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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

Detecting and Tracking Moving Objects from a Small Unmanned Air Vehicle

DeFranco, Patrick 01 March 2015 (has links) (PDF)
As the market for unmanned air vehicles (UAVs) rapidly expands, the need for algorithmsthat improve the capabilities of those vehicles is also growing. One valuable capability for UAVsis that of persistent tracking—the ability to find and track another moving object, usually on theground, from an aerial platform. This thesis presents a method for tracking multiple ground targetsfrom an airborne camera. Moving objects on the ground are detected by using frame-to-frameregistration. The detected objects are then tracked using the newly developed recursive RANSACalgorithm. Much video tracking work has focused on using appearance-based processing for tracking,with some approaches using dynamic trackers such as Kalman filters. This work demonstratesa fusion of computer vision and dynamic tracking to increase the ability of an unmanned air platformto identify and robustly track moving targets. With a C++ implementation of the algorithmsrunning on the open source Robot Operating System (ROS) framework, the system developed iscapable of processing 1920x1080 resolution video at over seven frames per second on a desktopcomputer.
22

Peugeot Liminal Space

van den Broek, Thijs January 2023 (has links)
Contemporary life and its fast-paced nature have created a shift in how we behave. Moments of calm are often disturbed by the human temptation to distract the mind. We try to push away the ambiguous moments of silence. However, these moments have proven to have significant mental benefits. They allow people to reflect and come down to their senses.Liminal spaces are spaces that can be described both as inside as well as outside. They are so powerful in their presence and aesthetic that they lead the occupant to question their surroundings and ultimately allow them to transition their mind. Mostly used in architecture and psychology, I wanted to explore what the limen could do in the transportation design field. During this project, I asked the question: How can Liminal spaces in the mobility sector develop a deeper connection with our environment and ourselves?The Peugeot Liminal Space is a service designed to provide a convenient getaway from society, in order to connect with nature and oneself. With the mindset that there is no destination needed, the mental journey is the end product.The design is a personal air balloon that serves as a transformative space for users to find solace, a quiet place that interacts with the user in a calm and non-intrusive manner.Throughout the journey, the user will pass several thresholds as they move further away/ get closer to society. By changing the vehicle’s attributes the user is stimulated to respond to the changes in their environment, requiring them to focus on the here and now. The balloon can be described as a mindfulness practice that adapts to the user’s needs while emphasizing movements from fauna and flora. Passing wind gusts, animals or moving trees can initiate a playful motion inside the vehicle.
23

Wing/Wall Aerodynamic Interactions in Free Flying, Maneuvering MAVs

Geyman, Matthew Kenneth 11 May 2012 (has links)
No description available.
24

High-Fidelity Simulations of Transitional Flow Over Pitching Airfoils

Garmann, Daniel J. 03 August 2010 (has links)
No description available.
25

Tracking of Ground Mobile Targets by Quadrotor Unmanned Aerial Vehicles

Tan, Ruoyu 23 October 2013 (has links)
No description available.
26

Electric Propulsion System for Exceptionally Short Takeoff and Landing Electric Air Vehicles

Mahvelatishamsabadi, Parisa January 2019 (has links)
Over the past few years, electric propulsion systems have been widely used in automotive applications. The next decade is likely to see the electrification of aerial vehicles. In the past 20 years, the passengers demand in the aviation industry has increased by roughly 5% annually. Drastic increment in the passengers demand leads to many problems such as emission, noise pollution, airports capacity shortage, and high fuel consumption. An electric airplane that can take off and land in an extremely short runway can solve all the mentioned problems. Also, an airplane that is smaller and lighter with the ability to take off and land from an extremely short runway can be used as a new transportation system in congested cities and solve the urban road traffic and compensate for people’s time wasted in traffic. With this in mind, in this thesis, the feasibility of converting a conventional fixed-wing direct-drive propeller airplane to an electric extremely short takeoff and landing airplane has been examined. An overview of the history of electric aerial vehicles and flying cars is conducted where some of these vehicles are still under development phase. The main aim of this thesis is to address the effect of takeoff and landing runway length on the electric motor main specifications, including power, torque, and speed. Also, the effect of cruising speed on the motor specifications are investigated, and it is observed that there is a considerable difference between the amount of required power for the cruising mode and takeoff mode. In the end, the impact of the braking system and airplane weight on the landing distance are examined, and It is found that for an airplane with a cruise-efficient propeller, usage of thrust reverser is not practical and hence it is not recommended. Although if the propeller is designed to have high efficiency at takeoff and landing, the thrust reverser can be a good solution to make the landing runway shorter. / Thesis / Master of Applied Science (MASc)
27

Algoritmo genético aplicado à otimização de asas de material compósito de veículos aéreos não tripulados / Genetic algorithm applied to optimization of composite material wings of unmanned air vehicles

Widmaier, Klaus 19 December 2005 (has links)
O advento dos veículos aéreos não tripulados (VANTs) representa uma quebra de paradigma no ramo aeronáutico. São revisados os conceitos de projeto envolvidos no desenvolvimento de VANTs e levantadas as suas potenciais aplicações. São também analisadas as características de sua operação e discutidas as questões regulatórias envolvidas na certificação e integração dos VANTs ao tráfego aéreo civil. Dentre as várias características singulares dos VANTs, enfatiza-se a sua necessidade de realizar vôos a grande altitude e com longa autonomia. Isso leva ao emprego de materiais mais leves e configurações com asas de grande alongamento, que provocam menor arrasto induzido. É feita uma revisão sobre materiais compósitos, que são materiais de uso crescente no ramo aeronáutico por sua leveza e resistência, e que por sua característica de anisotropia, são suscetíveis à otimização estrutural. Métodos e ferramentas de otimização estrutural de compósitos laminados ainda são pouco empregados, por suas características discretas e pelo grande número de parâmetros envolvidos. Um método eficiente e adequado à otimização de um problema desse tipo é o método dos algoritmos genéticos (AG). Assim foi desenvolvida uma sub-rotina de otimização baseada em algoritmos genéticos, usando a linguagem de programação Fortran. A sub-rotina desenvolvida trabalha em conjunto com um programa comercial de análise estrutural baseado no método dos elementos finitos, o Ansys. Foi também proposta uma configuração de asa de um VANT típico, de grande alongamento e fabricada com materiais compósitos reforçados com fibras (CRF). A asa proposta teve o número e a orientação das camadas do laminado otimizadas com o uso da sub-rotina desenvolvida, e resultados satisfatórios foram encontrados. Foram também analisados os efeitos da variação dos parâmetros dos operadores do AG, como probabilidades de mutação, cruzamento, tipo de escalonamento, entre outros, no desempenho do mesmo. Também foram feitas otimizações no mesmo modelo de asa proposto, empregando outros métodos disponíveis no próprio programa de análise estrutural. Os resultados das otimizações através desses métodos foram comparados com os resultados obtidos com a sub-rotina desenvolvida / The advent of the unmanned air vehicles (UAVs) represents a paradigm break in the aeronautical field. The project concepts involved in the development of UAVs are revised and its potential applications are rose. Also the issues related to UAVs operation are assessed and the regulatory questions involved in their certification and integration to the civil air space are argued. Amongst many singular characteristics of the UAV, its necessity of performing flights at high altitudes and with long endurance is emphasized. This leads to the employment of lighter materials and to configurations with high aspect ratio wings that cause minor induced drag. A revision on composite materials, which are of increasing use in the aeronautical field for their lightness and strength, and that are appropriate for being optimized due to their anisotropy characteristics, is made. Methods and tools of structural optimization of laminated composites are still seldom employed, due to their discrete nature and to the large number of parameters involved. An efficient and suitable method for the optimization of this kind of problem is the genetic algorithm (GA). Thus, an optimization sub-routine based on genetic algorithms was developed, using FORTRAN programming language. The developed sub-routine works in combination with Ansys, a structural analysis commercial program based on the finite elements method. A configuration of a typical UAV wing, made from composite reinforced plastics (CRP) was also proposed. The proposed wing had the number of plies and the orientations of its layers optimized using the developed sub-routine, and satisfactory results had been found. Also the effect of the variation of AG’s operator parameters in its performance, as mutation probabilities, crossover probabilities, fitness scaling, among others, have been assessed. The same wing model considered was also optimized using other build-in methods of the structural analysis program. The results of these optimizations have been compared with the results obtained with the developed sub-routine
28

Energy Optimal Path Planning Of An Unmanned Solar Powered Aircraft

Pinar, Erdem Emre 01 January 2013 (has links) (PDF)
In this thesis, energy optimal route of an unmanned solar powered air vehicle is obtained for the given mission constraints in order to sustain the maximum energy balance. The mission scenario and the constraints of the solar powered UAV are defined. Equations of motion are obtained for the UAV with respect to the chosen structural properties and aerodynamic parameters to achieve the given mission. Energy income and loss equations that state the energy balance, up to the position of the UAV inside the atmosphere are defined. The mathematical model and the cost function are defined according to the mission constraints, flight mechanics and energy balance equations to obtain the energy optimal path of the UAV. An available optimal control technique is chosen up to the mathematical model and the cost function in order to make the optimization. Energy optimal path of the UAV is presented with the other useful results. Optimal route and the other results are criticized by checking them with the critical positions of the sun rays.
29

Vamzdyne skraidančių bepiločių aparatų akustinės regos sistemos kūrimas ir tyrimas / Acoustics vision system‘s of unmanned air vehicle (UAV), flying in pipeline, development and research

Nazaras, Paulius 29 June 2007 (has links)
Darbe analizuojama akustinės regos sistema (ARS) skirta specializuotiems bepiločiams skraidantiems aparatams (BSA) apribotoje erdvėje. Aprašyti esami ir kuriami bepiločiai skraidantys aparatai. Parinkus atitinkamus elementus sudaryta tokios ARS elektrinė principinė schema. Pateiktas valdymo algoritmas. / In this graduate work acoustics vision system of unmanned air vehicle (UAV) is projected. It fit to control UAV in the limit space (pipeline). The operating algorithm of the effect of control system is created and this system construction is analyzed. In the closing part of this graduate work conclusions are formulated and the content of the sources is given. The graphical part of this work covers tables of element’s, control system functional schemes and principal electrical schemes of aforesaid control system.
30

Design, testing, and performance of a hybrid micro vehicle - the Hopping Rotochute

Beyer, Eric W. 04 May 2009 (has links)
A new hybrid micro vehicle, called the Hopping Rotochute, was developed to robustly explore environments with rough terrain while minimizing energy consumption over extended periods of time. Unlike traditional robots, the Hopping Rotochute maneuvers through complex terrain by hopping over or through impeding obstacles. A small coaxial rotor system provides the necessary lift while a movable internal mass controls the direction of travel. In addition, the low mass center and egg-like shaped body creates a means to passively reorient the vehicle to an upright attitude when in ground contact while protecting the rotating components. The design, fabrication, and testing of a radio-controlled Hopping Rotochute prototype as well as an analytical study of the flight performance are documented. The aerodynamic, mechanical, and electrical design of the prototype is outlined which were driven by the operational requirements assigned to the vehicle. The aerodynamic characteristics of the rotor system as well as the damping characteristics of the foam base are given based on experimental results using a rotor test stand and a drop test stand respectively. Experimental flight testing results using the prototype are outlined which demonstrate that all design and operational requirements are satisfied. A dynamic model associated with the Hopping Rotochute is then developed including a soft contact model which estimates the forces and moments on the vehicle during ground contact. A comparison between the vehicle's motion measured using a motion capture system and the simulation results are presented to determine the validity of the experimentally-tuned dynamic model. Using this validated simulation model, key parameters such as system weight, rotor speed profile, internal mass weight and location, as well as battery capacity are varied to explore the flight performance characteristics. The sensitivity of the hopping rotochute to atmospheric winds is also investigated as well as the ability of the device to perform trajectory shaping.

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