Dynamic performances of kinematically and dynamically adjustable planar mechanisms

Download
2003
İyiay, Erdinç
In this thesis, the dynamic performances of kinematically and dynamically adjustable planar mechanisms have been investigated. An adjustable mechanism is here defined to be a mechanism where some of the kinematic and/or dynamic parameters are changed in a controlled manner in order to optimize the dynamic behaviour of the mechanism in spite of variable operating conditions. Here, variable operating conditions refer to variable load(s) on the mechanism and/or variable desired input motion. The dynamic behaviour of the mechanism may be optimized via minimization of the actuator torque/force fluctuations, minimization of energy consumed by the actuators etc. According to the type of the adjustable parameter, the adjustable mechanisms are classified into two groups namely, dynamically adjustable mechanisms and kinematically adjustable mechanisms. Mechanisms, where the main concern is to change a dynamic parameter(s) are called dynamically adjustable mechanisms. In the kinematically adjustable mechanisms, on the other hand , the main concern is to change a kinematic parameter(s). The main objective of this study is to investigate the benefits of adjustable planar mechanisms, regarding different dynamic behaviours under variable operating conditions. To achieve this objective , various simulations have been performed on the computer. In these simulations, practical constraints that will exist in a real application have been taken into account as much as possible. The results reveal that, in many cases, the dynamic behaviour of a planar mechanism may be improved quite extensively via adjustable mechanisms which are obtained from the original mechanisms with slight modifications.

Suggestions

Dynamic modeling of optical systems in order to study vibration effect on performance
Avsar, Ahmet Levent; Özgüven, Hasan Nevzat (2010-08-03)
In order to determine the vibration effects on performance in optical system, a simple vibratory model is proposed. The model suggested is compared with FE model. Both models are validated by modal tests for an existing simple optical system. The material properties of adhesive, which play an imported role in the vibratory model of an optical system, are found experimentally by using a simple test setup. The model suggested is used to investigate the dynamic behavior of the optical system under random vibra...
Experimental evaluation of cable drum systems as linear motion sensors
KILIÇ, ERGİN; Dölen, Melik; Koku, Ahmet Buğra (2011-04-15)
This study evaluates cable-drum mechanisms as linear motion sensors for certain CNC applications. In this work, the dynamical attributes of a generic device are studied experimentally. The conducted research indicates that despite the significant traction force induced between the cable and its drum, small fluctuations in mechanism's speed yields a considerable (micro) slip at the interface.
Real-Time Detection of Interharmonics and Harmonics of AC Electric Arc Furnaces on GPU Framework
Uz-Logoglu, Eda; Salor, Ozgul; Ermiş, Muammer (2019-11-01)
In this paper, a method based on the multiple synchronous reference frame analysis is recommended and implemented to detect time-varying harmonics and interharmonics of rapidly fluctuating asymmetrical industrial loads. The experimental work has been carried out on a typical three-phase alternating current arc furnace installation. In the recommended method, the reference frame is rotated in both directions at speeds corresponding to the positive and negative sequences of all harmonics and all interharmonic...
Real-Time Detection of Interharmonics and Harmonics of AC Electric Arc Furnaces on GPU Framework
Uz-Logoglu, Eda; Salor, Ozgul; Ermiş, Muammer (2017-10-05)
In this paper, a method based on the multiple synchronous reference frame (MSRF) analysis is recommended and implemented to detect time-varying harmonics and interharmonics of rapidly fluctuating asymmetrical industrial loads. The experimental work has been carried out on a typical three-phase alternating current arc furnace (AC EAF) installation. In the recommended method, the reference frame is rotated in both directions at speeds corresponding to the positive and negative sequences of all harmonics and a...
Optimization of Power Conversion Efficiency in Threshold Self-Compensated UHF Rectifiers With Charge Conservation Principle
Gharehbaghi, Kaveh; KOÇER, FATİH; Külah, Haluk (2017-09-01)
This paper presents a compact model for threshold self-compensated rectifiers that can be used to optimize circuit parameters early in the design phase instead of time-consuming transient simulations. A design procedure is presented for finding the optimum aspect ratio of transistors used in the converter and number of rectifying stages to achieve the maximum power conversion efficiency. In the presented analysis, the relation between the power conversion efficiency and the load current over the variation o...
Citation Formats
E. İyiay, “Dynamic performances of kinematically and dynamically adjustable planar mechanisms,” M.S. - Master of Science, Middle East Technical University, 2003.