Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
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Conference Object Citation - Scopus: 3A Continuously Variable Transmission System Designed for Human–robot Interfaces(Springer, 2021) Mobedi, Emir; Dede, Mehmet İsmet CanWithin a predefined limit, continuously variable transmission (CVT) systems can continuously vary the power transmission ratio. The transmission in CVTs is achieved via friction, belt or gear systems. If CVT designs can incorporate backdrivability, independent output position and impedance variation, shock absorbtion, and low mass and inertia, they can be employed in human–robot interfaces. Among various types of CVT designs, the two-cone drive CVT designs have a major drawback since the output torque and position cannot be changed independent of each other. The friction wheel used in this design does not have a holonomic motion capability and causes this inconvenience. 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 pretension 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. © 2021, Springer Nature Singapore Pte Ltd.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 The Effects of Admittance Term on Back-Drivability(Springer, 2018) Işıtman, Oğulcan; Ayit, Orhan; Dede, Mehmet İsmet CanIn the design of kinesthetic haptic devices, there are mainly impedance type and admittance type device. In a customary scenario, the human operator back-drives the haptic device by holding and providing motion to the handle of the haptic device. If the type of transmission system does not allow passive back-drivability, then the back-drivability is satisfied by the use of an admittance controller. This type of a haptic device is said to have admittance structure. The selection of the admittance term in this controller plays a critical part in the task execution performance. Determination of this term is not trivial and the optimal parameters depend on not only the key performance criteria but also on the human operator. An experimental study is carried out in this work to determine the effect of the admittance term parameters on the performance of human operators in terms of the energy efficiency and the best accuracy. In this paper, the experimental set-up and the results of the experiments are presented and discussed.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.Conference Object Kinematic Analysis Validation and Calibration of a Haptic Interface(Springer Verlag, 2014) Dede, Mehmet İsmet Can; Taner, Barış; Bilgincan, Tunç; Ceccarelli, MarcoInitial calibration tests of a novel hybrid-structured kinesthetic haptic device based on an R-CUBE mechanism is presented in this paper. Experimental validation of the kinematics along with the experimental test set-up description is provided for the manufactured R-CUBE mechanism.Conference Object Citation - WoS: 9Citation - Scopus: 13Design of a Haptic Device for Teleoperation and Virtual Reality Systems(Institute of Electrical and Electronics Engineers Inc., 2009) Dede, Mehmet İsmet Can; Selvi, Özgün; Bilgincan, Tunç; Kant, YalkınHaptics technology has increased the precision and telepresence of the teleoperation and precision of the in-house robotic applications by force and surface information feedback. Force feedback is achieved through sending back the pressure and force information via a haptic device as the information is created or measured at the point of interest. In order to configure such a system, design, analysis and production processes of a haptic device, which is suitable for that specific application, becomes important. Today, haptic devices find use in assistive surgical robotics and most of the teleoperation systems. These devices are also extensively utilized in simulators to train medical and military personnel. The objective of this work is to design a haptic device with a new structure that has the potential to increase the precision of the robotic operation. Thus, literature is reviewed and possible robot manipulator designs are investigated to increase the precision in haptics applications. As a result of the investigations, conceptual designs are developed. Ultimately, final design is selected and produced after it is investigated in computer-aided- design (CAD) environment and its kinematic and structural analyses are carried out.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.
