Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7755

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2016 - 20183

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  • Master Thesis
    Compliant Control of a Teleoperated Endoscope Robot
    (Izmir Institute of Technology, 2018) Işıtman, Oğulcan; Dede, Mehmet İsmet Can
    With 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.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Extending Model-Mediation Method To Multi-Degree Teleoperation Systems Experiencing Time Delays in Communication
    (Cambridge University Press, 2017) Uzunoğlu, Emre; Dede, Mehmet İsmet Can
    SUMMARY In this study, a bilateral teleoperation control algorithm is developed in which the model-mediation method is integrated with an impedance controller. The model-mediation method is also extended to three-degrees-of-freedom teleoperation. The aim of this controller is to compensate for instability issues and excessive forcing applied to the slave environment stemming from time delays in communication. The proposed control method is experimentally tested with two haptic desktop devices. Test results indicate that stability and passivity of the bilateral teleoperation system is preserved under variable time delays in communication. It is also observed that safer interactions of the slave system with its environment can be achieved by utilizing an extended version of the model-mediation method with an impedance controller.
  • Master Thesis
    Learning Control of Robot Manipulators With Telerobotic Applications
    (Izmir Institute of Technology, 2016) Doğan, Kadriye Merve; Tatlıcıoğlu, Enver
    Learning 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.