465 research outputs found

    Development of a Compact Piezoworm Actuator For Mr Guided Medical Procedures

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    In this research, a novel piezoelectric actuator was developed to operate safely inside the magnetic resonance imaging (MRI) machine. The actuator based on novel design that generates linear and rotary motion simultaneously for higher needle insertion accuracy. One of the research main objectives is to aid in the selection of suitable materials for actuators used in this challenging environment. Usually only nonmagnetic materials are used in this extremely high magnetic environment. These materials are classified as MRI compatible materials and are selected to avoid hazardous conditions and image quality degradation. But unfortunately many inert materials to the magnetic field do not possess desirable mechanical properties in terms of hardness, stiffness and strength and much of the available data for MRI compatible materials are scattered throughout the literature and often too device specific . Furthermore, the fact that significant heating is experienced by some of these devices due to the scanner’s variable magnetic fields makes it difficult to draw general conclusions to support the choice of suitable material and typically these choices are based on a trial-and-error with extensive time required for prototype development and MRI testing of such devices. This research provides a quantitative comparison of several engineering materials in the MRI environment and comparison to theoretical behavior which should aid designers/engineers to estimate the MRI compatible material performance before the expensive step of construction and testing. This work focuses specifically on the effects in the MRI due to the material susceptibility, namely forces, torques, image artifacts and induced heating

    Further infrared systems studies for the earth resources program Final report

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    Design of multispectral scanner for orbital earth resources detectio

    Experimental Investigation of Spacecraft Rendezvous and Docking by Development of a 3 Degree of Freedom Satellite Simulator Testbed

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    This thesis developed a 3 degree of freedom air bearing satellite simulator testbed. The major components of this testbed are a 2-meter by 4-meter granite table, a pair of satellite simulators, and a passive infrared marker array. The goal of this implementation was to achieve soft docking between 2 satellite simulators while relying only on hardware and systems onboard the satellite simulator. The satellite simulators make use of compressed air stored onboard in tanks to supply the air bearing and gas thrusters. The air bearing system provides a thin cushion of air for the satellite simulator to float on, removing surface contact and friction between the satellite simulator and the granite table. This produces a 3 degree of freedom system which is effectively free of the effects of gravity. The infrared marker array is used to provide reference points similar to stars to enable an onboard positioning system using a single observer. The experimental results obtained here demonstrate the successful implementation of this testbed

    Cable-driven parallel robot for curtain wall module installation

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    A cable-driven parallel robot (CDPR) was developed for the installation of curtain wall modules (CWM). The research addressed the question of whether the CDPR was capable installing CWMs with sufficient accuracy while being competitive compared to conventional manual methods. In order to develop and test such a system, a conceptual framework that consisted of three sub-systems was defined. The tests, carried out in two close-to-real demonstration buildings, revealed an absolute accuracy of the CWM installation of 4 to 23 mm. The working time for installing a CWM was reduced to 0.51 h. The results also show that the system is competitive for a workspace greater than 96 m2 compared to conventional manual methods. However, improvements such as reducing the hours for setting up the CDPR on the one hand and achieving a faster and more robust MEE on the other hand will be still necessary in the future.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 73251

    Model Validation and Simulation

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    The Bauhaus Summer School series provides an international forum for an exchange of methods and skills related to the interaction between different disciplines of modern engineering science. The 2012 civil engineering course was held in August over two weeks at Bauhaus-Universität Weimar. The overall aim was the exchange of research and modern scientific approaches in the field of model validation and simulation between well-known experts acting as lecturers and active students. Besides these educational intentions the social and cultural component of the meeting has been in the focus. 48 graduate and doctoral students from 20 different countries and 22 lecturers from 12 countries attended this summer school. Among other aspects, this activity can be considered successful as it raised the sensitivity towards both the significance of research in civil engineering and the role of intercultural exchange. This volume summarizes and publishes some of the results: abstracts of key note papers presented by the experts and selected student research works. The overview reflects the quality of this summer school. Furthermore the individual contributions confirm that for active students this event has been a research forum and a special opportunity to learn from the experiences of the researchers in terms of methodology and strategies for research implementation in their current work

    Design and realization of a master-slave system for reconstructive microsurgery

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