Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Now showing 1 - 8 of 8
  • Conference Object
    Citation - Scopus: 4
    Nonlinear Robust Control of 3 Phase Inverter With Output Lc Filter
    (Elsevier Ltd., 2014) Okur, Beytullah; Zergeroğlu, Erkan; Şeker, Murat; Tatlıcıoğlu, Enver
    Three phase inverters are commonly used to transfer energy from a source to the power grid. The quality of the power delivered to the grid, can be ensured via the use of an output LC filter. However inserting an output filter to an inverter circuitry would introduce new challenges to the controller design due to the additional parametric uncertainties imposed. In this study we present a new model based robust controller for a three phase inverter with output LC filter under the constraint that the output filter parameters are not exactly known. Specifically, d-q reference frame model of an inverter with output LC filter is used to develop a nonlinear robust controller that ensures the 3-phase output voltage with desired amplitude and frequency and with lowest harmonic distortion. Stability of the proposed method and the boundedness of the closed-loop system, is established via Lyapunov based tools in conjunction with a robust backstepping procedure. Simulation results are given in order to demonstrate performance and effectiveness of the proposed robust controller. © IFAC.
  • Conference Object
    Citation - WoS: 1
    Feedback Control Static Scheduling for Real-Time Distributed Embedded Systems
    (Institute of Electrical and Electronics Engineers Inc., 2005) Ayav, Tolga; Sorel, Yves
    This paper presents an implementation of feedback control strategy on distributed static scheduling. The static schedule is created taking into account the average execution times of the tasks. Feedback control algorithm handles the unestimated dynamic behaviors in the system and keeps the performance at a desired level. The approach of feedback control supporting static scheduling yields more flexible scheduling, low scheduling overhead and better resource utilization while preserving the realtime constraints.
  • Conference Object
    Citation - Scopus: 9
    Adaptive Rtp Rate Control Method
    (Institute of Electrical and Electronics Engineers Inc., 2011) Tos, Uras; Ayav, Tolga
    In this paper, we present an adaptive method for maximizing network bandwidth utilization for the real-time applications. RTP protocol is chosen as the transport protocol and the network utilization is provided by increasing and decreasing the transmission rate of the RTP traffic. Our method employs a PID controller that keeps the RTP packet loss fraction at a predefined reference point. Packet loss fraction parameter is gathered from the RTCP receiver reports and fed into the PID controller that controls the transmission rate of the RTP traffic. Simulations are performed to demonstrate the effectiveness of the method under a bottleneck network configuration with background UDP traffic competing against the RTP traffic for the available bandwidth.
  • Article
    Optimal Control for Real-Time Feedback Rate-Monotonic Schedulers
    (Springer Verlag, 2005) Ayav, Tolga; Ferrari-Trecate, Giancarlo
    This paper presents an optimal control scheme for a real-time feedback control rate-monotonic scheduling (FC-RMS) system. We consider two-version tasks composed of a mandatory and an optional part to be scheduled according to the FC-RMS. In FC-RMS, the controller provides a feedback strategy for deciding about the execution or rejection of the optional sub-tasks. By modeling the task execution times as random variables, we first find the statistical model of FC-RMS and then we design a pure optimal controller and an optimal controller with feedforward integral compensation. The comparison of these two schemes with common Proportional-Integral-Derivative (PID) controller highlights the benefit of the optimal scheme with integral compensation. The results are demonstrated through the real implementation of FC-RMS on RT-Linux.
  • Conference Object
    Citation - Scopus: 2
    Feedback Control Based Test Case Instantiation for Firewall Testing
    (Institute of Electrical and Electronics Engineers Inc., 2010) Tuğlular, Tuğkan; Gerçek, Gürcan
    A firewall's proper functioning is critical to the network it protects. Thus, a firewall should be tested with respect to its intended security policy. We propose a feedback control based approach for test case generation to detect mismatches between firewall's expected and executed behavior. In the proposed approach, abstract test cases are generated from firewall decision diagrams and instantiated with the test input values chosen using the proposed feedback control based selection algorithm. A case study is presented to validate the presented approach.
  • Conference Object
    Citation - WoS: 4
    Citation - Scopus: 7
    Robust Output Tracking Control of a Surface Vessel
    (Institute of Electrical and Electronics Engineers Inc., 2008) Lee, Dongbin; Tatlıcıoğlu, Enver; Burg, Timothy C.; Dawson, Darren M.
    In this paper, tracking control of a three degree-of-freedom marine vessel is examined. The primary motivation for this work is the compensation needed for the added mass common to surface vessels, resulting in an asymmetric inertia matrix. Two control schemes are considered: a full-state feedback controller and an output feedback controller. Numerical simulation results are shown to demonstrate the validity of these proposed controllers.
  • Conference Object
    Citation - WoS: 6
    Citation - Scopus: 8
    Adaptive Output Tracking Control of a Surface Vessel
    (Institute of Electrical and Electronics Engineers Inc., 2008) Lee, Dongbin; Tatlıcıoğlu, Enver; Burg, Timothy C.; Dawson, Darren M.
    In this paper, the tracking control of a three degree-of-freedom marine vessel is examined. The novelty of this work is the transformation of the asymmetric inertia matrix into a symmetric, positive definite matrix. The asymmetry arises from the added mass common to practical surface vessels and creates a significant challenge for control design. The control design is further complicated by the parametric uncertainties in the dynamic model of the vessel. Two adaptive control schemes with a projection-based adaptation law are proposed: a full-state feedback controller and an output feedback controller. Both controllers are known to yield a uniformly ultimately bounded tracking result in the presence of parametric uncertainty. Numerical simulation results are shown to demonstrate the validity of the proposed controllers.
  • Conference Object
    Citation - Scopus: 5
    Partial and Analog Feedback for Miso Precoding Systems
    (Institute of Electrical and Electronics Engineers Inc., 2007) Le Ruyet, Didier; Özbek, Berna
    We consider a multiple input single output antenna system with a feedback link. While most of the previous works have considered perfect feedback channels, in this paper, we evaluate the impact of a noisy feedback channel on the quality and the performance of the transmission. We compare the finite rate feedback scheme with the analog feedback schemes where the channel parameters are transmitted without quantization over the uplink channel. Two analog feedback schemes are considered : the feedback of the channel vector and the feedback of the normalized channel vector. We provide bounds on the performance and give numerical results. We have shown that at low to medium uplink SNR the analog feedback of the normalized channel vector outperforms the analog feedback of the channel vector. Depending on the range of uplink SNR, quantized feedback can perform poorlz y compared to analog feedback.