Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - Scopus: 1İnsan el derisi özelliklerinin kutuplamalı ışık görüntülemesi ile incelenmesi(IEEE, 2010) Öztürk, Yavuz; Engin, Mehmet; Engin, Erkan Zeki; Bayrak, AlperIn this study, the texture of skin on the back of the hand was investigated for men and women of different ages. The images obtained from superficially back scattered light at the parallel and perpendicular position of the analyzer for different wavelengths, were processed and quantitatively analyzed. At the end of the analysis, we observed that the skin textures have many different segments and the size and number of segments change with ages. Finally, we can say that the hand skin texture becomes less complex with age. ©2010 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.Conference Object Citation - Scopus: 1Robust Adaptive Control of Nonlinear Systems With Unknown State Delay(Institute of Electrical and Electronics Engineers Inc., 2013) Bayrak, Alper; Tatlıcıoğlu, Enver; Bıdıklı, Barış; Zergeroğlu, ErkanIn this work, we propose a new robust adaptive controller for a class of multi-input multi-output nonlinear systems subject to uncertain state delay. The proposed method is proven to yield semi-global asymptotic tracking despite the presence of additive input and output disturbances and parametric uncertainty in the system dynamics. An adaptive desired system compensation in conjunction with a continuous nonlinear integral feedback component is utilized in the design of the controller and Lyapunov-based techniques, are used to prove that the tracking error is asymptotically driven to zero. Numerical simulation results are presented to demonstrate the effectiveness of the proposed method. © 2013 IEEE.Conference Object Filter-based control for parallel plate micro electrostatic actuators(Institute of Electrical and Electronics Engineers Inc., 2011) Salah, Mohammed H.; Bayrak, Alper; Tatlıcıoğlu, EnverIn this paper, a filter-based nonlinear control strategy for parallel-plate micro electrostatic actuators is designed. The proposed control technique utilizes the measurements of the micro actuator's movable plate displacement and the device internal charge. The information of the micro actuator's movable plate velocity is utilized as well in the control synthesis but since it is difficult to be measured, filtered signals are designed and utilized to facilitate the control development. A Lyapunov-based analysis is presented which proves that a desired time-varying displacement of the micro actuator's movable plate is accurately tracked. The proposed nonlinear controller is capable of controlling the movable plate beyond the pull-in boundary that is one third of the capacitive gap. Representative numerical simulations are introduced to demonstrate the performance of the proposed filter-based nonlinear control strategy in accurately tracking the deflection of the micro electrostatic movable plate within the entire capacitive gap. Finally, a comparison with a standard PID controller is also presented to demonstrate the effectiveness of the proposed control design. © 2011 IEEE.Conference Object Citation - WoS: 2Citation - Scopus: 4A novel online adaptive time delay identification technique(Institute of Electrical and Electronics Engineers Inc., 2011) Bayrak, Alper; Tatlıcıoğlu, EnverIn this study, an online time delay identification technique is proposed. Different from the relevant literature, the time delay is considered as a nonlinear parameter and nonlinear parameter estimation techniques are adopted. The stability of the adaptive update law can be guaranteed via Lyapunov based arguments and numerical simulations are conducted to demonstrate the proof of concept. © 2011 IEEE.Conference Object Citation - WoS: 5Citation - Scopus: 16Automatic Synchronization Unit for the Parallel Operation of Synchronous Generators(Institute of Electrical and Electronics Engineers Inc., 2009) Bekiroğlu, Erdal; Bayrak, AlperIn this study, an automatic synchronization unit has been developed for the parallel connection of synchronous generators. Two synchronous generators are connected in parallel automatically with the developed control unit. Synchronous generators are also connected in parallel with the line. The voltages, frequencies, phase sequences and synchronism time data have been transferred to the microcontroller. These data are monitored and evaluated by the control algorithm coded into the microcontroller. Parallel operation of generators are realized automatically when all parallel connection conditions are occur. The system doesn't require additional measuring tools for monitoring and control processes. The developed automatic synchronization unit is fast, cost effective, reliable and precise to be used for monitoring, measurement and parallel operation of the synchronous generators.