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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.
31

Autonomous terminal area operations for unmanned aerial systems

McAree, Owen January 2013 (has links)
After many years of successful operation in military domains, Unmanned Aerial Systems (UASs) are generating significant interest amongst civilian operators in sectors such as law enforcement, search and rescue, aerial photography and mapping. To maximise the benefits brought by UASs to sectors such as these, a high level of autonomy is desirable to reduce the need for highly skilled operators. Highly autonomous UASs require a high level of situation awareness in order to make appropriate decisions. This is of particular importance to civilian UASs where transparency and equivalence of operation to current manned aircraft is a requirement, particularly in the terminal area immediately surrounding an airfield. This thesis presents an artificial situation awareness system for an autonomous UAS capable of comprehending both the current continuous and discrete states of traffic vehicles. This estimate forms the basis of the projection element of situation awareness, predicting the future states of traffic. Projection is subject to a large degree of uncertainty in both continuous state variables and in the execution of intent information by the pilot. Both of these sources of uncertainty are captured to fully quantify the future positions of traffic. Based upon the projection of future traffic positions a self separation system is designed which allows an UAS to quantify its separation to traffic vehicles up to some future time and manoeuvre appropriately to minimise the potential for conflict. A high fidelity simulation environment has been developed to test the performance of the artificial situation awareness and self separation system. The system has demonstrated good performance under all situations, with an equivalent level of safety to that of a human pilot.
32

Design of an All-In-One Embedded Flight Control System

Elmore, Joel D 01 January 2015 (has links)
This thesis describes an all-in-one flight control system (FCS) that was designed for unmanned aerial vehicles (UAVs). The project focuses on the embedded hardware aspect of a stand-alone system with low-cost and reliability in mind.
33

Mezinárodněprávní aspekty používání bezpilotních letounů v moderním ozbrojeném konfliktu / International legal aspects of the use of no-pilot aircrafts in a modern armed conflict

Janák, Michal January 2013 (has links)
The thesis deals with the armed conflict phenomenon of past several years - unmanned aerial vehicles (UAV). Despite the fact that the present deployment of UAVs is often presented as a revolutionary, it is possible to track down the roots of remotely controlled planes without crew on board back to the years short after the Second World War. Today's versions of UAVs represent this historical concept brought to perfection thanks to the modern technologies. Their deployments raise legitimate considerations whether they may represent prohibited mean of warfare in terms of humanitarian law or whether their usage is not in contrary to law of armed conflict. This thesis aims to identify those differences between UAVs and traditional piloted aircrafts that may cause different legal classification of the UAVs to the traditional piloted aircrafts. First chapter includes short historical background which may bring interesting connections with political atmosphere after Second World War. It is also pointed out that the concept of unmanned aircrafts is not new. This chapter also includes technical facts and details about current modern UAVs like Predator, Reaper or Global Hawk which may serve for an easier legal analysis. Second chapter deals with the definitions and differences between two main types of armed...
34

Quantifying the physical effects of stream restoration: With unmanned aerial vehicles and geographic information systems

Karlsten, Annika January 2019 (has links)
Stream restoration efforts often aim at restoring the physical complexity in streams, as an increased habitat heterogeneity is believed to increase biodiversity. It is important to quantify the physical complexity of streams before and after restoration, to know what actions are needed, and to monitor the results of the restoration. The use of unmanned aerial vehicles (UAVs) and geographic information systems (GIS) for data acquisition is rapidly increasing, and the use of UAVs and GIS could facilitate the monitoring process. The aim of this study was to determine how the spatial complexity in streams can be determined by using UAVs and GIS. The physical features and the spatial complexity were quantified in five reaches in the Lögde River, pre- and post-restoration, by analyzing UAV photos in a GIS program. Three of six reach descriptive metrics, and three of seven complexity metrics, were shown significantly different after restoration. To validate the GIS analyzing method, a qualitative comparison of data from the GIS analysis to field survey data was conducted. The GIS method was shown effective for distinguishing morphological features on a larger spatial scale, and to show the spatial distribution of instream features, such as wood pieces and boulders. The accuracy when digitizing the bankfull edge of the stream was low on small scales, and the method likely underestimates the number of wood pieces and boulders in the streams. Preferable camera settings and weather conditions to avoid blurry UAV photos, and thereby enhance the accuracy of the GIS analysis, are discussed.
35

The Virtuous Drone Pilot

Chapa, Joseph January 2014 (has links)
Thesis advisor: Kenneth Himes / This thesis responds to two distinct claims about drone (or remotely piloted aircraft) pilots. The first is the general claim that the martial virtues function as a kind of role morality for soldiers; the second, that drone pilots, based on the absence of personal risk and their distance from the battlefield, are unable to meet the demands of such a role morality. Chapter One explains what is meant by role morality, and determines whether the martial virtues do in fact function in a role morality capacity. The second chapter applies this general conception of a role morality for soldiers to military drone pilots in particular. This investigation finds that, insofar as "soldier" is in fact a role that generates a role morality, military drone pilots are as capable of meeting the demands of such a role morality as other military members. The second half of the thesis challenges the premise that drone pilots do not face personal risk. Chapter Three identifies psychological risk among drone pilots and seeks to determine how this kind of non-physical risk may affect the cultivation of the martial virtues. The fourth chapter argues that by placing military drone pilots within domestic territory, drone-capable militaries (such as the US military) have redrawn the battlespace such that it includes the drone operators, wherever they may be, and that as a result, drone pilots do in fact face some physical risk. Finally, in closing, this thesis presents a positive account of the martial virtues that enables military ethicists and strategists to bring centuries of philosophical investigation to bear on contemporary military issues. / Thesis (MA) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Philosophy.
36

Análise dos modelos para cálculo de níveis de segurança relacionados à operação de veículos aéreos não tripulados. / Analysis of models for calculation of levels of security related to operation of unmanned aerial vehicles.

Oliveira, Cristiane Paschoali de 16 June 2009 (has links)
Desde o início do século XX que há registros do uso de Veículos Aéreos Não Tripulados (VANTs) utilizados com finalidade militar. Mas esta não é a única forma que se pode utilizá-los, o ambiente civil também é próspero em possíveis utilizações deste tipo de aeronave. Faltam ainda estudos e comprovações de que a integração dos VANTs no espaço aéreo juntamente com a aviação tripulada convencional não vá trazer alterações nos níveis de segurança já estabelecidos. Juntam-se a este desafio alguns outros, tais como padronizações de normas, classificações e legislação que regulamente o vôo das aeronaves não tripuladas. A presente dissertação faz uma coletânea de alguns modelos relacionados a cálculos de níveis de segurança no vôo de VANTs, bem como compara esses modelos entre si visando o estabelecimento de um método de escolha do modelo mais adequado para aplicação em alguns cenários civis de utilização. Esse trabalho ainda faz a aplicação desse método considerando os modelos relacionados à segurança dos VANTs. / There are records of the use of Unmanned Aerial Vehicles (UAVs) used for military activities since the beginning of the 20th century. But that is not the only way to use it; the civil environment is also promising as to the use of this kind of aircraft. More studies and validations have to be performed about the alterations in the safety levels with the integration of UAVs in the air space with classic manned air vehicles. There are others challenges such as the standardization of norms, classification and legislation to regulate the Unmanned Aerial Vehicle flights. This dissertation presents some models related to the calculation of the safety levels in UAVs flight, it compares them to establish a method for choosing the most suitable model to apply in some civil scenarios. This work also brings the application of this method considering the models related to the safety of UAVs.
37

Hot-Wire Anemometer Measurements of Atmospheric Surface Layer Turbulence via Unmanned Aerial Vehicle

Canter, Caleb A. 01 January 2019 (has links)
An instrumented unmanned aerial vehicle (UAV) was developed and employed to observe the full range of turbulent motions that exist within the inertial subrange of atmospheric surface layer turbulence. The UAV was host to a suite of pressure, temperature, humidity, and wind sensors which provide the necessary data to calculate the variety of turbulent statistics that characterize the flow. Flight experiments were performed with this aircraft, consisting of a large square pattern at an altitude of 100 m above ground level. In order to capture the largest turbulent scales it was necessary to maximize the size of the square pattern. The smallest turbulent scales, on the other hand, were measured through the use of a fast response constant temperature hot wire anemometer. The results demonstrates that the UAV system is capable of directly measuring the full inertial subrange of the atmospheric surface layer with high resolution and allowing for the turbulence dissipation rate to be calculated directly.
38

gRAID: A Geospatial Real-Time Aerial Image Display for a Low-Cost Autonomous Multispectral Remote Sensing

Jensen, Austin M. 01 May 2009 (has links)
Remote sensing helps many applications like precision irrigation, habitat mapping, and traffic monitoring. However, due to shortcomings of current remote sensing platforms - like high cost, low spatial, and temporal resolution - many applications do not have access to useful remote sensing data. A team at the Center for Self-Organizing and Intelligent Systems (CSOIS) together with the Utah Water Research Laboratory (UWRL) at Utah State University has been developing a new remote sensing platform to deal with these shortcomings in order to give more applications access to remote sensing data. This platform (AggieAir) is low cost, fully autonomous, easy to use, independent of a runway, has a fast turnover time, and a high spatial resolution. A program called the Geospatial Real-Time Aerial Image Display (gRAID) has also been developed to process the images taken from AggieAir. gRAID is able to correct the camera lens distortion, georeference, and display the images on a 3D globe, and export them in a conventional Geographic Information System (GIS) format for further processing. AggieAir and gRAID prove to be innovative and useful tools for remote sensing.
39

Architecture, Inertial Navigation, and Payload Designs for Low-Cost Unmanned Aerial Vehicle-Based Personal Remote Sensing

Coopmans, Calvin 01 May 2010 (has links)
This thesis presents work done towards a Personal Remote Sensing (PRS) system: small Unmanned Aerial Vehicles (UAVs) with electronic, control, and sensing subsystems. Based on papers presented to conferences (AutoTestCon2008 and MESA2009), as well as other work on PRS, multiple levels of engineering are detailed: complex multi-UAV data flow; attitude estimation filters; real-time microprocessor functionality; and small, mobile power systems. Wherever possible, Open-Source tools and designs have been used, modified, or studied, providing excellent cost to performance ratios in most cases. First, the overall PRS UAV architecture, AggieAir, is presented with a motivating examples (GhostEye and EagleEye camera payloads). Then, AggieNav, an inertial navigation system for small UAVs, is detailed, along with information about a Kalman filter for estimation of UAV navigation, position, and attitude. Finally the Spatial Environment Autonomous Logger (SEAL), a general-purpose wireless datalogger for small UAV applications, is presented, with application examples with and without small UAVs. This work represents designs based on two years of organic small UAV system growth, and provides integrated solutions to many problems of small UAV communication, sensing, and control.
40

Angle-only based collision risk assessment for unmanned aerial vehicles / Vinkelbaserad kollisionsriskbedömning för obemannade flygfarkoster

Lindsten, Fredrik January 2008 (has links)
<p>This thesis investigates the crucial problem of collision avoidance for autonomous vehicles.  An anti-collision system for an unmanned aerial vehicle (UAV) is studied in particular. The purpose of this system is to make sure that the own vehicle avoids collision with other aircraft in mid-air. The sensor used to track any possible threat is for a UAV limited basically to a digital video camera. This sensor can only measure the direction to an intruding vehicle, not the range, and is therefore denoted an angle-only sensor. To estimate the position and velocity of the intruder a tracking system, based on an extended Kalman filter, is used. State estimates supplied by this system are very uncertain due to the difficulties of angle-only tracking. Probabilistic methods are therefore required for risk calculation. The risk assessment module is one of the essential parts of the collision avoidance system and has the purpose of continuously evaluating the risk for collision. To do this in a probabilistic way, it is necessary to assume a probability distribution for the tracking system output. A common approach is to assume normality, more out of habit than on actual grounds. This thesis investigates the normality assumption, and it is found that the tracking output rapidly converge towards a good normal distribution approximation. The thesis furthermore investigates the actual risk assessment module to find out how the collision risk should be determined. The traditional way to do this is to focus on a critical time point (time of closest point of approach, time of maximum collision risk etc.). A recently proposed alternative is to evaluate the risk over a horizon of time. The difference between these two concepts is evaluated. An approximate computational method for integrated risk, suitable for real-time implementations, is also validated. It is shown that the risk seen over a horizon of time is much more robust to estimation accuracy than the risk from a critical time point. The integrated risk also gives a more intuitively correct result, which makes it possible to implement the risk assessment module with a direct connection to specified aviation safety rules.</p>

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