Phd Degree / Doktora
Permanent URI for this collectionhttps://hdl.handle.net/11147/2869
Browse
6 results
Search Results
Doctoral Thesis Actuation System Design of Kinesthetic Type Haptic Devices(01. Izmir Institute of Technology, 2024) Küçükoğlu, Sefa Furkan; Dede, Mehmet İsmet CanManyetoreolojik sıvı tabanlı (MR) frenler kinestetik tipindeki haptik cihazların eyleyici sistem tasarımında tercih edilmektedir. Fakat MR frenin giriş (akım) ve çıkışı (tork) arasında histeri ilişkisine sahip olması istenmeyen bir özelliktir. Bundan dolayı, MR frenin histeri davranışının modellenmesi için iki gelişmiş ve ileri seviye derin öğrenme yöntemleri kullanılmıştır. Ayrıca eğitim ve test sinyallerinin çeşitliliğini artırmak için ön bir veri işleme adımı önerilmiştir. MR frenin doğrusal olmayan davranışının bir sonucu olan ters histeri içinde bir model önerilmiş ve önerilen model deneysel olarak doğrulanmıştır. Düz ve ters histeri yöntemlerinin doğrulanmasından sonra, bir aktif eyleyici ve bir MR frenden oluşan bir hibrit eyleyici sistem (HES) sunulmuştur. MR frenin kapalı hal torku ve yavaş tepkiye sahip olması gibi diğer kısıtlamaları da incelendi ve bu kısıtlamalar HES tarafından çözüldü. MR frenin geçici rejim davranışı analiz edildi ve bu geçici rejim tepkisini taklit eden bir matematiksel model önerilmiştir. Önerilen matematiksel modelinin performansının geleneksel olarak kullanılan birinci dereceden transfer fonksiyonun performansına kıyasla daha iyi olduğu tespit edilmiştir. Daha sonra HES oluşturulup, aktif eyleyici hem sistemin tepkisini hızlandırmada hem de kapalı hal torkunu elimine etmede kullanılmıştır. Kapalı hal torku; 0.178 Nm'den 0.008 Nm'ye düşürülerek büyük ölçüde ortadan kaldırılmış olup sistemin dinamik aralığı ise 15 dB'den 42.4 dB'e artırılmıştır. Sistemin zaman sabiti sadece MR fren yerine HES kullanıldığında 69.6ms'den 4.4ms'ye geliştirilmiştir.Doctoral Thesis Robotların Esnekliği: Tasarım, Modelleme ve Kontrol(2024) Görgülü, İbrahimcan; Dede, Mehmet İsmet CanTüm malzemeler bir miktar esneklik sergiler. Sonuç olarak, herhangi bir malzemeden yapılmış bir robot manipülatörü bu yapısal esnekliği miras alır. Tipik olarak esnek robotların konumlandırma doğruluğu daha düşüktür. Bununla birlikte esneklik, kontrollü bir mekanik empedansa ve fiziksel insan-robot etkileşimlerinde artırılmış güvenliğe katkıda bulunduğundan avantajlı da olabilir. Temel zorluk esnek bir robotun giriş/çıkış performansını arttırmaktır. Bu performans büyük ölçüde üç temel bileşene dayanır: robotun mekanik yapısı, denetleyicisi ve denetleyici tarafından kullanılan matematiksel modelin doğruluğu. Bu bileşenlerde yapılan herhangi bir değişiklik veya ayarlama, genel giriş/çıkış performansını etkiler. Bu tez şu üç temel bileşeni kapsamaktadır: model, tasarım ve kontrol. İlk bölüm, çalışma sırasındaki titreşimleri tahmin etmek için aşırı kısıtlanmış bir paralel robot manipülatörünün direngenlik modelinin tasarlanmasına ayrılmıştır. İstenilen yörüngenin (veya girdinin) bu tahminlere göre ayarlanması, çıktı üzerindeki titreşim etkilerinin azaltılmasını mümkün kılar. İkinci kısım da istenilen mekanik empedans için esnek bir mafsal geliştirilir. Bu mafsal, küçük yükler altında esneklik göstermez, ancak etkileşim yükleri arttıkça yu\-mu\-şa\-yan davranışla esner. Mafsal, güvenli fiziksel insan-robot etkileşimlerini sağlarken robotun konumlandırma performansını düşük burulma seviyelerinde korur. Son olarak esnek robot için tasarlanan esnek mafsalı içeren bir denetleyici çerçevesi tasarlanmıştır. Kontrolcü, robotun mekanik durumları (sert ve esnek) arasında istikrarlı geçişler yapma ve istenen görevleri gerçekleştirme (yörünge izleme, istenen empedansı görüntüleme, kuvvet/konum izleme ve güvenliği sağlama) yeteneğine sahiptir.Doctoral Thesis Compliant Control of Robotic Co-Workers in Surgical Applications(01. Izmir Institute of Technology, 2023) Ayit, Orhan; Dede, Mehmet İsmet CanIn recent years, robots have taken place in surgical operations due to their advantages over humans, such as power, endurance, dexterity, and accuracy. Because of the lack of abilities, such as decision-making, adaptability, and creativity, human surgeons supervise the robots. The robots share the operation places with humans, called co-worker robots. Robots have the power to harm their environment; therefore, robots can generate dangerous situations for surgeons and patients. To deal with the issues, this dissertation aims to design active compliant control algorithms such as impedance control, admittance control, and hybrid position/force control to achieve safe interaction forces in surgical operations by considering the performance. The surgical co-worker robot’s type, actuation system, robot dynamics, and environment dynamics are important factors for designing the active compliant controller. Besides these, stability and robustness for safety, and agility and human effort for performance are considered for designing the controller. This dissertation takes into account three interaction scenarios encountered in surgical operations. In these scenarios, it is expected from the co-worker robot that it adapts to the sudden change in its environment dynamics. For instance, safe interaction is desired when the robot interacts with the stiff and soft tissues. To handle the issue, a switching control methodology is presented where the predefined control parameters are switched according to their environments. The methodology is implemented in a novel co-worker robot named NeuRoboScope, designed to assist the endoscopic pituitary gland surgery with the support of The Scientific and Technological Research Council of Turkey (TUBITAK). Moreover, active compliant control algorithms require a motion control algorithm as a low-level controller. In this dissertation, the computed torque method and independent joint controllers with gravity compensation are used as motion control algorithms. The computed torque method requires the dynamic model of the robot. Due to that, the dissertation proposes a simplified dynamic model with a correction coefficient for computational efficiency. ARM Cortex M4 processor runs the computed torque method with the proposed dynamic modeling method at 500 Hz. Also, this dissertation presents an independent joint controller which uses the simplified gravity matrix as a feedforward term for compensating the NeuRoboScope’s gravitational effect. The experimental results of both controllers are discussed in this dissertation.Doctoral Thesis Diagnosis and Recovery of Hardware Faults Encountered During Operation of Mobile Robots(01. Izmir Institute of Technology, 2020) Şahin, Osman Nuri; Dede, Mehmet İsmet Can; Özdemir, SehanMobile robots are used in many critical tasks. In such tasks, it is of great importance to tolerate the faults that the robot may encounter during the operation in order to complete the task successfully. This dissertation focuses on tolerating the faults that occur in the hardware of the mobile robots. To tolerate these faults, it is necessary to be prepared for the faults that the robot may encounter during the operation and to determine an appropriate fault toleration strategy. The mobile robot considered in this dissertation has holonomic motion ability in the plane thanks to its omnidirectional wheels. The types of faults focused on are the slippage of one of the wheels of this mobile robot and the performance degradation in the motor that actuates one of the wheels. To tolerate these two faults, an active fault tolerant control method is developed. A model-based fault diagnosis algorithm is developed for fault diagnosis algorithm, which is one of the two main parts of active fault tolerant control. To obtain the dynamic model of the mobile robot that is used in this algorithm, firstly, the friction between the wheel and the ground used is modeled. The parameters of the friction model are identified via the developed test setup. As a result of the tests performed for fault diagnosis, it is seen that these two types of faults occurring in the holonomic mobile robot can be diagnosed with developed fault diagnosis algorithm. In order to tolerate these faults, two different fault recovery algorithms which make use of kinematic redundancy of the mobile robot are developed, and the developed algorithms are tested. As a result of the fault recovery tests performed for the motor performance degradation, it is observed that the motion performance of the mobile robot improved despite the presence of the fault. Thanks to the developed recovery algorithm in the recovery tests for wheel slippage, it is observed that there is a significant decrease in the amount of slippage occurring on the faulty wheel and accordingly the mobile robot performs the desired motion more accurately.Doctoral Thesis Design of a Robot Assisted Minimally Invasive Surgical System for Pituitary Tumor Surgery Based on Safety Features(Izmir Institute of Technology, 2020) Maaroof, Omar Waleed Najm; Dede, Mehmet İsmet CanThe study is on the designing a robot assisted endonasal endoscopic surgical system; NeuRoboScope, the pituitary tumor resection surgery system. This system comprises a passive and an active arm. The passive arm positions the active arm in the surgery zone while the active arm assists the surgeon by positioning the endoscope during the surgery. The focus of this thesis is the mechanical and control safety features that can be implemented in the system. The safety enhancement methods of robot assisted minimally invasive surgery systems are investigated. Among the seventeen robot assisted endoscope holders, sixteen of them have been implemented in pituitary tumor and sinus surgeries. Safety is the main criterion that advances the progress of these systems and places them in operation rooms. Accordingly, two optimization procedures have been applied during the design of the NeuRoboScope system that have a direct effect on the suggested safety features. A novel optimization technique is proposed by employing a redundancy resolution method. The most suitable fixing point of the passive arm and its first link length is optimized to achieve the maximum manipulability with restrictions imposed by a modified condition number index and impedance of the passive arm. The active arm's partial gravity compensation is studied. Three spiral springs are used as counter-springs as the most compact and lightweight partial gravity compensation method. Particle swarm optimization method is employed for the optimization of the design parameters: spiral spring stiffnesses and preload angles. Consequently, at least 66% of actuator loads are compensated.Doctoral Thesis Macro-micro robotic manipulation: A laser cutting case study(Izmir Institute of Technology, 2019) Uzunoğlu, Emre; Dede, Mehmet İsmet Can; Kiper, GökhanThis dissertation focuses on investigation and devising of proper methodology to utilize a special type of kinematic redundancy, namely macro–micro manipulation, in the scope of robotic science. Briefly, macro-micro manipulation is comprised of two kinematically different mechanisms that have distinct characteristics, which work on macro and micro-scale. Aim of this dissertation is to present the most convenient motion planning and control algorithm to resolve kinematic redundancy for macro-micro manipulation concept. Controller designs, including the motion planning algorithms are devised taking into account the selected industrial case study. Additionally, a general framework controller is developed for macro-micro manipulation. Experiments with industrial setup and simulation verifications are done for the proposed methodologies. It is proven with simulation test results and experiments that the task completion duration for a laser cutting machine is reduced by enhancing the acceleration capability with the macro-micro manipulation. Although the proposed methodologies are implemented for a specific case, it can also be used for other systems considering the versatility of the proposed methodology. The core novelty of this research is the introduction of methodologies in order to achieve the maximum efficiency for the combined use of macro and micro-scaled manipulators. As an outcome of this study, a redundant laser cutting machine that can move with higher accelerations by making use of macro-micro manipulation is developed as a first of its kind in the Turkish machine industry and third of its kind in the world.