The application of robotic manipulators in machining systems has gained a great interest in manufacturing because of their lower prices, higher kinematic flexibility and larger workspace compared to conventional CNC machine tools. However, their performance is limited due to the much lower structural rigidity which makes them more susceptible to excessive and unstable vibrations, known as chatter, during the machining process. Highly effective chatter modeling and avoidance methods that have been developed for CNC machining in the past decades are now being used by the industry to design high-performance chatter-free machining operations. The available methods, however, face major difficulties when applied to robotic machining, mainly due to the high flexibility and pose-dependency of the vibration response in robots. High flexibility leads to high-amplitude vibrations which affect the process dynamics and excite structural nonlinearities. The existing approaches to modeling machining vibrations assume linearity of the structural dynamics of the robotic manipulator. This assumption, considering the inherent nonlinearities in the robot’s revolute joints, may cause considerable inaccuracies in predicting the stability of vibrations during the process. This thesis studies the high flexibility and nonlinearity of the robot’s structural dynamics and their effects on chatter vibrations. The research starts with investigating the effects of high flexibility of robot's structure in the process dyamics by considering the modulation of cutting forces by axial vibrations, which is normally ignored in CNC milling due to high rigidity of the machine in this direction. The results of chatter prediction considering this effect are shown and discussed. The rest of the thesis focuses on the structural nonlinearity. Firstly, an experimental study is presented to investigate the extent of nonlinearity in structural dynamics of the robot. The results confirm that structural nonlinearities in robotic machining systems can be effectively excited in the presence of high-amplitude vibrations due to milling forces, such that they cause remarkable differences in chatter prediction. The following step is modeling the structural nonlinearities. For this purpose, the variation of restoring forces with the dynamic response (displacement and velocity) are observed when the robot is subjected to harmonic excitation. Based on the experimental observations, the nonlinear effects are modeled by cubic stiffness and damping characteristics. Parameters of the nonlinear model are then identified using Higher-order Frequency Response Functions (HFRF) extracted from measurements. The identified model can predict the vibration behavior of the robotic machining system when subjected to periodic loads such as milling forces. The developed model of nonlinear structural dynamics is then coupled with the chatter model. Consequently, the system is described by nonlinear Delay Differential Equations (DDE) with periodic coefficients. Bifurcation diagrams for the forced vibrations in the described system are developed using the numerical continuation method. The effects of cutting parameters such as feedrate as well as the nonlinear parameters are studied. The thesis is concluded by proposing the use of in-process FRF in the linear model of chatter stability for quick prediction of stability limits. In this approach, the exact characteristics of the nonlinear mechanisms are not studied; instead, the measured FRF during the milling process are used, which are assumed to represent the nonlinear structural dynamics that are linearized about the applied operational conditions. Two methods of measuring in-process FRF are proposed and employed in the robotic milling system. The measured FRF are then used in the linear chatter model to develop the Stability Lobes Diagram (SLD) which shows the combination of cutting parameters that lead to stable or unstable vibrations. Experimental chatter tests show that better agreement with predictions can be achieved by using in-process FRF instead of FRF measured at the idle state of the system. The results of this thesis contribute to better characterization of vibrations in robotic machining with high-amplitude forces and selecting suitable strategies to enhance productivity of the operation. / Graduate

Laparoscopic Surgery has been revolutionized by the world of Surgical Robotics. Robot-Assisted Surgeries have been proven to have many advantages over the fundamental, traditional "by-hand" procedures previously conducted, and still currently being done for certain operations. Robot-assisted surgery may offer benefits to patients through the use of minimally invasive techniques, which may result in reduced blood loss, reduced blood transfusion, fewer complications, reduced postoperative pain, shorter hospital stays, and reduced recovery times (Ho et al., 2011). Studies have proven that robotic surgery may lead to patients recovering faster depending on the timeframe and the type of procedure (Tang et al., 2018). These benefits provide the highest quality care for the patient that can be provided. Robotic-assisted surgical platforms may overcome many of the shortcomings of laparoscopy while preserving the patient benefits (Boggess, 2007). Laparoscopic Surgery provides many benefits over open surgery as well and including the Robotic Surgical Assist allows for further/amplified benefits for the parties involved. The idea is to minimize the need for lengthy patient recovery time, discomfort, and complications caused by the procedure itself. The pain, discomfort, and disability, or other morbidities as a result of surgery is more frequently due to trauma involved in gaining access to the area to perform the intended procedure rather than from the procedure itself (Mack, 2001). Regulating certain areas of the procedure, such as required incision size, allows the patient a smoother recovery. With laparoscopic surgery, it limits risks and complications as a minimally invasive approach but, with robot-assisted laparoscopic surgery, it is even more as such. Currently, there seems to be a struggle in the field of medicine between how best to improve the surgical robots in comparison to how to better optimize, or create, smaller surgical devices to assist in surgeries. A factor that was found to be lacking in the field of medicine was the definition of actions done during surgical procedures. While used widely from a medical standpoint, from an operational standpoint it is not common practice to question the mathematical symbolization of the movements and actions done during surgery. The goal of this research is to determine, analyze, evaluate, and simplify the parameters that are present during Laparoscopic Surgery. These parameters will be compared between traditional surgery and robot-assisted surgery. The robot-assisted condition will be established using the Semi-Robotic Laparoscopic Surgery Support System developed by a University of Central Florida Senior Design Team finalized in the academic semester of Spring 2020. This system utilizes the aspects and features of a surgical robot while maintaining a small form factor and cheap production and purchasing price. Ultimately, this will allow for further evaluation of technologies exploiting the developed surgical robot for research in semi-autonomous control, and safety mechanisms in the context of robotic surgery. It is important to note that this technology is developed as a kinematic guide for laparoscopic surgery. This guiding assist is similar to the features incorporated in robot-assisted laparoscopic surgery which is what allows us to use this surgical assist device to represent the robot-assisted condition. This technology optimizes the condition of conventional laparoscopic surgery by introducing a braking mechanism into the standard procedure without requiring the major application of the full surgical systems. Through the utilization of this guiding system, this research has established and compared the kinematic and workspace parameters for robot-assisted laparoscopic surgery when the system is equipped vs. when it is equipped and activated; creating two different conditions of Workspace Controlled Laparoscopic Surgery and Kinematically Constrained Laparoscopic Surgery. It was deemed necessary to accomplish an understanding of both domains as well as in comparison to traditional laparoscopic surgical practices in order to engage the argument from a holistic point of view. Throughout this research, it was determined that, when evaluating traditional Laparoscopic Surgery, there are a series of parameters that are present when discussing the workspace of the human abdomen and the kinematics of the trocar, surgical tool, and camera placed into that workspace. Between these parameters, a variety of similarities was discovered using geometric rules and algebraic functional relationships within the kinematics. Upon equipping the Semi-Robotic Laparoscopic Surgery Support System to the procedure, certain parameters get "zeroed out" due to the fixed nature of the device from one abdominal insertion point to the next. While most parameters may maintain the same behaviors upon the installation of the technology, the majority of these same parameters get "zeroed out" when the technology is activated. The overall purpose and intent of this research is to define, evaluate, and compare various surgical parameters associated with the practice of laparoscopic surgery while running a comparison between the effectiveness of traditional surgery against robot-assisted surgery that can be made from a new perspective by evaluating the differences in their respective parameters. Results which will be discussed include: specific parameter definitions and labeling, how these parameters benefit the medical field, direct parameter comparison between the evaluated conditions of traditional surgery and robot-assisted surgery (represented by kinematic guiding technology and comparing when the device is applied, Workspace Controlled condition, versus when the braking system is activated, Kinematically Constrained condition), and how these different surgical techniques modify the conditions of surgery for the surgeon and the patient.

In recent decades human workers in manufacturing and overall industry have largely been replaced with robots and automated machines, but there are still plenty of tasks where human cognition is necessary. This paper presents the development of a wireless robotic arm controlled by a human arm, allowing both for the combination of a robotic arms strength to be combined with a humans cognition, and also for a human to execute dynamic tasks without being present. An application suited for work in toxic or otherwise harmful environments. This was accomplished by using a controller in the form of an exo-skeleton attached to the operators right arm and connected to the robotic arm through a transmitter. The controller measures the movements in each joint using potentiometers and the robotic arm mimics these movements. A glove with a flex sensor on the index finger was then attached to the controller to measure the finger motions. All the information containing the angle of rotations are sent wirelessly to the robotic arm using Arduino Uno and transceiver modules. The robotic arm received the information through another set of Arduino Uno and transceiver module which made each servomotor on the robotic arm to move accordingly. The result showed that the robotic arm could imitate the operator’s arm very well and was able to grab and move dierent objects with dierent weight and surfaces. The wireless control was reliable and could control the robotic arm while being in a dierent room, making it possible to use this robot for harmful environments for humans. / Under senare årtionden har mänskliga arbetare inom tillverkning och industri över lag i stor utsträckning ersatts av robotar och automatiserade maskiner, men det finns fortfarande uppgifter som kräver mänsklig tankeförmåga. Denna rapport presenterar utvecklingen av en trådlös robotarm styrd av en människas arm, vilket möjliggör både att kombinera en maskins styrka med en människas intelligens, samt för en människa att utföra dynamiska uppgifter utan att vara närvarande. En applikation lämplig för arbete i farliga miljöer. Detta uppnåddes med en styrenhet i form av ett exo-skelett fastsatt på operatörens högra arm och kopplad till robotarmen genom en sändare. Styrenheten mäter rörelserna i varje led med potentiometrar och robotarmen härmar dessa rörelser. En handske med en flexsensor på pekfingret fästes sedan på styrenheten för att mäta fingerrörelsen. All information som innehåller vinklar skickas trådlöst till robotarmen med hjälp av Arduino Uno och transceiver moduler. Robotarmen mottog informationen via en annan uppsättning Arduino Uno och transceiver modul som fick varje servomotor på robotarmen att rotera i enlighet. Resultatet visade att robotarmen kunde imitera operatörens arm väl och kunde bära olika föremål med olika vikter och ytor. Den trådlösa styrningen var pålitlig och kunde styra robotarmen från ett annat rum, vilket gör det möjligt att använda denna robot i skadliga miljöer för människor.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24799号 / 医博第4991号 / 新制||医||1066(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 石見 拓, 教授 川口 義弥 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22784号 / 農博第2427号 / 新制||農||1081(附属図書館) / 学位論文||R2||N5304(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 飯田 訓久, 教授 近藤 直, 教授 中嶋 洋 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

No description available.

Distance learning is facing a critical moment finding a balance between high quality education for remote students and engaging them in hands-on learning. This is particularly relevant for project-based classrooms and makerspaces, which typically require extensive trouble-shooting and example demonstrations from instructors. We present RobotAR, a teleconsulting robotics system for creating Augmented Reality (AR) makerspaces. We present the hardware and software for an AR-compatible robot, which behaves as a student’s voice assistant and can be embodied by the instructor for teleconsultation. As a desktop-based teleconsulting agent, the instructor has control of the robot’s joints and position to better focus on areas of interest inside the workspace. Similarly, the instructor has access to the student’s virtual environment and the capability to create AR content to aid the student with problem-solving. We also performed a user study which compares current techniques for distance hands-on learning and an implementation of our system.

No description available.

The role of job automation technology within the financial services sector has gained prominence recent years. Decision-makers are faced with questions from the external and internal environment relating to the future of work and career outlook of human capital. While the benefits of job automation are undoubtedly a key driver towards adopting this technology, ethical questions on responsible and ethical leadership have been put under a lens so as to understand what this means for employees within the financial sector. The study explores the ethical considerations made by decision-makers within the financial services sector in South Africa in relation to the employees disrupted by job automation adoption. The findings of this qualitative study were obtained through eighteen semi-structured interviews with decision-makers from the financial services sector and consulting firms with exposure to the financial services industry. The study found that the intent of job automation technology adoption goals coupled with the predominant mindset of decision makers was influenced the nature of considerations made decision makers. These consideration categories were largely aligned to the extant literature and the study contributed to the business ethics domain by sharing specific considerations made by decision makers in industry. Communication, transitions services, change management, shared value framing, empowerment through custodianship, an analysis of transferable skills and skills profiling were the main emergent findings found in the study. / Mini Dissertation (MBA)--University of Pretoria, 2021. / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted

No description available.