WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Author: search.filters.author.Kiper, GökhanCOAR Access Rights: search.filters.coarAccessRights.open access

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Now showing 1 - 10 of 24
  • Article
    Citation - WoS: 10
    Citation - Scopus: 10
    Stiffness Modeling of a 2-Dof Over-Constrained Planar Parallel Mechanism
    (Elsevier, 2023) Görgülü, İbrahimcan; Dede, Mehmet İsmet Can; Kiper, Gökhan
    Stiffness model acquisition of over-constrained parallel mechanisms is relatively difficult since they have more than necessary kinematic loops. In this study, a stiffness modeling solution for over-constrained parallel mechanisms is proposed while considering the computational cost efficiency. Three contributions of the paper are: (1) Presenting the stiffness modeling procedure for serially connected closed-loop structures by using the Virtual Joint Method (2) Considering the effect of dynamic auxiliary forces and dynamic external forces on the mobile platform's deflection and achieving a direct solution by using superposition principle (3) A model fitting procedure for modifying the stiffness coefficients to comply with the experimental data. A 2 degrees-of-freedom over-constrained parallel mechanism is investigated as a case study. However, the proposed stiffness model is 6-DoF since compliant deflections occur in any direction. A finite element analysis and an experimental study verify the model's results.
  • 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.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Loop Based Classification of Planar Scissor Linkages
    (Springer, 2022) Kiper, Gökhan; Korkmaz, Koray; Gür, Şebnem; Yar Uncu, Müjde; Maden, Feray; Akgün, Yenal; Karagöz, Cevahir
    Scissor linkages have been used for several applications since ancient Greeks and Romans. In addition to simple scissor linkages with straight rods, linkages with angulated elements have been introduced in the last decades. In the related literature, two methods have been used to design scissor linkages, one of which is based on scissor elements, and the other is based on assembling loops. This study presents a systematic classification of scissor linkages as assemblies of rhombus, kite, dart, parallelogram and anti-parallelogram loops using frieze patterns and long-short diagonal connections. After the loops are replicated along a curve as a pattern, the linkages are obtained by selection of proper common link sections for adjacent loops. The resulting linkages are analyzed for their motions and they are classified as realizing scaling deployable, angular deployable or transformable motion. Some of the linkages obtained are novel. Totally 10 scalable deployable, 1 angular deployable and 8 transformable scissor linkages are listed. Designers in architecture and engineering can use this list of linkages as a library of scissor linkage topologies.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Human-Robot Interfaces of the Neuroboscope: a Minimally Invasive Endoscopic Pituitary Tumor Surgery Robotic Assistance System
    (ASME, 2021) Dede, Mehmet İsmet Can; Kiper, Gökhan; Ayav, Tolga; Özdemirel, Barbaros; Tatlıcıoğlu, Enver; Hanalioğlu, Şahin; Işıkay, İlkay
    Endoscopic endonasal surgery is a commonly practiced minimally invasive neurosurgical operation for the treatment of a wide range of skull base pathologies including pituitary tumors. A common shortcoming of this surgery is the necessity of a third hand when the endoscope has to be handled to allow active use of both hands of the main surgeon. The robot surgery assistant NeuRoboScope system has been developed to take over the endoscope from the main surgeon's hand while providing the surgeon with the necessary means of controlling the location and direction of the endoscope. One of the main novelties of the NeuRoboScope system is its human-robot interface designs which regulate and facilitate the interaction between the surgeon and the robot assistant. The human-robot interaction design of the NeuRoboScope system is investigated in two domains: direct physical interaction (DPI) and master-slave teleoperation (MST). The user study indicating the learning curve and ease of use of the MST is given and this paper is concluded via providing the reader with an outlook of possible new human-robot interfaces for the robot assisted surgery systems.
  • Other
    Corrigendum To “kinematic Design of a Non-Parasitic 2r1t Parallel Mechanism With Remote Center of Motion To Be Used in Minimally Invasive Surgery Applications” [mechanism and Machine Theory 153 (2020) 104013] (mechanism and Machine Theory (2020) 153, (s0094114x20302342), (10.1016/J.mechmachtheory.2020.104013))
    (Elsevier, 2021) Yaşır, Abdullah; Kiper, Gökhan; Dede, Mehmet İsmet Can
    The authors regret that one of the affiliation information for Gökhan Kiper is wrong. Dr. Kiper is not affiliated to Delft University of Technology. Dr. Kiper is affiliated to İzmir Institute of Technology. The data administrators of Elsevier and the corresponding author would like to apologise for any inconvenience caused. © 2021 International Federation for the Promotion of Mechanism and Machine Science
  • Article
    Citation - WoS: 31
    Citation - Scopus: 37
    Kinematic Design of a Non-Parasitic 2r1t Parallel Mechanism With Remote Center of Motion To Be Used in Minimally Invasive Surgery Applications
    (Elsevier Ltd., 2020) Yaşır, Abdullah; Kiper, Gökhan; Dede, Mehmet İsmet Can
    In minimally invasive surgery applications, the use of robotic manipulators is becoming more and more common to enhance the precision of the operations and post-operative processes. Such operations are often performed through an incision port (a pivot point) on the patient's body. Since the end-effector (the handled surgical tool) move about the pivot point, the manipulator has to move about a remote center of motion. In this study, a 3-degrees-of-freedom parallel mechanism with 2R1T (R: rotation, T: translation) remote center of motion capability is presented for minimally invasive surgery applications. First, its kinematic structure is introduced. Then, its kinematic analysis is carried out by using a simplified kinematic model which consists of three intersecting planes. Then the dimensional design is done for the desired workspace and a simulation test is carried out to verify the kinematic formulations. Finally, the prototype of the final design is presented.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 5
    Design of Anti-Parallelogram Loop Assemblies
    (Int. Association for Shell and Spatial Structures, 2019) Gür, Şebnem; Korkmaz, Koray; Kiper, Gökhan
    Scissor mechanisms are frequently used for deployable structures and many studies have been conducted on the subject. Most of the studies consider scissor units as modules in the design process. An alternative approach is to utilize loops as the modules for design. In this paper, the design alternatives of single degree-of-freedom planar linkages comprising anti-parallelogram loops using the loop assembly method is presented. First, scissor mechanisms are reviewed. Next, the types of four-bar loops and the resulting linkages in the literature are introduced and those which are yet to be explored, anti-parallelogram being one of them, are identified. Then the loop assembly method and the examples in the literature are reviewed. As a method to form as many alternatives as possible, symmetry operations are proposed. Suitable frieze symmetry groups utilized for obtaining the assemblies are explained and the anti-parallelogram loop patterns are derived. Next, the single degree-of-freedom linkages are obtained from the loop assemblies. Finally, a selection of the resulting linkages with novel properties are presented. This study shows that loop assemblies are efficient in systematic type synthesis of scissor linkages, some types of which could not be foreseen by using units as modules.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 3
    Reconfigurable deployable umbrella canopies
    (Institute of Electrical and Electronics Engineers Inc., 2018) Jovichikj, R.; Yaşır, Abdullah; Kiper, Gökhan
    The kinematic design of reconfigurable deployable canopy mechanisms with radially distributed limbs are presented in this study. The mechanisms allow a compact form and are reconfigurable with several alternative deployed forms which can be in the form of a tent, a canopy or a form in between. Each limb of the canopy possesses at least two assembly modes which enables reconfigurability. The conditions for deployment and reconfiguration of the mechanism are derived. These conditions impose equality and inequality constraints for the link lengths of the mechanism. A parametric model of the mechanism is constructed in Excel for design and simulation purposes. Solid models and a prototype are presented as examples.
  • Conference Object
    Citation - Scopus: 2
    A Critical Review of Unpowered Performance Metrics of Impedance-Type Haptic Devices
    (Springer Verlag, 2019) Görgülü, İbrahimcan; Kiper, Gökhan; Dede, Mehmet İsmet Can
    A kinesthetic haptic device’s performance relies on unpowered, powered and controlled system characteristics. In this paper, a critical review is carried out for the well-known metrics for kinematics, stiffness and dynamic aspects of robots that can be applied in evaluating the unpowered system performance of kinesthetic haptic devices. The physical meanings of these metrics are discussed and the important factors that affect the unpowered system performance of a kinesthetic haptic device are revealed.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 2
    Synthesis of Scalable Planar Scissor Linkages With Anti-Parallelogram Loops
    (Springer Verlag, 2019) Gür, Şebnem; Karagöz, Cevahir; Kiper, Gökhan; Korkmaz, Koray
    Scissor linkages are commonly used as mechanisms for scaling objects. They constitute a significant portion of deployable structures. Since 1960s many researchers sought to form novel structures using the scissor units. In 1990s Hoberman brought a new perspective to the field when he used the loops, not the units to form linkages. Starting from mid 2000s, other researchers joined into this new approach of design. One of the latest researches presented a design for scaling a circular forms with anti-parallelogram loops. This study shows that an anti-parallelogram loop assembly can also be used for scaling planar curves with variable curvature.