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Chan, Nicholas Y. S. "Scaling considerations for small aircraft engines." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45236.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2008.Includes bibliographical references (p. 81-84).
Small aircraft engines traditionally have poorer performance compared to larger engines, which until recently, has been a factor that outweighed the aerodynamic benefits of commoditized and distributed propulsion. Improvements in the performance of small engines have, however, prompted another look at this old concept. This thesis examines aspects of aircraft engines that may have application to commodity thrust or distributed propulsion applications. Trends of engine performance with size and time are investigated. These trends are further extended to justify parameter choices for conceptual engines of the current, mid-term (10 years) and far-term (20 years). Uninstalled and installed performances are evaluated for these engines, and parametric studies are performed to determine the most influential and limiting factors. It is found that scaling down of engines is detrimental to SFC and fuel burn, mainly due to the Reynolds number effect. The more scaling done, the more prominent the effect. It is determined that new technology such as higher TIT, OPR and turbomachinery [eta]poly's for small aircraft engines enable the operation of larger bypass ratios, which is the most influential parameter to SFC and fuel bum. The increase of bypass ratio up to a value of 8 is found to be effective for such improvement. SFC decrease from the current to mid-term model is found to be ~20% and ~9% from mid-term to far-term. Range and endurance improvements are found to be ~30% and ~10% respectively for the mission examined. Finally, the mid-term engine model has performance comparable to that of a current, larger state-of-the-art engine, thus suggesting that improvement in small gas turbine technology in the next 10 years will make the application of commodity thrust or distributed propulsion an attractive option for future aircraft.
by Nicholas Y.S. Chan.
S.M.
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Gavrilets, Vladislav 1975. "Avionics systems development for small unmanned aircraft." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50382.
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Munisami, Ari. "Aircraft financing: Perspectives for small and emerging economies." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95158.
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ABSTRACT The worst recession that affected the world's economy since the Great Depression has had an even more devastating effect on the aviation industry. Following such a crisis, one of the most significant challenges awaiting airlines worldwide in the coming decade is the financing of their enormous fleet replacement and expansion activities. And this demands a tremendous effort, given that airline earnings are cyclical and, industry returns on capital investments have traditionally been poor. As international markets develop, especially in the emerging economies, there is a need for a constant search for new sources and methods to finance and acquire new equipment. Aircraft financiers and investors have always been wary to invest in developing countries. Aircraft are highly movable assets that can travel to various jurisdictions and this faculty has always posed a threat on lessors and owners' property interest, the more so, in small and emerging countries in Africa, Asia and Latin America. The challenges are obvious and seem insurmountable. Aircraft financing legal structures and practices that have worked in developed countries may be structured to apply to the benefit of States of small emerging economies. The point has been made for several years now in numerous international conferences that there is a lacuna in this area. This thesis seeks to address some of the legal aspects of aircraft financing generally and, in these small and emerging economies.RESUME La pire des récessions qu'ait connu le monde depuis la grande dépression des années trente a eu un effet encore plus dévastatrice sur l'industrie aéronautique. Après une crise de cette ampleur, le défi de taille auquel doivent faire face les compagnies aériennes de par le monde dans la prochaine décennie est le financement du renouvellement et de l'expansion de leur flotte d'aéronefs. Et ceci demande un effort colossal, vu la nature aléatoire et incertaine des recettes des compagnies aériennes. Aussi, le retour sur les investissements capitaux ont été traditionnellement bien moindres. En ligne avec le développement continuel des marchés internationaux, particulièrement dans les pays émergents, il y a un besoin pour une recherche constante de nouvelles sources et de nouveaux modes de financement et d'acquisition d'aéronefs. Les investisseurs ont été très réticents à investir dans les pays en développement. Les avions sont des biens mobiliers et ceux-ci peuvent donc aisément passer d'une juridiction à l'autre. Ce caractère particulier a constamment posé une menace aux droits de propriété des bailleurs et propriétaires de l'avion, et c'est encore plus prononcé dans des pays émergents en Afrique, Asie ou Amérique Latine. Les défis sont évidents et apparaissent insurmontables. Des structures légales de financement d'aéronefs et des pratiques qui ont fait leurs preuves dans les pays développés peuvent être remodelées pour le bénéfice des petits états émergents. C'est un point qui a été constamment débattu dans des conférences internationales et il y a un manquement dans ce domaine. Cette présente thèse est une tentative d'adresser quelques uns des aspects légaux relatif au financement d'aéronefs en général, et dans ces pays émergents.
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Zelnio, Anne M. "Detection of Small Aircraft using an Acoustic Array." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1247075795.
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Foster, Tyler M. "Dynamic stability and handling qualities of small unmanned-aerial-vehicles /." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd643.pdf.
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Beneke, Jeremy Michael. "Small diameter particle dispersion in a commercial aircraft cabin." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4150.
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Lusk, Parker Chase. "Vision-Based Emergency Landing of Small Unmanned Aircraft Systems." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7029.
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Emergency landing is a critical safety mechanism for aerial vehicles. Commercial aircraft have triply-redundant systems that greatly increase the probability that the pilot will be able to land the aircraft at a designated airfield in the event of an emergency. In general aviation, the chances of always reaching a designated airfield are lower, but the successful pilot might use landmarks and other visual information to safely land in unprepared locations. For small unmanned aircraft systems (sUAS), triply- or even doubly-redundant systems are unlikely due to size, weight, and power constraints. Additionally, there is a growing demand for beyond visual line of sight (BVLOS) operations, where an sUAS operator would be unable to guide the vehicle safely to the ground. This thesis presents a machine vision-based approach to emergency landing for small unmanned aircraft systems. In the event of an emergency, the vehicle uses a pre-compiled database of potential landing sites to select the most accessible location to land based on vehicle health. Because it is impossible to know the current state of any ground environment, a camera is used for real-time visual feedback. Using the recently developed Recursive-RANSAC algorithm, an arbitrary number of moving ground obstacles can be visually detected and tracked. If obstacles are present in the selected ditch site, the emergency landing system chooses a new ditch site to mitigate risk. This system is called Safe2Ditch.
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DiOrio, Austin Graf. "Small core axial compressors for high efficiency jet aircraft." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77107.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2012.Cataloged from department-submitted PDF version of thesis. This electronic version was submitted and approved by the author's academic department as part of an electronic thesis pilot project. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 115-117).
This thesis quantifies mechanisms that limit efficiency in small core axial compressors, defined here as compressor exit corrected flow between 1.5 and 3.0 lbm/s. The first part of the thesis describes why a small engine core with high overall pressure ratio (OPR) is desirable for an efficient aircraft and shows that fuel burn can be reduced by up to 17% compared to current engines. The second part examines two specific effects: Reynolds number and tip clearance. At a core size of 1.5 lbm/s, Reynolds number may be as low as 160,000, resulting in reductions in stage efficiency up to 1.9% for blades designed for high Reynolds number flow. The calculations carried out indicate that blades optimized for this Reynolds number can increase stage efficiency by up to 1.6%. For small core compressors, non-dimensional tip clearances are increased, and it is estimated that tip clearances can be up to 4.5% clearance-to-span ratio at the last stage of a 1.5 lbm/s high pressure compressor. The efficiency penalty due to tip clearance is assessed computationally and a 1.6% decrease in polytropic efficiency is found for a 1% increase in gap-to-span ratio. At the above clearance, these efficiency penalties increase aircraft mission fuel burn by 3.4%, if current design guidelines are employed. This penalty, however, may be reduced to 0.4% if optimized blades and a smaller compressor radius than implied by geometric scaling, which allows reduced non-dimensional clearance, are implemented. Based on the results, it is suggested that experiments and computations should be directed at assessing: (i) the effects of clearance at values representative of these core sizes, and (ii) the effect of size on the ability to achieve a specific blade geometry and thus the impact on loss.
by Austin Graf DiOrio.
S.M.
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Landolfo, Giuseppe. "Aerodynamic and Structural Design of a Small Nonplanar Wing UAV." University of Dayton / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1262089704.
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Jenkins, Glenn E., and William J. Snodgrass. "The Raven Small Unmanned Aerial Vehicle (SUAV), investigating potential dichotomies between doctrine and practice." Monterey, California. Naval Postgraduate School, 2005. http://hdl.handle.net/10945/834.
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MBA Professional ReportThe goal of this MBA Project is to investigate possible disconnects between doctrine and practice in the employment of the Raven Small Unmanned Aerial Vehicle (SUAV). The Army's current Small UAV requirements are based upon the Future Combat System's Operations Requirements Document and has not been validated at the platoon or company level. The Raven SUAV is a Commercial off the Shelf (COTS) item that swiftly became the Army's Small UAV of choice for operations in Afghanistan and Iraq. Doctrine and Techniques, Tactics, and Procedures (TTP) have been written for the Raven SUAV; however, it is not standard practice for all units operating the system abroad. The last review of the SUAV operational requirements was conducted in 2003 but did not specifically address its usage on the battlefield. In an attempt to fill that gap, this project focuses on real-world usage of the Raven SUAV system. We compare doctrine versus practice using the Department of Defense's (DOD) Doctrine, Organization, Training, Material, Leadership, Personnel, Facilities (DOTML-PF) model as the primary logic construct. The report begins by providing a background of the Raven SUAV, to include its evolution from a COTS item to the Army's SUAV of choice, and how it has impacted the warfighter. Next, the authors provide an overview of DOTML-PF in order to provide a basis for comparing doctrine and practice. The study then looks in-depth at doctrine and practice using DOTML-PF as the model for revealing differences between the two. Finally, the authors analyze these differences and recommend solutions to mitigate shortfalls in actual Raven SUAV usage on the battlefield.--p. i.
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Schömann, Joachim [Verfasser]. "Hybrid-Electric Propulsion Systems for Small Unmanned Aircraft / Joachim Schömann." München : Verlag Dr. Hut, 2014. http://d-nb.info/1063222060/34.
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Dermentzoudis, Marinos. "Establishment of models and data tracking for small UAV reliability." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FDermentzoudis.pdf.
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Thesis (M.S. in Operations Research and M.S. in Systems Engineering)--Naval Postgraduate School, June 2004.Thesis advisor(s): David Olwell. Includes bibliographical references (p. 217-224). Also available online.
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Jackson, Joseph A. "Panoramic video for efficient ground surveillance from small unmanned air vehicles /." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1811.pdf.
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Tang, Yi Rui. "Development, dynamic modeling, and autonomous flight control of small UAV helicopters." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691051.
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Cason, Roman K. "Analysis of the Vertical Takeoff and landing Unmanned Aerial Vehicle (VTUAV) in small unti urban operations." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Sept%5FCason.pdf.
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Romanoski, Glenn Roy. "The fatigue behavior of small cracks in aircraft turbine disk alloys." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/32577.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990.Includes bibliographical references (leaves 245-258).
by Glenn R. Romanoski, Jr.
Ph.D.
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Forsberg, Fredrik. "Providing Air Traffic Control Services for Small Unmanned Aircraft Through LTE." Thesis, Luleå tekniska universitet, Rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-60039.
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Mcclelland, Hunter Grant. "Towards Detecting Atmospheric Coherent Structures using Small Fixed-Wing Unmanned Aircraft." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/90667.
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The theory of Lagrangian Coherent Structures (LCS) enables prediction of material transport by turbulent winds, such as those observed in the Earth's Atmospheric Boundary Layer. In this dissertation, both theory and experimental methods are developed for utilizing small fixed-wing unmanned aircraft systems (UAS) in detecting these atmospheric coherent structures. The dissertation begins by presenting relevant literature on both LCS and airborne wind estimation. Because model-based wind estimation inherently depends on high quality models, a Flight Dynamic Model (FDM) suitable for a small fixed-wing aircraft in turbulent wind is derived in detail. In this presentation, some new theoretical concepts are introduced concerning the proper treatment of spatial wind gradients, and a critical review of existing theories is presented. To enable model-based wind estimation experiments, an experimental approach is detailed for identifying a FDM for a small UAS by combining existing computational aerodynamic and data-driven approaches. Additionally, a methodology for determining wind estimation error directly resulting from dynamic modeling choices is presented and demonstrated. Next, some model-based wind estimation results are presented utilizing the experimentally identified FDM, accompanied by a discussion of model fidelity concerns and other experimental issues. Finally, an algorithm for detecting LCS from a single circling fixed-wing UAS is developed and demonstrated in an Observing System Simulation Experiment. The dissertation concludes by summarizing these contributions and recommending future paths for continuing research.Doctor of Philosophy
In a natural or man-made disaster, first responders depend on accurate predictions of where the wind might carry hazardous material. A mathematical theory of Lagrangian Coherent Structures (LCS) has shown promise in ocean environments to improve these predictions, and the theory is also applicable to atmospheric flows near the Earth’s surface. This dissertation presents both theoretical and experimental research efforts towards employing small fixed-wing unmanned aircraft systems (UAS) to detect coherent structures in the Atmospheric Boundary Layer (ABL). These UAS fit several “gaps” in available sensing technology: a small aircraft responds significantly to wind gusts, can be steered to regions of interest, and can be flown in dangerous environments without risking the pilot’s safety. A key focus of this dissertation is to improve the quality of airborne wind measurements provided by inexpensive UAS, specifically by leveraging mathematical models of the aircraft. The dissertation opens by presenting the motivation for this research and existing literature on the topics. Next, a detailed derivation of a suitable Flight Dynamic Model (FDM) for a fixed-wing aircraft in a turbulent wind field is presented. Special attention is paid to the theories for including aerodynamic effects of flying in non-uniform winds. In preparation for wind measurement experiments, a practical method for obtaining better quality FDMs is presented which combines theoretically based and data-driven approaches. A study into the wind-measurement error incurred solely by mathematical modeling is presented, focusing on simplified forms of the FDM which are common in aerospace engineering. Wind estimates which utilize our best available model are presented, accompanied by discussions of the model accuracy and additional wind measurement concerns. A method is developed to detect coherent structures from a circling UAS which is providing wind information, presumably via accurate model based estimation. The dissertation concludes by discussing these conclusions and directions for future research which have been identified during these pursuits.
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Gates, Melinda M. "The Effect of Icing on the Dispatch Reliability of Small Aircraft." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/35946.
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In 2000, the National Aeronautics and Space Administration (NASA) initiated a program to promote the use of small aircraft as an additional option for national public transportation. The Small Aircraft Transportation System (SATS) asserted the idea of everyday individuals piloting themselves on trips, within a specified distance range, using a small (4 person), piston powered, un-pressurized aircraft and small airports in close proximity to their origin and destination.
This thesis investigates how one weather phenomenon, in-flight icing, affects the dispatch reliability of this transportation system. Specifically, this research presumes that a route is considered a "no-go" for low time pilots in a small, piston powered aircraft if any icing conditions are forecast along the route at the altitude of the flight during the time the traveler desires to make the trip.
This thesis evaluates direct flights between Cleveland and Boston; Boston and Washington, D.C.; and Washington, D.C. and Cleveland during the months of November through May for the years 2001 to 2003 at maximum cruising altitudes of 6,000 feet, 8,000 feet, 10,000 feet, and 12,000 feet above mean sea level (MSL). It was found that the overall probability of a "no-go" for all three flight paths at the normal cruising altitude of 12,000 feet is 56.8%. When the cruising altitude is reduced to 10,000 feet, 8,000 feet, and 6,000 feet the probability of a "no-go" for all three flight paths reduces to 54.6%, 48.5%, and 43.7% respectively.
Master of Science
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Kang, Changkoo. "Small UAV Trajcetory Prediction and Avoidance using Monocular Computer Vision." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/79950.
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Small unmanned aircraft systems (UAS) must be able to detect and avoid conflicting traffic, an especially challenging task when the threat is another small UAS. Collision avoidance requires trajectory prediction and the performance of a collision avoidance system can be improved by extending the prediction horizon. In this thesis, an algorithm for predicting the trajectory of a small, fixed-wing UAS using an estimate of its orientation and for maneuvering around the threat, if necessary, is developed. A computer vision algorithm locates specific feature points of a threat aircraft in an image and the POSIT algorithm uses these feature points to estimate the pose (position and attitude) of the threat. A sequence of pose estimates is then used to predict the trajectory of the threat aircraft and to avoid colliding with it. To assess the algorithm's performance, the predictions are compared with predictions based solely on position estimates for a variety of encounter scenarios. Simulation and experimental results indicate that trajectory prediction using orientation estimates provides quicker response to a change in the threat aircraft trajectory and results in better prediction and avoidance performance.Master of Science
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Weimer, Florian [Verfasser]. "Nonlinear State and Parameter Estimation for Small Unmanned Aircraft Systems / Florian Weimer." Aachen : Shaker, 2016. http://d-nb.info/1098038967/34.
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Ayeni, Temitope, and Nolan Roggenkamp. "The future of small Navy ship sickbays and Army aeromedical evacuation aircraft." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44516.
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Approved for public release; distribution is unlimitedThe Office of the Chief of Naval Operations commissioned a study to investigate the future configuration of Navy ship sickbays. Due to space constraints, sickbay capabilities are limited. Similarly, Army aeromedical evacuation helicopters have limited space to treat patients. This joint study explores how to best utilize advanced medical technologies in the sickbay of the future for the Navy’s cruiser, littoral combat ship, and mine countermeasure ship and Army aeromedical evacuation platforms. This study assesses the current portable medical technologies in the selected Navy ship authorized medical allowance lists to support the force health protection functions. The study also evaluates portable medical devices in Army aeromedical evacuation medical equipment sets. Collectively, capability gaps are identified and serve as the baseline for recommending future medical technologies. This study recommends medical devices with the potential to advance patient care and proposes significant investments in bandwidth, network, and infrastructure. Smart technologies will be important in space-constrained medical environments; however, organizational restructuring and policy change is required to address the root cause of outdated medical systems. This study also recommends more inter-service collaboration, the establishment of an aeromedical evacuation program of record, and the utilization of open systems architecture for procuring future medical devices.
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Duffield, Matthew Owen. "Automatic Dependent Surveillance-Broadcast for Detect and Avoid on Small Unmanned Aircraft." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6365.
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Small unmanned aircraft systems (UAS) are rapidly gaining popularity. As the excitement surrounding small UAS has grown, the Federal Aviation Administration (FAA) has repeatedly stated that UAS must be capable of detecting and avoiding manned and unmanned aircraft. In developing detect-and-avoid (DAA) technology, one of the key challenges is identifying a suitable sensor. Automatic Dependent Surveillance-Broadcast (ADS-B) has gained much attention in both the research and consumer sectors as a promising solution. While ADS-B has many positive characteristics, further analysis is necessary to determine if it is suitable as a DAA sensor in environments with high-density small UAS operations. To further the understanding of ADS-B, we present a characterization of ADS-B measurement error that is derived from FAA regulations. Additionally, we analyze ADS-B by examining its strengths and weaknesses from the perspective of DAA on small UAS. To demonstrate the need and method for estimation of ADS-B measurements, we compare four dynamic filters for accuracy and computational speed. The result of the comparison is a recommendation for the best filter for ADS-B estimation. We then demonstrate this filter by estimating ADS-B measurements that have been recorded from the National Airspace System (NAS). We also present a novel long-range, convex optimization-based path planner for ADS-B-equipped small UAS in the presence of intruder aircraft. This optimizer is tested using a twelve-state simulation of the ownship and intruders.We also consider the effectiveness of ADS-B in high-density airspace. To do this we present a novel derivation of the probability of interference for ADS-B based on the number of transmitting aircraft. We then use this probability to document the need for limited transmit range for ADS-B on small UAS. We further leverage the probability of interference for ADS-B, by creating a tool that can be used to analyze self-separation threshold (SST) and well clear (WC) definitions based on ADS-B bandwidth limitations. This tool is then demonstrated by evaluating current SST and WC definitions and making regulations recommendations based on the analysis. Coupling this tool with minimum detection range equations, we make a recommendation for well clear for small UAS in ADS-B congested airspace. Overall these contributions expand the understanding of ADS-B as a DAA sensor, provide viable solutions for known and previously unknown ADS-B challenges, and advance the state of the art for small UAS.
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Klaus, Robert Andrew. "Development of a Sense and Avoid System for Small Unmanned Aircraft Systems." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3761.
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Unmanned aircraft systems (UAS) represent the future of modern aviation. Over the past 10 years their use abroad by the military has become commonplace for surveillance and combat. Unfortunately, their use at home has been far more restrictive. Due to safety and regulatory concerns, UAS are prohibited from flying in the National Airspace System without special authorization from the FAA. One main reason for this is the lack of an on-board pilot to "see and avoid" other air traffic and thereby maintain the safety of the skies. Development of a comparable capability, known as "Sense and Avoid" (SAA), has therefore become a major area of focus. This research focuses on the SAA problem as it applies specifically to small UAS. Given the size, weight, and power constraints on these aircraft, current approaches fail to provide a viable option. To aid in the development of a SAA system for small UAS, various simulation and hardware tools are discussed. The modifications to the MAGICC Lab's simulation environment to provide support for multiple agents is outlined. The use of C-MEX s-Functions to improve simulation performance and code portability is also presented. For hardware tests, two RC airframes were constructed and retrofitted with autopilots to allow autonomous flight. The development of a program to interface with the ground control software and run the collision avoidance algorithms is discussed as well. Intruder sensing is accomplished using a low-power, low-resolution radar for detection and an Extended Kalman Filter (EKF) for tracking. The radar provides good measurements for range and closing speed, but bearing measurements are poor due to the low-resolution. A novel method for improving the bearing approximation using the raw radar returns is developed and tested. A four-state EKF used to track the intruder's position and trajectory is derived and used to provide estimates to the collision avoidance planner. Simulation results and results from flight tests using a simulated radar are both presented. To effectively plan collision avoidance paths a tree-branching path planner is developed. Techniques for predicting the intruder position and creating safe, collision-free paths using the estimates provided by the EKF are presented. A method for calculating the cost of flying each path is developed to allow the selection of the best candidate path. As multiple duplicate paths can be created using the branching planner, a strategy to remove these paths and greatly increase computation speed is discussed. Both simulation and hardware results are presented for validation.
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Wolfe, Neil A. "Development of a Tailored Flight Test Approach for small Unmanned Aircraft Systems." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2073.
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This document contains the details of a study conducted to determine an effective performance flight test approach specifically for small Unmanned Aircraft Systems (sUAS). This was done by taking proven procedures and documentation from the FAA and the Air Force for manned aircraft and tailoring them specifically for use with sUAS flight test programs. A ‘sUAS Flight Testing Handbook’ was created from the proceedings to aid commercial organizations and recreational developers conducting sUAS research without access to flight test experience. A performance flight test program was conducted with the AeroVironment RQ-20 Puma sUAS using the developed approach to verify that the ‘sUAS Flight Test Handbook’ was effective at guiding the test program safely and effectively. The development of the handbook, the results of the Puma Flight Test Program (PFTP), and the instructional ‘sUAS Flight Test Handbook’ itself are detailed throughout this report. The handbook includes a set of recommendations developed from experience with the PFTP that apply to both commercial and recreational developers of sUAS. A set of documentation is also provided in the form of instructional templates that plan the test program, report the results, and allow sUAS performance flight testing to be carried out safely and effectively.
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Vernacchia, Matthew T. "Development of low-thrust solid rocket motors for small, fast aircraft propulsion." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127069.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, May, 2020Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 281-289).
Small, uncrewed aerial vehicles (UAVs) are expanding the capabilities of aircraft systems. However, a gap exists in the size and capability of aircraft: no small aircraft are capable of sustained fast flight. A small, fast aircraft requires a propulsion system which is both miniature and high-power, requirements which current UAV propulsion technologies do not meet. Solid propellant rocket motors could be used, but must be re-engineered to operate at much lower thrust and for much longer burn times than conventional small solid rocket motors. This imposes unique demands on the motor and propellant. This work investigates technological challenges of small, low-thrust solid rocket motors: slow-burn solid propellants, motors which have low thrust relative to their size (and thus have low chamber pressure), thermal protection for the motor case, and small nozzles which can withstand long burn times.
Slow-burn propellants were developed using ammonium perchlorate oxidizer and the burn rate suppressant oxamide. By varying the amount of oxamide (from 0-20%), burn rates from 4mms⁻¹ to 1mms⁻¹ (at 1MPa) were achieved. Using these propellants, a low-thrust motor successfully operated at a (thrust / burn area) ratio 10 times less than that of typical solid rocket motors. This motor can provide 5-10N of thrust for 1-3 minutes. An ablative thermal protection liner was tested in these firings. Despite the long burn time, only a few millimeters of ablative are needed. A new ceramic-insulated nozzle was demonstrated on this motor. The nozzle has a small throat diameter (only a few millimeters) and can operate in thermal steady-state. Models were developed for the propellant burn rate, motor design, heat transfer within the motor and nozzle, and for thermal stresses in the nozzle insulation.
This work shows that small, low-thrust solid motors are feasible, by demonstrating these key technologies in a prototype motor. Further, the experimental results and models will enable engineers to design and predict the performance of solid rocket motors for small, fast aircraft. By providing insight into the physics of these motors, this thesis may help to enable a new option for aircraft propulsion.
by Matthew T. Vernacchia.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics
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Shea, Eric Joseph. "Air Surveillance for Smart Landing Facilities in the Small Aircraft Transportation System." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/31838.
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The Small Aircraft Transportation System (SATS) is a partnership among various organizations including NASA, the FAA, US aviation industry, state and local aviation officials, and universities. The program objectives are intend to reduce travel times by providing high-speed, safe travel alternatives by making use of small aircraft and underused small airports throughout the nation. A major component of the SATS program is the Smart Landing Facility (SLF). The SLF is a small airport that has been upgraded to handle SATS traffic. One of the services needed at SLFs is air surveillance of the airspace surrounding it.
This thesis researches the different surveillance techniques available for use at the SLFs. The main focuses of this paper are an evaluation of the Traffic Alert and Collision Avoidance System (TCAS) when used as a ground sensor at SLFs and the design of a Position and Identification Reporting Beacon (PIRB). The use of the TCAS ground sensor is modeled in Matlab and the results of that model are discussed. The PIRB is a new system that can be used in conjunction with the Automatic Dependent Surveillance-Broadcast (ADS-B) system or independently to provide position information for all aircraft using GPS based positioning.Master of Science
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van, Wyk David. "Guidance, navigation and control of a small, unmanned blended wing body aircraft." Master's thesis, Faculty of Engineering and the Built Environment, 2020. http://hdl.handle.net/11427/32426.
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The purpose of this research is to document the design and optimisation of a full suite of guidance, navigation and control (GNC) algorithms for a small unmanned aerial vehicle (UAV), the Skywalker X8. This was performed so as to fill a void in the available literature on the selected airframe, which currently only focuses on aspects such as aerodynamic modelling, advanced controller design, or uses of the airframe to perform higher level tasks. All of these research areas make use of off-the-shelf flight controllers, but these are not always the most appropriate foundations for more advanced work as they are inherently sluggish so as to be broadly applicable to a variety of airframes. Subsequently, the Skywalker X8 airframe was modelled, using existing literature, and then characterised so as to establish what the goals might be for an optimal set of controllers. An autopilot was then designed which was optimised so as to be as close to the identified optimal performance characteristics as possible, with effort being put into ensuring that all non-linearities and disturbances were taken into account. This included advanced modelling of sensors, actuators, the environment, and the system itself. The autopilot design was then extended with a set of guidance and navigation algorithms, also developed as part of this research. This consisted of both path planning and path following algorithms which allowed for the synthesis of general classes of paths useful to the application. With both the autopilot and guidance laws developed, the system could be tested under several atmospheric flight conditions. These took the form of various wind directions and intensity levels being applied to the airframe whilst transitioning between a range of different waypoint configurations. The system was subsequently shown to be able to follow a set of waypoints very accurately, even with winds and turbulence with magnitudes of in excess of 60% of the aircraft's nominal airspeed. With a strong autopilot designed and illustrated in a high fidelity simulation environment, this work can now easily be extended into many fields. All of the tools used for this research are available and well documented, and the processes followed repeatable with all justification available in the text. As such, should a project which aims to extend this work wish to adjust the autopilot design or guidance laws, based on different requirements, this is easily accomplished and recommendations of starting points are provided. The system model and autopilot are also made available and are usable exactly as they are should one wish to undertake additional research which does not aim to modify, but to extend this work.
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Chopra, Shubh. "Development of mobile applications for crop scouting with small unmanned aircraft systems." Kansas State University, 2017. http://hdl.handle.net/2097/35507.
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Master of ScienceDepartment of Computer Science
Antonio R. Asebedo
Mitchell L. Neilsen
Small unmanned aircraft systems (sUAS) have been in commercial use since the1980’s and over 8-12% of its current uses are in the agricultural sector, but only involving limited uses like surveying, mapping and imaging, which is expected to increase to 47% according to AUVSI with the association of Artificial Intelligence over the next decade. Our research is one such effort to help farmers utilize advanced sUAS technology coupled with Artificial Intelligence and give them meaningful results in a widely used and user friendly interface, like a mobile application. The vision for this application is to provide a completely automated experience to the farmer for a repetitive and periodic analysis of his/her crops where all the instruction needed from the farmer is a push of a button on a one time configured application and ultimately providing results in seconds. This would help the farmer scout their crops, assess yield potential, and determine if additional inputs are needed for increasing grain yield and profit per acre. For making this application we focused on user-friendliness by abstracting crop algorithms, minimized necessary user inputs, and automate the construction of flight paths. Due to internet connection not always being available at farm fields, processing was kept to on-board compute systems and the mobile device to give live results to farmers without reliance on cloud-based analytics. The application is configured to work with DJI Aircraft using OpenCv for video processing and mobile vision, GIS and GPS data for accurate mapping, locating device, sUAS on the mobile application, and FFMPEG for encoding and decoding compressed video data. An algorithm developed by Precision-Ag Lab at the K-State Agronomy Department was implemented into the sUAS application for providing real time yield estimations and nitrogen recommendation algorithm for winter wheat.
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Kingston, Derek Bastian. "Implementation issues of real-time trajectory generation on small UAVs /." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd357.pdf.
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Quek, Chin Khoon. "Vision based control and target range estimation for small unmanned aerial vehicle." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Dec%5FQuek.pdf.
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Thesis (M.S. in Engineering Science (Mechanical Engineering))--Naval Postgraduate School, December 2005.Thesis Advisor(s): Isaac I. Kaminer. Includes bibliographical references (p.39). Also available online.
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Gallimore, Craig Allen. "Passive Viscoelastic Constrained Layer Damping Application for a Small Aircraft Landing Gear System." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/35350.
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The main purpose of this report was to test several common viscoelastic polymers and identify key attributes of their applicability to a small aircraft landing gear system for improved damping performance. The applied viscoelastic damping treatment to the gear was of a constrained layer type, promoting increased shear deformation over free surface treatments, and therefore enhanced energy dissipation within the viscoelastic layer. A total of eight materials were tested and analyzed using cyclic loading equipment to establish approximate storage modulus and loss factor data at varying loading frequencies. The three viscoelastic polymers having the highest loss factor to shear modulus ratio were chosen and tested using a cantilever beam system. A Ross, Kerwin, and Ungar analysis was used to predict the loss factor of the cantilever beam system with applied treatment and the predictions were compared to experimental data.
Customer requirements often govern the scope and intensity of design in many engineering applications. Limitations and constraints, such as cost, weight, serviceability, landing gear geometry, environmental factors, and manufacturability in regards to the addition of a viscoelastic damping treatment to a landing gear system are discussed.
Based on results found from theoretical and experimental testing, application of a damping treatment to a small aircraft landing gear system is very promising. Relatively high loss factors were seen in a cantilever beam for simple single layer constrained treatments for very low strain amplitudes relative to strains seen during loading of the landing gear. With future design iterations, damping levels several times those seen in this document will be seen with a constrained treatment applied to a landing gear system.Master of Science
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Burke, David Alexander. "System Level Airworthiness Tool: A Comprehensive Approach to Small Unmanned Aircraft System Airworthiness." NCSU, 2010. http://www.lib.ncsu.edu/theses/available/etd-03032010-142548/.
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One of the pillars of aviation safety is assuring sound engineering practices through airworthiness certification. As Unmanned Aircraft Systems (UAS) grow in popularity, the need for airworthiness standards and verification methods tailored for UAS becomes critical. While airworthiness practices for large UAS may be similar to manned aircraft, it is clear that small UAS require a paradigm shift from the airworthiness practices of manned aircraft. Although small in comparison to manned aircraft these aircraft are not merely remote controlled toys. Small UAS may be complex aircraft flying in the National Airspace System (NAS) over populated areas for extended durations and beyond line of sight of the operators. A comprehensive systems engineering framework for certifying small UAS at the system level is needed. This work presents a point based tool that evaluates small UAS by rewarding good engineering practices in design, analysis, and testing. The airworthiness requirements scale with vehicle size and operational area, while allowing flexibility for new technologies and unique configurations.
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Wikle, Jared Kevin. "Integration of a Complete Detect and Avoid System for Small Unmanned Aircraft Systems." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6361.
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For unmanned aircraft systems to gain full access to the National Airspace System (NAS), they must have the capability to detect and avoid other aircraft. This research focuses on the development of a detect-and-avoid (DAA) system for small unmanned aircraft systems. To safely avoid another aircraft, an unmanned aircraft must detect the intruder aircraft with ample time and distance. Two analytical methods for finding the minimum detection range needed are described. The first method, time-based geometric velocity vectors (TGVV), includes the bank-angle dynamics of the ownship while the second, geometric velocity vectors (GVV), assumes an instantaneous bank-angle maneuver. The solution using the first method must be found numerically, while the second has a closed-form analytical solution. These methods are compared to two existing methods. Results show the time-based geometric velocity vectors approach is precise, and the geometric velocity vectors approach is a good approximation under many conditions. The DAA problem requires the use of a robust target detection and tracking algorithm for tracking multiple maneuvering aircraft in the presence of noisy, cluttered, and missed measurements. Additionally these algorithms needs to be able to detect overtaking intruders, which has been resolved by using multiple radar sensors around the aircraft. To achieve these goals the formulation of a nonlinear extension to R-RANSAC has been performed, known as extended recursive-RANSAC (ER-RANSAC). The primary modifications needed for this ER-RANSAC implementation include the use of an EKF, nonlinear inlier functions, and the Gauss-Newton method for model hypothesis and generation. A fully functional DAA system includes target detection and tracking, collision detection, and collision avoidance. In this research we demonstrate the integration of each of the DAA-system subcomponents into fully functional simulation and hardware implementations using a ground-based radar setup. This integration resulted in various modifications of the radar DSP, collision detection, and collision avoidance algorithms, to improve the performance of the fully integrated DAA system. Using these subcomponents we present flight results of a complete ground-based radar DAA system, using actual radar hardware.
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Morgan, Hayden Matthew. "Small-Target Detection and Observation with Vision-Enabled Fixed-Wing Unmanned Aircraft Systems." BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/8998.
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This thesis focuses on vision-based detection and observation of small, slow-moving targets using a gimballed fixed-wing unmanned aircraft system (UAS). Generally, visual tracking algorithms are tuned to detect motion of relatively large objects in the scene with noticeably significant motion; therefore, applications such as high-altitude visual searches for human motion often ignore target motion as noise. Furthermore, after a target is identified, arbitrary maneuvers for transitioning to overhead orbits for better observation may result in temporary or permanent loss of target visibility. We present guidelines for tuning parameters of the Visual Multiple Target Tracking (Visual MTT) algorithm to enhance its detection capabilities for very small, slow-moving targets in high-resolution images. We show that the tuning approach is able to detect walking motion of a human described by 10-15 pixels from high altitudes. An algorithm is then presented for defining rotational bounds on the controllable degrees of freedom of an aircraft and gimballed camera system for maintaining visibility of a known ground target. Critical rotations associated with the fastest loss or acquisition of target visibility are also defined. The accuracy of these bounds are demonstrated in simulation and simple applications of the algorithm are described for UAS. We also present a path planning and control framework for defining and following both dynamically and visually feasibly transition trajectories from an arbitrary point to an orbit over a known target for further observation. We demonstrate the effectiveness of this framework in maintaining constant target visibility while transitioning to the intended orbit as well as in transitioning to a lower altitude orbit for more detailed visual analysis of the intended target.
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Hinze, Nicolas Karlsson. "Integration of the Transportation Systems Analysis Model for the Small Aircraft Transportation System." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/43911.
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Standalone computer modules for county to county travel demand forecasting have been
integrated. The Trip Generation, Trip Distribution and Mode Choice modules have been unified
under one Graphical User Interface (GUI). The outputs are automatically mapped using
Geographic Information Systems (GIS) technology to allow immediate and spatial analysis. The
integrated model allows for faster running times and quicker analysis of the results. The ability to
calculate travel time savings for travelers was also included to the final model. The modeling
framework developed is known as the Transportation Systems Analysis Model (TSAM).Master of Science
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Altamirano, George V. "Investigation of Longitudinal Aero-Propulsive Interactions of a Small Quadrotor Unmanned Aircraft System." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1607075603449697.
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Chavan, Harish Dnyandeo. "A Heuristic Approach to Solve Air Taxi Scheduling Problem." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/9840.
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All passengers travel at the hour most convenient to them. But it is not always possible to find a flight at the right time to fly them to their destination. In the case where service in any one time period is insufficient to meet air travel demanded, it may be expected that some unfilled demand passengers will either delay their flight or will advance it, thus adding to the effective demand of the adjoining time periods.The obvious alternate means of travel is a rental car. It takes a lot more time than flight, but it is readily available at any given time. This brings us to think of an airline system that will work in a similar fashion; A system that can be named an "Air Taxi System."
This would mean a virtual highway in air space leading to a vast network. The network would be served by small aircraft flying from one city to another loading and unloading passengers. Such a large network having dynamic demand will have many issues to resolve before successfully launching a Small Aircraft Transportation System. One of the most important problems to solve is scheduling of aircraft for such a stochastic demand flow.
The objective of the research is to study a given set of airports with dynamic demand and known aircraft type. The major task will be to analyze the flow of passengers between each origin-destination pair and then schedule flights. The research will be to develop a schedule for a fixed set of airports with dynamic demand and known type of aircraft. The main objective is to maximize demand satisfaction. The study will also analyze the number of aircraft required for a given set of airports and find a method to schedule them.Master of Science
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Paulson, Christopher A. "The rapid development of bespoke sensorcraft : a proposed design loop for small unmanned aircraft." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/412645/.
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The ability to quickly fabricate small unmanned aircraft through additive manufacturing methods opens a range of new possibilities for the design and optimisation of these vehicles. In this thesis, we propose a design loop that makes use of surrogate modelling and additive manufacturing to reduce the design and optimisation time of scientific small unmanned aircraft. Additive manufacturing reduces the time and effort required to fabricate a complete aircraft, allowing for rapid design iterations and flight testing. Co-Kriging surrogate models allow data collected from test flights to correct Kriging models trained with numerically simulated data. The resulting model provides physically accurate and computationally cheap aircraft performance predictions. A global optimiser is used to search this model to find an optimal design for a bespoke aircraft. We apply the proposed design loop in a real-world case study. A parameterised joined wing aircraft is optimised to fulfil the mission requirements of a sensorcraft, or a small unmanned aircraft capable of carrying a payload of scientific sensors. Following the proposed design loop, three parametric aircraft were fabricated using additive manufacturing and flight tested. These flight testing data were used to construct a co-Kriging surrogate model capable of being used for the rapid optimisation of future sensorcraft.
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Rubenking, Samuel Kim. "Dual Mode Macro Fiber Composite-Actuated Morphing Tip Feathers for Controlling Small Unmanned Aircraft." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78433.
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The transition of flight from manned to unmanned systems has led to new research and applications of technology within the field that, until recently, were previously thought to be unfeasible. The industry has become interested in alternative control surfaces and uses for smart materials. A Macro Fiber Composite (MFC), a smart material, takes advantage of the piezoelectric effect and provides an attractive alternative actuator to servos in the Small Unmanned Aerial Systems (SUAS) regime of flight. This research looks to take MFC actuated control surfaces one step further by pulling inspiration from and avian flight. A dual mode control surface, created by applying two sets of two MFCs to patch of carbon fiber, can mimic the tip feathers of a bird. This actuator was modeled both using Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD). Real-world static testing on a feather confirmed preliminary FEA results, and wind tunnel tests simulating assumed cruise conditions confirmed the feather would not exhibit any adverse structural behaviors, such as flutter or aeroelastic divergence. From its modeled performance on a wing using CFD, the MFC feather proved to be a success. It was able to produce a wing that, when compared to a traditional rectangular wing, yielded 73% less induced drag and generated proverse yaw. However, the MFC feathers alone, in the configuration tested, did not produce enough roll authority to feasibly control an aircraft.Master of Science
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Alshahrani, Ali. "Analysis and Initial Optimization of The Propeller Design for Small, Hybrid-Electric Propeller Aircraft." Thesis, KTH, Flygdynamik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-287726.
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This thesis focuses on the optimization of the electric aircraft propeller in order to increaseflight performance. Electric aircraft have limited energy, particularly the electricmotor torque compared to the fuel engine torque. For that, redesign of the propeller forelectric aircraft is important in order to improve the propeller efficiency. The airplanepropeller theory for Glauert is selected as a design method and incorporated with Brattimprovements of the theory. Glauert theory is a combination of the axial momentum andblade element theory. Pipistrel Alpha Electro airplane specifications have been chosen asa model for the design method. Utilization of variable pitch propeller and the influence ofnumber of blades has been investigated. The obtained design results show that the variablepitch propellers at cruise speed and altitude 3000 m reducing the power consumptionby 0.14 kWh and increase the propeller efficiency by 0.4% compared to the fixed pitchpropeller. Variable pitch propeller improvement was pretty good for electric aircraft. Theoptimum blade number for the design specifications is 3 blades.Denna rapport har som fokus att optimera propellern på ett eldrivet flygplan för att förbättraflygprestationen. Eldrivna flygplan har begränsad energi, i synnerhet motorns vridmomenti jämförelse med bränslemotorns vridmoment. Därav behöver propellern designas om föratt uppnå en större verkningsgrad i propellern. Glauerts teori om flygplanspropellrar haranvänts som metod för designen där vissa modifieringar i teorin har tillämpats enligt Brattför att förbättra teorin. Glauerts teori är en kombination mellan axiell momentum- ochbladelement teori. Specifikationerna för Pipistrel Alpha Electro flygplan har använts sommodell i design metoden. Utnyttjande av propeller med justerbara bladvinklar samt antalblads påverkan har undersökts. De erhållna designresultaten visade att propellern medjusterbara bladvinklar vid planflykt på 3000 m höjd har sparat 0,14 kWh samt ökat propellernsverkningsgrad med 0,4% jämfört med propellern med icke justerbara bladvinklar.Propeller med justerbara stigning var lämplig för elflygplan. Det optimala antalet blad fördesignspecifikationerna är 3 blad.
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Tay, Boon Chong. "Development and implementation of new control law for vision based target tracking system onboard small Unmanned Aerial Vehicles." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FTay.pdf.
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Thesis (M.S. in Engineering Science (Mechanical Engineering))--Naval Postgraduate School, December 2006.Thesis Advisor(s): Isaac I. Kaminer, Vladimir N. Dobrokhodov. "December 2006." Includes bibliographical references (p. 89). Also available in print.
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Kestell, Colin D. "Active control of sound in a small single engine aircraft cabin with virtual error sensors." Title page, abstract and contents only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phk423.pdf.
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Lillis, Julia A. "Analysis of the applicability of aircraft vulnerability assessment and reduction techniques to small surface craft." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FLillis.pdf.
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Eddy, Joshua Galen. "A Hardware-Minimal Unscented Kalman Filter Framework for Visual-Inertial Navigation of Small Unmanned Aircraft." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/77927.
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This thesis presents the development and implementation of a software framework for estimating the position of a drone during flight. This framework is based on an algorithm known as the Unscented Kalman Filter (UKF), a recursive method of estimating the state of a highly nonlinear system, such as an aircraft. In this thesis, we present a UKF formulation specially designed for a quadcopter carrying an Inertial Measurement Unit (IMU) and a downward-facing camera. The UKF fuses data from each of these sensors to track the position of the quadcopter over time. This work supports a number of similar efforts in the robotics and aerospace communities to navigate in GPS-denied environments with minimal hardware and minimal computational complexity. The software framework explored in this thesis provides a means for roboticists to easily implement similar UKF-based state estimators for a wide variety of systems, including surface vessels, undersea vehicles, and automobiles. We test the system's effectiveness by comparing its position estimates to those of a commercial motion capture system and then discuss possible applications.Master of Science
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Vetter, Raymond Thomas. "Small unmanned aircraft system integration into the Mode C Veil using an enterprise architecting framework." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122260.
Full textAbstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 152-159).
Integrating small unmanned aerial systems (sUAS) into the national airspace system (NAS) represents a challenging problem set that requires consideration through multiple lenses. Like most complex problems, considering one class of constraints is inadequate to developing a solution that satisfies all interested stakeholders. Rather than focusing solely on the technological limitations of sUAS operation, this work employs the Architecting Innovative Enterprise Strategy (ARIES) Framework to understand the current and future landscapes for the NAS. This work considers the ecosystem that influences the NAS and the key stakeholders with decision-making authority. The author uses the ARIES elements (strategy, information, infrastructure, products, services, processes, organizations, and knowledge) to holistically describe the current architecture that allows for very limited sUAS operations in the Mode C Veil.
After considering the ongoing efforts to integrate sUAS into the NAS, the envisioned future describes how the enterprise may transform under ideal conditions. This thesis incorporates aspects of the current architecture for sUAS operations and provides a recommended future architecture that expands sUAS use. By identifying current limitations and incorporating emerging mitigation techniques, the author is able to develop and evaluate different alternatives. These alternatives seek to address externalities that emerge from the increased use of sUAS in close proximity to the general public. Such externalities include safety, security, privacy, and transparency concerns. The recommended future architecture relies on airborne systems to detect and avoid manned aircraft and utilizes an unmanned traffic management system for information sharing and flight coordination.
This architecture requires significant investment in developing a shared database to manage unmanned vehicle operations, but provides the structure and functions required to make sUAS operations feasible when considering constraints, externalities, and public acceptance.
by Raymond Thomas Vetter.
S.M. in Engineering and Management
S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
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Bodin, Jan. "Perpetual product development : a study of small technology-driven firms." Doctoral thesis, Umeå universitet, Företagsekonomi, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-60865.
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This dissertation focuses the attention toward inventors and key actors involved in product development projects. The study focuses on how a new product development process is carried out operationally and strategically in small, technology-driven firms. The study is based on findings from four case studies among small aircraft manufacturers, two from Sweden, one from Germany, and one from northern Finland. By using one of the Swedish cases as a platform, issues concerning the development process emerged and were summarized in sixteen statemens. The statements were then used as themes and checkpoints when gathering information from the three additional cases. The analysis has been made in two steps; first, a comparison between the platform case and the additional case were made based on the statements, second, issues emerging from all four cases are discussed. The dissertation introduces perpetual product development as a terminology suitable for explaining the behaviour found in the studied firms. A foundation for perpetual product development is presented based on both actor and process characteristics. The actors are technology devotees with numerous ideas to pursue. Their technological interest result in a preference for the first part of the development process since they experience a higher degree of technological freedom from start. Once the product starts to materialize, the actors' possibility of incorporating new technical gadgets diminishes. As a consequence, a weaker interest for the exploitation/launch phase is present. The actors also have a time conception that differs from what is normally assumed. They do not consider speeding-to-market important, since the actors prefer a superior product than being first out on the market. Their attitude toward speeding-to- market also demand actors with a high degree of stamina, since it often involves projects carried out over a long period of time. Due to the individual characteristics described above, the process is technology-driven. The process also experience a fuzzy start and culmination. The actors will continue to make adjustments to the construction even after the product has been launched, if they believe it can be technically improved. A consequence regarding the way the actors are managing their firm is that there is a tendency to regard the product development as a leisure-time activity. In view of the findings, it can be established that each case has to be evaluated on its own merits, with regard to the central actors' personal objectives.digitalisering@umu
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Galvin, James J. "Air Traffic Control Resource Management Strategies and the Small Aircraft Transportation System: A System Dynamics Perspective." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/29988.
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The National Aeronautics and Space Administration (NASA) is leading a research effort to develop a Small Aircraft Transportation System (SATS) that will expand air transportation capabilities to hundreds of underutilized airports in the United States. Most of the research effort addresses the technological development of the small aircraft as well as the systems to manage airspace usage and surface activities at airports. The Federal Aviation Administration (FAA) will also play a major role in the successful implementation of SATS, however, the administration is reluctant to embrace the unproven concept.
The purpose of the research presented in this dissertation is to determine if the FAA can pursue a resource management strategy that will support the current radar-based Air Traffic Control (ATC) system as well as a Global Positioning Satellite (GPS)-based ATC system required by the SATS. The research centered around the use of the System Dynamics modeling methodology to determine the future behavior of the principle components of the ATC system over time.
The research included a model of the ATC system consisting of people, facilities, equipment, airports, aircraft, the FAA budget, and the Airport and Airways Trust Fund. The model generated system performance behavior used to evaluate three scenarios. The first scenario depicted the base case behavior of the system if the FAA continued its current resource management practices. The second scenario depicted the behavior of the system if the FAA emphasized development of GPS-based ATC systems. The third scenario depicted a combined resource management strategy that supplemented radar systems with GPS systems.
The findings of the research were that the FAA must pursue a resource management strategy that primarily funds a radar-based ATC system and directs lesser funding toward a GPS-based supplemental ATC system. The most significant contribution of this research was the insight and understanding gained of how several resource management strategies and the presence of SATS aircraft may impact the future US Air Traffic Control system.Ph. D.
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Call, Brandon R. "Obstacle Avoidance for Small Unmanned Air Vehicles." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1556.pdf.
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Palframan, Mark C. "Robust Control Design and Analysis for Small Fixed-Wing Unmanned Aircraft Systems Using Integral Quadratic Constraints." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/71881.
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The main contributions of this work are applications of robust control and analysis methods to complex engineering systems, namely, small fixed-wing unmanned aircraft systems (UAS). Multiple path-following controllers for a small fixed-wing Telemaster UAS are presented, including a linear parameter-varying (LPV) controller scheduled over path curvature. The controllers are synthesized based on a lumped path-following and UAS dynamic system, effectively combining the six degree-of-freedom aircraft dynamics with established parallel transport frame virtual vehicle dynamics. The robustness and performance of these controllers are tested in a rigorous MATLAB simulation environment that includes steady winds, turbulence, measurement noise, and delays. After being synthesized off-line, the controllers allow the aircraft to follow prescribed geometrically defined paths bounded by a maximum curvature. The controllers presented within are found to be robust to the disturbances and uncertainties in the simulation environment. A robust analysis framework for mathematical validation of flight control systems is also presented. The framework is specifically developed for the complete uncertainty characterization, quantification, and analysis of small fixed-wing UAS. The analytical approach presented within is based on integral quadratic constraint (IQC) analysis methods and uses linear fractional transformations (LFTs) on uncertainties to represent system models. The IQC approach can handle a wide range of uncertainties, including static and dynamic, linear time-invariant and linear time-varying perturbations. While IQC-based uncertainty analysis has a sound theoretical foundation, it has thus far mostly been applied to academic examples, and there are major challenges when it comes to applying this approach to complex engineering systems, such as UAS. The difficulty mainly lies in appropriately characterizing and quantifying the uncertainties such that the resulting uncertain model is representative of the physical system without being overly conservative, and the associated computational problem is tractable. These challenges are addressed by applying IQC-based analysis tools to analyze the robustness of the Telemaster UAS flight control system. Specifically, uncertainties are characterized and quantified based on mathematical models and flight test data obtained in house for the Telemaster platform and custom autopilot. IQC-based analysis is performed on several time-invariant H∞ controllers along with various sets of uncertainties aimed at providing valuable information for use in controller analysis, controller synthesis, and comparison of multiple controllers. The proposed framework is also transferable to other fixed-wing UAS platforms, effectively taking IQC-based analysis beyond academic examples to practical application in UAS control design and airworthiness certification. IQC-based analysis problems are traditionally solved using convex optimization techniques, which can be slow and memory intensive for large problems. An oracle for discrete-time IQC analysis problems is presented to facilitate the use of a cutting plane algorithm in lieu of convex optimization in order to solve large uncertainty analysis problems relatively quickly, and with reasonable computational effort. The oracle is reformulated to a skew-Hamiltonian/Hamiltonian eigenvalue problem in order to improve the robustness of eigenvalue calculations by eliminating unnecessary matrix multiplications and inverses. Furthermore, fast, structure exploiting eigensolvers can be employed with the skew-Hamiltonian/Hamiltonian oracle to accurately determine critical frequencies when solving IQC problems. Applicable solution algorithms utilizing the IQC oracle are briefly presented, and an example shows that these algorithms can solve large problems significantly faster than convex optimization techniques. Finally, a large complex engineering system is analyzed using the oracle and a cutting-plane algorithm. Analysis of the same system using the same computer hardware failed when employing convex optimization techniques.Ph. D.