Browsing by Author "Ablay, Gunyaz"

Now showing 1 - 20 of 22

Citation - WoS: 2
Cascade Control of Magnetic Levitation With Sliding Modes
(EDP Sciences, 2016) Eroglu, Yakup; Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 26
Citation - Scopus: 31
Cascade Sliding Mode-Based Robust Tracking Control of a Magnetic Levitation System
(Sage Publications Ltd, 2016) Eroglu, Yakup; Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 7
Citation - Scopus: 11
Chaotic Map Construction From Common Nonlinearities and Microcontroller Implementations
(World Scientific Publ Co Pte Ltd, 2016) Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 9
Citation - Scopus: 10
Coefficient Ratios-Based Robust Sliding Surface and Integral Sliding Mode Control Designs With Optimal Transient Responses
(Inst Engineering Technology-IET, 2014) Ablay, Gunyaz; 01. Abdullah Gül University
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 - Division Reed Elsevier India Pvt Ltd, 2024) Ates, Ertugrul; Tekgun, Burak; Ablay, Gunyaz; Barut, Murat; 01. Abdullah Gül University; 02. Mühendislik Fakültesi; 02.05. Elektrik & Elektronik Mühendisliği
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.
Citation - WoS: 5
Citation - Scopus: 6
Design, Modeling, and Control of a Horizontal Magnetic Micromanipulator
(Sage Publications Ltd, 2019) Ablay, Gunyaz; Boyuk, Mustafa; Icoz, Kutay; 01. Abdullah Gül University
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; 01. Abdullah Gül University
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.
Citation - WoS: 3
Citation - Scopus: 5
Feedback Controller Designs for an Electromagnetic Micromanipulator
(Sage Publications Ltd, 2020) Boyuk, Mustafa; Eroglu, Yakup; Ablay, Gunyaz; Icoz, Kutay; 01. Abdullah Gül University
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.
Citation - WoS: 1
Citation - Scopus: 1
A Generalized PID Controller for High-Order Dynamical Systems
(Slovak Univ Technology, 2021) Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 2
Citation - Scopus: 2
Key Role of High-Tc Twinned Martensitic Materials to Gain a Magnetic Actuation Higher Than 15%
(Elsevier Science SA, 2021) Sarli, Numan; Paran, Nejdet; Ablay, Gunyaz; Ocak, Hamza Y.; Yildiz, Yasin G.; Yildiz, Gokcen D.; Yagci, Nermin K.; 01. Abdullah Gül University
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.
Citation - WoS: 1
Citation - Scopus: 2
Model-Free Controller Designs for a Magnetic Micromanipulator
(ASME, 2021) Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 40
Citation - Scopus: 46
A Modeling and Control Approach to Advanced Nuclear Power Plants With Gas Turbines
(Pergamon-Elsevier Science Ltd, 2013) Ablay, Gunyaz; 01. Abdullah Gül University
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 modeling and load following control strategies. (C) 2013 Elsevier Ltd. All rights reserved.
Citation - WoS: 22
Citation - Scopus: 24
Novel Chaotic Delay Systems and Electronic Circuit Solutions
(Springer, 2015) Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 22
Citation - Scopus: 24
Online Condition Monitoring of Battery Systems With a Nonlinear Estimator
(IEEE-Inst Electrical Electronics Engineers Inc, 2014) Ablay, Gunyaz; 01. Abdullah Gül University
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.
Citation - WoS: 2
PI-V Plus Sliding Mode Based Cascade Control of Magnetic Levitation
(IEEE, 2015) Eroglu, Yakup; Ablay, Gunyaz; 01. Abdullah Gül University
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 design. The position control problem of the magnetic levitation can be solved with robust current control approaches. A cascade control approach consisting of PI-velocity plus sliding mode control (PI-V plus SMC) is designed to render high control performance and robustness to the magnetic levitation. It will be shown that the SMC designed for electrical part of the plant (current controller) is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant. Experimental results are provided to validate the efficacy of the approach.
Citation - WoS: 10
Citation - Scopus: 13
A Robust Estimator-Based Optimal Algebraic Approach to Steam Generator Feedwater Control System
(Tubitak Scientific & Technological Research Council Turkey, 2016) Ablay, Gunyaz; 01. Abdullah Gül University
Feedwater control systems are used to maintain the steam generator water level within prescribed narrow limits and to provide constant supply of steam during power demand variations. Current feedwater control systems are often found to be unsatisfactory during startup and low power operations. A robust nonlinear estimator-based optimal algebraic control is developed for feedwater control systems to solve the water level tracking problem during power demand variations. It is shown that the proposed control provides an optimal and robust water level tracking with a single automatic controller over the complete range of power operations in the presence of plant uncertainties and noisy measurements.
Citation - WoS: 7
Citation - Scopus: 11
Robust Estimator-Based Optimal Control Designs for U-Tube Steam Generators
(Sage Publications Ltd, 2015) Ablay, Gunyaz; 01. Abdullah Gül University
U-tube steam generator level control systems are used to maintain the water level within prescribed narrow limits and to provide constant supply of high-quality steam during power demand variations. Traditional level control systems are often found to be unsatisfactory during low power operations and start-up conditions. Robust non-linear estimator-based optimal control systems are proposed for steam generator level control systems to solve the water level tracking problem during power (or steam) demand variations. It is shown that the proposed control strategies provide optimal and robust water level tracking with a single controller over the complete range of power operation with model and parameter uncertainties and noisy measurements.
Citation - WoS: 2
Citation - Scopus: 1
Robust Integral Controllers for High-Order Class-D Power Amplifiers
(Inst Engineering Technology-IET, 2018) Ablay, Gunyaz; 01. Abdullah Gül University
This study presents variable structure system theory based robust integral controllers for class-D power amplifiers. These amplifiers are highly efficient switching type power amplifiers with negligible losses. Sensorless and current feedback based integral controllers with sliding modes are designed to provide robust tracking performance with negligible phase delays and distortions. The methods are capable of providing high-quality outputs by maximising gain and minimising the tracking error and phase shifts. The validity, feasibility and robustness performance of the controllers are investigated through circuit realisations.
Citation - WoS: 3
Citation - Scopus: 3
Robust Reactivity, Neutron Source, and Precursor Estimators for Nuclear Reactors
(Elsevier Science SA, 2013) Ablay, Gunyaz; 01. Abdullah Gül University
Reactivity, precursor concentration, and external neutron source strength determine control, operation and performance of nuclear reactors. These main reactor quantities are not directly measurable and must be calculated or estimated using reactor kinetics. This study presents efficient and robust nonlinear estimation algorithms for predicting these fundamental reactor quantities. The effectiveness of the proposed estimators is assessed through chirp and step test signals in the presence of parameter uncertainties and measurement noise. (C) 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Sensorless Position and Speed Control of IPMSM With Sliding Mode Observer and Voltage Signal Injection
(IEEE, 2021) Ates, Ertugrul; Tekgun, Burak; Ablay, Gunyaz; 01. Abdullah Gül University; 02. Mühendislik Fakültesi; 02.05. Elektrik & Elektronik Mühendisliği
A sensorless control approach based on a sliding mode observer for predicting the rotor position and speed is studied in this work. For predicting the motor speed and position, the sliding mode observer followed by a phase locked loop is formulated by means of the back EMF model. The voltage signal injection method is utilized for accurate estimation in zero or low speed region. Numerical simulation results are provided for an 8-pole IPMSM, which shows that the motor speed and position in zero or low-speed region are accurately estimated with the designed observer and voltage signal injection approach.