No description available.

Thesis: B.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1981 / Vita. / Includes bibliographical references. / by Paul Stephen Ranyak. / B.S. / B.S. Massachusetts Institute of Technology, Department of Mechanical Engineering

This dissertation proposes a new type of modular, long-reach, truss-type manipulator. Variable Geometry Trusses (VGT’s) are used to construct a reconfigurable manipulator system in which all primary members are loaded in pure tension or compression. Each module of the manipulator system is either a static truss link or one of several possible VGT actuators. This results in an extremely stiff and strong manipulator system with minimal overall weight. While many potential applications exist for this technology, the present work was largely motivated by the need for a robotic waste remediation system for underground radioactive waste storage tanks. This new manipulator system provides several advantages when used for this application. The reconfigurable nature of the proposed system allows the manipulator to be adapted on site to unforeseen conditions. Additionally, the kinematic redundancy of the manipulator ensures that solutions can be accomplished even in a highly obstructed workspace. The parallel structure of the truss modules enables the manipulator to be withdrawn in the event of a structural failure. Finally, of particular importance to this task, the open framework of the modules provide a passageway for waste conveyance or additionally, could act as a shielded conduit for control and power cabling. Kinematic analysis algorithms tailored to address the peculiarities of this new manipulator system have also been developed. In this work, the kinematic redundancy of the system is exploited to provide alternative solutions, to avoid numerical difficulties at singularities, or to avoid workspace obstacles. These issues are addressed through a combination of null space optimization procedures and order reduction methods. The null space optimization procedures are accomplished by extracting information from a full singular value decomposition of the Jacobian matrix. This method is shown to converge quickly, even for systems with thirty or more degrees of freedom. This represents a significant increase over most of the current literature which typically addresses systems of eight or fewer degrees of freedom. This dissertation presents the first application of null space optimization techniques for the positional control of a high degree-of-freedom parallel manipulators. This work also formalizes the concept of a canonical input specification set. The application of this concept results in greatly simplified analyses of many parallel manipulators. Although the manipulator system discussed was specifically developed for robotic handling of radioactive waste, the final resulting methodology is suited to a much broader class of problems, namely, under-constrained, redundant manipulator systems in general. / Ph. D.

No description available.

Tang Wai Sum. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 68-70). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Redundant Manipulators --- p.1 / Chapter 1.2 --- Inverse Kinematics of Robotic Manipulators --- p.2 / Chapter 1.3 --- Inverse Dynamics of Robotic Manipulators --- p.4 / Chapter 1.4 --- Redundancy Resolutions of Manipulators --- p.5 / Chapter 1.5 --- Motivation of Using Neural Networks for these Applications --- p.9 / Chapter 1.6 --- Previous Work for Redundant Manipulator Inverse Kinematics and Inverse Dynamics Computation by Neural Networks --- p.9 / Chapter 1.7 --- Advantages of the Proposed Recurrent Neural Networks --- p.11 / Chapter 1.8 --- Contribution of this work --- p.11 / Chapter 1.9 --- Organization of this thesis --- p.12 / Chapter 2 --- Problem Formulations --- p.14 / Chapter 2.1 --- Constrained Optimization Problems for Inverse Kinematics Com- putation of Redundant Manipulators --- p.14 / Chapter 2.1.1 --- Primal and Dual Quadratic Programs for Bounded Joint Velocity Minimization --- p.14 / Chapter 2.1.2 --- Primal and Dual Linear Programs for Infinity-norm Joint Velocity Minimization --- p.15 / Chapter 2.2 --- Constrained Optimization Problems for Inverse Dynamics Com- putation of Redundant Manipulators --- p.17 / Chapter 2.2.1 --- Quadratic Program for Unbounded Joint Torque Mini- mization --- p.17 / Chapter 2.2.2 --- Primal and Dual Quadratic Programs for Bounded Joint Torque Minimization --- p.18 / Chapter 2.2.3 --- Primal and Dual Linear Programs for Infinity-norm Joint Torque Minimization --- p.19 / Chapter 3 --- Proposed Recurrent Neural Networks --- p.20 / Chapter 3.1 --- The Lagrangian Network --- p.21 / Chapter 3.1.1 --- Optimality Conditions for Unbounded Joint Torque Min- imization --- p.21 / Chapter 3.1.2 --- Dynamical Equations and Architecture --- p.22 / Chapter 3.2 --- The Primal-Dual Network 1 --- p.24 / Chapter 3.2.1 --- Optimality Conditions for Bounded Joint Velocity Min- imization --- p.24 / Chapter 3.2.2 --- Dynamical Equations and Architecture for Bounded Joint Velocity Minimization --- p.26 / Chapter 3.2.3 --- Optimality Conditions for Bounded Joint Torque Mini- mization --- p.27 / Chapter 3.2.4 --- Dynamical Equations and Architecture for Bounded Joint Torque Minimization --- p.28 / Chapter 3.3 --- The Primal-Dual Network 2 --- p.29 / Chapter 3.3.1 --- Energy Function for Infinity-norm Joint Velocity Mini- mization Problem --- p.29 / Chapter 3.3.2 --- Dynamical Equations for Infinity-norm Joint Velocity Minimization --- p.30 / Chapter 3.3.3 --- Energy Functions for Infinity-norm Joint Torque Mini- mization Problem --- p.32 / Chapter 3.3.4 --- Dynamical Equations for Infinity-norm Joint Torque Min- imization --- p.32 / Chapter 3.4 --- Selection of the Positive Scaling Constant --- p.33 / Chapter 4 --- Stability Analysis of Neural Networks --- p.36 / Chapter 4.1 --- The Lagrangian Network --- p.36 / Chapter 4.2 --- The Primal-Dual Network 1 --- p.38 / Chapter 4.3 --- The Primal-Dual Network 2 --- p.41 / Chapter 5 --- Simulation Results and Network Complexity --- p.45 / Chapter 5.1 --- Simulation Results of Inverse Kinematics Computation in Re- dundant Manipulators --- p.45 / Chapter 5.1.1 --- Bounded Least Squares Joint Velocities Computation Using the Primal-Dual Network 1 --- p.46 / Chapter 5.1.2 --- Minimum Infinity-norm Joint Velocities Computation Us- ing the Primal-Dual Network 2 --- p.49 / Chapter 5.2 --- Simulation Results of Inverse Dynamics Computation in Redun- dant Manipulators --- p.51 / Chapter 5.2.1 --- Minimum Unbounded Joint Torques Computation Using the Lagrangian Network --- p.54 / Chapter 5.2.2 --- Minimum Bounded Joint Torques Computation Using the Primal-Dual Network 1 --- p.57 / Chapter 5.2.3 --- Minimum Infinity-norm Joint Torques Computation Us- ing the Primal-Dual Network 2 --- p.59 / Chapter 5.3 --- Network Complexity Analysis --- p.60 / Chapter 6 --- Concluding Remarks and Future Work --- p.64 / Publications Resulted from the Study --- p.66 / Bibliography --- p.68

At a platform singularity, a parallel manipulator loses constraint. Adding redundant actuation in an existing leg or new leg can eliminate these types of singularities. However, redundant manipulators have been designed with little attention to frame invariant techniques. In this dissertation, physically meaningful measures for closeness to singularities in non-redundant manipulators are developed. Two such frameworks are constructed. The first framework is a constrained optimization problem that unifies seemingly unrelated existing measures and facilitates development of new measures. The second is a clearance propagation technique based on workspace generation. These closeness measures are expanded to include redundancy and thus can be used as objective functions for designing redundant actuation. The constrained optimization framework is applied to a planar three degree of freedom redundant parallel manipulator to show feasibility of the technique.

Orientadores: Helder Anibal Hermini, João Mauricio Rosario / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-14T02:05:53Z (GMT). No. of bitstreams: 1 Paracencio_LuisGustavodeMello_D.pdf: 6716809 bytes, checksum: 4cd9dbc748f0f532de18ea5573d7c2fb (MD5) Previous issue date: 2009 / Resumo: Com o avanço tecnológico na área de engenharia mecatrônica, cada vez mais é necessário acompanhar e aperfeiçoar os estudos. Este trabalho pretende apresentar metodologias para integração de células de manufatura robotizadas com ênfase na modelagem e controle de um dispositivo robótico. O modelo do dispositivo em estudo é composto de três graus de liberdade acionados hidraulicamente, o que permite o posicionamento de uma mesa, onde uma peça possa ser trabalhada por dois robôs industriais, constituindo assim um sistema colaborativo de manufatura. São apresentados estudos referentes à modelagem cinemática e dinâmica, e ao cálculo dos parâmetros do sistema de controle utilizando MatLab-SimulinkTM. Foi desenvolvida uma interface em linguagem LabVIEWTM para aquisição e tratamento de informações provenientes dos sensores das juntas e da implementação do sistema de supervisão e controle. A partir da publicação de uma página de aplicação HTML, a célula colaborativa poderá ser disponibilizada na WEB, permitindo a criação de um laboratório virtual, direcionado à pesquisa científica e tecnológica e com possibilidade de se interligar com outros laboratórios de ensino e pesquisa. Isso permitirá, por exemplo, a realização de experiências e ensino à distância, executando tarefas complexas em tempo real / Abstract: In recent years, with technological advances in mechatronics engineering it is necessary to monitor and improve the studies of these new trends. This research aims to present a methodology to integrate robotic manufacturing cells with emphasis on modeling and controlling of a robotic device. The model of the device of this study consists of three degrees of freedom, driven hydraulically allowing the placement of a table where a piece can be worked by two industrial robots constituting a system of collaborative manufacturing. Studies are presented concerning kinematic and dynamic models and the calculation of parameters of the control system using MatLab-SimulinkTM. An interface was developed in LabVIEWTM language for acquisition and processing of the information from the sensors of the joints and the implementation of the system of supervision and control. Since the publication of an HTML page, a cell collaborative application may be available on the collaborative WEB allowing the creation of a virtual laboratory directed to scientific and technological research and the possibility to connect with other laboratories for teaching and research. For instance, this will allow carrying out the implementation of distance learning experience and performing complex tasks in real time / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

Human-scale mobile robots that manipulate objects (mobile manipulators) have the potential to perform a variety of useful roles in healthcare. Many promising roles for robots require physical contact with patients and caregivers, which is fraught with both psychological and physical implications. In this thesis, we used a human factors approach to evaluate system performance and participant responses when potential end users performed a healthcare task involving physical contact with a robot. We performed four human-robot interaction studies with 100 people who were not experts in robotics (naive participants). We show that physical contact between naive participants and human-scale mobile manipulators can be acceptable and effective in a variety of healthcare contexts. In this thesis, we investigated two forms of touch-based (haptic) interaction relevant to healthcare. First, we studied how participants responded to physical contact initiated by an autonomous robotic nurse. On average, people responded favorably to robot-initiated touch when the robot indicated that it was a necessary part of a healthcare task. However, their responses strongly depended on what they thought the robot's intentions were, which suggests that this will be an important consideration for future healthcare robots. Second, we investigated the coordination of whole-body motion between human-scale robots and people by the application of forces to the robot's hands and arms. Nurses found this haptic interaction to be intuitive and preferred it over a standard gamepad interface. They also navigated the robot through a cluttered healthcare environment in less time, with fewer collisions, and with less cognitive load via haptic interaction. Through a study with expert dancers, we demonstrated the feasibility of robots as dance-based exercise partners. The experts rated a robot that used only haptic interaction to be a good follower according to subjective measures of dance quality. We also determined that healthy older adults were accepting of using a robot for partner dance-based exercise. On average, they found the robot easy and enjoyable to use and that it performed a partnered stepping task well. The findings in this work make several impacts on the design of robots in healthcare. We found that the perceived intent of robot-initiated touch significantly influenced people's responses. Thus, we determined that autonomous robots that initiate touch with patients can be acceptable in some contexts. This result highlights the importance of considering the psychological responses of users when designing physical human-robot interactions in addition to considering the mechanics of performing tasks. We found that naive users across three user groups could quickly learn how to effectively use physical interaction to lead a robot during navigation, positioning, and partnered stepping tasks. These consistent results underscore the value of using physical interaction to enable users of varying backgrounds to lead a robot during whole-body motion coordination across different healthcare contexts.

Motion planning for redundant manipulators poses special challenges because the required inverse kinematics are difficult and not complete. This thesis investigates and proposes methods for motion planning for these systems that do not require inverse kinematics and are potentially complete. These methods are also compared in performance to standard inverse kinematics based methods.

Robustness of the closed-loop system has repercussions on both stability and performance, making the study of robustness very important. Fundamentally, the performance and stability of closed-loop systems utilizing state-feedback are tied to that of the observers. The primary goal of this thesis is to develop a robust nonlinear observer and closely examine the usefulness of the observer in the presence of non-collocation and parametric uncertainty and as an integral component in closed-loop control. The usefulness of the observer being investigated depends on robustness, accuracy, computational burden, tunability, ease of design, and ease of implementation on an actual flexible motion system. The design and subsequent integration of the Kalman filter, an optimal observer, into a closed-loop system is well known and systematic. However, there are shortcomings of the Kalman filter in the presence of model uncertainty which are highlighted in this work. Simulation studies are conducted using the Simulation Module in National Instruments LabVIEW 8.5 and experiments are conducted on a physical system consisting of a single flexible link with non-collocation of actuators and sensors using LabVIEW Real Time 8.5. Simulations serve as a means to analyze the performance of the optimal observer and the robust observer by analyzing their dynamic behavior as well as that of the closed-loop system with each observer in place. The focus of experiments is on investigating implementation of the robust observer, including initialization and tuning of observer design parameters off-line and on-line. Simulations verify the robustness properties of the sliding mode observer while experiments show that the robust observer can be implemented at fast control rates and that replacing the Kalman filter with a robust observer has direct ramifications on closed-loop performance.