Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/11

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Institution Author: search.filters.institutionAuthor.Tatlıcıoğlu, EnverPublisher: search.filters.publisher.Elsevier Ltd.

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Now showing 1 - 7 of 7
  • Article
    Citation - WoS: 14
    Citation - Scopus: 15
    Compensating of Added Mass Terms in Dynamically Positioned Surface Vehicles: a Continuous Robust Control Approach
    (Elsevier Ltd., 2017) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, Erkan
    In this work, we provide a tracking controller formulation for dynamically positioned surface vessels with an asymmetric added mass terms that affects the overall system dynamics at the acceleration level. Specifically a novel continuous robust controller is proposed for surface vessels that in addition to unstructured uncertainties in its dynamics, contains added mass effects in its inertia matrix. The proposed controller compensates the overall system uncertainties while ensuring asymptotic tracking by utilizing the knowledge of the leading principal minors of the input gain matrix. Stability of the closed–loop system and asymptotic convergence are proven via Lyapunov based approaches. Simulation studies are also presented to illustrate the viability of the proposed method
  • Article
    Citation - WoS: 30
    Citation - Scopus: 35
    Robust Dynamic Positioning of Surface Vessels Via Multiple Unidirectional Tugboats
    (Elsevier Ltd., 2016) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, Erkan
    In this paper, the problem of accurate positioning of an unactuated surface vessel by using multiple uni-directional tugboats is investigated. Specifically a robust controller that ensures asymptotic position tracking is designed. The control design procedure is implemented in two steps: Initially by locating opposing tugboats to specific configurations, the overall problem is transformed into a second order system with an uncertain non-symmetric input gain matrix. Then via a matrix decomposition, a novel robust controller methodology is proposed. The stability of the overall system is ensured via rigorous stability analysis where asymptotic position tracking is ensured. Numerical simulation results are presented to demonstrate the efficiency of the proposed controller.
  • Conference Object
    Citation - Scopus: 3
    A Robust Adaptive Tracking Controller for an Aircraft With Uncertain Dynamical Terms
    (Elsevier Ltd., 2014) Tanyer, İlker; Tatlıcıoğlu, Enver; Zergeroğlu, Erkan
    This work presents, the design and the corresponding analysis of a nonlinear controller for an aircraft system subject to uncertainties in the dynamics and additive state-dependent nonlinear disturbance-like terms. Specifically; dynamic inversion technique in conjunction with a robust integral of the signum of the error feedback and an adaptive term is utilized in the overall controller design. Lyapunov based stability analysis techniques are then utilized to prove global asymptotic convergence of the tracking error. © IFAC.
  • Conference Object
    Citation - Scopus: 4
    Nonlinear Robust Control of 3 Phase Inverter With Output Lc Filter
    (Elsevier Ltd., 2014) Okur, Beytullah; Zergeroğlu, Erkan; Şeker, Murat; Tatlıcıoğlu, Enver
    Three phase inverters are commonly used to transfer energy from a source to the power grid. The quality of the power delivered to the grid, can be ensured via the use of an output LC filter. However inserting an output filter to an inverter circuitry would introduce new challenges to the controller design due to the additional parametric uncertainties imposed. In this study we present a new model based robust controller for a three phase inverter with output LC filter under the constraint that the output filter parameters are not exactly known. Specifically, d-q reference frame model of an inverter with output LC filter is used to develop a nonlinear robust controller that ensures the 3-phase output voltage with desired amplitude and frequency and with lowest harmonic distortion. Stability of the proposed method and the boundedness of the closed-loop system, is established via Lyapunov based tools in conjunction with a robust backstepping procedure. Simulation results are given in order to demonstrate performance and effectiveness of the proposed robust controller. © IFAC.
  • Conference Object
    Citation - Scopus: 13
    Predictor-Based Robust Control of Uncertain Nonlinear Systems Subject To Input Delay
    (Elsevier Ltd., 2012) Obuz, Serhat; Tatlıcıoğlu, Enver; Çekiç, Sadettin Ç.; Dawson, Darren M.
    In this paper, a tracking controller is developed for a class of nonlinear systems subject to time delay in the control input, uncertainties in the dynamic model, and additive disturbances. The control development is based on a novel predictor-like method to address the time delay in the control input. Lyapunov based stability analysis is used to prove semi-global asymptotic tracking. © 2012 IFAC.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 9
    Range Identification for Nonlinear Parameterizable Paracatadioptric Systems
    (Elsevier Ltd., 2010) Nath,N.; Tatlicioglu,E.; Dawson,D.M.
    In this paper, a new range identification technique for a calibrated paracatadioptric system mounted on a moving platform is developed to recover the range information and the three-dimensional (3D) Euclidean coordinates of a static object feature. The position of the moving platform is assumed to be measurable. To identify the unknown range, first, a function of the projected pixel coordinates is related to the unknown 3D Euclidean coordinates of an object feature. This function is nonlinearly parameterized (i.e., the unknown parameters appear nonlinearly in the parameterized model). An adaptive estimator based on a minmax algorithm is then designed to estimate the unknown 3D Euclidean coordinates of an object feature relative to a fixed reference frame which facilitates the identification of range. A Lyapunov-type stability analysis is used to show that the developed estimator provides an estimation of the unknown parameters within a desired precision. Numerical simulation results are presented to illustrate the effectiveness of the proposed range estimation technique. © 2010 Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 19
    Sensing of the Time-Varying Angular Rate for Mems Z-Axis Gyroscopes
    (Elsevier Ltd., 2010) Salah, M. H.; McIntyre, M. L.; Dawson, Darren M.; Wagner, John R.; Tatlıcıoğlu, Enver
    In this paper, a nonlinear estimation strategy for sensing the time-varying angular rate of a Z-axis MEMS gyroscope is presented. An off-line adaptive least-squares estimation strategy is first developed to accurately estimate the unknown model parameters. Both axes of a Z-axis MEMS gyroscope are then actively controlled utilizing an on-line controller/observer to facilitate time-varying angular rate sensing. The proposed nonlinear estimation strategy is developed based on a Lyapunov-based analysis, which proves that the time-varying angular rate experienced by the device can be estimated accurately. Two cases for angular rate are investigated which are time-varying and constant magnitudes. An adaptive controller/observer was also utilized for sensing the angular rate to investigate the performance of the proposed controller/observer. Representative numerical results are discussed to demonstrate the performance of the proposed nonlinear strategy in accurately sensing the applied angular rate. Overall, the proposed nonlinear controller/observer improves sensing the constant angular rate by 50% and the time-varying angular rate by 90% when compared with an adaptive controller/observer. © 2010 Elsevier B.V. All rights reserved.