Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Optimum Design and Analysis of Torsion Spring Used in Series Elastic Actuators for Rehabilitation Robots(01. Izmir Institute of Technology, 2021) Erten, Hacer İrem; Artem, Hatice SeçilAlong with the developing technology, robotic systems have started to take place in areas where there is one-to-one interaction with people, as well as their use in industrial areas. As the robotic system began to take place in daily life, safety and reliability between humans and robots have become a critical issue. In this context, a series elastic actuator has been developed for the aforementioned robotic systems, which has an elastic element placed in series between the motor output and the mechanical output. In this thesis, the torsion spring, as a critical part for the rotary series elastic actuators of rehabilitation robots, which helps support the extension and flexion of the knee joint during physical therapy of individuals with lower extremity disorders, is discussed. First of all, the data required for modeling was produced by making analyses with the design of experiment and finite element method. In line with the design goal of a light, compact, durable and stiff spring, the torsion spring whose topology was determined was modelled using a hybrid method: Neuro-regression approach and cross-validation technique. To minimize the mass and von Mises stress of the torsion spring, the thickness of the spring and the inner corner radius of the flexible leg are taken as the design variables and multi-objective optimization problems are created. The design and optimization of the torsion spring was done with the help of Differential Evolution, Nelder-Mead, Random Search and Simulated Annealing algorithms. By comparing the obtained optimization results with the finite element method and the results in the literature, it has been seen that the model and optimization methods used in the study are reliable and applicable.Master Thesis Enhancement of Trajectory Following Accuracy of High Acceleration Robots by Using Their Stiffness Properties(01. Izmir Institute of Technology, 2021) Paksoy, Erkan; Dede, Mehmet İsmet Can; Paksoy, Erkan; Dede, Mehmet İsmet CanIn recent years, there has been a push for the incorporation of robots into manufacturing processes. In general, parallel robots are preferred for processes requiring high repeatability and positioning accuracy. If the positioning accuracy of the end-effector of a robot has high priority, compliance characteristics of the elements of its mechanism should be considered. Due to the high accelerations or external loading on the robot, the dimensions of the elements change and this leads to positioning errors for the end-effector. This thesis describes an experimental test setup and an experimental procedure for determining the compliance characteristics of planar mechanisms, followed by a comparison of the repeatability and stiffness performance of a parallel and an over-constrained mechanism. Finally, assumptions and methodology for using this compliance information to improve the trajectory tracking accuracy of high-accelerated robots are given. Portable coordinate measurement machine and calibrated weights are used to collect compliance information. The compliance behavior of the mechanisms defined for entire workspace by using the least squares and bilinear interpolation techniques. The D'Alambert principle is used to estimate fictitious forces that cause the compliance of the mechanism's end-effector while the mechanism operates at up to 5 g accelerations. As a result of this thesis, it is demonstrated that the mechanism's center of gravity and joint types play an important role in the mechanism's trajectory tracking accuracy, and that tracking accuracy can be improved by a simple data-driven compliance prediction algorithm.Master Thesis Learning Control of Robot Manipulators With Telerobotic Applications(Izmir Institute of Technology, 2016) Doğan, Kadriye Merve; Tatlıcıoğlu, EnverLearning control of teleoperation systems that can be utilized in telerehabilition applications is investigated in this thesis. Specifically, considering the fact that in rehabilitation the patient is required to perform a task over and over again, learning controllers are considered as the most feasible solution, in which desired trajectories are periodic with a known period. Since control of teleoperation systems are directly related with the control of robots that are included to the system, learning control of joint space and task space of these robots are simulated in the first part of this study. Joint space learning controller is designed under the restrictions that the robot dynamic model being uncertain and that joint velocities are unmeasurable. Then, a task–space learning controller is designed by considering the fact that the most desired tasks are defined in the end–effector space. Via Lyapunov based stability analysis methods, asymptotic tracking is ensured for both controllers. Numerical simulation results and experimental studies are utilized to illustrate the performance of the designed controllers. In the second part of this thesis, performance of the direct teleoperation and model mediated teleoperation methods under time delays in the communication cahannel are examined in a comparative manner. In direct teleoperation, the information between master and slave systems are exchanged directly, while the model of the environment of the slave system is learnt and integrated at the master side as proxy dynamics in model mediated teleoperation. Experimental studies are realized to evaluate the performance of both of mentioned methods.Master Thesis Robotization of Hand Woven Carpet Technology Process(Izmir Institute of Technology, 2008) Selvi, Özgün; Alizade, RasimThis thesis covers a study on the structural design of new overconstrained mechanisms and manipulators and their application to the robotization of hand woven carpet technology process.Moreover, recurrent vector equations are investigated for the synthesis of linkages, and used for the design of new mechanisms with linear-angular conditions in the subspace with general constraint one. These conditions are generalized for defining the structural groups of subspace ..5 and these structural groups are used both for the creation of new parallel manipulators and new serial-parallel platform manipulators.After investigating hand woven carpets, the knowledge gained during the structural design of mechanisms is applied to the robotization of hand woven carpet technology process. Finally, design of carpet weaving robot is introduced.Master Thesis Path Generation Analysis of Flexible Manipulators(Izmir Institute of Technology, 2008) Bingöl, Hakan; Atan, EbubekirBy the improving technology, usage of robotic manipulators has been increased a lot in last decades. Robotic manipulators are usually used in continuous production and dangerous operations. General industries, medical applications and space missions are the most important usage areas for these manipulators. In these applications, the manipulator faces to deviation of the end effecter which depends on many reasons like friction, vibration, elastic and plastic deformations. However, the robotic calculations made, as the links of the manipulator are rigid and other effects are neglected.The aim of this thesis is to improve a path generation analysis method for the three link flexible planer manipulator. The three link manipulator is considered to investigate the flexibility effect of links on path generation. Firstly the problem and solution method is introduced then the inverse kinematic analysis is applied for the three link rigid planer manipulator. The finite element model of the three link flexible planer manipulator is developed by using the plane frame element. The general equations of the tip point displacements of the three link flexible planer manipulator are expressed and Matlab program is coded. Finally, the library robots made by aluminum and steel are chosen for numerical examples. In conclusion the results of numerical example are shown for each position of the manipulator and discussed.