Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Article Citation - WoS: 6Citation - Scopus: 7Neural Network Based Robust Control of an Aircraft(ACTA Press, 2020) Tanyer, İlker; Tatlıcıoğlu, Enver; Zergeroǧlu, ErkanOutput tracking control of an aircraft subject to uncertainties in the dynamic model and additive state-dependent nonlinear disturbancelike terms is aimed. Uncertainties in the aircraft dynamic model yield an uncertain input gain matrix, which is neither positive definite nor symmetric and an uncertain term in the error dynamics. To deal with the uncertain input gain matrix, a decomposition method is utilized to put error dynamics in a form where an uncertain positive definite matrix multiplies the auxiliary error but this results in the control input to be pre-multiplied first with a unity upper triangular matrix which is uncertain and then with a known diagonal matrix. A novel controller composed of a neural network compensation term and an integral of signum of error is designed. A novel Lyapunov type stability analysis is utilized to prove global asymptotic tracking of output of a reference model. Extensive numerical simulations are presented to demonstrate the efficacy of the proposed controller where robustness to variation of initial states and a comparison with a robust controller are also shown. © 2020 Acta Press. All rights reserved.Article Citation - Scopus: 1A New Robust Controller Formulation for the Full–state Feedback Position Tracking of a Small–scaled Unmanned Model Helicopter(IFAC Secretariat, 2017) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanThis work focuses on the robust attitude tracking control problem for a small– scaled unmanned helicopter where the actual system inputs, namely the elevator servo input, the aileron servo input and the rudder servo input, are used in the controller formulation. The design process is divided into two parts. Initially the problem is transformed into a second order system with an uncertain non–symmetric input gain matrix by utilizing some reasonable simplifications for the rotor model under the hovering flight conditions. Then a novel robust control methodology is utilized via a matrix decomposition method. The stability of the overall system is ensured by Lyapunov type analysis where asymptotic position tracking is ensured. Numerical simulation results are presented to demonstrate the efficiency of the proposed method.Article Citation - WoS: 14Citation - Scopus: 15Compensating of Added Mass Terms in Dynamically Positioned Surface Vehicles: a Continuous Robust Control Approach(Elsevier Ltd., 2017) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanIn 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 methodArticle Citation - WoS: 30Citation - Scopus: 35Robust Dynamic Positioning of Surface Vessels Via Multiple Unidirectional Tugboats(Elsevier Ltd., 2016) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanIn 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.Article Citation - WoS: 14Citation - Scopus: 20Non-Linear Control of Variable-Speed Wind Turbines With Permanent Magnet Synchronous Generators: a Robust Backstepping Approach(Taylor and Francis Ltd., 2016) Şeker, Murat; Zergeroğlu, Erkan; Tatlıcıoğlu, EnverIn this study, a robust backstepping approach for the control problem of the variable-speed wind turbine with a permanent magnet synchronous generator is presented. Specifically, to overcome the negative effects of parametric uncertainties in both mechanical and electrical subsystems, a robust controller with a differentiable compensation term is proposed. The proposed methodology ensures the generator velocity tracking error to uniformly approach a small bound where practical tracking is achieved. Stability of the overall system is ensured by Lyapunov-based arguments. Comparative simulation studies with a standard proportional-integral-type controller are performed to illustrate the effectiveness, feasibility and efficiency of the proposed controller. © 2015 Taylor & Francis.Article Citation - WoS: 9Citation - Scopus: 13Nonlinear Robust Control of Tendon–driven Robot Manipulators(Springer Verlag, 2015) Okur, Beytullah; Aksoy, Orhan; Zergeroglu, Erkan; Tatlıcıoglu, EnverThis work addresses the position tracking control problem for tendon–driven robotic mechanisms in the presence of parametric uncertainty and additive external disturbances. Specifically, a full state feedback nonlinear robust controller is proposed to tackle the link position tracking problem for tendon–driven robot manipulators with uncertain dynamical system parameters. A robust backstepping approach has been utilized to achieve uniformly ultimately bounded tracking performance despite the lack of exact knowledge of the dynamical parameters and presence of additive but bounded disturbance terms. Stability of the overall system is proven via Lyapunov based arguments. Simulation studies performed on a two link planar robot manipulator driven by a six tendon mechanism are presented to illustrate the effectiveness and viability of the proposed approach.Article Citation - WoS: 4Citation - Scopus: 5An Asymptotically Stable Robust Controller Formulation for a Class of Mimo Nonlinear Systems With Uncertain Dynamics(Taylor and Francis Ltd., 2016) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, Erkan; Bayrak, AlperIn this work, we present a novel continuous robust controller for a class of multi-input/multi-output nonlinear systems that contains unstructured uncertainties in their drift vectors and input matrices. The proposed controller compensates uncertainties in the system dynamics and achieves asymptotic tracking while requiring only the knowledge of the sign of the leading principal minors of the input gain matrix. A Lyapunov-based argument backed up with an integral inequality is applied to prove the asymptotic stability of the closed-loop system. Simulation results are presented to illustrate the viability of the proposed method.Conference Object Citation - WoS: 3Citation - Scopus: 5Robust Control Design for Positioning of an Unactuated Surface Vessel(Institute of Electrical and Electronics Engineers Inc., 2015) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanIn this paper, a robust controller is designed to achieve accurate positioning of an unactuated surface vessel by using multiple unidirectional tugboats. After initially locating opposing tugboats to specific configurations, the control problem is transformed into a second order system with an uncertain non-symmetric input gain matrix. Upon applying a matrix decomposition, a robust controller is proposed. Detailed stability analysis ensured asymptotic tracking. Numerical simulation results demonstrate the efficiency of the proposed controller © 2015 IEEE.Conference Object Citation - Scopus: 3A Robust Adaptive Tracking Controller for an Aircraft With Uncertain Dynamical Terms(Elsevier Ltd., 2014) Tanyer, İlker; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanThis 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: 4Nonlinear Robust Control of 3 Phase Inverter With Output Lc Filter(Elsevier Ltd., 2014) Okur, Beytullah; Zergeroğlu, Erkan; Şeker, Murat; Tatlıcıoğlu, EnverThree 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.