Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - WoS: 5Citation - Scopus: 7Online Time Delay Estimation in Networked Control Systems With Application To Bilateral Teleoperation(Institute of Electrical and Electronics Engineers Inc., 2017) Çetin, Kamil; Bayrak, Alper; Tatlıcıoğlu, EnverThe problem of forward and backward time delays is significantly important for both control and feedback loop of networked control systems. These time delays give rise to latency in performance and thereby may destabilize the system. Therefore numerous methods have been proposed about time delay identification/estimation and compensation for networked control systems, especially for bilateral teleoperation systems. However, most compensation methods have been accomplished by considering offline time delay estimation for linear/nonlinear time delay control systems. In this work, we propose an observer based estimation algorithm for round trip delay which is the sum of forward and backward time delays for a 1 degree-of-freedom nonlinear bilateral teleoperation system. Via Lyapunov based stability analysis, global boundedness of the observer errors along with their ultimate convergence and the convergence of the round trip delay estimator to the vicinity of its real value can be guaranteed in the closed-loop system. Finally, simulation and experimental studies are carried out utilizing the last link of a PHANToM Omni Haptic device moving like a one-link robot in the vertical plane.Article Citation - WoS: 8Citation - Scopus: 8Online Time Delay Identification and Control for General Classes of Nonlinear Systems(SAGE Publications Inc., 2013) Bayrak, Alper; Tatlıcıoğlu, EnverIn this study, online identification of state delays is discussed. First, a novel adaptive time delay identification technique is proposed for general classes of nonlinear systems subject to state delays. The stability of the time delay identification algorithm is analyzed via Lyapunov-based techniques. In this work, we consider the time delay as a nonlinear parameter effecting the system which is a seemingly novel departure from the existing literature. As an extension, this technique is modified to design a tracking controller for general classes of nonlinear systems subject to state delays. The main novelty of this controller is that identification of unknown state delays are ensured while output tracking objective is satisfied. Numerical simulations are conducted that demonstrate the efficiency of the time delay identification algorithm and the tracking controller.Conference Object Citation - WoS: 3Citation - Scopus: 6Online Time Delay Identification and Control for General Classes of Nonlinear Systems(Institute of Electrical and Electronics Engineers Inc., 2012) Bayrak, Alper; Tatlıcıoğlu, EnverIn this study, online identification of state delays is discussed. First, a novel adaptive time delay identification technique is proposed for general classes of autonomous nonlinear systems subject to state delays. As an extension, this technique is modified to design a tracking controller for general classes of nonlinear systems subject to state delays. The main novelty of this controller is that identification of unknown state delays is ensured while output tracking objective is satisfied. Extensive numerical simulations are presented that demonstrate the efficiency of the time delay identification algorithm and the tracking controller. © 2012 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.Article Citation - WoS: 10Citation - Scopus: 11A novel online adaptive time delay identification technique(Taylor and Francis Ltd., 2016) Bayrak, Alper; Tatlıcıoğlu, EnverTime delay is a phenomenon which is common in signal processing, communication, control applications, etc. The special feature of time delay that makes it attractive is that it is a commonly faced problem in many systems. A literature search on time-delay identification highlights the fact that most studies focused on numerical solutions. In this study, a novel online adaptive time-delay identification technique is proposed. This technique is based on an adaptive update law through a minimum-maximum strategy which is firstly applied to time-delay identification. In the design of the adaptive identification law, Lyapunov-based stability analysis techniques are utilised. Several numerical simulations were conducted with Matlab/Simulink to evaluate the performance of the proposed technique. It is numerically demonstrated that the proposed technique works efficiently in identifying both constant and disturbed time delays, and is also robust to measurement noise.