Browsing by Author "Gezgin, Erkin"

Now showing 1 - 14 of 14

Biokinematic Analysis of Human Arm
(Izmir Institute of Technology, 2006) Gezgin, Erkin; Alizade, Rasim
Theory of Machines and Mechanisms is one of the main branches of science including many sub-branches such as biomechanics, human machine systems, computational kinematics, mechatronics, robotics, design methodology, dynamics of machinery, gearings and transmissions, cams and linkages, micro machines, nonlinear oscillations, reliability of machines and mechanisms etc. In this large area of interest, this study can be matched with the sub groups biomechanics, robotics, computational kinematics and design methodology. The main concern of the thesis is the biokinematics of the human arm. In the process of design, a suitable tool for the kinematics of human arm is investigated as quaternions along with examples. Moreover, the history of the formulas of Dof is presented as 38 equations with the unique key controlling parameters that are used in the design of new Cartesian and serial platform type robot manipulators. Structural syntheses of new manipulators are considered.Simple serial platform structural groups in subspace 8.3, and general space 8.6 are presented along with examples. Furthermore, type synthesis of human arm is accomplished with the new proposed parallel manipulator for the shoulder, elbow and wrist complex. Finally, computational kinematics of the serial human wrist manipulator and the geometrical kinematic analysis of the orientation platforms of the new parallel manipulator design for the human arm are accomplished.
Biokinematic Analysis of Human Body
(Izmir Institute of Technology, 2011) Gezgin, Erkin; Alizade, Rasim
This thesis concentrates on the development of rigid body geometries by using method of intersections, where simple geometric shapes representing revolute (R) and prismatic (P) joint motions are intersected by means of desired space or subspace requirements to create specific rigid body geometries in predefined octahedral fixed frame. Using the methodical approach, space and subspace motions are clearly visualized by the help of resulting geometrical entities that have physical constraints with respect to the fixed working volume. Also, this work focuses on one of the main areas of the fundamental mechanism and machine science, which is the structural synthesis of robot manipulators by inserting recurrent screws into the theory. After the transformation unit screw equations are presented, physical representations and kinematic representations of kinematic pairs with recurrent screws are given and the new universal mobility formulations for mechanisms and manipulators are introduced. Moreover the study deals with the synthesis of mechanisms by using quaternion and dual quaternion algebra to derive the objective function. Three different methods as interpolation approximation, least squares approximation and Chebyshev approximation is introduced in the function generation synthesis procedures of spherical four bar mechanism in six precision points. Separate examples are given for each section and the results are tabulated. Comparisons between the methods are also given. As an application part of the thesis, the most important elements of the human body and skeletal system is investigated by means of their kinematic structures and degrees of freedom. At the end of each section, an example is given as a mechanism or manipulator that can represent the behavior of the related element in the human body.
Citation - WoS: 6
Citation - Scopus: 7
Classification of Manipulators of the Same Origin by Virtue of Compactness and Complexity
(Elsevier Ltd., 2011-10) Gezgin, Erkin; Özdemir, Serhan
This work deals with a classification method that employs concepts such as complexity and compactness. The idea is to classify manipulators, or any other mechanism for that matter, of the same origin, based on the geometry of the joints, the tasks performed by the joints, the efficiency and the manufacturing cost to generate the specified efficiency. It is known that successive units on a single branch create individual uncertainties that affect the eventual quality of the performed operation [1]. An entropic expression quantifies this uncertainty in terms of the number of links and the unit effectiveness. The concepts of compactness and complexity have been formulated, and these concepts are explained through serial and parallel manipulators with varying parameters. Eventually, a cost function is created which is a function of complexity, uncertainty and the manufacturing cost. A worked example on M = 6 Stewart-Gough platform is given how this cost function could be taken advantage of when deciding an initial manipulator. A genetic algorithm is used for the optimization of the cost function, where the results are tabulated.
Design and Analysis of a Parallel Mechanism for Kinematically Redundant Hybrid Planar Laser Cutting Machine
(2014) Dede, Mehmet İsmet Can; Gezgin, Erkin; Kiper, Gökhan; Mastar, Ercan; Sığırtmaç, Tayfun; Uzunoğlu, Emre
Conventional planar laser cutting machines cannot achieve high accelerations, because the required precision values cannot be achieved due to the high inertial loads. Machines configured as kinematically redundant mechanisms are able to reach 5-6 g acceleration levels since they include a parallel mechanism with a smaller workspace which is exposed to smaller inertial loads. The study presented in this paper focuses on the design of a parallel planar mechanism to be integrated to the main axes of conventional planar laser cutting machines to achieve higher accelerations of the laser head up to 6 g. Parallel mechanism’s conceptual design and dynamic balancing studies are provided along with the joint clearance effect on precision due to having more joint structures.
Citation - Scopus: 1
The Effects of Bias, Population Migration and Credit Assignment in Optimizing Trait-Based Heterogeneous Populations
(CSREA Press, 2005) Gezgin, Erkin; Sevil, Hakkı Erhan; Özdemir, Serhan
Population based search algorithms are becoming the mainstay in nonlinear problems with discontinuous search domains. The generic name of genetic algorithms (GAs) basicly applies to all population based methods. GAs have spawned many versions to suit new applications. Some of these alterations have reached such points that the algorithms may no longer be called GAs. One similar study may be found in [1], in which a perturbation based search algorithm was proposed, called Responsive Perturbation Algorithm (RPA). In a later work [2], instead of a population of homogenous individuals, as is the case for generic GAs, a population of heterogeneous individuals has been set to compete. Replacing the set of winner parents, the fittest individual is made the parent to yield offspring. The current work is now called, with the supplements, trait-based heterogeneous populations plus (TbHP+). Credit assignment and bias concepts in the form of immunity and instinct has been added to provide the populations with a more efficient guidance. Simulations were made through an RBF neural network training, as it was carried out in earlier works, mentioned above, for comparison. Results were prsented at the end as network testing errors which showed further improvement with TbHP+.
Citation - WoS: 4
Citation - Scopus: 7
General subtask controller for redundant robot manipulators
(Institute of Electrical and Electronics Engineers Inc., 2012) Maaroof, Omar W.; Gezgin, Erkin; Dede, Mehmet İsmet Can
This paper will utilize the property of self-motion for redundant robot manipulators by designing the general subtask controller that control the joint motion in the null-space of the Jacobian matrix. The general subtask controller is used for minimizing the total joint motion and for singularity avoidance in this study. Specifically, objective function for each subtask is formed and then the gradient of the objective function is used in the subtask controller to either minimize the joint motion or avoid singularities while tracking a given end-effector trajectory. A 7-DOF LWA4-Arm (SCHUNK) is modeled first in SolidWorks® and then converted to MATLAB® Simulink using SimMechanics CAD translator for the simulation tests of the controller. The kinematics and dynamics equations are derived to be used in the controllers and the simulation results are presented for the 7-DOF redundant robot manipulator operating in 3D space. © 2012 ICROS.
Integration of the Hybrid-Structure Haptic Interface: Hiphad V1.0
(Curran Associates, 2010) Bilgincan, Tunç; Gezgin, Erkin; Dede, Mehmet İsmet Can
Design, manufacturing, integration and initial test results of the 6-DoF haptic interface, HIPHAD v1.0, are presented in this paper. The hybrid haptic robot mechanism is composed of a 3-DoF parallel platform manipulator, R-Cube, for translational motions and a 3-DoF serial wrist mechanism for monitoring the rotational motions of the handle. The device is capable of displaying point-type of contact since only the R-Cube mechanism is actuated. The dimensions and the orientation of the R-Cube mechanism are reconfigured to comply with the requirements of the haptic system design criteria. The system has several advantages such as relatively trivial kinematical analysis, compactness and high stiffness. The integration of the system along with its mechanism, data acquisition card (DAQ), motor drivers, motors, position sensors, and computer control interface are outlined.
Kinematik Olarak Artıksıl Düzlemsel Lazer Kesme Makinaları Üzerine
(Atatürk Üniversitesi, 2013) Dede, Mehmet İsmet Can; Gezgin, Erkin; Kiper, Gökhan; Mastar, Ercan; Sığırtmaç, Tayfun; Uzunoğlu, Emre
Alışılagelmiş düzlemsel lazer kesme tezgahları XY düzleminde hareket için X ve Y doğrultularında doğrusal kızaklar üstünde eylemi gerçekleştirirken yüksek atalet kuvvetleri etkisi ile hassasiyet kaybı meydana geldiği için yüksek ivmelere çıkamamaktadır. Son yıllarda bazı yurt dışı bazlı firmalar geleneksel düzlemsel lazer kesme tezgahlarına fazladan eyleyici sistem ekleyerek kinematik olarak artıksıl hibrit mekanizmalar oluşturmuş ve kesici kafa için yüksek ivme seviyelerine çıkabilmişlerdir. Bu çalışmada geçmiş çalışmalarda ve piyasada bulunan yüksek ivmeli lazer kesim makinaları incelenmiştir. Lazer kesim makinalarında kullanılabilecek farklı mekanizmalar, bunların birleşimleriyle hibrit makina oluşturulması ve hassasiyet arttırıcı önlemler bildiri kapsamında irdelenmiştir. Makinanın işi en kısa sürede bitirmesi için eyleyici hareketlerini eniyileyecek kinematik olarak artıksıl robot denetleyicileri de bu çalışma kapsamında araştırılmıştır.
Koklear Mikrorobot Operasyonları için Artıksıl Makro-mikro Cerrahi Robot Manipülatör Sistemi
(2022) Bıdıklı, Barış; Can, Fatih Cemal; Çetin, Levent; Gezgin, Erkin
Hızla gelişen teknolojik ilerlemeler sayesinde robotik teknolojilerin sağlık alanında kullanımı gün geçtikçe artmaktadır. Bu teknolojiler içerisinde öne çıkan en önemli başlıklar insan robot etkileşimleri, minimal invaziv robotik cerrahi operasyonlar, mikrorobotların sağlık alanına kazandırılması ve klinik robotizasyon süreçleri olarak görülmektedir. Bu doğrultuda gerçekleştirilen çalışma cerrahi medikal robotik alanında kurgulanmıştır. Literatürde medikal mikrorobotların potansiyel kullanım alanları içerisinde yer alan ve ucu açık problem olarak nitelendirilen konulardan biri de işitme kaybı durumunda olası iç kulak bölgesi kök hücre uygulamalarıyla işitmenin gerçekleşmesini sağlayan koklea içerisindeki tüy hücrelerinin üretilebilmesidir. Fakat kök hücrelerin in vivo olarak koklea içerisindeki dar kanallara taşınabilmesi problemi belirsizliğini korumaktadır. Bu alanda kablosuz medikal mikrorobot kullanımının sağlanabilmesi çözülmeyi bekleyen problemler arasında yer almaktadır. Bu bağlamda proje kapsamında, koklea içerisine yerleştirilecek bir mikrorobotun, ilgili çalışma uzayı içerisinde oluşturulan manyetik akı yoğunluğu ve manyetik akı yoğunluğu gradyenini üretilerek temassız olarak koklea içerisinde bulunan kanallar içerisinde istenilen bir yörüngede ilerletilebilmesini sağlayacak temassız eyleyiciye sahip artıksıl yapıda bir makro-mikro cerrahi robot manipülatör sistemi tasarlanmıştır. İlgili sistem, koklea içerisindeki mikrorobotun hareketini sağlayacak sabit mıknatıslardan oluşan temassız eyleyici, cerrahi operasyon bölgesinde sabit mıknatısları taşıyarak birbirlerine göre bağıl hareketlerini sağlayacak mikro manipülatör, mikro manipülatörü hem cerrahi operasyon bölgesine istenilen pozda ulaştıracak hem de sistemin genel hareketlerinden sorumlu bir makro manipülatör ve bu birimlerin denetleyicilerinden oluşmaktadır. Ayrıca mikrorobotun kurgulanan cerrahi operasyon senaryosu sırasında koklea içerisindeki hareketinin, hareket yakalama sistemleri kullanılarak sanal gerçeklik ortamında takip edilebilmesi için bir cerrahi navigasyon yöntemi oluşturulmuştur. Çalışma sonunda tasarımı gerçekleştirilen makro-mikro cerrahi robot manipülatör sisteminin performans değerlendirmesi ve donanım doğrulama çalışmaları proje kapsamında üretilen prototipler ve koklea mock-up modeli üzerinde gerçekleştirilmiştir.
Citation - WoS: 6
Citation - Scopus: 8
Structural Design of Parallel Manipulators With General Constraint One
(Elsevier Ltd., 2010) Alizade, Rasim; Selvi, Özgün; Gezgin, Erkin
In this paper structural design of parallel manipulators with general constraint one regarding angular and linear-angular conditions are considered. Four known overconstrained mechanisms with angular and two new designs with linear-angular conditions are presented. 14 structural groups and end effector chains in subspace λ = 5 are examined. New formulations and definitions of constructing overconstrained manipulators are described. Using examined structural groups, all architectures of subspace λ = 5 parallel manipulators with revolute joints and single-loop are introduced via structural bonding.
Citation - WoS: 15
Citation - Scopus: 20
Structural Synthesis of Euclidean Platform Robot Manipulators With Variable General Constraints
(Elsevier Ltd., 2008-11) Alizade, Rasim; Can, Fatih Cemal; Gezgin, Erkin
In this paper, new method for structural synthesis of Euclidean platform robot manipulators with variable general constraints (EPRM) is presented. Three dimensional motion of the base moving platform is generated by the motion of dyads on the Euclidean planes. Each dyad is connected to the moving base platform by universal, spherical or spherical in torus (St) kinematic pairs. This allows solving the structural synthesis of Euclidean robot manipulators with various DoF and different platform motions. New structural formulations with variable general constraints for the platform motion and the mobility of robot manipulators are presented. The new structural classification of simple structural groups with variable general constraints including platforms, hinges, legs and branch loops from different subspaces and space is also introduced. Moreover, new method for structural synthesis of serial, parallel and serial-parallel EPRM is illustrated along with examples. © 2007 Elsevier Ltd. All rights reserved.
Citation - WoS: 39
Citation - Scopus: 42
Structural Synthesis of Serial Platform Manipulators
(Elsevier Ltd., 2007-05) Alizade, Rasim; Bayram, Çağdaş; Gezgin, Erkin
In this paper, structural synthesis of serial platform manipulators is considered. Serial platform manipulators are created according to the development of the platforms and closed loops. Also a new structural formula of mobility of parallel Cartesian platform robot manipulators is presented. Structural synthesis of serial platform manipulators with lower and higher kinematic pairs with respect to their structures are also examined. Structural synthesis of parallel Cartesian platform robot manipulators is also introduced. History of structural formulas DOF are presented as a table with equations, authors, years and some commentaries. New and revised methods for structural synthesis of serial platform manipulators and parallel Cartesian platform robot manipulators are illustrated along with examples.
Citation - WoS: 24
Citation - Scopus: 26
Synthesis of Function Generating Spherical Four Bar Mechanism for the Six Independent Parameters
(Elsevier Ltd., 2011-09) Alizade, Rasim; Gezgin, Erkin
This study deals with the function generation synthesis of spherical four bar mechanism for six independent construction parameters φ0, ψ0, α1, α2, α3, and α4 by giving six or more design points with respect to the methods that are used in synthesis procedure. Quaternion algebra is used to derive the objective function of spherical four bar mechanism by following some rotational sequences. Three different methods as interpolation approximation, least squares approximation and Chebyshev approximation are used during synthesis procedure. During the consecutive trials in Chebyshev approximation, a new approach is taken to renew the design points φi by plotting the graph of the objective functions derivative and taking the roots of it as new design points with two boundary points. Separate examples are given for each section and the results are tabulated. Discussions about the study and comparisons between the used methods are given at the end of the study.
Citation - WoS: 2
Citation - Scopus: 2
Trait-based heterogeneous populations plus (TbHP+) genetic algorithm
(Elsevier Ltd., 2009-02) Tayfur, Gökmen; Sevil, Hakkı Erhan; Gezgin, Erkin; Özdemir, Serhan
This study developed a variant of genetic algorithm (GA) model called the trait-based heterogeneous populations plus (TbHP+). The developed TbHP+ model employs a memory concept in the form of immunity and instinct to provide the populations with a more efficient guidance. Also, it has an ability to vary the number of individuals during the search process, thus allowing an automatic determination of the size of the population based on the individual qualities such as character fitness and credit for immunity. The algorithm was tested against the classical GA model in convergence and minimum error performance. For this purpose, 5 different mathematical functions from the literature were employed. The selected functions have different topological characteristics, ranging from simple convex curves with 2 variables to complex trigonometric ones having several hilly shapes with more than 2 variables. The developed model and the classical GA model were applied to finding the global minima of the functions. The comparison of the results revealed that the developed TbHP+ model outperformed the classical GA in faster convergence and minimum errors, which may be explained by the adaptive nature of the new paradigm.