98 research outputs found

    Design of an autonomous Lunar construction utility vehicle

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    In order to prepare a site for a manned lunar base, an autonomously operated construction vehicle is necessary. A Lunar Construction Utility Vehicle (LCUV), which utilizes interchangeable construction implements, was designed conceptually. Some elements of the machine were studied in greater detail. Design of an elastic loop track system has advanced to the testing stage. A standard coupling device was designed to insure a proper connection between the different construction tools and the LCUV. Autonomous control of the track drive motors was simulated successfully through the use of a joystick and computer interface. A study of hydrogen-oxygen fuel cells has produced estimates of reactant and product size requirements and identified multi-layer insulation techniques. Research on a 100 kW heat rejection system has determined that it is necessary to house a radiator panel on a utility trailer. The impact of a 720 hr use cycle has produced a very large logistical support lien which requires further study

    14th Conference on Dynamical Systems Theory and Applications DSTA 2017 ABSTRACTS

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    From Preface: This is the fourteen time when the conference “Dynamical Systems – Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and the Ministry of Science and Higher Education. It is a great pleasure that our invitation has been accepted by so many people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcome nearly 250 persons from 38 countries all over the world. They decided to share the results of their research and many years experiences in the discipline of dynamical systems by submitting many very interesting papers. This booklet contains a collection of 375 abstracts, which have gained the acceptance of referees and have been qualified for publication in the conference proceedings [...]

    Dynamical systems : mathematical and numerical approaches

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    Proceedings of the 13th Conference „Dynamical Systems - Theory and Applications" summarize 164 and the Springer Proceedings summarize 60 best papers of university teachers and students, researchers and engineers from whole the world. The papers were chosen by the International Scientific Committee from 315 papers submitted to the conference. The reader thus obtains an overview of the recent developments of dynamical systems and can study the most progressive tendencies in this field of science

    Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau, 8 - 12 September 2014 ; programme

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    Druckausgabe erschienen im Universitätsverlag Ilmenau: Shaping the future by engineering : 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau, 8 - 12 September 2014 ; programme / Department of Mechanical Engineering, Technische Universität Ilmenau. [Hrsg.: Peter Scharff. Red.: Andrea Schneider] Ilmenau : Univ.-Verl. Ilmenau, 2014. - 155 S. ISBN 978-3-86360-085-

    Design and application of a cellular, piezoelectric, artificial muscle actuator for biorobotic systems

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 219-227).One of the foremost challenges in robotics is the development of muscle-like actuators that have the capability to reproduce the smooth motions observed in animals. Biological muscles have a unique cellular structure that departs from traditional electromechanical actuators in several ways. A muscle consists of a vast number of muscle fibers and, more fundamentally, sarcomeres that act as cellular units or building blocks. A muscle's output force and displacement are the aggregate effect of the individual building blocks. Thus, without using gearing or transmissions, muscles can be tailored to a range of loads, satisfying specific force and displacement requirements. These natural actuators are desirable for biorobotic applications, but many of their characteristics have been difficult to reproduce artificially. This thesis develops and applies a new artificial muscle actuator based on piezoelectric technology. The essential approach is to use a subdivided, cellular architecture inspired by natural muscle. The primary contributions of this work stem from three sequential aims. The first aim is to develop the operating principles and design of the actuator cellular units. The basic operating principle of the actuator involves nested flexural amplifiers applied to piezoelectric stacks thereby creating an output length strain commensurate with natural muscle. The second aim is to further improve performance of the actuator design by imparting tunable stiffness and resonance capabilities. This work demonstrates a previously unavailable level of tunability in both stiffness and resonance. The final aim is to showcase the capabilities of the actuator design by developing an underwater biorobotic fish system that utilizes the actuators for resonance-based locomotion. Each aspect of this thesis is supported by rigorous analysis and functional prototypes that augment broadly applicable design concepts.by Thomas William Secord.Ph.D

    Applicable Solutions in Non-Linear Dynamical Systems

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    From Preface: The 15th International Conference „Dynamical Systems - Theory and Applications” (DSTA 2019, 2-5 December, 2019, Lodz, Poland) gathered a numerous group of outstanding scientists and engineers who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without great effort of the staff of the Department of Automation, Biomechanics and Mechatronics of the Lodz University of Technology. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our event was attended by over 180 researchers from 35 countries all over the world, who decided to share the results of their research and experience in different fields related to dynamical systems. This year, the DSTA Conference Proceedings were split into two volumes entitled „Theoretical Approaches in Non-Linear Dynamical Systems” and „Applicable Solutions in Non-Linear Dynamical Systems”. In addition, DSTA 2019 resulted in three volumes of Springer Proceedings in Mathematics and Statistics entitled „Control and Stability of Dynamical Systems”, „Mathematical and Numerical Approaches in Dynamical Systems” and „Dynamical Systems in Mechatronics and Life Sciences”. Also, many outstanding papers will be recommended to special issues of renowned scientific journals.Cover design: Kaźmierczak, MarekTechnical editor: Kaźmierczak, Mare

    Vibration reponse analysis in orthopaedics and its application at the lumbar spine

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    Vibration response analysis has been carried out on human lumbar spines in-vitro and in-vivo. Random vibration in the frequency range between 20 Hz and 2 kHz was applied to the L5 spinous process in the antero-posterior direction while motion response was measured at the other spinous processes of the lumbar spine. Transfer mobility which defines the lumbar spine's motion response to vibratory force was evaluated by using the fast Fourier transform and spectral averaging technique. There was high damping during the in-vitro tests and the lumbar spine was found to behave as a segmented beam hinged at the thoracic and sacral ends. Fundamental mode shape was observed at frequencies lower than 150 Hz and this pattern was also observed with simulated fusion of the facet joints and interbody fusion. Mobility summated for the whole range of frequency could be modelled by an exponential expression. Useful parameters have been identified and they were found to relate to the lumbar spine's vibratory characteristics resulting from structural modifications. Vibration testing performed on normal subjects revealed that a relaxed lumbar spine was highly damped and non-resonant. First flexural vibration mode was observed only under the action of the back extensors. Averaged figures have been established for the coefficients of an exponential expression which fits closely to the summated mobility curve. The mobility and its attenuation coefficients in different frequency bands have been evaluated from twelve normal subjects. Localized attenuation of vibration response and the reduction in mobility were observed on a patient with osteoporotic lumbar spine. Mobility in the low frequencies was reduced while the medium and high band mobility were enhanced in patients with postero-lateral fusion and instrumentation for fixation of the lumbar spine. The attenuation pattern of these patients was consistent, and corresponded to the existence of structural enhancement.Vibration response analysis has been carried out on human lumbar spines in-vitro and in-vivo. Random vibration in the frequency range between 20 Hz and 2 kHz was applied to the L5 spinous process in the antero-posterior direction while motion response was measured at the other spinous processes of the lumbar spine. Transfer mobility which defines the lumbar spine's motion response to vibratory force was evaluated by using the fast Fourier transform and spectral averaging technique. There was high damping during the in-vitro tests and the lumbar spine was found to behave as a segmented beam hinged at the thoracic and sacral ends. Fundamental mode shape was observed at frequencies lower than 150 Hz and this pattern was also observed with simulated fusion of the facet joints and interbody fusion. Mobility summated for the whole range of frequency could be modelled by an exponential expression. Useful parameters have been identified and they were found to relate to the lumbar spine's vibratory characteristics resulting from structural modifications. Vibration testing performed on normal subjects revealed that a relaxed lumbar spine was highly damped and non-resonant. First flexural vibration mode was observed only under the action of the back extensors. Averaged figures have been established for the coefficients of an exponential expression which fits closely to the summated mobility curve. The mobility and its attenuation coefficients in different frequency bands have been evaluated from twelve normal subjects. Localized attenuation of vibration response and the reduction in mobility were observed on a patient with osteoporotic lumbar spine. Mobility in the low frequencies was reduced while the medium and high band mobility were enhanced in patients with postero-lateral fusion and instrumentation for fixation of the lumbar spine. The attenuation pattern of these patients was consistent, and corresponded to the existence of structural enhancement

    5th EUROMECH nonlinear dynamics conference, August 7-12, 2005 Eindhoven : book of abstracts

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    5th EUROMECH nonlinear dynamics conference, August 7-12, 2005 Eindhoven : book of abstracts

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    Aeronautical Engineering: A special bibliography with indexes, supplement 62

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    This bibliography lists 306 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1975
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