Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/11

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  • Research Project
    Farklı Kinematik Modellere Sahip Ana ve Bağımlı Robotları Olan Telerobotik Sistemin Geliştirilmesi: Teori ve Uygulamaları
    (2015) Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan; Dede, Mehmet İsmet Can
    Proje kapsamında farklı kinematik modellere sahip ana ve bağımlı robotları olan telerobotik sistemler için denetleyicilerin tasarlanması ve İzmir Yüksek Teknoloji Enstitüsü ve Gebze Teknik Üniversitesi (eski adı Gebze Yüksek Teknoloji Enstitüsü) arasında gerçekleştirilecek deneyler ile gerçeklenmesi hedeflenmiştir. Proje kapsamında robot kolları için görev uzayı ve eklem uzayı denetleyicileri tasarlanmıştır. Tasarlanan denetleyiciler kinematik ve/veya dinamik model belirsizlikleri ile mücadele ederken aynı zamanda da eklem hızlarının ölçümlerinin eksikliği hız gözlemcileri giderilmiştir. Kararlılık analizleri Lyaunov tarzı yöntemler kullanılarak gösterilmiştir. Tasarlanan denetleyicilerin başarımları benzetim çalışmaları ve deneylerle gösterilmiştir. Ardından telerobotik çalışmalarına geçilmiştir. Telerobotik sistemlerin görev uzayında denetlenmesini sağlayan iki denetleyici tasarlanmış ve başarımları benzetimlerle gösterilmiştir. Daha sonra model aracılı denetim ve doğrudan teleoperasyon yöntemleri farklı kinematik modellere sahip ana ve bağımlı robotlardan oluşan telerobotik sistemler için deneysel olarak kıyaslanmıştır. Son olarak İzmir Yüksek Teknoloji Enstitüsü ile Gebze Teknik Üniversitesi arasında internet ağı üzerinden farklı serbestlik derecelerine ve farklı kinematik modellere sahip robotlar arasında teleoperasyon deneyleri başarıyla yapılmıştır.
  • Conference Object
    İha'lar için Gürbüz Takip Denetçisi
    (Institute of Electrical and Electronics Engineers Inc., 2013) Tanyer, İlker; Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan
    In this study, a nonlinear control technique that guarantee exponential output tracking for unmanned aerial vehicles subject to uncertainties in system dynamics and additive nonlinear disturbances is developed. In the literature, dynamic inversion method which is a nonlinear control technique commonly used within the aerospace community to replace aircraft dynamics with a reference model. Dynamic inversion and robust control methods were usually utilized together to compensate for the uncertainties and ensure output tracking. Review of the literature highlights the fact that, in previous works, estimate of the uncertain system matrices was used in the controller design. In our study, we removed the requirement for the estimate of the uncertain system matrices and yet still guarantee exponential tracking of a reference model.
  • Conference Object
    A New Continuous Velocity Observer Formulation for a Class of Uncertain Nonlinear Mechanical Systems
    (Institute of Electrical and Electronics Engineers, 2015) Bayrak, Alper; Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan; Deniz, Meryem
    In this study, we present a smooth robust velocity observer for a class of uncertain nonlinear mechanical systems. The smoothness of the observers is guaranteed by utilizing hyperbolic tangent function as opposed to signum-type functions applied in most robust and sliding mode observers found in the literature. The proposed observer does not require a priori knowledge of an upper bound of the uncertain system dynamics and introduces a time-varying observer gain for uncertainty compensation. Practical stability of the observer error is ensured via Lyapunov-type stability analysis. Numerical simulation studies backed up by experimental results are presented to illustrate the performance of the proposed observer.
  • Conference Object
    Citation - WoS: 4
    Citation - Scopus: 5
    Backstepping Control of Electro-Hydraulic Arm
    (Institute of Electrical and Electronics Engineers, 2018) Bayrak, Alper; Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan
    In this study, positioning control of the electro hydraulic systems is considered. Backstepping control strategy is designed by defining an auxiliary error signal. The performance of the controller is investigated by conducting numerical simulations. From the simulation results, it is seen that the control objective achieved successfully. The performance is compared with PI controller via a comparison criteria and it is seen that the backstepping controller has better results in both error and controller performance aspects.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 7
    On Operational Space Tracking Control of Robotic Manipulators With Uncertain Dynamic and Kinematic Terms
    (American Society of Mechanical Engineers, 2019) Çetin, Kamil; Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan
    In this study, a continuous robust-adaptive operational space controller that ensures asymptotic end-effector tracking, despite the uncertainties in robot dynamics and on the velocity level kinematics of the robot, is proposed. Specifically, a smooth robust controller is applied to compensate the parametric uncertainties related to the robot dynamics while an adaptive update algorithm is used to deal with the kinematic uncertainties. Rather than formulating the tracking problem in the joint space, as most of the previous works on the field have done, the controller formulation is presented in the operational space of the robot where the actual task is performed. Additionally, the robust part of the proposed controller is continuous ensuring the asymptotic tracking and relatively smooth controller effort. The stability of the overall system and boundedness of the closed loop signals are ensured via Lyapunov based arguments. Experimental results are presented to illustrate the feasibility and performance of the proposed method.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 11
    Neural Network-Based Repetitive Learning Control of Euler Lagrange Systems: an Output Feedback Approach
    (IEEE, 2018) Tatlıcıoğlu, Enver; Çobanoğlu, Necati; Zergeroǧlu, Erkan
    In this letter, position tracking control problem of a class of fully actuated Euler Lagrange (EL) systems is aimed. The reference position vector is considered to be periodic with a known period. Only position measurements are available for control design while velocity measurements are not. Furthermore, the dynamic model of the EL systems has parametric and/or unstructured uncertainties which avoid it to be used as part of the control design. To address these constraints, an output feedback neural network-based repetitive learning control strategy is preferred. Via the design of a dynamic model independent velocity observer, the lack of velocity measurements is addressed. To compensate for the lack of dynamic model knowledge, universal approximation property of neural networks is utilized where an online adaptive update rule is designed for the weight matrix. The functional reconstruction error is dealt with the design of a novel repetitive learning feedforward term. The outcome is a dynamic model independent output feedback neural network-based controller with a repetitive learning feedforward component. The stability of the closed-loop system is investigated via rigorous mathematical tools with which semi-global asymptotic stability is ensured. © 2017 IEEE.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Neural Network Based Robust Control of an Aircraft
    (ACTA Press, 2020) Tanyer, İlker; Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan
    Output 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.