Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
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Conference Object Citation - Scopus: 2Adaptive Actuator Failure Compensation for Concurrently Actuated Manipulators(Elsevier, 2003) Keçeci, Emin Faruk; Tang, Xidong; Tao, GangThis paper presents an adaptive actuator failure compensation method, which compensates for uncertainties due to unknown actuator failures and system dynamics, for a class of redundant manipulators where some joints concurrently actuated. Physical realization of concurrently actuated manipulators and their advantageous of use have been understood before, but adaptive failure compensation is still an open issue. In this research, failure formulation, controller structure and adaptive update rules for handling uncertainties from both the system dynamics and the failures are studied. The system stability is shown by a modified Lyapunov. Simulation results show the effectiveness of the proposed adaptive failure compensation control design.Conference Object Adaptive Actuator Failure Compensation for Cooperating Multiple Manipulator Systems(Elsevier, 2003) Keçeci, Emin Faruk; Tang, Xidong; Tao, GangThis paper presents adaptive actuator failure compensation for a cooperating multiple manipulator system with uncertain actuator failures in the task space. Advantages of designing control schemes in task spaces are emphasized, applications of task space control in robotics are discussed and a short review on control algorithms for cooperating multiple manipulator systems is given. Dynamic equations of motion of the multiple manipulator system in the task space are derived, and the adaptive actuator failure compensation problem is formulated. A compensation controller structure is proposed, for which adaptive parameter update laws are developed. The adaptive control scheme is able to compensate for the uncertainties arising from both the system parameters and the actuator failures. Based on Lyapunov stability analysis, the closed-loop signal boundedness and the convergence of the tracking error to zero are ensured. © 2003 International Federation of Automatic Control.Conference Object Citation - Scopus: 2Importance of Load Based Automatic Control in Geothermal Energy Systems(Elsevier, 2003) Şener, Adil Caner; Toksoy, Macit; Aksoy, NiyaziGeothermal energy production is not possible without use of electricity, since electricity is needed to pump geothermal fluid from underground to consumption point. The biggest portion of the operating cost in geothermal district heating systems comes from pumping energy consumption. In ibis study Balcova-Narhdere geothermal district heating system has been analysed and the optimum control strategies minimising the energy consumption in the system discussed. Then decisive factors in the efficient control and operation of geothermal healing systems have been studied. Finally fundamental automation requirements for efficient operation of geothermal district heating systems has been introduced. Copyright © 2003 IFAC.Article Citation - WoS: 325Citation - Scopus: 366A Review on Adsorption Heat Pump: Problems and Solutions(Elsevier, 2008) Demir, Hasan; Mobedi, Moghtada; Ülkü, SemraAdsorption heat pumps have considerably sparked attentions in recent years. The present paper covers the working principle of adsorption heat pumps, recent studies on advanced cycles, developments in adsorbent-adsorbate pairs and design of adsorbent beds. The adsorbent-adsorbate pair features for in order to be employed in the adsorption heat pumps are described. The adsorption heat pumps are compared with the vapor compression and absorption heat pumps. The problems and troubles of adsorption heat pumps are classified and researches to overcome the difficulties are discussed.Article Citation - WoS: 25Citation - Scopus: 36Effect of Strain Rate on the Compression Behaviour of a Woven Fabric S2-Glass Fiber Reinforced Vinyl Ester Composite(Elsevier, 2003) Akil, Övünç; Yıldırım, Uygar; Güden, Mustafa; Hall, Ian W.Quasi-static (~10−3s−1) and high strain rate (>500 s−1) compression behavior of an S2-glass woven fabric/vinyl ester composite plate was determined in the in-plane and through-thickness directions. In both directions, modulus and failure strength increased with increasing strain rate. A higher strain rate sensitive modulus was found in the through-thickness direction while a higher strain rate sensitive failure strength was found in the in-plane direction. In the in-plane direction, the failure mode was observed to change from splitting followed by “kink banding” (localized fiber buckling) to predominantly splitting at increasing strain rates, while it remained the same in the through-thickness direction.