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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Unmanned Aerial Manipulators in Construction - Opportunities and Challenges

Nagori, Chinmay 23 December 2020 (has links)
Unmanned Aerial Vehicles (UAVs) have now been accepted as an alternative medium to human workers for data collection processes in various industries. The capabilities of UAVs are now being extended from passive tasks of data collection to active tasks of interacting with the environment by equipping them with robotic arms and function as Unmanned Aerial Manipulators (UAMs). Research on Unmanned Aerial Manipulators has been growing in the last few years. The applications of UAMs in terms of sensor installation, inspections, door opening, valve turning, pick and drop, etc. have been studied for the oil and gas industry, and civil applications, etc. However, there is a lack of studies in understanding applications of UAMs and their capabilities in construction and in advancing construction activities. The goal of this research is to identify potential opportunities and challenges of the application of UAM in construction projects. The study will undertake an extensive literature review and semi-structured interviews with industry experts to address research questions. This study will have a significant contribution to the introduction and development of new contact-based UAV-guided technologies in construction. / Master of Science / Drones or Unmanned Aerial Manipulators have been used in the construction industry to collect visual data in form of images, videos, or to map surveys, and visually inspect the structures. However, if equipped with a robotic arm, they attain the capability of touching and interacting with the environment to effectively function as an Unmanned Aerial Manipulator (UAM). UAMs have researched for various applications such as sensor installation, touch-based sensor inspections, door opening, and closing, and pick up and drop, etc. However, there is a lack of study for their opportunities and challenges in the construction industry. This research focuses on understanding the opportunities and challenges associated with the application of UAMs in the construction industry.
22

Sentience and Site

Powers, Shane Patrick 09 July 2020 (has links)
A contemporary understanding of site is integral towards the proper implementation of an architectural intervention which reconciles itself amongst the landscape. This thesis is situated at the convergence of technology and nature, investigating a constructive engagement of site in order to inform an architecture embedded into rural Appalachia. An integration of drone avionics, advanced imaging and sensing technologies, and traditional means of site-observation fosters the opportunity for a more holistic understanding of place. The corresponding architectural intervention thus manifests itself as a contemporary rendition of the fire tower, a US Forest Service outpost monitoring changing wildlife populations and behaviors within the George Washington and Jefferson National Forests. Dubbed The Aviary, the construct functions as a wilderness drone-port, supporting a large, integrated network of conservation-drone activity over the vast surrounding mountain-scape. / Master of Architecture / This thesis investigates the role of our built environment in relation to concurrent trends in drone technology and wildlife conservation. The thesis is broken up into two parts, the first exploring new methodologies of site-investigation, and the second exploring architecture as tool for ecological conservation and preservation. The architecutral site-exploration process is redifined using drone mapping and data visualization, in hopes of achieving a more holistic understanding of our rural and wilderness landscapes, with the goal of further utilizing this understanding to inform an architecture that resides harmoneously within it's "place." The eventual designed construct can be viewed as a modern reinterpretation of the American fire-tower, a declining typology tradtionally used to safeguard our natural and wilderness resources and landscapes. This new construct takes a dynamically diffent approach, and functions as a wilderness drone-port that facilitates a fleet of unmanned aerial vehicles to monitor the changes of behaviors and populations in Virginia's wildlife, advancing our methodologies of local conservation and ecological studies.
23

Quantitative Approach and Departure Risk  Assessment for Unmanned Aerial Systems

Gobin, Bradley Scott 26 October 2020 (has links)
The usage of unmanned aerial systems (UAS), also called drones, has grown at an increasing rate, with expectations of the number of unmanned aircraft (UA) to triple between 2019 and 2023 as commercial and government usage of UAS increases as per the Federal Aviation Administration. As the usage of UA increases, the probability of a UA crash resulting in injuries of 3rd parties on the ground also increases. The goal of this research was to create a method and software tool that gives the user an accurate representation of the risk to 3rd parties on the ground associated with a given flight plan. The main area of focus was on large rotorcraft and fixed-wing aircraft that are used by the military and that have the potential to do large amounts of damage if a crash were to occur. How unique types of failures affect the ground area at risk and the UA crash characteristics and how these characteristics affect population on the ground were all considered. With this information, a probability of fatality value is calculated, which helps the user determine if the mission risk is acceptable. The ability to optimize this flight path to find the lowest risk flight path is also possible, based upon user specifications. / Master of Science / Understanding the likelihood of an undesired event occurring is vital for the use of any system in the real world. This is especially true in the case of aircraft, were an undesired event can likely cause loss of life. A new area of aircraft that require additional insight into the failure characteristics are unmanned aerial systems, often referred to as drones. Drones do not have a pilot inside the aircraft, who could correct for any failures that might occur. Due to this potential inability to correct for a failure, a method must be developed to gain a better understanding of the potential failures and risks involved in drone operations. The method developed during this work was turned into a software tool, which allows a mission for a drone to be mapped out and the risk to be determined. Due to the drones being unmanned the risk is taken as the expected number of fatalities to the 3rd party individuals on the ground. This expected number of fatalities is determined by the population density of the area the flight is occurring over, and the crash characteristics for the aircraft. These methods and accompanying assumptions are outlined in the body of this work.
24

Método não destrutivo para predição da maturação de amendoim (arachis hypogaea l.) utilizando sensoriamento remoto /

Santos, Adão Felipe dos. January 2019 (has links)
Orientador: Rouverson Pereira Silva / Resumo: A utilização de técnicas de sensoriamento remoto teve expressivo aumento na agricultura nos últimos anos para muitas culturas, contudo, ainda são escassos os trabalhos que envolvem a cultura de amendoim, principalmente os que visam solucionar um dos seus principais problemas, a predição da maturação. Dessa forma, foram desenvolvidos trabalhos no Brasil e nos EUA visando verificar o potencial uso do sensoriamento aéreo e orbital na predição da maturação de amendoim. No primeiro capítulo desta tese, encontra-se a revisão de literatura. No segundo, realizou-se uma análise de variabilidade utilizando cartas de controle para identificar diferenças no comportamento da reflectância espectral e dos índices de vegetação obtidos por imagens de drone e do satélite PlanetScope, em que se chegou à conclusão que as duas plataformas apresentam comportamento similares ao longo do tempo. No terceiro capítulo, foram utilizadas duas áreas comerciais nos EUA, irrigada e não irrigada, e as imagens foram obtidas por meio de drone. Observou-se que os índices de vegetação que tiveram comportamento similar nas duas áreas foram aqueles em que se modificou a equação original, substituindo a banda do red pelo red edge (NLI e MNLI). No quarto capítulo, utilizou-se uma área comercial no Brasil, sendo as imagens utilizadas para extrair a reflectância obtidas do satélite PlanetScope. Os melhores índices de vegetação, com menores erros na predição da maturação foram o NDVI e o SR. Por fim, no capítulo cinco,... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of remote sensing techniques has had a significant increase in agriculture in recent years for many crops; however, the work involving peanut cultivation is still scarce, mainly to solve one of the main problems of the crop, the prediction of maturity. Thus, work was developed in Brazil and the USA to verify the potential use of aerial and orbital remote sensing in the prediction of peanut maturity. The first chapter of this thesis is the literature review. In the second, a variability analysis was performed using control charts to identify differences in reflectance response and vegetation indices obtained by drone images and PlanetScope satellite, in which it was concluded that the two platforms have similar responses over the period. In the third, two commercial areas were used in the USA, irrigated and non-irrigated, and the images were obtained by drone. It was observed that the vegetation indices that had similar responses in both areas were those in which the original equation was modified, replacing the red band by the red edge (NLI and MNLI). In the fourth chapter, a commercial area was used in Brazil, with the images used to extract the reflectance obtained from the PlanetScope satellite. The best vegetation indices, with the lowest errors in the prediction of maturity, were NDVI and SR. Finally, in chapter five, final considerations with some recommendations and the next steps of the research are stated. / Doutor
25

The conflict between foreign policy and civil liberties presented by the use of unmanned Predator drones

Abrams, Jeremy Isadore 21 February 2011 (has links)
In this paper I will offer an overview the evolution of civil liberties in the United States. These liberties, I argue, were meant to protect individuals from unwarranted exercises of power from the government, but ultimately were not intended to hamper the government’s ability to carry out basic government functions, such as self defense. Next, I examine the parallel evolution of the ability of the executive to exercise broad ranging powers in pursuit of foreign policy, especially in regard to self defense. After that I argue that the current policy not necessarily represent the administration choosing self defense over an individual’s civil liberties. Rather, it represents the notion that at a fundamental level, a state will always choose to pursue foreign policies designed to protect itself, and that even the domestic legal institutions that have evolved in the United States recognize that fact. / text
26

Hydrogen Fuel Cell Drones Against Battery Drones: Last Mile Delivery Perspective

Jayasurya Ragupathi (15361609) 26 April 2023 (has links)
<p>  </p> <p>Hydrogen fuel cells are an abundant and cleaner source of energy, making them an attractive option for powering transportation systems. Hydrogen fuel cell drones are a new type of drone that generates energy from fuel cells for flight and expels heat and water vapor as byproducts. Compared to battery-powered drones, hydrogen fuel cell drones have better endurance and payload capacity due to their higher energy density, making them more efficient for eCommerce delivery. This research compares the performance of hydrogen and battery delivery drones for both drone-only and truck-drone last-mile delivery systems. A mixed integer programming model has been formulated to minimize the total delivery time for small to medium customer instances using the two-echelon vehicle routing problem, where drones are launched from the truck to serve one or more customers. The study conducted a comparative analysis by varying different parameters of drones on multiple sets of customer instances from real-world data to determine the best choice of drones for different scenarios. The results of the analysis show that hydrogen fuel cell drones have significant delivery advantages over typical battery drones in terms of delivery time and efficiency. Additionally, a sensitivity analysis was conducted to demonstrate the impacts of different parameters on the objective function of the delivery systems.</p>
27

Modélisation et commande d'un robot volant robuste

St-Onge, David 18 April 2018 (has links)
Les Tryphons, tout comme leurs prédécesseurs du projet [ VOILES / The Tryphons and their predecessors from the [ VOILES | SAILS ] project are large cubic indoor blimps used autonomously or in remote control mode. Each of these aerobot is equipped with a main micro-computer on-board, a variety of sensors and a wireless communication interface. From a mechanical engineering point of view, the unique shape of these robots and the constraint of their original application field makes them the subject of a novel development path in the study of the dynamics and the flight control. Among the issues that this study had to deal with the focus was put on circuits, wires and connectors reliability, batteries manipulation and fixation while hovering above people, complex manual equilibration of the yaw and pitch moments, complex calibration of the controller's parameters before each performance. The research performed during this Master's degree focused on three main objectives: 1. To develop a numerical dynamic model of the robots in order to determine the critical aspects of the design and how to enhance their robustness. 2. To analyze the electromechanical components of the robots and to modify their design to allow long-lasting and repetitive public performances. 3. To select the appropriate optimal method of positioning in an indoor theater environment for robustness and maximum autonomy. This study demonstrates that the mechanical robustness of these aerobots can be achieved by a new design of the circuits and of the wiring, which integrates them to the structure, and by new custom battery fixations. For the control robustness, a modular approach led to multiple user-selectable controllers. The user can choose a controller and adapt its parameters to find the best fit for each specific situation. A new controller was also developed, which ensures a complete control of the six degrees of freedom by dead reckoning. This was achieved through the use of accelerometers, 3 axis magnetometer, an altimeter and a camera. / Les Tryphons, tout comme leurs prédécesseurs du projet [ VOILES | SAILS ], sont des aérostats intérieurs de forme cubique, autonomes ou pilotés. Ils sont tous équipés d'un micro-ordinateur de bord, de différents capteurs et d'une interface de communication sans fil. D'un point de vue mécanique, la géométrie unique et le domaine d'application original des Tryphons en font un sujet de recherche nouveau pour l'étude de la dynamique du vol et de son contrôle. Parmi les problèmes concernés par cette étude, l'emphase a été portée sur la fiabilité des circuits, câbles et connecteurs, la manipulation et la fixation des batteries pour des vols au-dessus d'une foule, l'équilibrage manuel complexe des moments d'assiette longitudinale et de gîte, la calibration complexe des nombreux paramètres du contrôleur à chaque performance. Dans le cadre de cette maîtrise les objectifs de recherche et le contenu de cette thèse couvrent : 1. Le développement d'un modèle dynamique virtuel des robots permettant de cerner les aspects critiques de la fiabilité et de la robustesse de leurs systèmes. Ce modèle est d'abord développé de manière théorique, en se basant sur la littérature pertinente, principalement du domaine des aérostats extérieurs. Ce modèle, comprenant une approximation des effets aérodynamiques, est optimisé au moyen de tests sur le robot. Grâce au modèle optimisé, différents facteurs, comme le positionnement d'équipement en différents endroits sur la structure et le rapprochement du centre de masse et du centroïde, sont étudiés numériquement. 2. L'analyse de la robustesse électro-mécanique des robots pour des interactions prolongées et répétitives. Cette étude se base principalement sur l'expertise empirique des divers intervenants ayant utilisé ces robots dans les dernières performances publiques. Les éléments critiques du design électro-mécanique sont identifiés puis leur conception est revue afin d'en augmenter la robustesse. 3. L'analyse de la méthode de positionnement absolue en salle de spectacle la plus robuste qui conserve un maximum d'autonomie du robot. En se référant à la littérature pertinente, et tout en considérant le temps limité de cette recherche, le système de positionnement complètement embarqué le plus prometteur a été sélectionné et développé. Les résultats de tests sur un partie du système sont présentés. Il est démontré dans cette étude que la robustesse mécanique, dans le contexte de ce projet, est atteinte en concevant des circuits et leur filage solidaires à la structure et des supports de batteries sur mesure. La robustesse au niveau du contrôle est quant à elle améliorée en permettant aisément à l'usager de passer d'un mode de contrôle à un autre afin de rapidement en ajuster les paramètres et de trouver le mode le mieux adapté à chaque situation. En terme de contrôle une nouvelle approche a permis de positionner les éléments nécessaires à un contrôle complet des six degrés de liberté en navigation à l'estime. Un ensemble de capteurs comprenant un accéléromètre, un magnétomètre 3 axes, un altimètre et une caméra permet d'obtenir suffisamment de données pour accomplir cette tâche.
28

Plataforma de comunicación entre Live Robot Programming y el Robot AR.Drone 2.0

Hernández Phillips, Carolina Massiel January 2016 (has links)
Ingeniera Civil en Computación / La robótica es un área de estudio joven que presenta gran potencial de progreso. Esto incita a expertos de diversas áreas a contribuir en su desarrollo mediante proyectos de investigación y de ingeniería. En este escenario el estudiante Miguel Campusano y el profesor Johan Fabry, ambos integrantes del DCC de la Universidad de Chile, proponen un lenguaje de programación para robots denominado LRP. Este lenguaje es implementado en Pharo Smalltalk, un lenguaje de programación caracterizado por su fuerte orientación a objetos y su poderoso ambiente de desarrollo. Utilizar LRP con un robot determinado requiere una aplicación estilo puente escrita en Pharo, que sirva como interfaz de comunicación entre el lenguaje y el robot. Previo a la realización de este trabajo, sólo dos puentes habían sido implementados. Estos permitieron hacer de pruebas con algunos robots. No obstante, para nes investigativos es muy deseable utilizar el lenguaje LRP con tantos robots como sea posible. El AR.Drone 2.0, de la empresa Parrot, es un cuadricóptero eléctrico no tripulado, controlado remotamente y que cuenta con diversos sensores. Este robot es un excelente caso de prueba para LRP, dada su gran diferencia con los robots utilizados anteriormente. La solución presentada en este trabajo de memoria contempla la implementación de la infraes- tructura necesaria para hacer pruebas utilizando LRP con el AR.Drone y su validación mediante distintos programas de prueba implementados en LRP. Se ha creado una API capaz de comuni- carse con el drone y la aplicación tipo puente requerida. Ambas aplicaciones fueron escritas en Pharo. La API permite establecer una conexión con el drone, recibir los datos que publica y enviar comandos de control y con guración. El puente adapta una serie de métodos de la API y permite utilizarlos desde LRP. Provee además mecanismos intuitivos para que el desarrollador interactúe directamente con el drone durante una sesión de programación. La mayoría de las di cultades enfrentadas durante el desarrollo de la API se debieron a la indocumentación de características o requerimientos impuestos por el rmware del drone. Por otro lado, el desarrollo de esta he- rramienta permitió generar conocimiento técnico especí co sobre el AR.Drone, relevante para trabajos posteriores que utilicen este robot. Los programas de ejemplo creados en LRP evidenciaron que no todas las cualidades de la modalidad de programación en vivo pueden ser aprovechadas trabajando con un robot aéreo. Esto porque es difícil restringir límites para el movimiento del robot, por su limitado tiempo de autonomía y porque la interrupción de una sesión, producto de un choque por ejemplo, implica que el desarrollador deba suspender su trabajo para reposicionar y despegar el robot. Sin embargo, live programming permitió ajustar las variables asociadas a programas ya creados, lo que adquiere gran valor al momento de establecer distancias esperadas para el recorrido del robot. Finalmente, la sintaxis de LRP y sus diagramas de estado animados en vivo facilitaron enormemente el proceso de desarrollo.
29

From Pulling the Trigger to Pushing the Button: Historical Precedents for Targeted Killings and Signature Strikes

Mencini, Damian January 2014 (has links)
Thesis advisor: Charles Gallagher / Thesis advisor: Peter Krause / Drone strikes are sensational events. The United States Government uses remotely piloted aircraft (or drones) equipped with precisions weapons systems to unilaterally hunt and kill its enemies across the globe. The American public, and many around the world, are startled by the pervasiveness of American lethal force. In many ways, drone strikes are unprecedented. The technology, the frequency of use, and the geographic scope are all by-products of the twenty-first century. However, the United States government has a deep history of debating whether to kill individual enemies, and has a history of authorizing operations to do so. Beneath the rhetoric, the arguments, and the opinions that dominate drone policy today there is something missing: the history. This thesis argues that there are historical precedents for targeted killings and signature strikes in American history that predate the September 11 terrorist attacks and examining these past operations can inform modern policy. / Thesis (BA) — Boston College, 2014. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: History.
30

Analysis of Energy Efficiency in Truck-Drone “Last Mile” Delivery Systems

Juan Carlos Orozco (6623699) 10 June 2019 (has links)
<div> <p>Truck-drone delivery systems have the potential to improve how the logistics industry approaches the “last mile problem”. For the purposes of this study, the “last mile” refers to the portion of the journey between the last transportation hub and the individual customer that will consume the product. Drones can deliver packages directly, without the need for an underlying transportation network but are limited by their range and payload capacity. Studies have developed multiple truck-drone configurations, each with different approaches to leverage the benefits and mitigate the limitations of drones. Existing research has also established the drone’s reduction to package delivery time over the traditional truck only model. Two key model factors that have not been considered in previous research are the distribution of package demand, and the distribution of package weight. This study analyzes the drone’s impact to the energy efficiency of a package delivery system, which has taken a backseat to minimizing delivery time. Demand distribution dictates the travel distances required for package delivery, as well as the proportion of delivery locations that are in range for drone delivery. Package weight determines the energy consumption of a delivery and further restricts the proportion of drone eligible packages. The major contributions of this study are the development of a truck-drone tandem mathematical model which minimizes energy consumption, the construction of a population-based package demand distribution, a realistic package weight distribution, and a genetic algorithm used to solve the mathematical model developed for problems that are too computationally expensive to be solved optimally using an exact method. Results show that drones can only have a significant impact to energy efficiency in package delivery systems if implemented under the right conditions. Using truck-drone tandem systems in areas with lower package demand density affords the drone the potential for larger energy savings as larger portions of the truck distance can be replaced. Further, the lower density translates to greater differences between the road-restricted driving distance and the flying distance between delivery points. Finally, energy savings are highly dependent on the underlying package weight distribution of the system. A heavier average package weight increases the energy consumption of the system, but more importantly the portion of packages above the drone’s payload capacity severely limit the savings afforded by the incorporation of drones. </p> </div> <br>

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