Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - WoS: 1Citation - Scopus: 1A Dynamic Model Free Observer Based Output Feedback Tracking Control of Robot Manipulators in Task-Space(Institute of Electrical and Electronics Engineers Inc., 2018) Çobanoğlu, Necati; Çetin, Kamil; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanThis paper addresses the output feedback end-effector position tracking control of robotic manipulators. Specifically, via the design of a novel dynamic model independent observer constructed through a Lyapunov type analysis and under the assumption that the manipulator Jacobian is always invertible, we propose a model based nonlinear controller which ensures asymptotic robot end-effector tracking without the need of joint and/or task space velocity measurements. Simulation results are included to illustrate the performance and effectiveness of the proposed method.Conference Object Citation - WoS: 2Citation - Scopus: 3On Null-Space Control of Kinematically Redundant Robot Manipulators(Institute of Electrical and Electronics Engineers Inc., 2016) Çetin, Kamil; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanIn this study, we consider the null-space control problem of redundant robot manipulators. Specifically for robot manipulators with kinematically redundancy where at least one extra degree of freedom is present, we introduce a sub-task controller that will ensure the use of the extra degrees of freedom for possible control purposes while still ensuring the main objective. The stability of the main (end-effector tracking) and sub-task objectives are obtained via Lyapunov based arguments. Extension to adaptive controller formulation for robotic devices with uncertain system dynamics is also presented. Numerical studies for the adaptive controller are presented to illustrate the liability of the proposed method.Conference Object Citation - WoS: 5Citation - Scopus: 7Nonlinear Control of Tendon Driven Robot Manipulators: Elimination of Actuator Side Position Measurements(Institute of Electrical and Electronics Engineers Inc., 2015) Okur, Beytullah; Zergeroğlu, Erkan; Tatlıcıoğlu, EnverIn this study, a partial state feedback controller is proposed for the link position tracking control problem of flexible tendon driven robotic systems. Specifically; a nonlinear model based controller is formulated for tendon driven robot manipulators under the constraint that only the link position and tendon expansion force measurements are available. Despite the lack of link and actuator side velocity and actuator position measurements, the proposed controller ensures exponential link position tracking. To eliminate the need of actuator position and velocity measurements, a model based velocity observer has been utilized. Stability of the closed loop system and boundedness of system states are proven via Lyapunov based arguments. The performance of the purposed observer-controller couple is then verified by a set of numerical simulations.Conference Object Citation - WoS: 3Citation - Scopus: 3Inverse Optimal Adaptive Output Feedback Control of Euler-Lagrange Systems: a Variable Structure Observer Based Approach(Institute of Electrical and Electronics Engineers Inc., 2015) Aksoy, Orhan; Zergeroğlu, Erkan; Tatlıcıoğlu, EnverThis work focuses on inverse optimal, observer based output feedback control of Euler-Lagrange systems. Specifically a variable structure observer based output feedback controller is proposed which aside from ensuring asymptotic position tracking also ensures that a positive cost function, penalizing control input performance, is minimized. Simulation studies performed on a two link planar robot manipulator are included to illustrate the overall performance and feasibility of the proposed controller. © 2015 IEEE.Conference Object Citation - WoS: 2Citation - Scopus: 1A Self-Tuning Velocity Observer Formulation for a Class of Nonlinear Systems(Institute of Electrical and Electronics Engineers Inc., 2016) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanThis work presents the design and the corresponding stability analysis of a model free velocity observer formulation for nonlinear systems modeled by Euler-Lagrange formulation. The observation gains of the proposed formulation are tuned online according to an update algorithm removing the burden of observation gain tuning. Lyapunov based arguments are applied to prove the overall system stability. Performance of the observer proposed is illustrated via extensive simulation studies. Experimental studies are also utilized to demonstrate the viability of the proposed formulation.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.Conference Object Citation - WoS: 2Citation - Scopus: 2Nonlinear Adaptive Partial State Feedback Trajectory Tracking Control of Tendon Driven Robot Manipulators(Institute of Electrical and Electronics Engineers Inc., 2014) Okur, Beytullah; Zergeroğlu, Erkan; Tatlıcıoğlu, Enver; Aksoy, OrhanIn this work, the link position tracking control problem of a tendon driven robotic system is studied in the presence of parametric uncertainty and lack of velocity measurements both of links and actuators. A partial state feedback nonlinear adaptive controller is proposed to deal with the unmeasurable states and uncertain dynamical system parameters. A backstepping approach has been utilized to develop the control strategy. The proposed nonlinear tracking controller utilizes online update laws to adapt for parametric uncertainties, and requires only link and actuator position measurements and tendon tension measurements. Need for link velocity measurements are eliminated by using a nonlinear filter, and a set of linear filters is designed to estimate the actuator velocities. Lyapunov based arguments have been applied to prove the stability of the closed-loop system and semi-global asymptotic link position tracking is achieved. © 2014 IEEE.Conference Object Citation - WoS: 28Citation - Scopus: 34A New Robust 'integral of Sign of Error' Feedback Controller With Adaptive Compensation Gain(Institute of Electrical and Electronics Engineers Inc., 2013) Bıdıklı, Barış; Tatlıcıoğlu, Enver; Bayrak, Alper; Zergeroğlu, ErkanIn this paper, a new robust integral of signum of error (RISE) feedback type controller is designed for a class of uncertain nonlinear systems. Unlike the previous versions of RISE feedback type controllers, the proposed controller does not require prior knowledge of upper bounds of the vector containing the uncertainties of the dynamical system plus desired system dynamics (and their derivatives) for the control gain selection. The aforementioned enhancement is made possible via the design of a time-varying compensation gain as opposed to a constant gain used in previous RISE feedback type controllers. Asymptotic stability of the error signals and the boundedness of the closed-loop system signals are ensured via Lyapunov based arguments. Numerical simulation studies are presented to illustrate the viability of the proposed method. ©2013 IEEE.