Over the last few years, the concept of civil Unmanned Aircraft System(s) (UAS) has been realised, with small UASs commonly used in industries such as law enforcement, agriculture and mapping. With increased development in other areas, such as logistics and advertisement, the size and range of civil UAS is likely to grow. Taken to the logical conclusion, it is likely that large scale UAS will be operating in civil airspace within the next decade. Although the airborne operations of civil UAS have already gathered much research attention, work is also required to determine how UAS will function when on the ground. Motivated by the assumption that large UAS will share ground facilities with manned aircraft, this thesis describes the preliminary development of an Automated Taxiing System(ATS) for UAS operating at civil aerodromes. To allow the ATS to function on the majority of UAS without the need for additional hardware, a visual sensing approach has been chosen, with the majority of work focusing on monocular image processing techniques. The purpose of the computer vision system is to provide direct sensor data which can be used to validate the vehicle s position, in addition to detecting potential collision risks. As aerospace regulations require the most robust and reliable algorithms for control, any methods which are not fully definable or explainable will not be suitable for real-world use. Therefore, non-deterministic methods and algorithms with hidden components (such as Artificial Neural Network (ANN)) have not been used. Instead, the visual sensing is achieved through a semantic segmentation, with separate segmentation and classification stages. Segmentation is performed using superpixels and reachability clustering to divide the image into single content clusters. Each cluster is then classified using multiple types of image data, probabilistically fused within a Bayesian network. The data set for testing has been provided by BAE Systems, allowing the system to be trained and tested on real-world aerodrome data. The system has demonstrated good performance on this limited dataset, accurately detecting both collision risks and terrain features for use in navigation.

The use of unmanned combat aerial vehicles (UCAV) is relativity new with the first known lethal strike taking place in 2001. Few systems are operational but many are in development. The use of UCAVs is debated and many claim that UCAVs make it casual for the pilots to kill, and the pilots are not able to differentiate the ethics of what they do from those of a video game. When researched it is found that some factors regarding the use of UCAVs may make a pilot less reluctant to execute a remote lethal strike, yet it does not make it casual. The pilots know that what they do has real world implications and what they see on their screens are real people. Contrary to some people’s beliefs, UCAV pilots may have a greater connection with their victim as well as a greater reluctance towards killing compared to bomber pilots. / Användandet av bestyckade obemannade flygande farkoster (UCAV) är relativt nytt. Det första kända fallet där en UCAV:s vapensystem nyttjats för att döda skedde 2001. Få system är operativa men flera är under utveckling. Användandet av UCAV:er är debatterat. Flera hävdar att hur de nyttjas leder till att piloten blir likgiltig till att döda och att piloten inte kan skilja på det piloten gör och att spela ett tv-spel. När ämnet studerats så har det visat sig att flertalet av de faktorer som spelar in i användande av UCAV:er gör det lättare för piloter at övervinna det motstånd en person känner till att ta en annans liv. Dock så blir piloten inte likgiltig till det. Piloterna är medvetna om att deras handlingar har en påverkan på den riktiga världen och vad de ser på sina skärmar är riktiga människor. I motsatts till vad vissa tror så har UCAV piloter en större koppling till de piloterna dödar samt upplever ett större motstånd till att döda än bombpiloter. / <p>SA skriven i Tjeckien vid University of Defence i Brno genom ERASMUS.</p>

SILVA, Cristiano Alves da. Avaliação da acurácia dos ortomosaicos e modelos digitais do terreno gerados por VANT e sua aplicação no cálculo de volume de pilhas de rejeito da Pedra Cariri. 2015. 146 f. Dissertação (Mestrado em Geologia)-Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Vitor Campos (vitband@gmail.com) on 2016-10-05T23:02:45Z No. of bitstreams: 1 2015_dis_casilva.pdf: 5268107 bytes, checksum: c3a0b833ecc7a09a72b7062054e67836 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-10-06T20:47:38Z (GMT) No. of bitstreams: 1 2015_dis_casilva.pdf: 5268107 bytes, checksum: c3a0b833ecc7a09a72b7062054e67836 (MD5) / Made available in DSpace on 2016-10-06T20:47:38Z (GMT). No. of bitstreams: 1 2015_dis_casilva.pdf: 5268107 bytes, checksum: c3a0b833ecc7a09a72b7062054e67836 (MD5) Previous issue date: 2015 / Recently, the technological advancement of Unmanned Aerial Vehicles (UAVs) has been exponential. This equipment are capable of generating remote sensing products of high accuracy at low operating costs, carrying out activities previously performed exclusively by manned aircraft. In this context, the National Department of Mineral Production (DNPM), aiming to maximize their actions of oversight and management of mining, has partnered with the University of Brasilia (UnB) for the development of a small UAV capable of generating orthomosaics and Terrain Digital models (TDM) with high accuracy. To achieve such objective, UnB has developed a 2,5 kg aircraft equipped with a small-format camera, nonmetric, capable of obtaining high-resolution photographs, after being processed through method of computing similarities between overlapping images, generates a cloud of points of the three-dimensional coordinates (x, y, z) of the surface, allowing to generate orthomosaics and TDMs. However, UAV technology is still considered emerging, being common questions about the survey method, used sensor and mainly accuracy of obtained results, a fact that motivated the elaboration in this case study. The main purpose this research is to evaluate of the accuracy of orthomosaics and TDMs generated from the data collected by the UAV developed by UnB, as well it's application in calculating the volume of laminate sedimentary limestone tailings piles of Araripe Basin in Ceará, extracted in the form of tiles in natura marked under the name of Cariri Stone, compared it's accuracy with the results obtained with Global Navigation Satellite System (GNSS) and Light Detecting and Ranging (LIDAR) technologies, more commonly used by mining for this purpose. To evaluating the accuracy was used hypothesis testing method, from the trend and precision of analysis, and the results classified according to the Standard Cartographic Accuracy of Digital Cartographic Products (PEC-PCD). After the experiments performed, it was possible to acknowledge that the UAVUnB/DNPM is capable of generating with accuracy orthomosaics and MDTs, consistent with those obtained by conventional aerial photography, if properly oriented by ground control points. In this case study, the UAV showed better results when compared with modeling performed through GNSS and LIDAR technologies. / Nos últimos anos foi exponencial o avanço tecnológico dos denominados Veículos Aéreos Não Tripulados (VANT) Estes equipamentos são capazes de gerar produtos de sensoriamento remoto de elevada acurácia com baixo custo operacional desempenhando atividades antes executadas exclusivamente por aeronaves tripuladas Neste contexto o Departamento Nacional de Produção Mineral (DNPM) para maximizar suas ações de fiscalização e gestão da mineração firmou parceria com a Universidade de Brasília (UnB) para desenvolvimento de um VANT de pequenas dimensões capaz de gerar ortomosaicos e Modelos Digitais do Terreno (MDT) de alta acurácia Para alcançar esse objetivo a UnB desenvolveu uma aeronave de 25 kg equipada com uma câmera não métrica capaz de obter fotografias de alta resolução que após processadas utilizando o método de correlação de imagens sobrepostas gera uma nuvem de pontos das coordenadas tridimensionais da superfície permitindo a geração de ortomosaicos e MDTs Contudo a tecnologia VANT ainda é considerada emergente São comuns indagações sobre o método de levantamento o sensor utilizado e principalmente a acurácia dos resultados obtidos fato que motivou a elaboração deste estudo de caso O objetivo principal desta pesquisa foi realizar a avaliação da acurácia dos ortomosaicos e MDTs gerados a partir dos dados coletados pelo VANT desenvolvido pela UnB bem como sua aplicação no cálculo do volume de pilhas de rejeito do calcário sedimentar laminado da Bacia do Araripe no Ceará comercializado com o nome de Pedra Cariri sendo comparada sua acurácia com as obtidas pelas tecnologias Global Navigation Satellite System (GNSS) e Light Detecting and Ranging (LIDAR) mais utilizadas pelo seguimento da mineração para esta finalidade Para avaliação da acurácia foi usado o método de testes de hipóteses a partir da análise de tendência e precisão sendo os resultados classificados de acordo com o Padrão de Exatidão Cartográfica dos Produtos Cartográficos Digitais (PEC-PCD) Após os experimentos realizados foi possível constatar que o VANT-UnB/DNPM é capaz de gerar ortomosaicos e MDTs de alta acurácia compatíveis com os obtidos por aerofotogrametria convencional desde que devidamente orientado por pontos de apoio de solo apresentando melhor acurácia no cálculo de volume neste estudo de caso se comparado com a modelagem realizada com as tecnologias GNSS e LIDAR.

Recent advances in through-water photogrammetry and optical imagery indicate that accurate, continuous bathymetric mapping may be possible in shallow, clear streams. This research directly compares the ability of through-water photogrammetry and spectral depth approaches to extract water depth for monitoring fish habitat. Imagery and cross sections were collected on a 140 meter reach of the Salmon River, Oregon, using an unmanned aerial vehicle (UAV) and rtk-GPS. Structure-from-Motion (SfM) software produced a digital elevation model (DEM) (1.5 cm) and orthophoto (0.37 cm). The photogrammetric approach of applying a site-specific refractive index provided the most accurate (mean error 0.009 m) and precise (standard deviation of error 0.17 m) bathymetric data (R2 = 0.67) over the spectral depth and the 1.34 refractive index approaches. This research provides a quantitative comparison between and within bathymetric mapping methods, and suggests that a site-specific refractive index may be appropriate for similar gravel-bed, relatively shallow, clear streams.

A cada dia novos modelos de Veículos Aéreos Não Tripulados (VANTs) estão sendo lançados no mercado para serem utilizados em diversas aplicações, tais como mapeamento de ambientes e vigilância. Geralmente, estes robôs utilizam um sensor GPS como fonte de estimativa de localização. Contudo, para um bom funcionamento, este sensor depende de um número mínimo de satélites sincronizados com ele e que o sinal emitido pelos satélites seja recebido com boa qualidade, o que pode ser considerado um fator negativo. Uma forma de contornar este problema é empregar um sistema de localização baseado em visão computacional utilizando a câmera que já está embarcada no robô e imagens de satélite como mapa. Este sistema estima a localização do VANT através de comparações entre as imagens capturadas por ele e uma imagem de satélite, buscando encontrar a sua posição nesta imagem de satélite. Neste contexto, apresentamos uma variação do descritor BRIEF, o abBRIEF, para ser utilizado em um novo modelo de observação que também está sendo proposto. O modelo de observação é responsável por medir quão parecidas são as leituras do robô com diversas partes do mapa, para estimar a sua localização correta. Devido ao grande número de comparações necessárias, é importante que o descritor utilizado no processo seja rápido, não consuma muitos recursos computacionais e seja robusto para lidar com as várias diferenças entre as imagens. O modelo proposto foi utilizado no algoritmo de Monte Carlo (Monte Carlo Localization, MCL) para realizar a localização de VANTs e apresentou resultados satisfatórios que corroboram a eficácia do modelo e do descritor. / New models of Unnamed Aerial Vehicles (UAVs) are developed on a daily basis and applied to several tasks, such as mapping terrains and surveillance. GPS sensors are usually the main source of information to estimate the robot position, however, a downside of these sensors is that a minimum number of satellites must be available and emitting high quality signals. A vision-based system can be used to overcome this problem by using a robot embedded camera and satellite images as maps. Computational vision systems estimate the UAV localization through the comparison between the robot extracted image and several parts of the satellite image. These comparisons are performed in order to localize the part of the map which is most similar to the robot perspective. Taking into account all this information, we propose BRIEF descriptor variation, called abBRIEF, to be used on a novel observation model, also proposed in this master thesis. An observation model is responsible for evaluate how similar the robot measurements and the different map parts are. The used descriptor must run fast, consume low computational resources and be robust regarding image changes, all to compensate the large number of necessary comparisons. The proposed model is applied with Monte Carlo Localization (MCL) method to the auto localization of UAVs and presented solid results that corroborate the model and descriptor efficiency.

Recentemente, o uso dos Veículos Aéreos Não Tripulados (VANTs) surgiu como uma ferramenta para a aquisição de dados geoespaciais. Os Modelos Digitais de Elevação (MDEs), as ortoimagens e os modelos tridimensionais gerados a partir de imagens de VANT são produtos cartográficos de grande utilidade para as mais diversas aplicações. Em vista das limitações dos VANTs e da recentidade desta ferramenta, este estudo visa determinar a correlação da configuração dos pontos de apoio e dos parâmetros do voo com a acurácia de ortofotomosaicos elaborados a partir de dados de VANT. Esta pesquisa utilizou dados de três levantamentos aerofotogramétricos distintos realizados com três aeronaves diferentes e considerou parâmetros relacionados à configuração dos pontos de apoio e à execução do voo. Foram gerados 200 ortofotomosaicos e 200 MDEs. Ao todo foram feitas 4616 observações de pontos de controle. Os resultados mostraram baixa correlação linear entre acurácia planimétrica e altimétrica. Os melhores resultados foram obtidos de forma inversa às alturas de voo. No geral, sob as condições de processamento utilizadas neste trabalho, recomenda-se o uso de 4 a 5 pontos de apoio por km², além do uso de voo cruzado. / Recently, the use of Unmanned Aerial Vehicle (UAV) emerged as a tool for geospatial data acquisition. Digital Elevation Models (DEMs), orthoimages and three- dimensional models generated from UAV images are cartographic products of great utility for many different applications. Considering the recency and limitations of UAV, this study aims at determining the correlation of ground control points and flight configuration with the accuracy of orthophotomosaics based on UAV data. This research used data from three different aerial surveys, performed with three different aircrafts, and considered parameters related to ground-control points distribution and to flight missions. 200 orthophotomosaics and 200 DEMs were generated and a total of 4616 ground-control points measurements were performed. Results did not show a linear correlation between planimetric and altimetric accuracy. The best correlation results were obtained inversely related to flight height. In general, under the processing conditions used in this work, we recommend the use of 4 control points per km² and a cross flight pattern.

Submitted by GABRIELA TAKAHASHI MIYOSHI null (takahashi.gabi@gmail.com) on 2016-03-24T18:48:17Z No. of bitstreams: 1 MIYOSHI_GT_DISSERTACAO.pdf: 6445481 bytes, checksum: 7e46eb0d4d485bf0b3f7498d99fe9d65 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-24T20:29:25Z (GMT) No. of bitstreams: 1 miyoshi_gt_me_prud.pdf: 6445481 bytes, checksum: 7e46eb0d4d485bf0b3f7498d99fe9d65 (MD5) / Made available in DSpace on 2016-03-24T20:29:25Z (GMT). No. of bitstreams: 1 miyoshi_gt_me_prud.pdf: 6445481 bytes, checksum: 7e46eb0d4d485bf0b3f7498d99fe9d65 (MD5) Previous issue date: 2016-02-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Florestas têm importante papel na manutenção da biodiversidade, retenção de carbono e regulação do regime hidrológico, além de garantir proteção ao solo e às fontes d’água. Podem ser classificadas em diferentes estádios de desenvolvimento, caracterizados pela presença de espécies secundárias e clímax. Atualmente, no Brasil, as florestas estão reduzidas em fragmentos espalhados em diversas regiões do país sendo seu monitoramento necessário para realização de planos de manejo. Uma das formas de realizar o monitoramento florestal é utilizando o Sensoriamento Remoto hiperespectral, que fornece informação espectral detalhada dos alvos as quais são úteis para a discriminação das espécies de vegetação que compõem o remanescente florestal. Sensores hiperespectrais acoplados a VANTs (Veículos Aéreos Não Tripulados) possibilitam a aquisição de dados para posterior delimitação das copas das espécies de vegetação. A Mata Atlântica, bioma rico em biodiversidade, está distribuída de norte a sul do Brasil, sendo classificada conforme a localização e características de cada formação florestal, dentre elas a Mata Atlântica de Interior. O objetivo desse trabalho é a caracterização espectral de espécies de vegetação em nível foliar e de copa para contribuir com informações que possam ser utilizadas para o monitoramento florestal. Foram adquiridas imagens hiperespectrais com câmara baseada no Interferômetro de Fabry-Perot acoplada em VANT. As imagens foram adquiridas na gleba Ponte Branca, pertencente à Estação Ecológica Mico-Leão-Preto. O processamento das imagens considerou 5 diferentes correções que permitiram mostrar a importância da geometria de aquisição das imagens e do ajustamento radiométrico em bloco. Copas de 12 espécies de vegetação foram delimitadas manualmente no mosaico de imagens gerado e nelas foram medidos valores de Fator de Reflectância Hemisférico Cônico. A caracterização espectral em nível foliar de 16 espécies de vegetação foi realizada em laboratório utilizando espectrorradiômetro. Por meio da análise de agrupamento, verificou-se a similaridade entre as respostas espectrais de tais espécies, tanto em nível de copa como foliar. Para minimizar a similaridade entre tais respostas, foram aplicados e normalizados 7 índices de vegetação. Por fim, utilizando os índices que apresentaram menor correlação entre si, uma nova análise de agrupamento foi realizada onde se verificou que a similaridade entre as espécies foi atenuada. / Forests have an important role to support biodiversity, carbon stocks and water regime. In addition, provide fundamental protection to soil and water resources. Pioneers and climax species characterize successional stages of forest. In Brazil, forests are reduced to fragments spread out over the country, being their monitoring necessary to perform management plans. Hyperspectral Remote Sensing provides detailed spectral information about targets and is feasible to discriminate trees species. Hyperspectral sensor attached to UAVs (Unmanned Aerial Vehicles) makes possible the delineation of trees canopies. The Atlantic Forest, biome rich in biodiversity, is distributed from north to south in Brazil, being classified according to the different locations and characteristics, such as the Interior Atlantic Forest. The main objective of this project is spectral characterization of tree species in leaf and canopy level to contribute with forest monitoring. Hyperspectral images acquired with camera based on Fabry-Perot Interferometer coupled to an UAV were acquired. The interest area, Ponte Branca, belongs to the ecological station called Estação Ecológica Mico-Leão-Preto in the western region of São Paulo State. Imaging process where realized with 5 different corrections showing the importance of geometry during image acquisition and radiometric block adjustment. Trees canopies from 12 species were manually delimited in the images mosaic and Hemispherical Conical Reflectance Factor were obtained. Leaf spectral characterization was realized in laboratory using spectrorradiometer. Clustering analyses were applied to verify similarity between spectral responses of species, in canopy and leaf level. 7 vegetation indexes were applied and normalized in order to reduce the similarity between the spectral responses. Lastly, a new clustering analyses was realized using the less correlated normalized indexes, concluding that the similarity between species was reduced. / CNPq: 130871/2014-1

In this work, unmanned aerial vehicle-based non-destructive testing methods for concrete structures are evaluated and developed. There exists a need for improved infrastructure inspection techniques with increased expediency. Unmanned aerial vehicles (UAVs) are highly mobile and have shown promise towards achieving this directive, but more work is required to adapt traditional NDT methods to be UAV-compatible. To this end, concrete sounding techniques were evaluated with a quantitative acoustic frequency analysis procedure on a series of concrete slabs. One such method was adapted for use with a UAV and was used to detect subsurface voids in one of the concrete samples and offer a means of depth estimation. This work was complemented with experiments concerning UAV-based visual and infrared imaging techniques already in practice for UAV-based concrete inspection. Together, findings indicate the strengths and weaknesses of the NDTs tested and suggest further improvements for UAV-based NDTs and inspection strategies moving forward. Development of a novel sensor platform for UAV-based measurement, as well as results of an actual bridge inspection using infrared and optical methods demonstrate the present capabilities of the UAV-based instrumentation. / Graduate / 2019-07-03

abstract: As electric powered unmanned aerial vehicles enter a new age of commercial viability, market opportunities in the small UAV sector are expanding. Extending UAV flight time through a combination of fuel cell and battery technologies enhance the scope of potential applications. A brief survey of UAV history provides context and examples of modern day UAVs powered by fuel cells are given. Conventional hybrid power system management employs DC-to-DC converters to control the power split between battery and fuel cell. In this study, a transistor replaces the DC-to-DC converter which lowers weight and cost. Simulation models of a lithium ion battery and a proton exchange membrane fuel cell are developed and integrated into a UAV power system model. Flight simulations demonstrate the operation of the transistor-based power management scheme and quantify the amount of hydrogen consumed by a 5.5 kg fixed wing UAV during a six hour flight. Battery power assists the fuel cell during high throttle periods but may also augment fuel cell power during cruise flight. Simulations demonstrate a 60 liter reduction in hydrogen consumption when battery power assists the fuel cell during cruise flight. Over the full duration of the flight, averaged efficiency of the power system exceeds 98%. For scenarios where inflight battery recharge is desirable, a constant current battery charger is integrated into the UAV power system. Simulation of inflight battery recharge is performed. Design of UAV hybrid power systems must consider power system weight against potential flight time. Data from the flight simulations are used to identify a simple formula that predicts flight time as a function of energy stored onboard the modeled UAV. A small selection of commercially available batteries, fuel cells, and compressed air storage tanks are listed to characterize the weight of possible systems. The formula is then used in conjunction with the weight data to generate a graph of power system weight versus potential flight times. Combinations of the listed batteries, fuel cells, and storage tanks are plotted on the graph to evaluate various hybrid power system configurations. / Dissertation/Thesis / Masters Thesis Engineering 2016

A Tilt-Wing Unmanned Aerial Vehicle (TW-UAV) and the preliminary evaluation of its hovering characteristics in extended simulation studies and experiments are presented in this Master Thesis. In the beginning, an overview of the TW-UAV's design properties are established, highlighting the novelties of the proposed structure and the overall merits. The TW-UAV's design and structural properties are mathematically modelled and utilized for the synthesis of a cascaded P-PI and PID based control structure for the regulation of its hovering performance. In addition, extensive simulation trials are performed in order to evaluate the structure's efficiency in controlling the TW-UAV's attitude and position under various noise and disturbance scenarios. The model and aircraft are then put through experimental evaluation with an on-board processor, namely the KFly, in a Motion-capture equipped laboratory to evaluate the control structure and physical behaviour of the TW-UAV. The results of these experiments are presented and discussed. The system and control scheme are shown to work well. However, an unfortunate crash forced the premature termination of experimentation and thus the conclusion of this thesis. Nevertheless, the reason for the crash is understood and discussed for future work.