Yazar "Yeroglu, C." seçeneğine göre listele

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    Computation of the Value Set of Fractional Order Uncertain Polynomials: A 2q Convex Parpolygonal Approach
    (Ieee, 2012) Senol, B.; Yeroglu, C.
    Fractional order models are frequently used to describe real processes especially in the last decades. Uncertainties in this processes mostly yield to some bad results and brings computational complexity. So this comes up as a new problem waiting to be analyzed. In this paper, a 2q convex parpolygonal approach is applied to the computation of value set of fractional order uncertain polynomials to reduce the computational complexity. The analysis steps are given and the results are shown via graphical examples. It is shown that this approach is an effective way of analyzing fractional order uncertain polynomials and can be used to investigate the stability.
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    Note on fractional-order proportional-integral-differential controller design
    (Inst Engineering Technology-Iet, 2011) Yeroglu, C.; Tan, N.
    This study deals with the design of fractional-order proportional-integral-differential (PID) controllers. Two design techniques are presented for tuning the parameters of the controller. The first method uses the idea of the Ziegler-Nichols and the Astrom-Hagglund methods. In order to achieve required performances, two non-linear equations are derived and solved to obtain the fractional orders of the integral term and the derivative term of the fractional-order PID controller. Then, an optimisation strategy is applied to obtain new values of the controller parameters, which give improved step response. The second method is related with the robust fractional-order PID controllers. A design procedure is given using the Bode envelopes of the control systems with parametric uncertainty. Five non-linear equations are derived using the worst-case values obtained from the Bode envelopes. Robust fractional-order PID controller is designed from the solution of these equations. Simulation examples are provided to show the benefits of the methods presented.
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    Optimal Fractional Order PID Controller Design for Fractional Order Systems by Stochastic Multi Parameter Divergence Optimization Method with Different Random Distribution Functions
    (Ieee, 2019) Ates, A.; Alagoz, B. B.; Chen, Y. Q.; Yeroglu, C.; HosseinNia, S. Hassan
    This paper modifies Stochastic Multi Parameter Divergence Optimization Method (SMDO) by using some types of random distribution functions in order to show effects of different random distribution functions on optimization performance. SMDO is a parameter wise random search algorithm in random walk class. A prominent feature of SMDO method lies in using random number with standard uniform distribution while diverging a parameter of solution point in backward and forward directions to reach an optimal solution. SMDO method benefits from the success of random backward and forward divergences. This study investigates effects of four types of random distribution functions on performance of SMDO algorithm for controller tuning problem. These distributions are Chi-Square Distribution (CSD), Rayleigh Distribution (RD), Log Normal Distribution (LND) and Uniform random (LTD) distribution. To illustrate effects of these random distribution functions, SMDO is employed to fractional order PID (FOPID) controller tuning problems for fractional order model (FOM) and results obtained for different distribution functions are demonstrated.
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    Space Charge Formation In Non-cristalline Polymers And GaSe By DBD In SF6 Medium
    (Ieee, 2008) Alisoy, H. Z.; Yeroglu, C.; Koseoglu, M.
    In this study, we investigate the formation mechanism of space charges in PI-Polyimide, PTFE-Polytetrafluoroethylene, PET - Polyethylene Terephtalate and GaSe(Sn) - GaSe dopped with (0.05at%) Sn which are exposed to dielectric barrier discharge (DBD) in SF6 medium. The expressions for the concentration of trapped electrons in materials, electrical field strength and total charge are derived by solving total current equation at stationary state. Space charges are determined experimentally by using thermally stimulated depolarization current (TSDC) method, and TSDC spectrums are illustrated for investigated materials.