Mechanical Engineering / Makina Mühendisliği

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

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  • 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.
  • Data Paper
    Citation - WoS: 15
    Citation - Scopus: 20
    Database Covering the Prayer Movements Which Were Not Available Previously
    (Nature Publishing Group, 2023) Mihçin, Şenay; Şahin, Ahmet Mert; Yılmaz, Mehmet; Alpkaya, Alican Tuncay; Tuna, Merve; Akdeniz, Sevinç; Can, Nuray Korkmaz; Tosun, Aliye; Şahin, Serap
    Lower body implants are designed according to the boundary conditions of gait data and tested against. However, due to diversity in cultural backgrounds, religious rituals might cause different ranges of motion and different loading patterns. Especially in the Eastern part of the world, diverse Activities of Daily Living (ADL) consist of salat, yoga rituals, and different style sitting postures. A database covering these diverse activities of the Eastern world is non-existent. This study focuses on data collection protocol and the creation of an online database of previously excluded ADL activities, targeting 200 healthy subjects via Qualisys and IMU motion capture systems, and force plates, from West and Middle East Asian populations with a special focus on the lower body joints. The current version of the database covers 50 volunteers for 13 different activities. The tasks are defined and listed in a table to create a database to search based on age, gender, BMI, type of activity, and motion capture system. The collected data is to be used for designing implants to allow these sorts of activities to be performed.
  • 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.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 8
    Kinematic Synthesis of Over-Constrained Double-Spherical Six-Bar Mechanism
    (Elsevier Ltd., 2014) Maaroof, Omar W.; Dede, Mehmet İsmet Can
    The main problem in the synthesis of any mechanism is the fact that the objective function of the mechanism, which will be synthesized, should be found and simplified by using appropriate algebraic method. Finding objective function and calculation process can become complicated especially when the number of design parameters is increased for the over-constrained mechanisms. A new technique for solving the kinematic synthesis of over-constrained double-spherical six-bar mechanism is developed and applied in this work. Interpolation approximation is used during synthesis procedure. A numerical example for the kinematic synthesis procedure is given to validate the theory in application.