Mechanical Engineering / Makina Mühendisliği

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

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Institution Author: search.filters.institutionAuthor.Kiper, Gökhan

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  • Conference Object
    Redundancy resolution options for the twin-it-romans robotic hybrid manufacturing system
    (Springer Science and Business Media B.V., 2025) Gündüz, G.M.; Dede, Mehmet İsmet Can; Kiper, Gökhan; Schmitz, M.; Corves, B.
    The Twinnig Iztech in Robotics Manufacturing System (TWIN-IT-ROMANS) project funded by EU Horizon -Widera-2023-Access-02-01 aims to develop a hybrid manufacturing system that can perform additive and subtractive manufacturing processes and inline quality control using a robotic system. The system will incorporate a 6-degree-of-freedom robot arm and a positioner with 2-degree-of-freedom, which will operate synchronously. This manipulation system is to be designed for performing different manufacturing operations with different degrees-of-freedom requirements. In order to reveal alternative trajectory planning scenarios for this system, this paper presents an initial review of redundancy resolution approaches for kinematically redundant robotic manipulators. First, the four main approaches for redundancy resolution techniques are introduced. Then main studies on energy minimization and stiffness maximization for kinematically redundant robotic manipulators are reviewed. Similar or new approaches are planned to be generated and implemented for the redundant system for hybrid manufacturing. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.
  • Book Part
    Citation - WoS: 1
    Citation - Scopus: 1
    A Historical Review of Polyhedral Linkages
    (Springer, 2024) Kiper, Gökhan
    Polyhedral linkages are linkages that resemble polyhedral shapes at different configurations. This paper summarizes the necessary geometrical fundamentals of polyhedral geometry and presents a historical and critical review of the polyhedral linkage designs available in the literature. Basic definitions of polyhedral geometry and operations are needed to comprehend and design polyhedral linkages. First, early works on polyhedral linkages are presented, where flexible polyhedra with rigid faces and flexible edges are issued. The final part is reserved to conformal polyhedral linkages, which go through shape transformations while plane, dihedral and solid angles are preserved. Conformal polyhedral linkages are examined in four categories: 1) Jitterbug-like linkages with screwing polygonal links connected to each other with dihedral angle preserving links, 2) polyhedral linkages with planar kinematic chains in radial motion planes, 3) polyhedral linkages with planar kinematic chains on faces, that are connected to each other with dihedral angle preserving links, and 4) other conformal polyhedral linkages. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
  • Conference Object
    Citation - Scopus: 3
    Four-bar function generation using excel solver
    (Springer, 2023) Söylemez, Eres; Kiper, Gökhan
    The Chapter presents a simple and efficient way of approximating a function with a four-bar mechanism using four or five design parameters including one or both of the initial crank angles. The method only involves solution of linear set of equations and evaluating determinants, whereas nonlinear equations are numerically solved using a simple program such as Excel. So, the method is easy to explain and can be taught in an undergraduate course along with the wellknown linear three precision point synthesis problem. Precision point synthesis, order synthesis, mixed order synthesis, least squares approximation and extreme point synthesis can all be treated using the same method. The proposed method is illustrated with numerical examples for all mentioned synthesis problems and shown to be quite efficient with very low amount of structural error values.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 13
    Mobility Analysis of Tripod Scissor Structures Using Screw Theory
    (Pergamon-elsevier Science Ltd, 2024) Liao, Yuan; Kiper, Gokhan; Krishnan, Sudarshan
    Mechanisms consisting of spatial scissor units have different kinematic behaviors than those of planar scissors. However, their kinematics, especially the mobility analysis, has not received enough attention. Two types of deployable asseblies are analyzed in this paper, namely the translational and mirrored assemblies. Both the assemblies are made of tripod scissor units, and their instantaneous mobility are examined using screw theory. The study starts on the configuration where all the members have the identical deployment angle. Firstly, the geometric property of each assembly was studied. Then, screw-loop equations were developed based on graph theory and closure equations. Finally, the mobility of each assembly was computed using linear algebra. Following the analysis, physical prototypes were constructed to validate the results, and several different motion modes were obtained for the translational assembly. The analysis reveals different kinematic behaviors of the two assemblies. In the given configuration, the translational assemblies have four instantaneous degrees of freedom, while the mirrored assemblies have only a single instantaneous degree of freedom.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 4
    Design of a Novel Hybrid Cable-Constrained Parallel Leg Mechanism for Biped Walking Machines
    (Cambridge University Press, 2023) Demirel, M.; Kiper, G.; Carbone, G.; Ceccarelli, M.
    In this paper, a novel cable-constrained parallel mechanism is presented as a lightweight, low-cost leg mechanism design for walking machines to be used on flat surfaces. The proposed leg mechanism has three translational degrees of freedom. It is based on two specific hybrid kinematic topologies being herewith proposed. The paper reports the kinematic analysis formulation and a position performance evaluation to confirm the main characteristics of the proposed solutions. A 3D CAD model and simulations are carried out to demonstrate the feasibility of the proposed design for performing a human-like gait trajectory. A prototype has been built, and preliminarily tests have been conducted to confirm the motion capabilities of the proposed mechanism design. Then a second, enhanced prototype has been designed and built. An experimental validation is carried out for tracking a planar walking trajectory with the built prototypes by using a real-time PCI controller. Results are presented to validate the operation characteristics of the proposed mechanism and to prove its feasibility for legged walking machines. © The Author(s), 2023.
  • Conference Object
    Citation - Scopus: 2
    Experimental Compliance Matrix Derivation for Enhancing Trajectory Tracking of a 2-Dof High-Accelerated Over-Constrained Mechanism
    (Springer, 2022) Paksoy, Erkan; Dede, Mehmet İsmet Can; Kiper, Gökhan
    If the positioning accuracy of the end-effector of a robot has high priority, compliance characteristics of the elements of its mechanism should be considered. Due to the external loading on the robot, the dimensions of the elements change and this leads to positioning errors for the end-effector. In this paper, an experimental test setup and an experimental procedure are described to derive the compliance characteristics of a planar 2-degree-of-freedom mechanism.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Gravity Compensation of a 2r1t Mechanism With Remote Center of Motion for Minimally Invasive Transnasal Surgery Applications [article]
    (Cambridge University Press, 2023) Aldanmaz, Ataol Behram; Ayit, Orhan; Kiper, Gökhan; Dede, Mehmet İsmet Can
    This work addresses the gravity balancing of a 2R1T (2 rotations – 1 translation) mechanism with remote center of motion. A previously developed balancing solution is modified and applied to a prototype and test results are presented. The mechanism is an endoscope holder for minimally invasive transnasal pituitary gland surgery. In this surgery, the endoscope is inserted through a nostril of the patient through a natural path to the pituitary gland. During the surgery, it is vital for the manipulator to be statically balanced so that in case of a motor failure, the patient is protected against any harmful motion of the endoscope. Additionally, static balancing takes the gravitational load from the actuators and hence facilitates the control of the mechanism. The mechanism is a 2URRR-URR type parallel manipulator with three legs. The payload mass is distributed to the legs on the sides. By using counter-masses for two links of each leg, the center of mass of each leg is lumped on the proximal link which simplifies the problem to balancing of a two degree-of-freedom inverted pendulum. The two proximal links with the lumped mass are statically balanced via springs. Dynamic simulations indicate that when the mechanism is statically balanced, generated actuator torques are reduced by 93.5%. Finally, the balancing solution is implemented on the prototype of the manipulator. The tests indicate that the manipulator is statically balanced within its task space when the actuators are disconnected. When the actuators are connected, the torque requirements decrease by about 37.8% with balancing.
  • Conference Object
    Krank Açıları Verilen Üç Konum ve Bir Ölü Konum için Dört-çubuk Mekanizmasının İşlev Sentezi
    (Makina Teorisi Derneği, 2021) Kadak, Tarık; Kiper, Gökhan
    Dört-çubuk mekanizmasının işlev sentezi, krank açıları ilişkisi ve ölü konum sentezinin karışık bir problemi olarak formüle edilebilir. Bu sentez probleminde, üç konum için krank ve sarkaç açıları ve dördüncü bir konum olarak bir ölü konumun krank açısı girdi olarak alınmıştır. Yazılan denklemler ve değişken elemeleri sonucunda herhangi bir nümerik yöntem ile çözülebilen tek değişkenli bir doğrusal olmayan denklem elde edilmiştir. Tek değişkenin hızlı çözümü ile mekanizmanın uzuv boyları bulunabilmektedir. Parametrik model kullanılarak Excel’de sayısal çözüm sayfası hazırlanmıştır. Sayısal örnekler genelde iki gerçel çözümün olduğunu göstermektedir.
  • Conference Object
    Rehabilitasyon Egzersizleri için Bir Parmak Diş İskelet Mekanizması
    (Makina Teorisi Derneği, 2021) Kıpcak, Furkan; İnanç, Emirhan; Özkan, Mert; Öztürk, Rüstem Can; Güleç, Ege Toprak; Kiper, Gökhan
    Bu çalışmada, özellikle inme ve yaralanmalar sonrasında rehabilitasyon amaçlı kompakt, düşük maliyetli ve iki serbestlik dereceli bir parmak dış iskeletinin tasarımı, prototip üretimi ve testleri sunulmuştur. Kompakt bir tasarım olması çalışmanın özgün yanı olarak parmak etrafında fazla-kısıtlı çift-küresel 6-çubuk mekanizması kullanılmıştır. Önce bir el işaret parmağının hareketi tespit edilmiş ve bu hareket uyarınca 6-çubuk mekanizmasının kinematik sentezi yapılmıştır. Literatürdeki kuvvet değerleri uyarınca iş hesabı yapılarak motor-tork gereksinimleri hesaplanmış ve uygun motorlar seçilmiştir. Servo motorların denetim için Arduino kartı ve Matlab Simulink kullanılmış ve mekanizma uzuvları büyük ölçüde 3D yazıcıda üretilmiş olup kişiye özel üretime yönelik bir sistem mimarisi oluşturulmuştur. Son olarak üretilen prototipin işlevsellik testleri gerçekleştirilmiştir. Ortaya çıkan çift-küresel 6-çubuk mekanizmalı bu ilk prototip ancak kavram kanıtlama amaçlı olup sonuçlar ile ileriki çalışmalara ışık tutmak hedeflenmiştir.
  • Conference Object
    10. Kuruluş Yıldönümünde Makina Teorisi Derneği
    (Makina Teorisi Derneği, 2021) Kiper, Gökhan; Söylemez, Eres
    31 Mayıs 2011’de Ankara’da kurulan Makine Teorisi Derneği (MakTeD) [1], Meksika’nın Guanajuato şehrinde gerçekleştirilen 13. Uluslararası Mekanizmalar ve Makina Teorisi Federasyonu (IFToMM) [2] Dünya Kongresi sırasında 22 Haziran 2011’de IFToMM üye kuruluşu olmuştur. IFToMM, 29 Eylül 1969’da Polonya’nın Zakopane şehrinde 2. Mekanizma ve Makine Teorisi Dünya Kongresi sırasında Prof. Ivan I. Artobolevski (SSCB) ve Prof. Erskine F.R. Crossley (ABD) öncülüğünde soğuk savaştan etkilenmeden Mekanizma ve Makina Bilimi (MMB) alanında uluslararası işbirliğini geliştirmek üzere kurulmuştur [3]. IFToMM’un ana hedefleri MMB alanlanında kuramsal, deneysel ve uygulamalı çalışmalarda araştırma ve geliştirmeyi desteklemek, MMB ya da ilgili alanlarda bilimsel ve mühendislik çalışmaları yürüten farklı ülkelerdeki kişi ve kuruluşların temaslarını yaygınlaştırmak ve gelişmekte olan ülkelere uzmanların seyahat desteği, özel kurslar düzenlenmesi ve diğer girişimlerle MMB çalışmalarını desteklemektir [4]. IFToMM camiası halen özellikle gelişmemiş ve gelişmekte olan ülkelerde MMB çalışmalarını destekleme misyonunu sürdürmektedir.