879 research outputs found

    Design and realization of a microassembly workstation

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    With the miniaturization of products to the levels of micrometers and the recent developments in microsystem fabrication technologies, there is a great need for an assembly process for the formation of complex hybrid microsystems. Integration of microcomponents made up of different materials and manufactured using different micro fabrication techniques is still a primary challenge since some of the fundamental problems originating from the small size of parts to be manipulated, high precision necessity and specific problems of the microworld in that field are still not fully investigated. In this thesis, design and development of an open-architecture and reconfigurable microassembly workstation for efficient and reliable assembly of micromachined parts is presented. The workstation is designed to be used as a research tool for investigation of the problems in microassembly. The development of such a workstation includes the design of: (i) a manipulation system consisting of motion stages providing necessary travel range and precision for the realization of assembly tasks, (ii) a vision system to visualize the microworld and the determination of the position and orientation of micro components to be assembled, (iii) a robust control system and necessary fixtures for the end effectors that allow easy change of manipulation tools and make the system ready for the desired task. In addition tele-operated and semi-automated assembly concepts are implemented. The design is verified by implementing tasks in various ranges for micro-parts manipulation. The versatility of the workstation is demonstrated and high accuracy of positioning is shown

    Cost Oriented Robots for Kosovo

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    The cost of developing and operating control and automation systems is a crucial factor of productivity and competitiveness for a number of applications in manufacturing plants, quality control systems and robotics. This paper has been focused on practical use of technologies that provided significant cost reduction in operating automated systems for a variety of industrial applications and buildings/facilities operations in Kosovo. Topics that have been discussed were as following: key technologies reducing cost of automation systemsindustrial applications of variety technologies, such as smart devices, wireless sensors and control systems, field robots, etc.cost reducing engineering strategies as well as simulation of manufacturing systems and processes form cost estimation

    Catalog 1979-81

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    https://openspace.dmacc.edu/catalogs/1010/thumbnail.jp

    Haptics in Robot-Assisted Surgery: Challenges and Benefits

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    Robotic surgery is transforming the current surgical practice, not only by improving the conventional surgical methods but also by introducing innovative robot-enhanced approaches that broaden the capabilities of clinicians. Being mainly of man-machine collaborative type, surgical robots are seen as media that transfer pre- and intra-operative information to the operator and reproduce his/her motion, with appropriate filtering, scaling, or limitation, to physically interact with the patient. The field, however, is far from maturity and, more critically, is still a subject of controversy in medical communities. Limited or absent haptic feedback is reputed to be among reasons that impede further spread of surgical robots. In this paper objectives and challenges of deploying haptic technologies in surgical robotics is discussed and a systematic review is performed on works that have studied the effects of providing haptic information to the users in major branches of robotic surgery. It has been tried to encompass both classical works and the state of the art approaches, aiming at delivering a comprehensive and balanced survey both for researchers starting their work in this field and for the experts

    A METHODOLOGY FOR AUTONOMOUS ROOF BOLT INSTALLATION USING INDUSTRIAL ROBOTICS

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    The mining sector is currently in the stage of adopting more automation, and with it, robotics. Autonomous bolting in underground environments remains a hot topic for the mining industry. Roof bolter operators are exposed to hazardous conditions due to their proximity to the unsupported roof, loose bolts, and heavy spinning mass. Prolonged exposure to the risk inevitably leads to accidents and injuries. The current thesis presents the development of a robotic assembly capable of carrying out the entire sequence of roof bolting operations in full and partial autonomous sensor-driven rock bolting operations to achieve a high-impact health and safety intervention for equipment operators. The automation of a complete cycle of drill steel positioning, drilling, bolt orientation and placement, resin placement, and bolt securing is discussed using an anthropomorphic robotic arm.A human-computer interface is developed to enable the interaction of the operators with the machines. Collision detection techniques will have to be implemented to minimize the impact after an unexpected collision has occurred. A robust failure-detection protocol is developed to check the vital parameters of robot operations continuously. This unique approach to automation of small materials handling is described with lessons learned. A user-centered GUI has been developed that allows for a human user to control and monitor the autonomous roof bolter. Preliminary tests have been conducted in a mock mine to evaluate the developed system\u27s performance. In addition, a number of different scenarios simulating typical missions that a roof bolter needs to undertake in an underground coal mine were tested

    Technology assessment of advanced automation for space missions

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    Six general classes of technology requirements derived during the mission definition phase of the study were identified as having maximum importance and urgency, including autonomous world model based information systems, learning and hypothesis formation, natural language and other man-machine communication, space manufacturing, teleoperators and robot systems, and computer science and technology

    Concept of an exoskeleton for industrial applications with modulated impedance based on Electromyographic signal recorded from the operator

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    The introduction of an active exoskeleton that enhances the operator power in the manufacturing field was demonstrated in literature to lead to beneficial effects in terms of reducing fatiguing and the occurrence of musculo-skeletal diseases. However, a large number of manufacturing operations would not benefit from power increases because it rather requires the modulation of the operator stiffness. However, in literature, considerably less attention was given to those robotic devices that regulate their stiffness based on the operator stiffness, even if their introduction in the line would aid the operator during different manipulations respect with the exoskeletons with variable power. In this thesis the description of the command logic of an exoskeleton for manufacturing applications, whose stiffness is modulated based on the operator stiffness, is described. Since the operator stiffness cannot be mechanically measured without deflecting the limb, an estimation based on the superficial Electromyographic signal is required. A model composed of 1 joint and 2 antagonist muscles was developed to approximate the elbow and the wrist joints. Each muscle was approximated as the Hill model and the analysis of the joint stiffness, at different joint angle and muscle activations, was performed. The same Hill muscle model was then implemented in a 2 joint and 6 muscles (2J6M) model which approximated the elbow-shoulder system. Since the estimation of the exerted stiffness with a 2J6M model would be quite onerous in terms of processing time, the estimation of the operator end-point stiffness in realtime would therefore be questionable. Then, a linear relation between the end-point stiffness and the component of muscle activation that does not generate any end-point force, is proposed. Once the stiffness the operator exerts was estimated, three command logics that identifies the stiffness the exoskeleton is required to exert are proposed. These proposed command logics are: Proportional, Integral 1 s, and Integral 2 s. The stiffening exerted by a device in which a Proportional logic is implemented is proportional, sample by sample, to the estimated stiffness exerted by the operator. The stiffening exerted by the exoskeleton in which an Integral logic is implemented is proportional to the stiffness exerted by the operator, averaged along the previous 1 second (Integral 1 s) or 2 seconds (Integral 2 s). The most effective command logic, among the proposed ones, was identified with empirical tests conducted on subjects using a wrist haptic device (the Hi5, developed by the Bioengineering group of the Imperial College of London). The experimental protocol consisted in a wrist flexion/extension tracking task with an external perturbation, alternated with isometric force exertion for the estimation of the occurrence of the fatigue. The fatigue perceived by the subject, the tracking error, defined as the RMS of the difference between wrist and target angles, and the energy consumption, defined as the sum of the squared signals recorded from two antagonist muscles, indicated the Integral 1 s logic to be the most effective for controlling the exoskeleton. A logistic relation between the stiffness exerted by the subject and the stiffness exerted by the robotic devices was selected, because it assured a smooth transition between the maximum and the minimum stiffness the device is required to exert. However, the logistic relation parameters are subject-specific, therefore an experimental estimation is required. An example was provided. Finally, the literature about variable stiffness actuators was analyzed to identify the most suitable device for exoskeleton stiffness modulation. This actuator is intended to be integrated on an existing exoskeleton that already enhances the operator power based on the operator Electromyographic signal. The identified variable stiffness actuator is the DLR FSJ, which controls its stiffness modulating the preload of a single spring

    Model-based operator guidance in interactive, semi-automated production processes

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    This contribution focuses on the task of guiding and supervision of technical processes realized by human operators. The review of publications of the last decades discloses that especially technical processes with strong interconnection of human operator and manufacturing process are not adequately addressed by the evolved automation approaches. Integrating human process knowledge and experience into the resulting automation system is still a major concern. Besides the introduction of automation in a handcrafting process that is increasing the overall system complexity, the design of the human-machine interface to the automation system is of central importance. Within this thesis, the trade-off between manual manufacturing and automation is addressed by a semi-automation approach. The application example is the no-bake molding process, a mold manufacturing process for casts that is traditionally handmade. Within this process the human operator plays a central role (i.e. knowledge and expertise), whereas the (intelligent) automation is carrying out physical operation, which is guided and supervised by the human operator. This is achieved by experimentally identified quality representing process variables that allow for in-process feedback to the human operator. Process guiding assistance is given using a formalization approach of the human-automation-interaction. By deducing situative information of interest from the resulting human-automation-system model with respect to the current process goal, the established process model is used for supervision and assistance of the overall process. The design of the human-machine-interface is based on a detailed analysis of the handcrafted process and is realized as a direct, intuitively usable, marker-based interaction technique. The integrated human-automation-system and the corresponding human-machine-interface with process guidance assistance functionality is initially evaluated. The results are discussed for the future work with respect to the individual, human operator-specific process understanding and process reproducibility.Diese Arbeit befasst sich mit Fachkraftaufgaben in der Führung und Überwachung von technischen Prozessen. Die Übersicht der Publikationen der letzten Jahrzehnte eröffnet, dass insbesondere technische Prozesse mit enger Verknüpfung von Mensch und Herstellungsprozess bei den entwickelten Automatisierungsansätzen nicht hinreichend berücksichtigt werden. Die Integration von Prozesswissen und -erfahrung in das resultierende Automatisierungssystem bleibt eine offene Fragestellung. Neben der Einführung von Automation in Handarbeitsprozesse, die die Komplexität des Gesamtsystems erhöhen, ist die Gestaltung der Mensch-Maschine-Schnittstelle zum Automatisierungssystem von zentraler Bedeutung. Der Konflikt zwischen Handarbeit und Automatisierung wird in dieser Arbeit durch die Einführung einer Teilautomatisierung gelöst. Das Anwendungsbeispiel ist das Kaltharzverfahren, ein traditionell in Handarbeit bewältigter Herstellungsprozess für Gussformen. In diesem Prozess spielt die Fachkraft eine zentrale Rolle (z. B. durch ihr Prozesswissen und ihre Expertise), während die (intelligente) Automatisierung –geführt und überwacht durch die Fachkraft– anfallende physische Aktionen ausführt. Dies wird durch experimentell ermit- telte qualitäts-beschreibende Prozessgrößen erreicht, die eine in-prozess Rückführung zum Bedienpersonal ermöglichen. Prozessführungsassistenz ist basierend auf die Formalisierung der Mensch-Automation-Interaktion gegeben. Durch die Bestimmung von situativen Informationen hoher Wichtigkeit aus dem resultierenden Mensch-Automation-System Modell bezogen auf das aktuelle Prozessziel, wird das bestehende Prozessmodell zur Überwachung und Prozessführungsassistenz des Gesamtprozesses genutzt. Die Gestaltung der Mensch-Maschine-Schnittstelle basiert auf einer detaillierten Analyse des Handarbeitsprozesses und ist als direkte, intuitiv bedienbare, markerbasierte Interaktionstechnik realisiert. Das integrierte Mensch-Automation-System sowie die zugehörige Mensch-Maschine-Schnittstelle inklusive Prozessführungsassistenzfunktionen wurden initial evaluiert. Die erzielten Ergebnisse werden hinsichtlich des individuellen, fachkraftabhängigen Prozesswissens und der Reproduzierbarkeit für den Ausblick diskutiert

    Third International Symposium on Artificial Intelligence, Robotics, and Automation for Space 1994

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    The Third International Symposium on Artificial Intelligence, Robotics, and Automation for Space (i-SAIRAS 94), held October 18-20, 1994, in Pasadena, California, was jointly sponsored by NASA, ESA, and Japan's National Space Development Agency, and was hosted by the Jet Propulsion Laboratory (JPL) of the California Institute of Technology. i-SAIRAS 94 featured presentations covering a variety of technical and programmatic topics, ranging from underlying basic technology to specific applications of artificial intelligence and robotics to space missions. i-SAIRAS 94 featured a special workshop on planning and scheduling and provided scientists, engineers, and managers with the opportunity to exchange theoretical ideas, practical results, and program plans in such areas as space mission control, space vehicle processing, data analysis, autonomous spacecraft, space robots and rovers, satellite servicing, and intelligent instruments
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