systems, control optimisation algorithm and the method for estimate the worst case output uncertainty norm of the system.
  • Miniatura
    PozycjaOpen Access
    Selected Problems of Uncertainty Estimates for Non-linear Discrete-Time Systems
    (2000) Orłowski, Przemysław; Technical University of Szczecin
    The paper develops a mathematical framework which helps to analyse the following class of finite horizon control problems for uncertain nonlinear discrete-time systems. [ WZORY] Uncertainty in the system description are modelled by unknown (norm bounded) mixed additive-multiplicative perturbations of the system matrix. It is assumed that the nominal control has feedback form. If the nominal control will be applied to the uncertain system the state and output will be (in general) different. Formulas for deriving estimates for the deviations of the output of perturbed system from the output of the nominal one has been presented. These estimates use norms of certain dynamical operators defined on a finite time interval.