Browsing by Author "Ablay, Gunyaz"

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Cascade Control of Magnetic Levitation with Sliding Modes
(E D P SCIENCES, 17 AVE DU HOGGAR PARC D ACTIVITES COUTABOEUF BP 112, F-91944 CEDEX A, FRANCE, 2016) Eroglu, Yakup; Ablay, Gunyaz; AGÜ, Mühendislik Fakültesi, Bilgisayar Mühendisliği Bölümü;
The effectiveness and applicability of magnetic levitation systems need precise feedback control designs. A cascade control approach consisting of sliding mode control plus sliding mode control (SMC plus SMC) is designed to solve position control problem and to provide a high control performance and robustness to the magnetic levitation plant. It is shown that the SMC plus SMC cascade controller is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant and achieve a robust and precise position control. Experimental and numerical results are provided to validate the effectiveness and feasibility of the method.
Cascade sliding mode-based robust tracking control of a magnetic levitation system
(SAGE PUBLICATIONS LTD1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2016) Ablay, Gunyaz; Eroglu, Yakup; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz; Eroglu, Yakup
Magnetic levitation systems are able to provide frictionless, reliable, fast and economical operations in wide-range applications. The effectiveness and applicability of these systems require precise feedback control designs because the magnetic levitation is an unstable process and have highly nonlinear dynamics. In this article, a robust sliding mode-based cascade control approach is proposed for effectively tracking the reference position of a magnetic levitation system. The magnetic levitation plant is described with electrical and mechanical models, and the control problems of these parts are treated with cascade controllers. An integral sliding mode and an output feedback sliding mode controllers are designed for use in the cascade loops. The performance of the sliding mode controllers is compared with a proportional-integral-velocity plus proportional-integral control structure. It is shown that the proposed control structure is able to provide a highly satisfactory tracking performance and can eliminate the effects of the inductance-related uncertainties and operating point originated disturbances. The experimental results are provided to validate the efficacy and feasibility of the approach.
Chaos in PID Controlled Nonlinear Systems
(SPRINGER SINGAPORE PTE LTD, #04-01 CENCON I, 1 TANNERY RD, SINGAPORE 347719, SINGAPORE, 2015) Ablay, Gunyaz; AGÜ, Mühendislik Fakültesi, Elektrik & Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
Controlling nonlinear systems with linear feedback control methods can lead to chaotic behaviors. Order increase in system dynamics due to integral control and control parameter variations in PID controlled nonlinear systems are studied for possible chaos regions in the closed-loop system dynamics. The Lure form of the feedback systems are analyzed with Routh's stability criterion and describing function analysis for chaos prediction. Several novel chaotic systems are generated from second-order nonlinear systems including the simplest continuous-time chaotic system. Analytical and numerical results are provided to verify the existence of the chaotic dynamics.
Chaotic Map Construction from Common Nonlinearities and Microcontroller Implementations
(WORLD SCIENTIFIC PUBL CO PTE LTD5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE, 2016) Ablay, Gunyaz; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
This work presents novel discrete-time chaotic systems with some known physical system non-linearities. Dynamic behaviors of the models are examined with numerical methods and Arduino microcontroller-based experimental studies. Many new chaotic maps are generated in the form of x(k + 1) = rx(k) + f(x(k)) and high-dimensional chaotic systems are obtained by weak coupling or cross-coupling the same or different chaotic maps. An application of the chaotic maps is realized with Arduino for chaotic pulse width modulation to drive electrical machines. It is expected that the new chaotic maps and their microcontroller implementations will facilitate practical chaos-based applications in different fields.
Coefficient ratios-based robust sliding surface and integral sliding mode control designs with optimal transient responses
(WILEY, 2014) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
A coefficient ratio-based sliding surface algorithm and an integral sliding mode control approach are proposed for multivariable dynamical systems. The sliding surface design problem is reduced to the specification of the desired time constant of closed-loop systems. The proposed scheme is able to accomplish a non-overshoot transient response and a short settling time for multivariable systems. The resulting sliding surfaces are robust and optimal in the existence of parameter perturbations. An integral sliding mode control approach is also developed for robust tracking by using the coefficient ratio-based robust sliding surface designs. The developed methods are implemented on a flexible robotic manipulator and a strike aircraft system, and the numerical simulation results are provided in order to show the validity and feasibility of the methods.
Design and real-time implementation of a sliding mode observer utilizing voltage signal injection and PLL for sensorless control of IPMSMs
(ELSEVIER, 2024) Ates, Ertugrul; Tekgun, Burak; Ablay, Gunyaz; Barut, Murat; 0000-0001-6628-5350; 0000-0003-2720-8816; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ates, Ertugrul; Tekgun, Burak; Ablay, Gunyaz
In this study, a sliding mode observer (SMO) based on high-frequency (HF) voltage signal injection and a phase-locked loop (PLL) is proposed for estimating the extended electromotive force (EEMF), rotor position, and rotor velocity of an interior permanent magnet synchronous machine (IPMSM). This approach addresses real-time estimation challenges associated with standard SMO and PLL at very low speeds and standstill. A reliable and accurate sensorless speed control system for IPMSM is then developed and implemented in real time using the proposed SMO and PLL, covering a wide range of speeds, including low-speed and standstill conditions. The SMO effectively estimates the EEMF, while the PLL extracts the rotor velocity and position based on these estimates. Compared to conventional SMO and PLL methods, real-time results from an 8-pole, 0.4 kW IPMSM demonstrate the superior efficiency of the proposed system.
Design, modeling, and control of a horizontal magnetic micromanipulator
(SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2019) Ablay, Gunyaz; Boyuk, Mustafa; Icoz, Kutay; 0000-0002-0947-6166; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
Magnetic micromanipulators with a wide range of force generating capabilities are able to manipulate micron size particles for various applications and measurements. These magnetic particles can be coated with receptors to specifically bind to target biomolecules. In this work, a horizontal magnetic micromanipulator is designed, modeled and controlled for single micron size magnetic particle manipulations. A method is presented for dynamic modeling of magnetic micromanipulators. A feedback control method is designed that allows direct linearization of the system. It is shown that the proposed controller guarantees the stability of the closed-loop system, and yields zero steady-state error in a wide range of operation conditions. We show that the micromanipulator is able to generate a wide range of piconewton (pN) scale forces on a superparamagnetic particle for single molecule separation, and biosensor developments.
Elektromanyetik Levitasyon ile Çalışan Biyosensör- Mikrorobot Sistemlerinin Geliştirilmesi ve Kontrolü
(TUBİTAK, 2020) Ablay, Gunyaz; İçöz, Kutay; 0000-0003-2862-6761; 0000-0002-0947-6166; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Günyaz; İçöz, Kutay
Bu arastırma mikron seviyesinde hareket etme yetenegine sahip manyetik levitasyon ile çalısan biyosensör-mikrorobot tasarımını gerçeklestirmeye çalısmaktadır. Manyetik levitasyon teknigi, mikro/nano manyetik parçacıklar ile kuvvetlendirilmis veya paramanyetik bir ortama serpilmis biyolojik varlıkların (tümör hücresi gibi) tespitinde veya analizinde kullanılabilir. Benzer mantıkla, kontrollü manyetik levitasyon ile mikro-manyetik parçacıklar içeren mikrorobotlar gelistirilerek mikron seviyesindeki tekrarlanan çesitli görevlerin otomatik bir sekilde yapılması saglanabilir. Manyetik levitasyon tahrik sistemleri biyolojik ortamlarda zararsızdır, nahos ortam sartlarında çalısabilmektedir ve sürtünmenin etkisini minimize edebilme özelligine sahiptir. Mikrorobot teknolojisi ile minyatür parçalar belli bir hedef noktaya tasınabilir ve nahos/tehlikeli ortamlarda kurulabilirler. Bu proje, etkin ve otomatik mikro-parçacık manipülasyonu için geribeslemeli kontrol yapılarından olusan ve yatay eksende bir ve iki boyutlu manipülasyon imkanı saglayan bir elektromanyetik aktüatör tabanlı manyetik mikromanipülatör tasarımı ve uygulaması üzerine yapılmıstır. Elektromıknatıs tasarımında, uygulanan kontrol akımı ve elektromıknatıs konfigürasyonu manyetik kuvvet ve tork degerlerini belirlemektedir ve bundan dolayı en uygun, kuvvetli ve hassas bir tasarım için uygun nüve yapılarıyla beraber geribeslemeli kontrol mekanizmasının gelistirilmesine ihtiyaç vardır. Manyetik aktüatörlerin, 1 ila 10 ?m çaplı süperparamanyetik parçacık üzerinde yaklasık olarak 1 ila 25 pN kuvvet üretmesi amaçlanmıstır. Bunun için 6-8 mm boyundaki koni sekilli uca sahip nikel-demir alasımlı nüve ve 2000 bakır sarımından yapılmıs bir, iki ve dört elektromıknatıstan olusan konfigürasyonlar elde edildi. Manyetik mikromanipülatör, ilk prensipler yoluyla modellendi ve bu model yardımıyla iki farklı kontrol metodu önerildi. Ilk kontrolör ofset akım tabanlı lineer kontrolör olup modeldeki lineer olmayan terimleri dogrusallastırabilme özelligine sahiptir. Ikinci kontrolör ise integral geriadımlama tabanlı nonlineer bir kontrolör olup yumusak ve etkin kontrol akımları üretebilmektedir. Tasarlanan kontrolörlerin bir boyutta ve 2-boyutta sistemin kapalı çevrimli dinamigini kararlı hale getirdigi, hızlı geçici rejim yanıtı verdigi ve sıfır kararlı durum hatası verdigi deneysel çalısmalarla gösterilmistir. Tasarlanan elektromanyetik mikromanipülatör özellikle biyolojik ayrıstırma, tıp ve biyosensör gelistirilmesi gibi alanlarda kullanılabilecek genis bir kuvvet aralıgında çalısabilme kapasitesine sahiptir.
Feedback controller designs for an electromagnetic micromanipulator
(SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2019) Boyuk, Mustafa; Eroglu, Yakup; Ablay, Gunyaz; Icoz, Kutay; 0000-0002-0947-6166; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
Magnetic micromanipulators are capable of generating wide range of magnetic forces to manipulate magnetic microparticles for biomedical applications. In this study, a multipole magnetic micromanipulator system including electromagnets, driver circuitry and control unit is designed, modeled and implemented. The micromanipulator can produce a broad range of magnetic forces up to 25 pN on a single magnetic microparticle (1-10 mu m diameter) that is 5 mm away from the electromagnet core tip. Both linear and nonlinear controllers are designed and implemented, and the proposed nonlinear controller produces smooth control currents to assure closed-loop stability of the system with 1 s non-overshoot transient response and zero steady-state tracking error. The maximum output current of the driver circuitry is set to 1 A. The single particle at the center is moved at a speed of 5 mm/s. The fully automatic system can be utilized in applications related to single cell or microparticle manipulations.
A generalized PID controller for high-order dynamical systems
(SLOVAK UNIV TECHNOLOGYFAC ELECTRICAL ENGINEERING & INFORMATION, ILKOVICOVA 3, BRATISLAVA 812 19, SLOVAKIA, 2021) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
This paper introduces a generalized PID type controller for controlling high-order dynamical systems. An optimal generalized PID control design method is developed to provide a simplified high-order output feedback control design procedure and tunable response characteristics. The controller design procedure is reduced to the specification of the desired natural frequency and the solution of a polynomial equation. The control method is capable of providing a desired control performance under set-point and disturbance variations. The performance of the proposed control method is implemented on some unstable and nonlinear mechatronic systems to illustrate the robustness, effectiveness and feasibility of the method.
A horizontal magnetic tweezer for single molecule micromanipulations
(IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2018) Ablay, Gunyaz; Boyuk, Mustafa; Eroglu, Yakup; Icoz, Kutay; 0000-0002-0947-6166; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
Magnetic tweezers are able to manipulate cells or biomolecules for various applications and measurements. In this work, a horizontal magnetic tweezer is designed, modeled and controlled for single molecule manipulations. A method is presented for dynamic modeling of horizontal magnetic tweezers. A linear control method is designed to ensure a wide range of operation conditions with zero steady-state error. The horizontal magnetic tweezer is able to generate a wide range of piconewton scale forces on a superparamagnetic microparticle for single molecule separation, and biosensor developments.
Key role of high-T-c twinned martensitic materials to gain a magnetic actuation higher than 15%
(ELSEVIER SCIENCE SAPO BOX 564, 1001 LAUSANNE, SWITZERLAND, 2021) Sarli, Numan; Paran, Nejdet; Ablay, Gunyaz; Ocak, Hamza Y.; Yildiz, Yasin G.; Yildiz, Gokcen D.; Yagci, Nermin K.; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Paran, Nejdet; Ablay, Gunyaz
Twinning angle outcomes of the twinned martensitic (TM) and detwinned martensitic (DTM) structural transformations on the magnetic features of the austenite (A) parent phase are researched by using the effective field theory established by Kaneyoshi. The implementation of the effective field theory verifies that the shape memory mechanism occurs with phase transformations, A -> TM -> DTM -> A. It also shows that the austenite parent phase has two types of actuations: one-dimensional actuation (in only y-axis) for TM, and two-dimensional actuation (in x and y-axes) for DTM. Magnetic field-induced actuation (strain) in the range of 5-15% at twinning angle theta >= 120.816 degrees of TM and DTM is reported for some materials in the literature. On the other hand, in this work, it is estimated that a twinning angle lower than this twinning angle (i.e., theta < 120.816 degrees) must be achieved to have a strain higher than 15%. We also suggest that materials with higher magnetization, Curie temperature, coercive field and remanence magnetization should be taken into account to get a strain higher than 15%, since all these features are directly affected by the twinning angle (theta). Our results on Curie temperature (T-c) match with the experimental results of Ni49.8Mn28.5Ga21.7 (achieved 6% strain) with T-c = 95 degrees C (368 K) by Murray et al., and Ni46Mn24Ga22Co4Cu4 with T-c = 393 K (achieved 12% strain) by Sozinov et al. (C) 2021 Elsevier B.V. All rights reserved.
A model-free continuous integral sliding mode controller for robust control of robotic manipulators
(Intelektual Pustaka Media Utama, 2023) Ablay, Günyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
This paper proposes a model-free continuous integral sliding mode controller for robust control of robotic manipulators. The highly nonlinear dynamics of robots and load disturbances cause control challenges. To achieve tracking control under load disturbances and nonlinear parameter variations, the controller is constructed with three continuous terms including an integral term that acts as an adaptive controller. The proposed controller is able to accomplish a nonovershoot transient response, a short settling time, and strong disturbance rejection performance for robotic manipulators. The developed model-free control method is implemented on the PUMA 560 robotic manipulator, and its performance is compared with the proportional-derivative (PD) plus gravity controller. Numerical results under measurement noise and load disturbances are provided in order to show the efficacy, validity, and feasibility of the method.
Model-Free Controller Designs for a Magnetic Micromanipulator
(ASMETWO PARK AVE, NEW YORK, NY 10016-5990, 2021) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
An optimal model-free controller and a linear controller are designed and applied to a horizontal magnetic micromanipulator for controlling microparticles in a liquid environment. An input-output relation based model for the magnetic micromanipulator is obtained, verified, and used in the analysis of controllers. A model-free linear controller is designed using the offset current approach. An optimal nonlinear controller based on Karush-Kuhn-Tucker conditions is designed and then modified to produce smooth control signals. Experimental results are provided to show the efficiency and feasibility of the proposed controllers. The model-free controllers yield short settling time and zero steady-state error in the control of magnetic microparticles.
A modeling and control approach to advanced nuclear power plants with gas turbines
(PERGAMON-ELSEVIER, 2013) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
Advanced nuclear power plants are currently being proposed with a number of various designs. However, there is a lack of modeling and control strategies to deal with load following operations. This research investigates a possible modeling approach and load following control strategy for gas turbine nuclear power plants in order to provide an assessment way to the concept designs. A load frequency control strategy and average temperature control mechanism are studied to get load following nuclear power plants. The suitability of the control strategies and concept designs are assessed through linear stability analysis methods. Numerical results are presented on an advanced molten salt reactor concept as an example nuclear power plant system to demonstrate the validity and effectiveness of the proposed mod- eling and load following control strategies.
MODELING AND SIMULATION OF ADVANCED NUCLEAR REACTORS
(IEEE, 2013) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
Advanced nuclear power plants are currently being proposed with a number of various designs. However, there is a lack of modeling and control strategies to deal with load following operations. This research investigates a possible modeling approach for advanced nuclear power plants in order to provide an assessment way to the concept designs. The modeling approach covers linear and nonlinear reactor modeling and linear modeling of heat exchanger-turbinegenerator systems. Numerical results are presented on an example molten-salt type nuclear power plant system to demonstrate the validity and effectiveness of the modeling approach.
New 4D and 3D models of chaotic systems developed from the dynamic behavior of nuclear reactors
(AIP Publishing, 2022) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
The complex, highly nonlinear dynamic behavior of nuclear reactors can be captured qualitatively by novel four-dimensional (that is, fourth order) and three-dimensional (that is, third order) models of chaotic systems and analyzed with Lyapunov spectra, bifurcation diagrams, and phase diagrams. The chaotic systems exhibit a rich variety of bifurcation phenomena, including the periodic-doubling route to chaos, reverse bifurcations, anti-monotonicity, and merging chaos. The offset boosting method, which relocates the attractor's basin of attraction in any direction, is demonstrated in these chaotic systems. Both constant parameters and periodic functions are seen in offset boosting phenomena, yielding chaotic attractors with controlled mean values and coexisting attractors. Published under an exclusive license by AIP Publishing.
Novel chaotic delay systems and electronic circuit solutions
(SPRINGER, 2015) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
Chaotic delay systems are abundant in nature and play a significant role in engineering applications and in describing global behaviors of physical systems. This work presents novel first-order chaotic delay systems with the simplest nonlinearities. The exponential, absolute value, and hyperbolic and signum functions, which arise in many systems like electronic circuits, are utilized to generate chaotic delay systems. The practical realization of chaotic delay systems is carried out with all-pass filters and diode-based electronic circuits. Bifurcation diagrams using numerical simulations and experimental results are provided to verify the existence and feasibility of the novel chaotic delay systems. It is expected that the novel chaotic delay systems and the novel electronic implementation circuits will contribute to some practical applications and modeling of physical systems or events in different fields.
An Observer-Based Fault Diagnosis in Battery Systems of Hybrid Vehicles
(IEEE, 2013) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
Hybrid electric vehicles (HEVs) currently use Nickel-Metal Hydride (Ni-MH) batteries which have advantages of design flexibility, superior power, environmental acceptability and recyclability, long life, wide-range operating temperature and low cost. No matter how good a battery is, a failure can always occur in a battery leading to serious inconvenience, performance deterioration and costly replacement. Thus, it is desirable to be able to detect the underlying degradation and to predict level of unsatisfactory performance. By using current, voltage and temperature measurements of Ni-MH batteries, they can be modeled so that the internal dynamics of the batteries can be estimated and state of health of the batteries can be predicted for secure and long-life operations. An observer-based fault diagnosis approach is designed to analyze the state of health of the Ni-MH battery system of HEVs in this study. Real-world input data is used to assess the efficiency of the approach in the existence of uncertainties. The possible sensor faults and unexpected parameter deviations are diagnosed efficiently with statistical evaluation of the generated residuals.
Online Condition Monitoring of Battery Systems With a Nonlinear Estimator
(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2014) Ablay, Gunyaz; 0000-0003-2862-6761; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Ablay, Gunyaz
The performance of batteries as uninterruptable power sources in any industry cannot be taken for granted. The failures in battery systems of safety-related electric systems can lead to performance deterioration, costly replacement, and, more importantly, serious hazards. The possible failures in battery systems are currently determined through periodic maintenance activities. However, it is desirable to be able to detect the underlying degradation and to predict the level of unsatisfactory performance by an online real-time monitoring system to prevent unexpected failures through early fault diagnosis. Such an online fault diagnosis method can also contribute to better maintenance and optimal battery replacement programs. A robust nonlinear estimator-based online condition monitoring method is proposed to determine the state of health of the battery systems online in industry. Real-world experimental data of a modern battery system are used to assess the efficiency of the proposed approach in the existence of parameter uncertainties.