Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Author: search.filters.author.Dede, Mehmet İsmet CanSubject: search.filters.subject.Haptics

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Now showing 1 - 4 of 4
  • Master Thesis
    Augmented Reality-Based Model-Mediated Teleoperation: a Mobile Telerobot Case Study
    (Izmir Institute of Technology, 2019) Kirişci, Nihat Çağhan; Dede, Mehmet İsmet Can
    Teleoperation is defined as operating a robot in a remote environment. Teleoperation utilizes the strength and dexterity of robots and the interpretation and problem solving skills of humans. In a teleoperation system, the robot to be controlled is referred as the slave. The master is a device that the human operator interacts with to send commands to the slave or receive feedback from the slave environment such as haptic or audio. However, teleoperation of a robot in an unknown environment solely based on haptic and visual feedback is a demanding task. The effects of time delay in communication channels makes completing this task even more challenging. Model-Mediated Teleoperation (MMT) aims to solve this problem by creating a virtual model of the slave robot and the environment. This virtual model receives commands from the master and returns haptic feedback just as the real slave robot is interacting with the environment, effectively with no delay. However, without actually knowing where the position of the virtual robot corresponds in the real environment, it is still challenging to carry out the task. In this project, a novel augmented reality based method is proposed to render the virtual robot into the real life live video feed. Integration of the non-delayed robot into the real environment intends to solve this problem by enhancing the perception of the user.
  • Master Thesis
    Design and Development of a Continuously Variable Transmission System To Be Used in Human-Robot Interfaces
    (Izmir Institute of Technology, 2018) Mobedi, Emir; Dede, Mehmet İsmet Can
    Continuously Variable Transmission (CVT) systems are being used for many applications such as automotive transmissions, robotics, and aerospace. In an ideal condition, these systems have the potential to provide continuously varying power transmission within a predefined limit. This transmission is accomplished with the help of friction, belt or gear systems. CVT can find application in a human-robot interface if a set of design criteria including backdrivability, independent output position and stiffness variation, shock absorbing and low mass and inertia can be satisfied. Even if there are various CVT designs in the literature for human-robot interfaces, the primary limitation of the two-cone drive CVT designs is that the output torque and the output position cannot be altered independently. Considering the friction drive CVT designs, the reason for this problem is that the friction wheel, which is designed to transmit the torque from the input cone to the output cone, gives rise to remarkable longitudinal friction force along the linear way. In order to overcome this problem, a sphere is used in the work presented in this thesis for the CVT design as the transmission element. In addition, it is stated in the literature that common CVT drive systems do not have the capability to be used in cyclic bidirectional motion. In the presented CVT design, a second sphere is added to the system with two springs from the lower part of the cones for pre-tension in order to solve the bidirectional transmission problem. Additionally, an adjustment of the normal force applied on the cones is designed in order to regulate the shock absorption limitations.
  • Master Thesis
    Optimal Design of a Kinesthetic Haptic Device Mechanism for Enhancing Its Impedance Characteristics
    (Izmir Institute of Technology, 2018) Görgülü, İbrahimcan; Dede, Mehmet İsmet Can; Kiper, Gökhan
    In this work, the optimal design of modified version of 3 degrees of freedom RCUBE mechanism has been studied in order to develop a high-performance haptic device mechanism. A high-performance haptic mechanism is achieved by having high transparency and high-frequency range. These two properties are determined by the mechanical impedance of the mechanism. Hence, to increase the quality of a haptic mechanism, its mechanical impedance performance must be enhanced. This refers to have low inertia, low friction, high back-drivability, high force output, high structural stiffness, and high manipulability for the mechanism. All these properties are designated by kinematic, stiffness, and dynamic properties of the mechanism. Hence, as a first step of this thesis, kinematic, stiffness and dynamic models of the mechanism are analytically procured. The analytical model of stiffness is achieved via the virtual joint method. Then, in order to obtain the objective function for the design procedure, performance metrics affecting the above-mentioned properties are reviewed and produced. Since these metrics have common parameters such as link lengths and the cross-section area of the links, there is a highly non-linear and contradictory relationship between the metrics. In order to deal with the non-linearity and to determine the global optimum design, an evolutionary optimization method, genetic algorithm, is preferred. The optimization time is reduced by investigating the most critical poses of the workspace and reducing the performance metrics to simpler forms. The link lengths and the cross-section areas are optimized. Carbon fiber tubes are used as links. The Pareto-front solution set is obtained as a result of the optimization procedure.Finally, an optimal solution is proposed and evaluated for the design of this modified R-CUBE mechanism to be used in haptic applications.
  • Master Thesis
    Development and Experimental Verification of the Stiffness Matrix of the Hiphad Haptic Device
    (Izmir Institute of Technology, 2015) Taner, Barış; Dede, Mehmet İsmet Can
    In this work the evaluation of stiffness performance of HIPHAD haptic device has been studied with 2 semi-analytical and an experimental method in order to obtain the stiffness characteristics of the haptic device for precise motion tracking performance. Since the compliance of a robot depends highly on robot configuration and force is variable in the haptic applications, stiffness properties of main robot elements and methods of evaluating stiffness of a robot manipulator is investigated considering the computational costs. Virtual Joint Method (VJM) and Structural Matrix Analysis (SMA) method is applied to the case study. Although, structural matrix analysis reduces the computational time dramatically by reducing the node elements it is not accurate as Finite Element Analysis (FEA) method. Comparing the VJM to the SMA, it is applicable to online application due to its simplicity and flexibility. In addition, with FEA based link modelling VJM is as accurate as FEA method in finding stiffness of the manipulator. While both methods can include flexible joints FEA based link stiffness parameters computational costs for these methods is the performance criteria for choosing one. For the case study HIPHAD, the VJM method provides better result in terms of flexibility and computation cost with 0.035 seconds finding the resultant force while SMA method calculates result in 0.074 seconds.