Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Dede, Mehmet Ismet CanScopus Q: search.filters.scopusQuartile.Q1

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  • Article
    A Hybrid Control Scheme for Backdriving a Surgical Robot About a Pivot Point
    (MDPI, 2025) Dede, Mehmet Ismet Can; Kurt, A. N. Olcay; Deniz, Mehmet Firat
    An incision point acts as the pivot point when a minimally invasive surgery procedure is applied. The assistive robot arms employed for such operation must have the capability to perform a remote center of motion (RCM) at this pivot point. Other than designing RCM mechanisms, a common practice is to use a readily available spatial serial robot arm and control it to impose this RCM constraint. When this assistive robot is required to be backdriven by the surgeon, the relation between the interaction forces/moments and the motion with RCM constraint becomes challenging. This paper carefully formulates a hybrid position/force control scheme for this relationship when any readily available robot arm that is coupled with a force/torque sensor is used for an RCM task. The verification of the formulation is carried out on a readily available robot arm by implementing the additional constraints that are derived from a surgical robot application.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    A New Safe Flexible Torsion Joint Design With Softening Stiffness Characteristics
    (Pergamon-elsevier Science Ltd, 2025) Gorgulu, Ibrahimcan; Dede, Mehmet Ismet Can; Kiper, Gokhan
    This paper introduces a novel flexible joint design that enhances mechanical versatility. The design shows how to obtain bidirectional deflections from a unidirectional spring. It enables the parallel and serial connections of springs. It features multiple stiffness regions determined by applied load levels, eliminating the need for a clutch mechanism. Mechanical limits can be added to customize stiffness, offering more hardening or softening regions. The design also allows for connecting multiple flexible joint units in series. In a case study, the series flexible joint design is developed with two flexible joint units, providing a softening stiffness characteristic. The joint has rigid, stiff, and soft regions. When used as a series elastic actuator in a robot manipulator, the rigid region aims to conduct the tasks at low torque levels, i.e., trajectory tracking. The stiff region is preserved for collaborative tasks in human-robot interaction, while the soft region enhances the robot's safety in case of control failure or collision. Static and dynamic test results comply with the ideal model. This flexible joint design improves mechanical performance, safety, and adaptability.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Torque-Current Relationship of an Mr Brake for Its Open-Loop Control
    (Ieee-inst Electrical Electronics Engineers inc, 2024) Kucukoglu, Sefa Furkan; Bozelli, Muhammed Rza; Dede, Mehmet Ismet Can
    Active and semiactive actuators have been widely preferred for designing an actuation system for kinesthetic-type haptic devices. Among them, magnetorheological fluid-based brakes (MR brakes) offer potent properties, such as high torque/inertia ratio and less power consumption. However, one of the most critical issues to be resolved is their hysteresis behavior. Various methods for modeling the input/output relationship with hysteresis behavior exist. However, hysteresis compensation approaches, i.e., torque-current hysteresis model, are not widely studied for MR Brakes. Therefore, a hysteresis compensation model approach to account for the nonlinear behavior of MR Brake is proposed, and the model is experimentally validated in this article. The model consists of multiple splines and an algorithm that uses these splines in hysteresis compensation. Being relatively simple and easily implementable are the distinguished features of the presented model since an optimization method is not required. Furthermore, the performance of the proposed method is compared with two methods, torque-to-current mapping and inverse Prandtl-Ishlinskii method. The obtained experimental results are investigated with three performance metrics. Finally, the effect of the operational speed on the performance of the hysteresis compensation model is also discussed.