281 |
ARQUITETURA DE SOFTWARE PARA OTIMIZAÇÃO DO USO DE AERONAVES REMOTAMENTE PILOTADAS NA AGRICULTURA DE PRECISÃO UTILIZANDO RACIOCÍNIO BASEADO EM CASOS / ARQUITETURA DE SOFTWARE PARA OTIMIZAÇÃO DO USO DE AERONAVES REMOTAMENTE PILOTADAS NA AGRICULTURA DE PRECISÃO UTILIZANDO RACIOCÍNIO BASEADO EM CASOSMikami, Malcon Miranda 06 March 2017 (has links)
Made available in DSpace on 2017-07-21T14:19:31Z (GMT). No. of bitstreams: 1
MIKAMI, M M.pdf: 3402794 bytes, checksum: cb934aeb85ce1c45338450c4767a924d (MD5)
Previous issue date: 2017-03-06 / The use of remotely piloted aircrafts (RPA) in precision agriculture (PA) is constantly evolving being a process comprised of the following steps: objective determination, capture and processing of images and the analisys of the obtained data. Although there is software and hardware made for those steps, the challange remains being the integration of the collected data, its reliability, and the intepretation of the resulting data for decision making. This work proposes a software architeture to make use of RPA on PA, allowing to perform all steps of the process using the Domain-Driven Design and Command and Query Responsability Segregation architectural patterns. The architecture, when used by researchers, allows the integration of new image processing modules, making use of case-based reasoning (CBR) for its evaluation. The architecture was evaluated in a case study under the following aspects: the reliability of the image processing methods and the adequacy of the CBR method when determining the best image processing algorithm for the specified objective. The results of the image processing algorithm for estimate the Normalized Difference Vegetation Index (NDVI) were compared to the results obtained by the field equipment (Greenseeker) and by processing made with the Pix4D software. Both the software and the equipment produced similar results, with a difference of about 7%. When doing the simulation for the best algorithm to be automaticaly used by the end user, the software correctly selected the algorithm with the highest probability of generating a correct outcome. In addition to the technical benefits, the developed architecture allows the results of field experiments analysis, associated with the algorithms used, to feed the knowledge base of the software so that it generates better parametrizations in the executions made by the end user. In addition to the technical benefits, the developed architecture allows the results of field experiments, associated with the used algorithms, to feed the knowledge base of the softwares that it generates better parametrizations when executed by the end user. The developed architecture in this work made possible integrating the several steps when using RPAs in PA, making easier its use by resaerchers and end users. The joint use by researchers and end users in the same environment could be an interesting alterative to publish new and better methods for image processing, giving to the end users more reliable results and more information about the crops. / O uso de aeronaves remotamente pilotadas (RPA) na agricultura de precisão (AP) está em constante evolução, sendo um processo que compreende as etapas de: determinação do objetivo, captura e processamento das imagens, e análise dos dados obtidos. Apesar de existirem alguns softwares e hardwares para essas etapas, a dificuldade ainda reside na integração dos dados coletados, sua confiabilidade, e na interpretação das informações resultantes para tomada de decisão. Este trabalho propõe uma arquitetura de software para o uso de RPA na AP que permite a execução de todas as etapas do processo utilizando os padrões arquiteturais Domain-Driven Design e Command e Query Responsability Segregation. Esta arquitetura, quando utilizada por pesquisadores, permite a integração de novos módulos de processamento de imagem, utilizando raciocínio baseado em casos (RBC) para sua avaliação. A arquitetura foi avaliada em um estudo de caso sob os seguintes aspectos: a confiabilidade dos métodos de processamento de imagem implementados e a adequação do método de RBC ao determinar o melhor algoritmo de processamento de imagem para objetivos específicos. O resultado do algoritmo de processamento de imagem para estimativa do índice de vegetação por diferença normalizada (NDVI) foi comparado aos resultados obtidos em equipamento de campo (Greenseeker) e pelo processamento via software Pix4D. Foi verificado que tanto os softwares quanto o equipamento geraram valores similares, com diferença média de 7%. Nas simulações de escolha do melhor algoritmo a ser utilizado automaticamente pelo usuário final, o software selecionou o algoritmo correto indicando para o mesmo a maior probabilidade de acerto. Além dos benefícios técnicos, a arquitetura desenvolvida permite que resultados de análises de experimentos em campo, associados aos algoritmos utilizados, alimentem a base de conhecimento do software para que o mesmo gere melhores parametrizações nas execuções feitas pelo usuário final. A arquitetura desenvolvida neste trabalho permitiu a integração das diversas etapas que envolvem o uso de RPA na AP, facilitando o uso por pesquisadores e usuários finais. A utilização conjunta de pesquisadores e usuários finais em um mesmo ambiente, pode ser uma alternativa interessante para publicação de novos e melhores métodos de processamento de imagem, fornecendo aos usuários finais mais informações sobre sua cultura e resultados mais confiáveis.
|
282 |
Assessing tropical forest degradation and restoration through lidar remote sensing / Avaliação da degradação e restauração de florestas tropicais através de sensoriamento remoto lidarDanilo Roberti Alves de Almeida 04 December 2018 (has links)
The present study investigates new frontiers of lidar technology knowledge assessessing of tropical forest degradation and restoration. The thesis is structured with an introductory chapter, four technical chapters, which explored technical and scientific aspects of the application of lidar technology to the evaluation of forest degradation in the Amazon and restoration of forests in the Atlantic Forest, and a final chapter with considerations and a summary of the main scientific results obtained in this thesis. The results of chapter 2 provided important insights for the correct modeling of leaf area density (LAD) proflies profiles usind airborne lidar. LAD profile is the decomposition of the leaf area index (LAI) along the vertical canopy profile and can be used to answer many ecological questions. The results of chapter 2 provided important insights for the correct modeling of LAD profiles. Chapter 3, using lidar data on aerial and portable ground platforms, in the Biological Dynamics of Forest Fragments Project (BDFFP), demonstrated in an unprecedented way the effect of forest fragmentation in the canopy structure (lidar-derived) and their relationships with the change of the tree community. In this chapter, the results showed that the lidar technology has enormous potential to monitor the impact of forest fragmentation in a high precision scale for large areas. Chapter 4, using data from several forest typologies in the Atlantic Forest biome restoration collect by a portable ground lidar system, demonstrated the potential of canopy structural attributes to distinguish different forest typologies and to estimate above ground woody dry biomass. However, the results were not positive for estimating tree community diversity (richness, Shannon index and species composition). Finally, chapter 5 demonstrated the potential of a novel lidar system on a drone platform (also known as UAV - unmanned aerial vehicle) to monitor forest restoration plantations. Lidar is revolutionizing the way we measure forest landscapes and can be an indispensable tool for the success of forest restoration projects, having the potential to support on planning, monitoring and inspection of forest restoration landscapes. In this thesis, we demonstrate several applications of remote sensing to address the context of forest restoration, and we established methodological bases for other studies to expand the use of this technology for decision making in tropical forest conservation, management and restoration. / O presente estudo investiga novas fronteiras do conhecimento da aplicação da tecnologia de sensoriamento remoto lidar à avaliação da degradação e restauração de florestas tropicais. A tese está estruturada na forma de um capítulo de introdução, quatro capítulos técnicos, que exploraram aspectos técnicos e científicos da aplicação da tecnologia lidar à avaliação da degradação de florestas na Amazônia e restauração de florestas na Mata Atlântica, e de um capítulo final com considerações gerais e uma síntese dos principais resultados científicos obtidos nesta tese. O capítulo 2, utilizando dados lidar aeroembarcados em avião, analisou uma questão técnica, sobre a influência da densidade de pulsos da nuvem lidar e da resolução de amostragem para a modelagem do perfil de densidade de áerea foliar em florestas tropicais (DAF). O perfil de DAF é a decomposição do índice de área foliar (IAF) ao longo do perfil vertical do dossel e pode ser utilizado para responder diversas questões ecológicas. Os resultados da capítulo 2 trouxeram importantes insights para a correta modelagem dos perfis de DAF. O capítulo 3, utilizando dados lidar em plataformas aeroembarcados e terrestre portátil, no Projeto Dinâmica Biologica de Fragmentos Florestais (PDBFF), demonstrou de maneira inédita o efeito da fragmentação florestal sobre a alteração da estrutura do dossel (derivados de dados lidar) e suas relações com a mudança da comunidade arbórea. Neste capítulo os resultados demonstraram que a tecnologia lidar tem enorme potencial para monitorar o impacto da fragmentação florestal para grandes áreas e em fina escala. O capítulo 4, utilizando dados de diversas tipologias florestais em restauração no bioma Mata Atlântica, a partir de um sistema lidar terrestre portátil, demonstrou a capacidade dos atributos estruturais do dossel em distinguir diferentes tipologias florestais, estimar diversidade e biomassa de madeira acima do solo. Contudo, os resultados não foram muito positivos para estimativa da diversidade da comunidade arbórea (riqueza, indice de Shannon e composição de espécies). Finalmente, o capitulo 5 demonstrou a capacidade de um sistema inovador lidar aeroembarcado em uma plataforma drone (também conhecida como VANT - veículo aéreo não tripulado) para monitorar plantios de restauração florestal. O lidar está revolucionando a maneira de mensurarmos as paisagens florestais, podendo ser uma ferramenta imprecindível para o sucesso dos projetos de restauração florestal em larga escala, tendo o potencial de auxiliar desde o planejamento ao monitoramento e fiscalização dos projetos florestais. Nesta tese, demonstramos diversas aplicações do sensoriamento remoto lidar ao contexto da restauração florestal, e estabelecemos bases metodológicas para que outros estudos expandam o uso desta tecnologia para tomada de decisão na conservação, manejo e restauração de florestas tropicias.
|
283 |
Avaliação da eficiência do uso da mineração de dados clássica e espacial na estimativa de produtividade de grãos em imagens obtidas por meio de aeronave remotamente pilotadaViniski, Antônio David 16 March 2018 (has links)
Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-05-08T17:08:26Z
No. of bitstreams: 2
license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5)
Antonio David Viniski.pdf: 3962317 bytes, checksum: f5afcd11e4083b0ae065ae21490ac77f (MD5) / Made available in DSpace on 2018-05-08T17:08:26Z (GMT). No. of bitstreams: 2
license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5)
Antonio David Viniski.pdf: 3962317 bytes, checksum: f5afcd11e4083b0ae065ae21490ac77f (MD5)
Previous issue date: 2018-03-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O sensoriamento remoto agrícola tem fornecido um volumoso conjunto de dados espaciais, os
quais podem ser utilizados em diferentes segmentos, como na estimativa de produtividade de
grãos. Dentre as tecnologias empregadas no SR, a utilização de aeronaves remotamente
pilotadas (RPA) na agricultura vêm crescendo, sendo uma alternativa na obtenção de dados
para a estimativa de produtividade. Porém, esses conjuntos de dados gerados demandam
métodos e técnicas capazes de extrair informações úteis e relevantes dos mesmos. Algumas
técnicas de geoestatística, como a krigagem, têm sido empregadas, mas a utilização da
mineração de dados (MD), assim como da mineração de dados espaciais (MDE), podem ser
alternativas viáveis para suprir essa demanda. Este trabalho teve como objetivo avaliar o uso
de técnicas de MD e MDE na estimativa da produtividade de grãos de soja e trigo, utilizando
dados de imagens obtidas por meio de RPA. A área de estudo localiza-se no município de Piraí
do Sul, Paraná. Foi utilizada uma RPA de asa fixa para o acompanhamento das culturas de soja
e trigo. No imageamento do trigo foram utilizadas duas câmeras, uma com a captura de imagens
no espectro visível (RGB), e outra no infravermelho próximo (NIR), tendo sendo analisadas
também as resoluções espaciais de 10 e 20 cm/pixel para cada câmera. Para a soja apenas a
câmera RGB foi utilizada e as resoluções espaciais sobrevoadas foram 10, 20 e 26 cm/pixel. Os
dados do atributo meta, a produtividade das culturas, foram obtidos por meio de colhedoras de
precisão. Os atributos de predição, correspondendo aos valores das bandas espectrais e altitude
do terreno, foram submetidos aos algoritmos de MD empregando as técnicas de regressão linear
múltipla (RLM), redes neurais artificiais (RNA) e máquina de vetores de suporte para regressão
(SVR). Para a MDE, foi utilizado o modelo aditivo generalizado (GAM). Para fins de
comparação, os dados foram também analisados pelo método tradicional de krigagem. As
técnicas foram testadas considerando duas abordagens principais: (i) utilizando apenas as
bandas espectrais para estimativa e, (ii) utilizando as bandas espectrais e os valores de altitude
do terreno. Para a MD clássica, os melhores resultados foram obtidos com a técnica SVR,
utilizando o kernel Laplacian. Na MDE, o método GAM com a função de ajuste gaussiana
apresentou os melhores resultados. Tanto para as técnicas clássicas de MD como para a MDE,
a incorporação da altitude nos modelos de regressão possibilitou aumento considerável nos
coeficientes de correlação e determinação, com consequente diminuição no erro (RMSE). Os
valores de correlação obtidos com a MDE foram semelhantes aos obtidos com o método de
krigagem, porém a MDE foi mais eficiente em avaliar o impacto dos atributos de predição
(valores das bandas espectrais e altitude) na estimativa do atributo meta. Com isso, conclui-se
que a MDE mostra-se viável de ser utilizada como ferramenta na geração de modelos para
estimativa de produtividade de grãos com base em dados de imagens de RPA. / Agricultural remote sensing (RS) has provided a massive set of spatial data which can be used
in different segments, such as in grain yield estimation. Among the technologies applied in RS,
the use of remotely piloted aircraft (RPA) in agriculture is growing as an alternative to obtain
data for estimating productivity. However, these generated data sets require methods and
techniques capable of extracting useful and relevant information from them. Some geostatistics
techniques have been applied, such as kriging, but the use of data mining (DM) as well as spatial
data mining (SDM) can be viable alternatives to meet that demand. The goal of this work was
to evaluate the use of DM and SDM techniques for estimating soybean and wheat grain yield
using image data obtained by RPA. The study area is located in Piraí do Sul, Paraná State. A
fixed wing RPA was used to monitor soybean and wheat crops. In wheat crop imaging two
cameras were used, one to capture images in the visible spectrum (RGB), and the other one
using the near infrared (NIR) spectrum. Also, it was analyzed the spatial resolutions of 10 and
20 cm / pixel for each camera. For soybean only the RGB camera was used and the overhead
spatial resolutions were 10, 20 and 26 cm / pixel. The goal attribute data (crop yield), was
obtained by precision harvester. The prediction attributes, corresponding to the values of
spectral bands and terrain altitude, were submitted to DM algorithms using the multiple linear
regression (MLR), artificial neural networks (ANN) and support vector regression (SVR)
techniques. For SDM, the generalized additive model (GAM) was used. For comparison
purposes, data were also analyzed by the traditional kriging method. The techniques were tested
using two main approaches: (i) using only spectral bands for estimation and, (ii) using spectral
bands and terrain altitude values. For classical DM, the best results were obtained with SVR
technique, using the Laplacian kernel. The GAM method with the Gaussian fit function
presented the best results for SDM. For both classical DM and SDM techniques, adding altitude
in the regression models allowed a considerable increase in correlation and determination
coefficients, with consequent decrease in error (RMSE). The correlation values obtained with
SDM were similar to those obtained with kriging method, but SDM was more efficient in
evaluating the impact of the prediction attributes (spectral bands and altitude) in the estimation
of the goal attribute. Thus, it is concluded that SDM can be useful as a tool for estimating grain
yield based on RPA image data.
|
284 |
Mission-based guidance system design for autonomous UAVsMoon, Jongki 01 October 2009 (has links)
The advantages of UAVs in the aviation arena have led to extensive research activities on autonomous technology of UAVs to achieve specific mission objectives. This thesis mainly focuses on the development of a mission-based guidance system. Among various missions expected of UAVs for future needs, autonomous formation flight (AFF) and obstacle avoidance within safe operation limits are investigated.
In the design of an adaptive guidance system for AFF, the leader information except position is assumed to be unknown to a follower. Thus, the only measured information related to the leader is the line-of-sight range and angle. Adding an adaptive element with neural networks into the guidance system provides a capability to effectively handle leader's velocity changes. Therefore, this method can be applied to the AFF control systems that use passive sensing methods. The simulation and flight test results clearly show that the adaptive guidance control system is a promising solution for autonomous formation flight of UAVs. The successful flight evaluations using the GTMax rotary wing UAV also demonstrate unique maneuvering aspects associated with rotary wing UAVs in formation flight.
In the design of an autonomous obstacle avoidance system, an integrated approach is proposed to resolve the conflict between aggressive maneuvering needed for obstacle avoidance and the constrained maneuvering needed for envelope protection. A time-optimal problem with obstacle and envelope constraints is used for an integrated approach for obstacle avoidance and envelope protection. The Nonlinear trajectory generator (NTG) is used as a real-time optimization solver. The computational complexity arising from the obstacle constraints is reduced by converting the obstacle constraints into a safe waypoint constraint along with an implicit requirement that the horizontal velocity during the avoidance maneuver must be non-negative. The issue of when to initiate a time-optimal avoidance maneuver is addressed by including a requirement that the vehicle must maintain its original flight path to the maximum extent possible. The simulation results using a rotary wing UAV demonstrate the feasibility of the proposed approach for obstacle avoidance with envelope protection.
|
285 |
Fault tolerant flight control of a UAV with asymmetric damage to its primary lifting surfaceBeeton, Wiaan 12 1900 (has links)
Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: In this thesis the design, analysis, implementation, and verification of a fault-tolerant unmanned aerial
vehicle (UAV) flight control system which is robust to structural damage causing the natural flight dynamics
of the vehicle to become asymmetric, is presented.
The main purpose of the robust control architecture is to maintain flight stability after damage has occurred.
The control system must be able to handle an abrupt change from an undamaged to a damaged
state, and must also not depend on explicit knowledge of the damage. A robust control approach is therefore
preferred above an adaptive control approach. As a secondary objective, the system must provide
robust flight performance to ensure adequate response times and acceptable transients’ behaviour, both
in normal flight, and after damage has occurred.
An asymmetric six degrees of freedom equations of motion model is derived. The model accounts for
the changes in the aerodynamic model of the aircraft as well as changes in the centre of gravity location.
Vortex lattice techniques are used to determine the aerodynamic coefficients of the aircraft for damage
to the main wing resulting in 0% to 40% spanwise lifting surface loss. A sequential quadratic programming
optimisation algorithm is applied to the force and moment equations to find the trim flight state and
actuator deflections of the asymmetric aircraft for constant airspeed and altitude. The trim flight state
can be further constrained to force zero bank angle, zero sideslip angle or a desired relative weighting
of nonzero bank angle and nonzero sideslip angle. The calculated trim actuator deflections are compared
to the physical deflection limits to determine the feasibility of maintaining trim flight for different percentages
of wing loss. Assuming that a valid trim condition exists, the relative stability of the aircraft’s
natural modes is analysed as a function of percentage wing loss by tracing the locus of the open-loop poles.
An acceleration-based flight control architecture is designed and implemented, and the robustness of the
flight control stability and performance is analysed as a function of percentage wing loss. The robustness
and performance of the flight control system is verified with a nonlinear simulation for spanwise wing loss
from 0 to 40%.
Practical flight tests are performed to verify the robustness and performance of the flight control systems
to in-flight damage. A detachable wing with release mechanism is designed and manufactured to
simulate 20% wing loss. The flight control system is implemented on a practical UAV and a successful
flight test shows that it performs fully autonomous flight control, and is able to accommodate an in-flight
partial wing loss. / AFRIKAANSE OPSOMMING: In hierdie tesis word die ontwerp, analise, implementasie en verifikasie van ’n fout-verdraende onbemande
vliegtuig beheerstelsel wat robuust is tot strukturele skade wat die natuurlike vlug dinamika van die voertuig
asimmetries maak, voorgestel.
Die hoofdoel van hierdie robuuste beheer argitektuur is om stabiliteit te verseker na die skade aangerig
is. Die beheerstelsel moet die skielike verandering van normale na beskadigde vlug hanteer sonder
enige eksplisiete kennis daarvan. Dus word ’n robuuste beheer aanslag verkies bo ’n aanpassende beheer
struktuur. Tweedens moet die vlugbeheerstelsel robuust genoeg wees om steeds die gewenste reaksietyd
en aanvaarbare oorgangsverskynsels te kan hanteer, tydens beide normale en beskadigde vlug.
’n Asimmetriese ses grade van vryheid beweginsvergelykings model word afgelei. Die model het die
vermoë om veranderinge in die aerodinamiese model van die vliegtuig, sowel as massamiddelpunt verskuiwing,
voor te stel. “Vortex Lattice” metodes is gebruik om die aerodinamiese koëffisiënte van die
beskadigde vlerk voor te stel tussen 0% en 40% verlies. ’n Sekwensiële kwadratiese programmering optimiserings
algorithme is aangewend op die krag en moment vergelykings om die ekwilibrium vlug toestand
en aktueerder defleksies te vind vir ’n asimmetriese vliegtuig met konstante lugspoed en hoogte. Die
ekwilibrium vlug toestand word verder beperk deur ’n nul rolhoek, ’n nul sygliphoek of ’n relatiewe weging
van die twee. Die bepaalde ekwilibrium defleksies word dan vergelyk met die fisiese limiete om hulle
geldigheid te bepaal vir ekwilibrium vlug. As ’n geldige ekwilibrium toestand bestaan, kan die relatiewe
stabiliteit van die vliegtuig se natuurlike modusse ontleed word as ’n persentasie van vlerkverlies deur die
wortellokusse van die ooplus pole na te gaan.
’n Versnellings-gebaseerde vlug beheerstelsel argitektuur is ontwerp en geïmplementeer. Daarna is die
robuustheid ontleed as ’n funksie van die persentasie vlerkverlies. Die robuustheid en gedrag van hierdie
vlugbeheerstelsel is geverifieer met ’n nie-linêre simulasie vir 0 tot 40% vlerkverlies.
Praktiese vlugtoetse is onderneem om die robuustheid en gedrag tydens/na skade gedurende ’n vlug,
te verifeer. ’n Vlerkverlies meganisme is ontwerp en vervaardig om 20% vlerkverlies te simuleer. Die
vlugbeheerstelsel is geïmplementeer op ’n onbemande vliegtuig en die daaropvolgende suksesvolle vlug
lewer bewys dat die vlugbeheerstelsel wel skade, in die vorm van gedeeltelike vlerkverlies, tydens vlug kan hanteer.
|
286 |
Modelagem e análise de topologias para veículos aéreos não-tripulados do tipo multirotor / Modeling and analysis of topologies for unmanned aerial vehicles of the multirotor typeSandi, Nathanyel 03 July 2017 (has links)
Com a evolução dos projetos de multirotores e dos seus componentes, os projetistas vem tendo inúmeras opções de combinações de componentes na fase de projeto do multirotor, buscando melhor performance e menor custo. Isto deixa um problema em aberto: como atingir o multirotor pode atingir uma boa performance ainda na fase de projeto. A motivação para realização deste estudo se justifica no fato que não há trabalhos relacionado ao levantamento de métricas e análise de performance dos multirotores. Assim como o fator de não haver formas de mensurar a qualidade dos projetos e ter possibilidade de comparação, uma vez que tem-se várias formas de projetar um multirotor para diferentes aplicações. Este trabalho propõe uma abordagem para a análise do projeto de multirotores em termos de sua capacidade de voo (definida como voabilidade), levando em consideração as características de seus rotores, peso e topologia. O principal objetivo é apresentar uma forma de qualificar e quantificar uma aeronave multirotor para otimizar seu projeto. A abordagem discutida tem como objetivo analisar as habilidades de voo dos multirotores em seu projeto teórico para suportar os requisitos de projeto (como tamanho da hélice, torque do motor, topologia de armação), garantindo as capacidades de voo exigidas pela tarefa. Como resultado deste trabalhos, um conjunto de índices foi proposto para avaliar a qualidade de projeto de multirotores, sendo eles: voo, estabilidade, posicionamento e flutuação. A soma destes índices compõem o índice de voabilidade. Este índice oferece a possibilidade de comparação da análise do veículo em função das especificações do conjunto motor, hélice, topologia e tamanho do quadro. Para a validação destas métricas, uma análise das topologias tradicionais foi realizada, permitindo uma comparação em função do desempenho e esforço delas. / With an evolution of the multi-curral projects and their components, the designers have been having numerous options of combinations of components in the multirotor design phase, seeking better performance and lower cost. This leaves an open problem: as what the multirotor can achieve a good performance still in the design phase. One motivation to carry out this study is justified in that there are no works related to the survey of metrics and analysis of the performance of multirotors. As well as the factor there are no ways to measure a quality of projects and possibility of comparison, since there are several ways to design a multirotor for different applications. This work proposes an approach for an analysis of the design of multirotors in terms of their flight capacity, defining as characteristics of their rotors, weight and topology. The main objective is to present a way to qualify and quantify a multirotor aircraft to optimize its design. An approach approached for design design to support design requirements (such as power size, engine torque, frame topology), ensuring as required flight capabilities. As a result of this work, a set of indexes proposed to evaluate a multirole project quality, being: flight, stability, hover and heading. The sum of these indices compose the voleability index. This index offers a possibility of comparing the vehicle analysis according to the specifications of the engine assembly, propeller, topology and frame size. For a metric validation, an analysis of the topologies was performed, allowing a comparison for the performance function and their effort.
|
287 |
Pour une approche heuristique du son d'or de Charlemagne Palestine : la reconstuction de Schlingen-Blängen / The golden sound of Charlemagne Palestine, a heuristic approach : the reconstruction of Schlingen-BlängenElla-Meye, Francois 24 March 2017 (has links)
La musique de Charlemagne Palestine semble transcender les approches musicales américaines comme européennes des vingtième et vingt-et-unième siècles. Si sa pratique de la musique drone prend ses racines dans ses années passées enfant à chanter des lamentations dans les synagogues en tant que choriste, puis jeune adulte dans son expérience de carillonneur à l'église Saint-Thomas de Manhattan, et plus tard dans les approches expérimentales post-cagiennes et son étude vocale de la musique hindoustanie, son oeuvre, qui à de nombreux égards évoque également certaines esthétiques musicales de l'avant-garde européenne, oscille entre musique, installation et performance. C'est au travers de l'étude de la pièce "Schlingen-Blängen" pour orgue, sous le prisme de l'heuristique musicale, que cette thèse tente d'appréhender la quête du "son d'or" du musicien contemporain new-yorkais d'origine, bruxellois d'adoption. / The music of Charlemagne Palestine seems to transcend both american and european musical mouvements of the twentieth and twentieth-first centuries. His approach of drone music finds its origins in his early years when he would participate in synanogue choirs, singing lamentations, as well as in his young adult years when he would work as a bell ringer in the church of Saint-Thomas in Manhattan. Later on, his experimental post-Cage music approach and his vocal studies of Hindustani music, all gave birth to a body of work that oscillates between music, installation and performance, not without recalling in various ways certain european avant-garde musical esthetics. The present doctoral thesis aims to study the piece "Schlingen-Blängen" for organ, via a musical heuristics approach, in order to apprehend the pursuit of the "golden sound" in the oeuvre of the New-York contemporary artist, based in Brussels.
|
288 |
Identificación de puntos críticos en carreteras con riesgo sísmico evaluado con drone topográfico / Identification of critical points on roads with seismic risk evaluated with a topographic droneCaytuiro Chavez, Jose Alberto, Guevara Solier, Diego Ernesto 09 September 2021 (has links)
Este trabajo de investigación busca identificar, bajo un enfoque determinístico, los riesgos sísmicos a lo largo de una carretera. Además, se empleará un dron topográfico y un GPS diferencial que facilitará la toma de datos georreferenciados. Para nuestro análisis se usó como referencia la metodología REDARS 2 la cual nos ofrece un procedimiento adecuado para la evaluación e identificación de riesgos sísmicos en redes de transporte terrestre en base a un escenario sísmico pertinente en la zona. Los resultados finales abarcan puntos críticos exactos en la Carretera que, debido a sus características, representan un peligro inminente a la estructura y a su funcionabilidad. / This research seeks to identify, under a deterministic approach, seismic risks along a road. In addition, a topographic drone and differential GPS will be used to facilitate the collection of geo-referenced data. For our analysis, the REDARS 2 methodology was used as a reference, which offers us a suitable procedure for the assessment and identification of seismic risks in terrestrial transport networks based on a relevant seismic scenario in the area. The final results cover exacts critical points on the road that, due to their characteristics, represent an imminent danger to the structure and its functionality. / Trabajo de investigación
|
289 |
Are U.S drone targeted killings within the confines of the law?Chengeta, Thompson 30 October 2011 (has links)
Equally discomforting is the PlayStation mentality that surrounds drone killings. Young military
personnel raised on a diet of video games now kill real people remotely using joysticks. Far
removed from the human consequences of their actions, how will this generation of fighters
value the right to life? How will commanders and policy makers keep themselves immune from
the deceptively antiseptic nature of drone killings? Will killing be a more attractive option than
capture? Will the standards of intelligence gathering justify a killing slip? Will the number of
acceptable collateral civilian deaths increase? / Prepared under the supervision of Mr Gus Waschefort at the International criminal court, The Hague, Netherlands / Thesis (LLM (Human Rights and Democratisation in Africa)) -- University of Pretoria, 2011. / http://www.chr.up.ac.za/ / nf2012 / Centre for Human Rights / LLM
|
290 |
Mobile Network performance analysis of UAV : A Simulation for UAVs utilizing 4G-LTE cellular networksZheng, Shuo January 2019 (has links)
The usage of UAVs (Unmanned Aircraft Vehicle) is soaring, not just for hobbyists but increasingly for a range of professional and civil applications. Some of the more sophisticated applications that have high data usage and long-range flight requirements are being developed now. The range and capability of typical wireless connectivity technologies are not enough for such applications. Connecting UAVs to the mobile network is a solution. There are lots of benefits which mobile network can provide for UAVs and UTM (Unmanned Aircraft System Traffic Management). However, the anticipation of UAVs was not considered at first in network planning, which creates unexpected coverage conditions. The introduction of UAVs impacts LTE (Long Term Evolution) network in several ways and the network coverage and capacity of UAVs at low altitude is significantly different from that of terrestrial UEs. The thesis work includes investigation about how UAVs impact LTE network and how mobile network coverage and capacity for UAVs change when other factor changes. The impact of methods to enhance the mobile network for UAVs would also part of the research. In this work, a successful simulation in order to investigate UAV’s situation while using 4G LTE cellular networks is developed. In order to properly test the developed framework for a range of different inputs, various generic scenarios were successfully developed and executed. Using this simulation, we have shown that UAV’s network situation is affected by 2 parameters: the height of UAV and the load of the eNodeBs (Evolved Node B). We have successfully demonstrated that UAV at higher attitude may cause more serious network condition in the suburban area compared with the case in the urban area. Finally, an interference mitigation technique: antenna beam selection is applied and tested. We show that it can improve the network condition for UAV at a higher altitude. Some improvements to the model could be a modeling of inter-cell interference and multipath effects. Models of weather condition in UAV’s flying space would also greatly improve the framework. Besides a scheme for modulation and bit error calculation could be used to build a more generic model. In the thesis, antenna propagation and gain models are not perfect, so more accurate model would also be a great improvement. Only antenna beam selection is tested in this thesis and the implementation does not include antenna mechanical design and model building. For further research, more methods like interference cancellation, power control and inter-cell interference coordination can be tested in both simulation and hardware. / Användningen av UAV(Unmanned Aircraft Vehicle): er är stigande, inte bara för hobbyister utan allt mer för en rad professionella och civila applikationer. Några av de mer sofistikerade applikationerna som har hög dataanvändning och krav på lång räckvidd utvecklas nu. Räckvidden och kapaciteten för typiska trådlösa anslutningstekniker räcker inte för sådana applikationer. Att ansluta UAV: er till mobilnätet är en lösning. Det finns många fördelar som mobilnätet kan ge för UAV: er och UTM (Unmanned Aircraft System Traffic Management). Förväntningen på UAV: er beaktades dock inte först i nätverksplanering, vilket skapar oväntade täckningsförhållanden.Införandet av UAV: er påverkar LTE-nätverk (Long Term Evolution) på flera sätt och nätverkets täckning och kapacitet för UAV: er på låg höjd skiljer sig väsentligt från markbundna UE: er.Examensarbetet inkluderar utredning om hur UAV: er påverkar LTE-nätverk och hur mobilnätstäckning och kapacitet för UAV: er förändras när andra faktorer ändras. Effekten av metoder för att förbättra mobilnätverket för UAV: er skulle också vara en del av forskningen. I detta arbete utvecklas en framgångsrik simulering för att undersöka UAV: s situation med användning av 4G LTE-mobilnät. För att korrekt testa det utvecklade ramverket för en rad olika ingångar, utvecklades och genomfördes olika generiska scenarier. Med denna simulering har vi visat att UAVs nätverkssituation påverkas av två parametrar: UAV: s höjd och belastningen på eNodeBs (Evolved Node B). Vi har framgångsrikt visat att UAV vid högre inställning kan orsaka allvarligare nätverkstillstånd i förortsområdet jämfört med fallet i stadsområdet. Slutligen tillämpas och testas en interferensbegränsande teknik: val av antennstråle. Vi visar att det kan förbättra nätverksvillkoret för UAV på högre höjd. Några förbättringar av modellen kan vara modellering av inter-cellstörningar och flervägseffekter. Modeller av väderförhållanden i UAV: s flygutrymme skulle också förbättra ramverket kraftigt. Förutom ett schema för modulering och beräkning av bitfel skulle kunna användas för att bygga en mer generisk modell. I avhandlingen är antennutbredningsoch förstärkningsmodeller inte perfekta, så en mer exakt modell skulle också vara en stor förbättring. Endast val av antennstråle testas i denna avhandling och implementeringen inkluderar inte antennmekanisk design och modellbyggnad. För ytterligare forskning kan fler metoder som interferensavbrott, effektkontroll och inter-cell-interferenskoordination testas i både simulering och hårdvara.
|
Page generated in 0.1876 seconds