Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

Browse

Filters

2013 - 20154

Settings

Author: search.filters.author.Bilgincan, TunçInstitution Author: search.filters.institutionAuthor.Kiper, Gökhan

Search Results

Now showing 1 - 4 of 4
  • Conference Object
    İki Serbestlik Dereceli Mekanizmalarla İşlev Sentezinde Tasarım Noktalarının Eşit ve Çebişev Aralıklandırması ile Seçiminin Karşılaştırılması
    (Makina Teorisi Derneği, 2015) Bilgincan, Tunç; Bilgincan, Tunç; Kiper, Gökhan; Kiper, Gökhan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Bu çalışmada iki serbestlik dereceli düzlemsel beş-kol mekanizması için işlev sentez problemi en küçük kareler yöntemi ile ele alınmıştır. Çok serbestlik dereceli mekanizmanın sentez problemi, analitik olarak ifade edilmiş ve mekanizmanın görev fonksiyonu belirlenmiştir. Tek serbestlik dereceli mekanizmaların işlev sentezi probleminde yaklaşım işlevi polinom şeklinde olmadığı halde Çebişev aralıklandırmasının diğer aralıklandırma seçeneklerine nispeten daha iyi sonuç verdiği bilinmekte ve işlev sentezinde tasarım noktalarının seçimi bir girdi değişkenli problemler için Çebişev aralıklandırması kullanılmaktadır. Bu sebeple bu çalışmada çok serbestlik dereceli mekanizmaların işlev sentezinde de Çebişev aralıklandırmasının etkisi araştırılmıştır. İki serbestlik dereceli düzlemsel beş-kol mekanizması ile iki girdili bir fonksiyonun aynı tanım kümesi için eşit aralıklandırma ve Çebişev aralıklandırması ile seçilen aynı sayıdaki tasarım noktaları ile iki ayrı çözüm yapılmış ve hata değerleri üzerine etkileri araştırılmıştır.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Function Generation Synthesis of Spherical 5r Mechanism With Regional Spacing and Chebyshev Approximation
    (Elsevier Ltd., 2015) Kiper, Gökhan; Kiper, Gökhan; Bilgincan, Tunç; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The Chebyshev approximation is well known to be applicable for the approximation of single input–single output functions by means of a function generator mechanism. The approximation method may be also applied to multi-input functions, although until recently, it was not used for function generation with multi-degrees-of-freedom mechanisms. In a recent study, the authors applied the approximation method to a two-degrees-of-freedom mechanism for the first time, however the selection and iteration of the design points at which the errors were minimized were not satisfactory. In this study, an alternative method of selection and iteration for these design points is introduced and the corresponding spacing is called the “regional spacing”. As a case study for the application of the approximation of multi-input functions, a spherical 5R mechanism is used to generate a two input-single-output function. The input joints of the mechanism are selected as one of the fixed joints and the moving mid-joint, whereas the remaining fixed joint represents the output. The synthesis problem is analytically formulated and presented in polynomial form for five and six unknown parameters. The synthesis problem for five unknown parameters is illustrated as a numerical example. Regional spacing is used for the selection and iteration of design points for the synthesis. The Chebyshev approximation along with the Remez algorithm is utilized to find the unknown construction parameters and the error of the function. The design points and the coefficients of the approximation polynomial are determined by numerical iteration using six moving points. At each iteration step, the design points are relocated at the extremum error points in their respective regions. Iterations are repeated until the magnitudes of the extremum point errors are approximately equal. Finally, the construction parameters of the mechanism are determined and the variation of the percentage error between the desired and generated function values is obtained.
  • Article
    Function Generation Synthesis of Planar 5r Mechanism
    (IFToMM, 2013) Kiper, Gökhan; Bilgincan, Tunç; Dede, Mehmet İsmet Can; Bilgincan, Tunç; Kiper, Gökhan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    This paper deals with the function generation problem for a planar five-bar mechanism. The inputs to the mechanism are selected as one of the fixed joints and the mid-joint, whereas the remaining fixed joint represents the output. Synthesis problem of the five-bar mechanism is analytically formulated and an objective function is expressed in polynomial form. Function generation synthesis is performed with equal spacing and Chebyshev approximation method. The four unknown construction parameters and the error are evaluated by means of five design points and the coefficients of the objective function are determined by numerical iteration using four stationary and one moving design point. Stationary points are placed at the boundaries of the motion and the moving point is re-selected at each iteration as the point corresponding to the extremum error. Iterations are repeated until the values are stabilized. The stabilization usually occurs at the third iteration. By this method, the maximum error values are approximately equated, hence the total error is bounded at certain limits. Finally the construction parameters of the mechanism are determined.
  • Book Part
    Citation - WoS: 3
    Function Synthesis of the Planar 5r Mechanism Using Least Squares Approximation
    (Springer, 2014) Kiper, Gökhan; Bilgincan, Tunç; Kiper, Gökhan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this paper, the problem of function generation synthesis of planar 5R mechanism is studied using the least squares approximation method with equal spacing of the design points. The study represents a case study for analytical function generation of multi-degrees-of-freedom systems. The planar 5R mechanism is designed with a fixed input joint and a moving input joint adjacent to the first input, whereas the remaining fixed joint is the output joint. The input/output relationship of the mechanism is expreseed as an objective function in polynomial form with four unknown construction parameters. The objective function involves nonlinearities, however the problem is linearized using Lagrange variables. The linear system is solved and finally the construction parameters of the mechanism are determined. A numerical example is presented as a case study.