58 research outputs found
Aeronautical engineering: A continuing bibliography with indexes (supplement 231)
This bibliography lists 469 reports, articles, and other documents introduced into the NASA scientific and technical information system in September, 1988
Biomimetic oscillating foil propulsion to enhance underwater vehicle agility and maneuverability
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2008Inspired by the swimming abilities of marine animals, this thesis presents "Finnegan
the RoboTurtle", an autonomous underwater vehicle (AUV) powered entirely by four
flapping foils. Biomimetic actuation is shown to produce dramatic improvements in
AUV maneuvering at cruising speeds, while simultaneously allowing for agility at
low speeds. Using control algorithms linear in the modified Rodrigues parameters to
support large angle maneuvers, the vehicle is successfully controlled in banked and
twisting turns, exceeding the best reported AUV turning performance by more than
a factor of two; a minimum turning radius of 0.7BL, and the ability to avoid walls
detected> 1.8BL ahead, are found for cruising speeds of 0.75BL/S, with a maximum
heading rate of 400
/ S recorded.
Observations of "Myrtle", a 250kg Green sea turtle (Chelonia mydas) at the New
England Aquarium, are detailed; along with steady swimming, Myrtle is observed performing
1800 level turns and rapidly actuating pitch to control depth and speed. Limb
kinematics for the level turning maneuver are replicated by Finnegan, and turning
rates comparable to those of the turtle are achieved. Foil kinematics which produce
approximately sinusoidal nominal angle of attack trace are shown to improve turning
performance by as much as 25%; the effect is achieved despite limited knowledge of
the flow field. Finally, tests with a single foil are used to demonstrate that biomimetically
inspired inline motion can allow oscillating foils utilizing a power/recovery style
stroke to generate as much as 90% of the thrust from a power/power stroke style
motion
Adaptive Morphology for Multi-Modal Locomotion
There is a growing interest in using robots in dangerous environments, such as for exploration, search-and-rescue or monitoring applications, in order to reduce the risks for workers or rescuers and to improve their efficiency. Typically, flying robots offer the possibility to quickly explore large areas while ground robots can thoroughly search specific regions of interest. While existing robotic solutions are very promising, they are often limited to specific use cases or environments. This makes them impractical for most missions involving complex or unpredictable scenarios, such as search-and-rescue applications. This limitation comes from the fact that existing robots usually exploit only a single locomotion strategy, which limits their flexibility and adaptability to different environments. In this thesis, a multi-modal locomotion strategy is investigated as a way to increase the versatility of mobile robots. We explore integrated design approaches, where the same actuators and structure are used for different modes of locomotion, which allows a minimization of the weight and complexity of the robot. This strategy is challenging because a single locomotor system must accommodate the potentially conflicting dynamics of multiple modes of locomotion. Herein, we suggest taking inspiration from nature, in particular the common vampire bat \emph{Desmodus rotundus}. The goal being to make multiple modes of locomotion dynamically compatible (i.e. have compatible speeds and torques requirements), by optimizing the morphology of the locomotor system and even by adapting the morphology of the robot to a specific mode of locomotion. It is demonstrated in this thesis that the integrated design approach can be effectively implemented on a multi-modal aerial and terrestrial robot, and that two modes of locomotion can be made dynamically compatible by optimizing the morphology. Furthermore, an adaptive morphology is used to increase the efficiency of the different modes of locomotion. A locomotor system used both for walking on the ground and controlling flight, has been successfully implemented on a multi-modal robot, which further has deployable wings to increase its performances on the ground and in the air. By successfully exploiting the concepts of integrated design and adaptive morphology, this robot is capable of hovering, forward flight and ground locomotion. This robot demonstrates a very high versatility compared to state of the art of mobile robots, while having a low complexity
Aeronautical engineering: A continuing bibliography with indexes (supplement 217)
This bibliography lists 450 reports, articles, and other documents introduced into the NASA scientific and technical information system in August, 1987
Aeronautical engineering: A continuing bibliography with indexes (supplement 301)
This bibliography lists 1291 reports, articles, and other documents introduced into the NASA scientific and technical information system in Feb. 1994. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
NASA LaRC Workshop on Guidance, Navigation, Controls, and Dynamics for Atmospheric Flight, 1993
This publication is a collection of materials presented at a NASA workshop on guidance, navigation, controls, and dynamics (GNC&D) for atmospheric flight. The workshop was held at the NASA Langley Research Center on March 18-19, 1993. The workshop presentations describe the status of current research in the GNC&D area at Langley over a broad spectrum of research branches. The workshop was organized in eight sessions: overviews, general, controls, military aircraft, dynamics, guidance, systems, and a panel discussion. A highlight of the workshop was the panel discussion which addressed the following issue: 'Direction of guidance, navigation, and controls research to ensure U.S. competitiveness and leadership in aerospace technologies.
Aeronautical enginnering: A cumulative index to a continuing bibliography (supplement 312)
This is a cumulative index to the abstracts contained in NASA SP-7037 (301) through NASA SP-7073 (311) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled by the Center for AeroSpace Information of the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract number, report number, and accession number indexes
Aeronautical engineering: A continuing bibliography with indexes (supplement 204)
This bibliography lists 419 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1986
Aeronautical engineering: A continuing bibliography with indexes (supplement 233)
This bibliography lists 637 reports, articles, and other documents introduced into the NASA scientific and technical information system in November, 1988. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
Aeronautical engineering: A continuing bibliography with indexes (supplement 304)
This bibliography lists 453 reports, articles, and other documents introduced into the NASA scientific and technical information system in May 1994. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
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