9 research outputs found

    Passive Dynamics in the Control of Gymnastic Maneuvers

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    The control of aerial gymnastic maneuvers is challenging because these maneuvers frequently involve complex rotational motion and because the performer has limited control of the maneuver during flight. A performer can influence a maneuver using a sequence of limb movements during flight. However, the same sequence may not produce reliable performances in the presence of off-nominal conditions. How do people compensate for variations in performance to reliably produce aerial maneuvers? In this report I explore the role that passive dynamic stability may play in making the performance of aerial maneuvers simple and reliable. I present a control strategy comprised of active and passive components for performing robot front somersaults in the laboratory. I show that passive dynamics can neutrally stabilize the layout somersault which involves an "inherently unstable" rotation about the intermediate principal axis. And I show that a strategy that uses open loop joint torques plus passive dynamics leads to more reliable 1 1/2 twisting front somersaults in simulation than a strategy that uses prescribed limb motion. Results are presented from laboratory experiments on gymnastic robots, from dynamic simulation of humans and robots, and from linear stability analyses of these systems

    Passive Dynamics in the Control of Gymnastic Maneuvers

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    The control of aerial gymnastic maneuvers is challenging because these maneuvers frequently involve complex rotational motion and because the performer has limited control of the maneuver during flight. A performer can influence a manuever using a sequence of limbmovements during flight. However, the same sequence may not produce reliable performances in the presence of off-nominal conditions. Howdo people compensate for variations in performance to reliably produce aerial maneuvers? In this report I explore the role that passive dynamic stabilitymay play in making the performance of aerial maneuvers simple and reliable

    Lamellar corneal transplantation: comparison of a simplified technique utilizing a contact lens splint supported by tissue adhesives with a standard suture graft procedure.

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    Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Not availabl

    Passive dynamics in the control of gymnastic maneuvers

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1994.Includes bibliographical references (p. 174-177).by Robert R. Playter.Ph.D

    Control system design using H [infinity] optimization

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1988.The bracketed word appears as the mathematical infinity symbol on the title page.Includes bibliographical references.by Robert Playter.M.S

    Design and analysis of a soft mobile robot composed of multiple thermally activated joints driven by a single actuator

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    Soft robotic systems have applications in industrial, medical, and security applications. Many applications require these robots to be small and lightweight. One challenge in developing a soft robotic system is to drive multiple degrees-of-freedom (DOF) with few actuators, thereby reducing system size and weight. This paper presents the analysis and design of an inchworm-like mobile robot that consists of multiple, independent thermally activated joints but is driven by a single actuator. To realize control of this under-actuated system, a solder-based locking mechanism has been developed to selectively activate individual joints without requiring additional actuators. The design and performance analysis of a prototype mobile robot that is capable of inchworm-like translational and steering motion is described. The design of novel “feet” with anisotropic friction properties is also described.United States. Defense Advanced Research Projects Agency. Chemical Robots Progra

    The Sedimentary Geochemistry and Paleoenvironments project

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    The Sedimentary Geochemistry and Paleoenvironments Project.

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    Authors thank the donors of The American Chemical Society Petroleum Research Fund for partial support of SGP website development (61017-ND2). EAS is funded by National Science Foundation grant (NSF) EAR-1922966. BGS authors (JE, PW) publish with permission of the Executive Director of the British Geological Survey, UKRI.Publisher PDFPeer reviewe
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