402 research outputs found

    Bio-inspired Flying Robots

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    A linear systems analysis of the yaw dynamics of a dynamically scaled insect model

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    Recent studies suggest that fruit flies use subtle changes to their wing motion to actively generate forces during aerial maneuvers. In addition, it has been estimated that the passive rotational damping caused by the flapping wings of an insect is around two orders of magnitude greater than that for the body alone. At present, however, the relationships between the active regulation of wing kinematics, passive damping produced by the flapping wings and the overall trajectory of the animal are still poorly understood. In this study, we use a dynamically scaled robotic model equipped with a torque feedback mechanism to study the dynamics of yaw turns in the fruit fly Drosophila melanogaster. Four plausible mechanisms for the active generation of yaw torque are examined. The mechanisms deform the wing kinematics of hovering in order to introduce asymmetry that results in the active production of yaw torque by the flapping wings. The results demonstrate that the stroke-averaged yaw torque is well approximated by a model that is linear with respect to both the yaw velocity and the magnitude of the kinematic deformations. Dynamic measurements, in which the yaw torque produced by the flapping wings was used in real-time to determine the rotation of the robot, suggest that a first-order linear model with stroke-average coefficients accurately captures the yaw dynamics of the system. Finally, an analysis of the stroke-average dynamics suggests that both damping and inertia will be important factors during rapid body saccades of a fruit fly

    Array of carbon black-based microthrusters for CubeSat applications

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    Access to space for small private companies requires to improve the ability to bring low-cost satellites into orbit. CubeSats offer a unique opportunity to meet these needs thanks to their reduced production times, the low manufacturing costs and ease of use. In order to be able to communicate with each other, exchange information and interact, it is necessary to place CubeSats in formation: in this context, miniature propulsion technologies, including chemical and electric propulsion, play a critical role in achieving mission requirements and maintaining satellites position. In this article, the feasibility of solid propellant micro rockets, fully integrated in an opposing array of printed thrust chambers is examined: each rocket can be fired together with the others or separately to modulate thrust. Theoretical and experimental results show that the microthruster, made of nylon and carbon fiber, have good mechanical and thermal resistance and simultaneously good performance is achieved. In particular, a microthruster with a diameter of 4 mm and a length of 6 mm, with 55 g of black powder propellant, achieves a thrust of about 3.5 N for about 7 ms

    Frontier In-Situ Resource Utilization for Enabling Sustained Human Presence on Mars

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    The currently known resources on Mars are massive, including extensive quantities of water and carbon dioxide and therefore carbon, hydrogen and oxygen for life support, fuels and plastics and much else. The regolith is replete with all manner of minerals. In Situ Resource Utilization (ISRU) applicable frontier technologies include robotics, machine intelligence, nanotechnology, synthetic biology, 3-D printing/additive manufacturing and autonomy. These technologies combined with the vast natural resources should enable serious, pre- and post-human arrival ISRU to greatly increase reliability and safety and reduce cost for human colonization of Mars. Various system-level transportation concepts employing Mars produced fuel would enable Mars resources to evolve into a primary center of trade for the inner solar system for eventually nearly everything required for space faring and colonization. Mars resources and their exploitation via extensive ISRU are the key to a viable, safe and affordable, human presence beyond Earth. The purpose of this paper is four-fold: 1) to highlight the latest discoveries of water, minerals, and other materials on Mars that reshape our thinking about the value and capabilities of Mars ISRU; 2) to summarize the previous literature on Mars ISRU processes, equipment, and approaches; 3) to point to frontier ISRU technologies and approaches that can lead to safe and affordable human missions to Mars; and 4) to suggest an implementation strategy whereby the ISRU elements are phased into the mission campaign over time to enable a sustainable and increasing human presence on Mars

    Aquatic escape for micro-aerial vehicles

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    As our world is experiencing climate changes, we are in need of better monitoring technologies. Most of our planet is covered with water and robots will need to move in aquatic environments. A mobile robotic platform that possesses efficient locomotion and is capable of operating in diverse scenarios would give us an advantage in data collection that can validate climate models, emergency relief and experimental biological research. This field of application is the driving vector of this robotics research which aims to understand, produce and demonstrate solutions of aerial-aquatic autonomous vehicles. However, small robots face major challenges in operating both in water and in air, as well as transition between those fluids, mainly due to the difference of density of the media. This thesis presents the developments of new aquatic locomotion strategies at small scales that further enlarge the operational domain of conventional platforms. This comprises flight, shallow water locomotion and the transition in-between. Their operating principles, manufacturing methods and control methods are discussed and evaluated in detail. I present multiple unique aerial-aquatic robots with various water escape mechanisms, spanning over different scales. The five robotic platforms showcased share similarities that are compared. The take-off methods are analysed carefully and the underlying physics principles put into light. While all presented research fulfils a similar locomotion objective - i.e aerial and aquatic motion - their relevance depends on the environmental conditions and supposed mission. As such, the performance of each vehicle is discussed and characterised in real, relevant conditions. A novel water-reactive fuel thruster is developed for impulsive take-off, allowing consecutive and multiple jump-gliding from the water surface in rough conditions. At a smaller scale, the escape of a milligram robotic bee is achieved. In addition, a new robot class is demonstrated, that employs the same wings for flying as for passive surface sailing. This unique capability allows the flexibility of flight to be combined with long-duration surface missions, enabling autonomous prolonged aquatic monitoring.Open Acces

    Advantages and challenges of unmanned aerial vehicle autonomy in the Postheroic age

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    Over the past decade, unmanned aerial vehicles (UAVs) have revolutionized how the U.S. engages elusive militants in low-intensity conflicts by allowing the U.S. to project continuous military power without risking combat casualties. While UAV usage promises additional tactical advantages in future conflicts, little agreement exists regarding a strategic vision for UAV research and development, necessary for the U.S. to allocate limited resources among UAV development programs that address national security objectives. The present research makes the case for a future UAV technology evolutionary path leading to fully autonomous intelligence, surveillance, and reconnaissance (ISR)/strike UAV systems for the United States Air Force that are capable of sensing their environments through multiple modalities, recognizing patterns, and executing appropriate actions in response to their real-time analyses. The thesis addresses enabling technology inroads stemming from major improvements in our understanding of human neural circuitry that promise to enable innovations in the artificial intelligence needed to achieve autonomous system function. Arguments are based on projected military and economic benefits of autonomous systems and extend the historical model established by the CIA\u27s successful UAV program to unconventional warfare (UW) conflicts that the U.S. Air Force finds itself ill-equipped to handle. Counter-arguments are addressed relating to uncontrolled lethal technology, conflict initiation thresholds, and the vulnerability of overreliance on high-technology systems. In making the case for fully automated UAV technology, research provides a strategic future vision for autonomous UAV usage by highlighting the important interaction of artificial intelligence, “smart” wide-area sensors, and cooperative micro UAVs

    Nanotechnology and Preventive Arms Control

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    Nanotechnology and preventive arms control

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    "Nanotechnology (NT) is about analysis and engineering of structures with size between 0.1 and 100 nanometres (1 nm = 10 -9 m). At this scale, new effects occur and the boundaries between physics, chemistry and biology vanish. NT is predicted to lead to stronger but lighter materials, markedly smaller computers with immensely increased power, large and small autonomous robots, tools for manipulation of single molecules, targeted intervention within cells, connections between electronics and neurones, and more. In recent years military research and development (R&D) of NT has been expanded markedly, with the USA far in the lead. US work spans the full range from electronics via materials to biology. While much of this is still at the fundamental level, efforts are being made to bring applications to the armed forces soon. One quarter to one third of the Federal funding for NT goes to military R&D, and the USA outspends the rest of the world by a factor 4 to 10. NT applications will likely pervade all areas of the military. Very small electronics and computers will be used everywhere, e.g. in glasses, uniforms, munitions. Large-scale battle-management and strategy-planning systems will apply human-like reasoning at increasing levels of autonomy, integrating sensors, communication devices and displays into an ubiquitous network. Stronger but light-weight materials, more efficient energy storage and propulsion will allow faster and more agile vehicles in all media. NT-based materials and explosives can bring faster and more precise projectiles. Small arms, munitions and anti-personnel missiles without any metal can become possible. Systems worn by soldiers could monitor the body status and react to injury. Systems implanted into the body could monitor the biochemistry and release drugs, or make contacts to nerves and the brain to reduce the reaction time, later possibly to communicate complex information. Autonomous land vehicles, ships and aircraft would become possible mainly through strongly increased computing power. By using NT to miniaturise sensors, actuators and propulsion, autonomous systems (robots) could also become very small, principally down to below a millimetre - fully artificial or hybrid on the basis of e.g. insects or rats. Satellites and their launchers could become small and cheap, to be used in swarms for earth surveillance, or for anti-satellite attack. Whereas no marked change is expected concerning nuclear weapons, NT may lead to various new types of chemical and biological weapons that target specific organs or act selectively on a certain genetic or protein pattern. On the other hand, NT will allow cheap sensors for chemical or biological warfare agents as well as materials for decontamination. Most of these applications are ten or more years away. Using criteria of preventive arms control, potential military NT applications are evaluated. New conventional, chemical and biological weapons would jeopardise existing arms-control treaties. Armed autonomous systems would endanger the law of warfare. Military stability could decrease with small distributed battlefield sensors and in particular with armed autonomous systems. Arms racing and proliferation have to be feared with all applications. Strong dangers to humans would ensue from armed mini-/ micro-robots and new chemical/ biological weapons used by terrorists. Negative effects on human integrity and human rights could follow indirectly if body manipulation were applied in the military before a thorough societal debate on benefits, risks and regulation." (excerpt)"Die Nanotechnologie (NT) befasst sich mit der Untersuchung und Gestaltung von Strukturen, die sich in Größen zwischen 0,1 and 100 Nanometer (1 nm = 10 -9 m) bewegen. Bei dieser Größenordnung treten neue Effekte auf, und die Grenzen zwischen Physik, Chemie und Biologie verschwinden. Die Experten sagen voraus, dass NT festere und gleichzeitig leichtere Materialien, erheblich kleinere Computer mit unermesslich gesteigerter Leistung, große und kleine autonome Roboter, Werkzeuge für die Handhabung einzelner Moleküle, gezielte Eingriffe in Zellen, Verbindungen zwischen Elektronik und Neuronen und anderes mehr hervorbringen wird. In den letzten Jahren ist die militärische Forschung und Entwicklung (FuE) im Bereich der NT erheblich ausgeweitet worden. Im weltweiten Vergleich liegen die USA deutlich in Führung. Dort wird die gesamte Bandbreite von Elektronik über Materialien bis hin zur Biologie bearbeitet. Auch wenn vieles davon noch Grundlagenforschung ist, gibt es dort doch heute schon Vorbereitungen, den Streitkräften bald Anwendungsmöglichkeiten zur Verfügung zu stellen. Ein Viertel bis ein Drittel der Regierungsausgaben für NT auf Bundesebene steht für militärische FuE zur Verfügung, und die USA geben 4 bis 10 mal so viel dafür aus wie der Rest der Welt. NT-Anwendungen werden alle Bereiche des Militärs durchdringen. Hierzu zählt der umfassende Einsatz sehr kleiner Elektronik und Computer, z.B. in Brillen, Uniformen, Munition. Komplexe Schlachtführungs- und Strategieplanungssysteme werden zunehmend autonom funktionieren und menschenähnliche Überlegungen anstellen, wobei sie Sensoren, Kommunikationsgeräte und Anzeigeeinheiten zu einem allgegenwärtigen Netzwerk verbinden. Festere und dabei leichtere Materialien, effizientere Energiespeicher und Antriebe ermöglichen den Bau schnellerer und beweglicherer Land-, Wasser-, Luft- und Raumfahrzeuge. Des weiteren können NT-basierte Materialien und Sprengstoffe zur Herstellung schnellerer und genauerer Geschosse verwendet werden. Denkbar sind metallfreie Kleinwaffen, Munition und Antipersonen-Flugkörper. Zwar ist bei Kernwaffen keine große Veränderung zu erwarten, NT kann aber zu verschiedenen neuen Arten von chemischen und biologischen Waffen führen, die auf spezifische Organe zielen oder selektiv auf eine bestimmte Eiweißstruktur oder auf ein genetisches Muster hin aktiv werden. Andererseits wird NT billige Sensoren für chemische oder biologische Waffen sowie Materialien zur Entgiftung zur Verfügung stellen. Mit den meisten dieser Anwendungen ist erst in einem Zeitraum von zehn oder mehr Jahren zu rechnen. Mögliche militärische NT-Anwendungen müssen unter den Kriterien der Präventiven Rüstungskontrolle bewertet werden." (Textauszug
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