Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
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Conference Object A Continuously Variable Transmission System Designed for Human-Robot Interfaces(IFToMM, 2018) Mobedi, Emir; Dede, Mehmet İsmet CanContinuously Variable Transmission (CVT) systems are being used for many applications such as automotive transmissions, robotics, 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 design criteria such as backdrivability, independent output position and impedance 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. 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 this work 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. In this paper, the working principle and conceptual design details of the novel two-cone CVT drive are presented. Experimental results showed that the novel CVT has the capacity to transmit bidirectional power with some accuracy.Conference Object Citation - Scopus: 5Design and Experimental Validation of an Mr-Fluid Based Brake for Use in Haptics(VDE Publishing House, 2018) Karabulut, Mehmet Görkem; Dede, Mehmet İsmet CanIn this work, the design of an MR-fluid based brake system is given which is aimed to be used in kinaesthetic haptic devices. The brake design proposes a solution to the stiction problem which is common among the MR brake based haptic devices. This problem occurs when the brake is activated to constrain the motion of the handle in one direction and the user wants to move the handle in the other direction. The development process, which consists of 3D designing, Finite Element Analysis (FEA) simulation and mathematical modelling, aims to achieve the optimal design with high performance to volume ratio. The prototype design is constructed, and its performance is evaluated via experimental tests. A polynomial equation is calculated to fit the experimental current-torque data, which captures the hysteresis behaviour of the system. According to the test results, the applicable torque range of the prototype is from a minimum of 0.15 Nm to a maximum of 3.84 Nm and the bandwidth is calculated to be 63 rad/s.Conference Object Applying Model Mediation Method To a Mobile Robot Bilateral Teleoperation System Experiencing Time Delays in Communication(Makina Teorisi Derneği, 2015) Taner, Barış; Dede, Mehmet İsmet Can; Uzunoğlu, EmreTeleoperation systems consist of two subsystems namely, the master and the slave. Master is used by the human operator to send commands to the slave to achieve a task. In bilateral teleoperation, the interaction forces acquired from the slave sub-system is sent to the master to increase the level of tele-presence. In this kind of a setting, data has to be transferred through a communication line in which package losses and time delays occur. Such deficiencies in the communication line results in stability problems in the system. In this paper, HIPHAD desktop haptic device as the master sub-system and an omni-directional mobile robot as the slave subsystem is used to develop an unlimited workspace teleoperation system. The system’s stability and tracking performance under a constant time delay is measured for direct teleoperation and when model mediation method is applied to ensure stability. The results of the tests are given and the conclusions are derived.Conference Object Citation - Scopus: 2A Critical Review of Unpowered Performance Metrics of Impedance-Type Haptic Devices(Springer Verlag, 2019) Görgülü, İbrahimcan; Kiper, Gökhan; Dede, Mehmet İsmet CanA 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.Book Part Citation - WoS: 3Citation - Scopus: 4Mechanism Design for Haptic Handwriting Assistance Device(Springer Verlag, 2015) Kiper, Gökhan; Dede, Mehmet İsmet CanOne of the applications of haptic technology is in education and training. Handwriting for first year-elementary students has been included in the curriculum for some years in Turkey as the first and only writing skill to be taught. Providing these students with a haptic assistance device during the handwriting learning process is the global aim of this work. Among the other components of the design such as electronics, controls and communication, mechanism design is a critical component to be considered for optimization of the device at different levels. This paper aims to address a solution to meet the design criteria through ergonomic design for user along with optimized force exertion capabilities.