Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Master Thesis Augmented Reality-Based Model-Mediated Teleoperation: a Mobile Telerobot Case Study(Izmir Institute of Technology, 2019) Kirişci, Nihat Çağhan; Dede, Mehmet İsmet CanTeleoperation 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 Teleoperation System Desing of a Robot Assisted Endoscopic Pituitary Surgery(Izmir Institute of Technology, 2018) Ateş, Gizem; Dede, Mehmet İsmet CanTeleoperation, also named telerobotics, is defined as controlling a robot over a distance by a remote controller. In a teleoperation setting, the human operator controls the master system(s) to the slave system(s) via wired or wireless communication channel. Genarally, in bilateral teleoperation, the human operator is informed about the slave environment via feedback signals (haptic, visual or audio) sent back from the slave environment. Commonly, teleoperated systems are more preferable in hazardous environments to protect the human operator; neverthless, there many other fields where the teleoperated systems are employed for various tasks. one of these areas, where teleoperation technology is becoming more popular,is the medical area. Telesurgical equipments allow more precise performance than a humman can achieve especially in minimally invasive surgeries. The purpose of this thesisis to develop a novel teleoperation system architecturewhich will be used to support the endoscopic pituitary surgery procedures which are classified under minimally invasive surgeries. Even though, the surgeon has only two hands, the proposed system aims to enable the surgeon to operate with three different surgical tools simultaneously including the endescope. he type of work is categorized under collaborative surgical robots, which incorporates a teleoperation system setup. he master control unit is a ring-shaped remote controller which consists of an inertial measurement unit and a wireless module. Surgeon wears the master system during the operation while holding a surgical tool such as the aspirator, and delivers the voluntary commands to the slave system by triggering a food pedal. The slave is the endescope holder robot which is a 8 degrees-of-freedom manipulator whose 3 degrees-of-freedom are active and the rest of them are passive. here is also an indicator panel which is used to provide visual feedback to the surgeon indicating the states of the surgey and excessive force application on the tissue.Master Thesis Design of Hybrid Cable-Constrained Parallel Mechanisms for Walking Machines(Izmir Institute of Technology, 2018) Demirel, Murat; Kiper, Gökhan; Demirel, Murat; Kiper, Gökhan; Carbone, GiuseppeThe objective of this thesis study is to propose novel cable-constrained parallel mechanisms for walking machines. According to the literature, hybrid structured parallel mechanisms can overcome mechanical design, control system and workspace limitations compared to other structures. This thesis study introduces two novel hybrid structured leg mechanisms comprising rigid links and passive cables. Kinematic structure of the proposed mechanisms are (UPU-2Pa)-(UPU-2Pa)and (UU-2Pa)-P. Both designs have a hip, a knee and a foot platform. Two rotational constraints about horizontal axes are added to the moving platforms by using parallelograms with passive cables. The rotational constraint about the vertical axis is provided by rigid links and joints. Thus, the proposed designs have pure translational motion. The detailed analysis of the mechanism design with anchored cables is conducted. A CAD model is constructed and a dynamic simulation for human-like gait trajectory is performed in SolidWorks® environment. Once the computed actuator torques and forces are found suitable, a first prototype is built to check the proposed solution. Considering the problems encountered in this first prototype, a second prototype of the (UU-2Pa)-P mechanism is built. The prototype is operated using a real-time PCI controller and experimental results are presented. The mechanisms presented in this thesis is one of the few cable-constrained parallel manipulator designs in the literature. Such a manipulator design is used for a walking machine for the first time. The prototype and test results are quite satisfactory, so hopefully more detailed research can be conducted on this topic in the future.Master Thesis Flame Characterization in Domestic Gas Boilers(Izmir Institute of Technology, 2018) Yenigün, Mustafa Can; Diez, AlvaroIn the last decades, pollutant emissions from burning fossil fuels have become of great public concern due to their impact on health and the environment. For this reason, strict legislations have come into force worldwide, which obligate to reduce these emissions. For heating devices such as boilers, it has been realized that these emissions’ reduction could be effectively done with the concept of lean premixed combustion. However, lean premixed combustion technology is more vulnerable to the interactions with system acoustics, which brings a negative side effect: Thermoacoustic instabilities. Thermoacoustic instabilities occur from the feedback loop between the heat release and the acoustic waves in the complete system. They can lead to unwanted noise, flame extinction and, in extreme cases, structural damages. In domestic boilers, these instabilities show themselves as loud noise and flame extinction. In order to eliminate thermoacoustic instabilities in domestic boilers, the trial and error method is used commonly, which requires significant amount of effort and time. Therefore, the researches are focussing on predicting these instabilities at the early stages, where the flame characterization is an important part of the prediction of the thermoacoustic instabilities. In this study, the flame characterization of the burners used in domestic gas boilers is done experimentally. The Flame Transfer Function method is employed, which is a popular approach for the characterization of the flame response to acoustic perturbations. First, an experimental setup is built, where the velocity fluctuations of the fuel/air mixture and the heat release fluctuations from the flame could be measured. Then, the effects of different parameters, i.e. equivalence ratio, gas quality, perturbation amplitude and burner type on the flame response are investigated.Master Thesis Compliant Control of a Teleoperated Endoscope Robot(Izmir Institute of Technology, 2018) Işıtman, Oğulcan; Dede, Mehmet İsmet CanWith the development of the technology, robots are started to be used in many medical application including minimally invasive surgery to overcome disadvantages of conventional open surgery procedures. This thesis is a part of the research project called “Robot-assisted endoscope control that can be controlled by the surgical tools (NeuRobo- Scope)” for the minimally invasive endoscopic pituitary gland tumor surgery side. During the procedure, endoscope is handled by a robot which moves the endoscope in the human nasal cavity and the movement of the endoscope is constrained by soft tissues. Another operation scenario is the positioning of the endoscope by the surgeon backdriving the endoscope holder robot. In the scope of this thesis, two research problems are addressed which are controlling the interaction between (1) surgeon - robot and (2) robot - soft tissue. First, the interaction of the surgeon and the robot is studied. Effects of the compliant controller parameters are experimentally tested by using a single degree of freedom non-backdrivable experimental set-up. A task is defined to quantitatively compare the effect of the controller parameters on the performance in terms of the energy efficiency and the accuracy. The second research problem involves human nasal tissue modeling in order to design an accurate controller. To acquire data from the human cadaver, a new hand-held measurement device is designed. The external forces and moments and the soft tissue models are obtained in an ex-vivo experiment. After the soft tissue models are identified, a modified interaction control is proposed for the teleoperated endoscope holder robot. The defined surgery procedure is tested with the proposed interaction controller via single degree-of-freedom experimental set-up. Experiments of the proposed controllers were successful for the defined operation scenario and the results show that it is possible to realize the motion control of the surgical robots in a constrained environment.Master Thesis Noise and Vibration Analysis of a Drum Brake Used in Heavy Commericial Trucks(Izmir Institute of Technology, 2018) Akdağ, Osman; Yardımoğlu, BülentHeavy commercial duty vehicles have been used to for many years. High energy dissipation is required to stop these types of vehicles. Selection of brake type is related with the brake resists to this physical and environment conditions and also comfortability of drivers and passengers. Brake squeal is the most common costumer complaint for brake systems. This problem is main interest and tackled in many ways. In this thesis, vibration characteristics of the heavy commercial duty brake system, which is a drum brake, is studied by Finite Element Method to analyze the brake squeal. Natural frequencies and mode shapes of drum and shoe which are in frictional contact are determined by using ANSYS. Block Lanczos solver is preferred for this analysis. Experimental modal tests are accomplished to compare finite element results with experimental ones. Then, the noise characteristics of the brake system are obtained by performing a series dynamometer tests. In these experiments, four parameters are selected to investigate the decreasing and eliminating the noise. The selected parameters are deceleration rate, pressure, temperature and friction coefficients. The results are presented in tables and graphs.Master Thesis Design Modification of a Front Window Mechanism for the Cabin of an Earth Moving Machine(Izmir Institute of Technology, 2017) Jovichikj, Radomir; Kiper, GökhanThis thesis study investigates the front window mechanism used in an earth moving machinery. Since the mechanism is actuated by the operator, the required actuation force for the mechanism needs to be as minimum as possible. The problem of this thesis is defined by Turkey branch of Mecalac Company and the final test of this study are performed in their facility. First, the problem definition and aim of the study is presented. Furthermore, the literature review is also presented. Then, the current mechanism attached on the earth moving machinery is investigated. Firstly, kinematic analysis is performed in order to be able to perform the force analysis. Following that, using three different approaches (Newton-Euler approach, virtual work method and graphical approach), the static force analysis is done. The aim of this analysis to obtain the required actuation force, both for opening and closing the mechanism. By using three different approaches, the result obtained after each method are compared and confirmed. Furthermore, a simulation of the mechanism is prepared in MATLAB/Simulink® environment. This step provided a numerical simulation verification for the resulting actuation forces. Then the work carried out for the minimization of the actuation force is presented. By changing the parameters of the springs attached on the current mechanism, changing the link lengths of the mechanism and changing the application point of the actuation force, the change in the magnitude of the required actuation force is observed and minimized. Among all trials, only changing the spring position led to useful results. Finally, the test setup to measure the performance and experimentally verify the proposed solution is explained and the results are given. The results show that with the modified location of the spring, both of the maximum force requirements and the work requirements are lowered.Master Thesis Modelling and Control of a 3-Rrs Parallel Manipulator(Izmir Institute of Technology, 2016) Tetik, Halil; Kiper, GökhanThe focus of this thesis study is to model and control a parallel robot manipulator located in Rasim Alizade Mechatronics Laboratory (Izmir Institute of Technology Mechanical Engineering Department). The purpose of this robot is to manipulate heavy payloads. It is considered as the base part of a hybrid manipulator. This thesis study deals with a 3-RRS parallel manipulator with 3 identical limbs. Each limb comprises two parallel revolute joint axes. The manipulator has a base and a moving platform which are in the shape of equilateral triangles. The mobile platform of this manipulator has 3-degrees-of-freedom: it can rotate around x- and y-axes and translate along the z-axis. To obtain the mathematical model of the parallel manipulator, firstly the mobility analysis is performed. Then, a constraint analysis is performed to obtain the dependent pose parameters of the moving platform in terms of the independent parameters. Following that kinematic, singularity, workspace and inverse dynamic analyses are performed. To validate the mathematical model of the PM, several simulations are run in MATLAB/Simulink R environment. Once the mathematical model is validated, the control studies are carried out. The motion of the 3-RRS PM is controlled by activating stepper motors with two different controllers (a CNC controller and a PCI card). To obtain a desired motion of the moving platform, firstly the desired task space coordinates of the moving platform are transformed into joint space coordinates using inverse kinematics. With the CNC controller a trapezoidal velocity, with the PCI card a trapezoidal jerk profile is generated. To test the control over the PM, 3 magnetic encoders are attached to the shafts of input links at each limb. Furthermore, a 3-axis gyroscope is attached to the center of the moving platform to track its rotational trajectory.Master Thesis Design of a Six Degree-Of Haptic Hybrid Platform Manipultor(Izmir Institute of Technology, 2010) Bilgincan, Tunç; Dede, Mehmet İsmet CanThe word Haptic, based on an ancient Greek word called haptios, means related with touch. As an area of robotics, haptics technology provides the sense of touch for robotic applications that involve interaction with human operator and the environment. The sense of touch accompanied with the visual feedback is enough to gather most of the information about a certain environment. It increases the precision of teleoperation and sensation levels of the virtual reality (VR) applications by exerting physical properties of the environment such as forces, motions, textures. Currently, haptic devices find use in many VR and teleoperation applications. The objective of this thesis is to design a novel Six Degree-of-Freedom (DOF) haptic desktop device with a new structure that has the potential to increase the precision in the haptics technology. First, previously developed haptic devices and manipulator structures are reviewed. Following this, the conceptual designs are formed and a hybrid structured haptic device is designed manufactured and tested. Developed haptic device.s control algorithm and VR application is developed in Matlab© Simulink. Integration of the mechanism with mechanical, electromechanical and electronic components and the initial tests of the system are executed and the results are presented. According to the results, performance of the developed device is discussed and future works are addressed.Master Thesis Position / Force Control of Systems Subjected To Communicaton Delays and Interruptions in Bilateral Teleoperation(Izmir Institute of Technology, 2012) Uzunoğlu, Emre; Dede, Mehmet İsmet CanTeleoperation technology allows to remotely operate robotic (slave) systems located in hazardous, risky and distant environments. The human operator sends commands through the controller (master) system to execute the tasks from a distance. The operator is provided with necessary (visual, audio or haptic) feedback to accomplish the mission remotely. In bilateral teleoperation, continuous feedback from the remote environment is generated. Thus, the operator can handle the task as if the operator is in the remote environment relying on the relevant feedback. Since teleoperation deals with systems controlled from a distance, time delays and package losses in transmission of information are present. These communication failures affect the human perception and system stability, and thus, the ability of operator to handle the task successfully. The objective of this thesis is to investigate and develop a control algorithm, which utilizes model mediated teleoperation integrating parallel position/force controllers, to compensate for the instability issues and excessive forcing applied to the environment arising from communication failures. Model mediation technique is extended for three-degrees-of-freedom teleoperation and a parallel position/force controller, impedance controller, is integrated in the control algorithm. The proposed control method is experimentally tested by using Matlab Simulink blocksets for real-time experimentation in which haptic desktop devices, Novint Falcon and Phantom Desktop are configured as master and slave subsystems of the bilateral teleoperation. The results of these tests indicate that the stability and passivity of proposed bilateral teleoperation systems are preserved during constant and variable time delays and data losses while the position and force tracking test results provide acceptable performance with bounded errors.