Now showing items 1-20 of 24

    • Adaptive human pilot model for uncertain systems 

      Tohidi, Shahab; Yıldız, Yıldıray (IEEE, 2019-06)
      Inspired by humans' ability to adapt to changing environments, this paper proposes an adaptive human model that mimics the crossover model despite input bandwidth deviations and plant uncertainties. The proposed human pilot ...
    • Constructing convex directions for stable polynomials 

      Özgüler, A. B. (IEEE, 2000)
      The constructions of convex directions based on phase-derivative interpretations were obtained for Hurwitz-stable polynomials. The phase-derivative conditions were based on the sensitivity of root-locus associated with the ...
    • Decentralised robust flow controller design for networks with multiple bottlenecks 

      Munyas, I.; Yelbaşi, Ö.; Biberovic, E.; İftar, A.; Özbay, Hitay (Taylor & Francis, 2009)
      Decentralised rate-based flow controller design in multi-bottleneck data-communication networks is considered. An H∞ problem is formulated to find decentralised controllers which can be implemented locally at the bottleneck ...
    • Delay margin optimization for systems with ınternal delayed feedback 

      Özbay, Hitay (Elsevier, 2021-07-16)
      In this brief paper, controller design for delay margin optimization is considered for systems with internal feedback delays (systems with delays in the state variables). Similar to existing results on delay margin ...
    • Design of a switched robust control scheme for drug delivery in blood pressure regulation 

      Ahmed, S.; Özbay, Hitay (Elsevier B.V., 2016)
      A control algorithm based on switching robust controllers is presented for a Linear Parameter Varying (LPV) time-delay system modeling automatic infusion of vasodilator drug to regulate postsurgical hypertension. The system ...
    • Financial stability under model uncertainty 

      Kantur, Z.; Özcan, G. (Elsevier B.V., 2018)
      This paper studies how asset price model misspecification affects the conduct of monetary policy under commitment in a New Keynesian model using robust control techniques. We find that monetary policy reacts aggressively ...
    • Flexible test-bed for unusual behavior detection 

      Petrás I.; Beleznai, C.; Dedeolğu, Yiğithan; Pards, M.; Kovács L.; Szlávik, Z.; Havasi L.; Szirányi, T.; Töreyin, B. Uğur; Güdükbay, Uğur; Çetin, A.hmet Enis; Canton-Ferrer, C. (ACM, 2007-07)
      Visual surveillance and activity analysis is an active research field of computer vision. As a result, there are several different algorithms produced for this purpose. To obtain more robust systems it is desirable to ...
    • H∞ filter design for vehicle tracking under delayed and noisy measurements 

      Ezercan, Sami; Özbay, Hitay (IEEE, 2007-06)
      In many intelligent vehicles applications tracking plays an important role. This paper considers tracking of a vehicle under delayed and noisy measurements. For this purpose we design an H∞ optimal filter for linear systems ...
    • Local convex directions 

      Özgüler, Arif Bülent; Saadaoui, Karim (IEEE, 2001)
      A proof of a strengthened version of the phase growth condition for Hurwitz stable polynomials is given. Based on this result, a necessary and sufficient condition for a polynomial p(s) to be a local convex direction for ...
    • Local convex directions for Hurwitz stable polynomials 

      Özgüler, A. B.; Saadaoui, K. (IEEE, 2002)
      A new condition for a polynomial p(s) to be a local convex direction for a Hurwitz stable polynomial q(s) is derived. The condition is in terms of polynomials associated with the even and odd parts of p(s) and q(s), and ...
    • Numerical computation and implementation of H-infinity controllers for retarded and neutral time delay systems 

      Yeğin, Mustafa Oğuz (Bilkent University, 2017-11)
      Being the most commonly encountered systems in engineering applications, design of robustly stabilizing H∞ controller with maximum performance for timedelay linear time-invariant systems has been an attractive topic in ...
    • Numerical computation of H∞ optimal controllers for time delay systems using YALTA 

      Yeğin, M. O.; Özbay, Hitay (Elsevier B.V., 2016)
      Numerical computation of H∞ controllers for time delay systems has been a challenge since 1980s. Even though significant techniques are developed to obtain direct optimal controllers, application of these methods may require ...
    • On the discrete adaptive posicast controller 

      Abidi, K.; Yıldız, Yıldıray (IFAC, 2015)
      In this paper, we present the discrete version of the Adaptive Posicast Controller (APC) that deals with parametric uncertainties in systems with input time-delays. The continuous-time APC is based on the Smith Predictor ...
    • On the robust controller design for Hard Disk Drive servo systems with time delays 

      Yan, P.; Özbay, Hitay (IEEE, 2013)
      Due to the existence of various sources of delays, the dynamical model of HDD (Hard Disk Drive) servo systems is actually infinite dimensional, although most of the control algorithms simplified the model with Padé expansions ...
    • On the structure and implementation of the optimal Q-Parameter in the one-block H-infinity control problem 

      Taştekin, Çetin (Bilkent University, 2020-11)
      In the robust control theory, H∞ methods are carried out to procure solutions to sensitivity minimization (nominal performance) and robust stability problems in general. These one – block control problems can be ...
    • An operator theoretic approach to robust control of infinite dimensional systems 

      Özbay, Hitay (Applied Mathematics Scientific Research Institute, 2013)
      The purpose of this paper is to give an overview of the skew Toeplitz approach to H∞ control of a class of infinite dimensional systems. Numerical steps involved in the computations of optimal and suboptimal controllers ...
    • Reactive planning and control of planar spring-mass running on rough terrain 

      Arslan, Ö.; Saranlı, U. (Institute of Electrical and Electronics Engineers, 2012)
      An important motivation for work on legged robots has always been their potential for high-performance locomotion on rough terrain. Nevertheless, most existing control algorithms for such robots either make rigid assumptions ...
    • Remarks on H ∞ controller design for SISO plants with time delays 

      Gümüşsoy, Suat; Özbay, Hitay (2006-07)
      The skew Toeplitz approach is one of the well developed methods to design H ∞ controllers for infinite dimensional systems. In order to be able to use this method the plant needs to be factorized in some special manner. ...
    • Robust adaptive sampled-data control of a class of systems under structured nonlinear perturbations 

      Ocah, O.; Sezer, M. E. (Institute of Electrical and Electronics Engineers, 1997-04)
      A robust adaptive sampled-data feedback stabilization scheme is presented for a class of systems with nonlinear additive perturbations. The proposed controller generates a control input by using high-gain static or dynamic ...
    • Robust flow control in data-communication networks with multiple time-delays 

      Ünal, H. U.; Ataşlar-Ayyildiz, B.; Iftar, A.; Özbay, Hitay (WILEY, 2009-11-20)
      Robust controller design for a flow control problem where uncertain multiple time-varying time-delays exist is considered. Although primarily data-communication networks are considered, the presented approach can also be ...