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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.
141

Investigation of an aeroelastic model for a generic wing structure

Cilliers, M. E. 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Computational Aeroelasticity is a complex research field which combines structural and aerodynamic analyses to describe a vehicle in flight. This thesis investigates the feasibility of including such an analysis in the development of control systems for unmanned aerial vehicles within the Electronic Systems Laboratory at the Department of Electrical and Electronic Engineering at Stellenbosch University. This is done through the development of a structural analysis algorithm using the Finite Element Method, an aerodynamic algorithm for Prandtl’s Lifting Line Theory and experimental work. The experimental work was conducted at the Low-Speed Wind Tunnel at the Department of Mechanical and Mechatronic Engineering. The structural algorithm was applied to 20-noded hexahedral elements in a winglike structure. The wing was modelled as a cantilever beam, with a fixed and a free end. Natural frequencies and deflections were verified with the experimental model and commercial software. The aerodynamic algorithm was applied to a Clark-Y airfoil with a chord of 0:1m and a half-span of 0:5m. This profile was also used on the experimental model. Experimental data was captured using single axis accelerometers. All postprocessing of data is also discussed in this thesis. Results show good correlation between the structural algorithm and experimental data. / AFRIKAANSE OPSOMMING: Numeriese Aeroelastisiteit is ’n komplekse navorsingsveld waar ’n vlieënde voertuig deur ’n strukturele en ’n aerodinamiese analise beskryf word. Hierdie tesis ondersoek die toepaslikheid van hierdie tipe analise in die ontwerp van beheerstelsels vir onbemande voertuie binne die ESL groep van die Departement Elektriese en Elektroniese Ingenieurswese by Stellenbosch Universiteit. Die ondersoek bevat die ontwikkeling van ’n strukturele algoritme met die gebruik van die Eindige Element Methode, ’n aerodinamiese algoritme vir Prandtl se Heflynteorie en eksperimentele werk. Die eksperimentele werk is by die Department Meganiese en Megatroniese Ingensierswese toegepas in die Lae-Spoed Windtonnel. Die strukturele algoritme maak gebruik van ’n 20-nodus heksahedrale element om ’n vlerk-tipe struktuur op te bou. Die vlerk is vereenvouding na ’n kantelbalk met ’n vasgeklemde en ’n vrye ent. Natuurlike frekwensies en defleksies is met die eksperimentele werk en kommersiële sagteware geverifieer. Die aerodinamiese algoritme is op ’n Clark-Y profiel met 0:1m koord lengte en ’n halwe vlerk length van 0:5m geïmplementeer. Die profiel is ook in die eksperimentele model gebruik. Die eksperimentele data is met eendimensionele versnellingsmeters opgeneem. Al die verdere berekeninge wat op ekperimentele data gedoen is, word in die tesis beskryf. Resultate toon goeie korrelasie tussen die strukturele algoritme en die eksperimentele data.
142

DESENVOLVIMENTO DE UM VEÍCULO AÉREO NÃO TRIPULADO PARA APLICAÇÃO EM AGRICULTURA DE PRECISÃO / THE DEVELOPMENT OF UNMANNED AERIAL VEHICLE FOR AGRICULTURAL FARM PURPOSES

Medeiros, Fabrício Ardais 27 January 2007 (has links)
This work presents the development of the unmanned aerial vehicles (UAV) as an important option for the monitoring and remote sensing of agricultural activities. The UAV application in recognition missions has been favored and helped mainly by the its current technological state of development, like reduced cost of manufacturing, reduction in the size and weight of navigation equipments, and the need of optimizing in the corps production. For a better understanding of this project, the contents were divided into three main subjects, methodology applied for each state, performance of the prototype, monitoring and processing of acquired aerial images. The development of the UAV was focused into the methodological activities used in the project and as well as in the results generated by its application to assemble the final prototype. The material and the technique used for the production of each component of the final UAV prototype, is described through modes and phases. Under the project conditions the set prototype and the equipments used with it showed acceptable results. The acquired and processed images by the set UAV and equipments were good enough for a preliminary analysis of crops and can give support in the identification of blotch and weed invasions in specific areas of them. / Este trabalho apresenta o desenvolvimento dos veículos aéreos não tripulados (VANT) como uma importante opção para o monitoramento e sensoriamento das atividades agrícola. Sua aplicação em missões de reconhecimento vem sendo favorecida e facilitada pelo atual estágio de desenvolvimento tecnológico, principalmente pela redução do custo e do tamanho dos equipamentos e pela necessidade de otimização da produção. Para o melhor entendimento do projeto na íntegra, dividiu-se em três partes, as quais são: metodologia aplicada para a construção do protótipo, desempenho do protótipo e monitoramento e tratamento das imagens aéreas capturadas. Seu desenvolvimento procurou ressaltar as atividades metodológicas envolvidas no processo de projeto e os resultados da metodologia aplicada para a construção do protótipo na concepção final, descrito nos módulos e fases em cada um dos componentes fabricados e nos diversos tipos de materiais empregados na construção do VANT. O protótipo, com seus devidos equipamentos, apresentou resultados satisfatórios para as situações requeridas no projeto e gerou imagens com qualidade suficiente para oferecer informações preliminares de uma determinada área, proporcionando suporte nas atividades agrícolas e o auxílio no planejamento e a tomada de decisões para a localização das manchas nas lavouras.
143

Fault-tolerant control of an octorotor unmanned aerial vehicle under actuators failures / Commande tolérante aux fautes lors de pannes de moteurs d’un drone

Saied, Majd 08 July 2016 (has links)
La sûreté de fonctionnement est devenue indispensable pour tous les systèmes critiques où des vies humaines sont en jeu (comme l’aéronautique, le ferroviaire, etc.). Ceci a conduit à la conception et au développement des architectures tolérantes aux fautes, l’objectif de ces architectures étant de maintenir un service correct délivré par le système malgré la présence de fautes, et en particulier de garantir la sécurité-innocuité et la fiabilité du système. La tolérance aux fautes sur les drones aériens multirotors a récemment reçu une attention importante de la part de la communauté scientifique. En particulier, plusieurs travaux ont été développés sur la tolérance aux fautes des quadrirotors suite à des fautes partielles sur les actionneurs, et récemment des recherches ont abordé le problème de panne totale de l’un des actionneurs. D’après ces études, il a été montré qu’une défaillance totale d’un actionneur dans un quadrirotor rend le système non complètement contrôlable. Une solution proposée est de considérer des multirotors avec des actionneurs redondants (hexarotors ou octorotors). La redondance inhérente disponible dans ces véhicules est exploitée, en cas de défaillance sur les actionneurs, pour redistribuer les efforts de commande sur les moteurs sains de façon à garantir la stabilité et la contrôlabilité complète du système. Dans ce travail de thèse, des approches pour la conception de systèmes de commande tolérants aux fautes des drones multirotors sont étudiées et appliquées au contrôle des octorotors. Toutefois, les algorithmes sont conçus de manière à être applicables sur les autres types de multirotors avec des modifications mineures. D’abord, une analyse de contrôlabilité de l’octorotor après l’occurrence de défaillances sur les actionneurs est présentée. Ensuite, un module de détection et d’isolation de pannes moteurs basé sur un observateur non-linéaire et les mesures de la centrale inertielle est proposé. Les mesures des vitesses et des courants de moteurs fournis par les contrôleurs de vitesse sont également utilisées dans un autre algorithme de détection pour détecter les défaillances des actionneurs et distinguer les pannes moteurs des pertes des hélices. Un module de rétablissement basé sur la reconfiguration du multiplexage est proposé pour redistribuer les efforts de commande d’une manière optimale sur les actionneurs sains après l’occurrence de défaillances dans le système. Une architecture complète, comprenant la détection et l’isolation des défauts suivie par le rétablissement du système est validée expérimentalement sur un octorotor coaxial puis elle est comparée à d’autres architectures basées sur l’allocation de commande et la tolérance aux fautes passive par mode glissant. / With growing demands for safety and reliability, and an increasing awareness about the risks associated with system malfunction, dependability has become an essential concern in modern technological systems, particularly safety-critical systems such as aircrafts or railway systems. This has led to the design and development of fault tolerant control systems (FTC). The main objective of a FTC architecture is to maintain the desirable performance of the system in the event of faults and to prevent local faults from causing failures. The last years witnessed many developments in the area of fault detection and diagnosis and fault tolerant control for Unmanned Aerial rotary-wing Vehicles. In particular, there has been extensive work on stability improvements for quadrotors in case of partial failures, and recently, some works addressed the problem of a quadrotor complete propeller failure. However, these studies demonstrated that a complete loss of a quadrotor motor results in a vehicle that is not fully controllable. An alternative is then to consider multirotors with redundant actuators (octorotors or hexarotors). Inherent redundancy available in these vehicles can be exploited, in the event of an actuator failure, to redistribute the control effort among the remaining working actuators such that stability and complete controllability are retained. In this thesis, fault-tolerant control approaches for rotary-wing UAVs are investigated. The work focuses on developing algorithms for a coaxial octorotor UAV. However, these algorithms are designed to be applicable to any redundant multirotor under minor modifications. A nonlinear model-based fault detection and isolation system for motors failures is constructed based on a nonlinear observer and on the outputs of the inertial measurement unit. Motors speeds and currents given by the electronic speed controllers are also used in another fault detection and isolation module to detect actuators failures and distinguish between motors failures and propellers damage. An offline rule-based reconfigurable control mixing is designed in order to redistribute the control effort on the healthy actuators in case of one or more motors failures. A complete architecture including fault detection and isolation followed by system recovery is tested experimentally on a coaxial octorotor and compared to other architectures based on pseudo-inverse control allocation and a robust controller using second order sliding mode.
144

Arquitetura de software aviônico de um VANT com requisitos de homologação. / Sem título em inglês

Giovani Amianti 20 February 2008 (has links)
Recentemente, um crescente número de institutos de pesquisa pelo mundo tem focado seus estudos em veículos aéreos não tripulados (VANT ou, em inglês, UAV - Unmanned Aerial Vehicle), que se revelam muito úteis tanto em aplicações militares quanto civis, pois suas principais vantagens são: a alta confiabilidade, baixo risco à vida, reduzido custo de implantação e manutenção. A pesquisa apresentada neste trabalho integra-se ao projeto BR-UAV em desenvolvimento na empresa Xmobots Sistemas Robóticos LTDA e no Laboratório de Veículos Não Tripulados (LVNT) da Escola Politécnica da USP. O projeto BR-UAV visa a contribuir para a inserção desta tecnologia no país e, para tanto, desenvolve atualmente a plataforma, aviônica e sistema de controle autônomo voltados ao objetivo de monitoramento no espectro visível e infravermelho. O principal requisito do projeto BR-UAV é o desenvolvimento de um sistema aéreo não tripulado capaz de voar dentro do espaço aéreo controlado. Esta pesquisa foca no desenvolvimento do software embarcado, assim este software deve ser desenvolvido de acordo com uma metodologia direcionada a homologação. Por isso, este trabalho propõe uma metodologia que foi baseada em cinco elementos: processo de desenvolvimento, normas, ferramentas de sistema operacional, ferramentas de aplicação e ferramentas matemáticas. Após o estabelecimento dos objetivos, de uma análise do estado da arte em sistemas aviônicos, e da metodologia de certificação, o processo de desenvolvimento foi inicializado. Na fase de engenharia de sistemas, os requisitos de sistema foram capturados. Então a arquitetura de sistema (hardware e software) foi modelada e analisada. A partir desta modelagem de sistema, os requisitos funcionais e temporais de software puderam ser capturados na etapa de análise da fase de engenharia de software. Na etapa de Implementação, o interior dos agentes foi codificado.Além disso, foi implementado o filtro de Kalman estendido para integrar informações de GPS, unidade de medição inercial e bússola. Na etapa de Testes, foram realizados testes de integração funcional e de desempenho computacional. Os resultados demonstraram que o sistema atendeu a todos os requisitos consumindo 38.3% de processamento. Finalmente, os próximos passos desta pesquisa são discutidos. / Recently, an increasing number of research institutes around the world has been focusing their efforts in the study of unmanned aerial vehicles (UAV), which have proved to be very useful both in military and civil applications because of their major advantages: high reliability, reduced risk to life, reduced maintenance and implantation costs. The research presented in this work is part of the BR-UAV project, which is in development at XMobots Sistemas Robóticos LTDA and at the Laboratório de Veículos Não Tripulados of USP (Brazil). This project aims to contribute for the insertion of this technology in Brazil. Particularly, at the present stage, the project includes the development of the platform, avionics and autonomous control system for environment monitoring via visible and infrared spectrums. The main requirement of BR-UAV Project is the development of an unmanned aerial system that could flight in controlled airspace. This research is focused on the development of embedded software, and therefore this software should be developed according to a certification methodology. For this purpose, this work proposes a methodology that was based into five guidelines: development process, norms, operating system tools, application tools and mathematical tools. The development process was started after the statement of objectives and the analysis of the state of art on UAV avionics. In the systems engineering phase, system requirements were captured and then the system architecture (hardware and software) was modeled and analyzed. From the system modeling, the functional and temporal software requirements could be captured in the analysis stage of the software engineering phase. In the Implementation stage, the agents were coded as well as the Extended Kalman Filter for integrating information from GPS, inertial measurement unit and Compass sensors. In the Tests stage, integration tests were performed.The results showed that the system could fulfill requirements using 38.3% of processing consumption. Finally, the next steps of this research are discussed.
145

Utilização de veículos aéreos não tripulados e desenvolvimento de um sistema de aquisição de dados de baixo custo para sondagem atmosférica / On the use of unmanned aerial vehicle and the development of a data acquisition system of law cost for atmospheric sounding

Hackbart, Theo, Hackbart, Theo 28 November 2008 (has links)
Made available in DSpace on 2014-08-20T14:25:47Z (GMT). No. of bitstreams: 1 dissertacao_theo_hackbart.pdf: 2892534 bytes, checksum: 4bd14c0e449a0233a7d5e1098733bf8f (MD5) Previous issue date: 2008-11-28 / This work describes the construction of an unmanned aerial vehicle (UAV) with electrical propulsion and instrumentation in order to obtain the vertical and horizontal profiles by measuring temperature, pressure, and GPS location, in surface atmosphere layer between two heterogeneous surfaces near terrain. Using embedded electronic, one developed and built a small platform with approximately 50 grams in order to collect and acquire meteorological data. The electronic circuit is based on a PIC microcontroller with pressure and temperature sensors, and GPS. After capturing aerosondes data, the first analysis was done. By using these data, surface boundary layer structure compatible with general concepts in the literature were identified. It was also identified some details of closed structures to the frontier which separates the heterogeneous region of landcover. According to several researches aiming at sdudying different alternatives to obtaining the data, one demonstrated through this experimental that small UAVs can be very useful for agrometheorology and metheorology researches because they provide the atmospheric sounding to be performed in places where the access is difficult. Furthermore, they present a low cost. / Este trabalho descreve a construção de um veículo aéreo não tripulado (VANT) com propulsão elétrica, instrumentalizado, para obter perfis verticais e horizontais de medidas de temperatura, pressão e localização por GPS, na camada superficial da atmosfera entre duas superfícies heterogêneas próximas ao solo. Utilizando eletrônica embarcada, desenvolveu-se e implementou-se uma pequena plataforma com aproximadamente 50 gramas para coleta e aquisição de dados meteorológicos. O circuito eletrônico é baseado no microcontrolador PIC com sensores de temperatura, pressão e GPS. Após a captação de dados na aerossondagem, foi realizada uma primeira análise. Usando esses dados, identificaram-se as estruturas da camada-limite superficial compatíveis com os conceitos gerais descritos na literatura, assim como detalhes da estrutura próximos às fronteiras de separação de regiões heterogêneas de coberturas de solo. Tendo em vista as inúmeras pesquisas que visam a alternativas diferenciadas para obtenção de tais dados, mostrou-se, através deste experimento, que pequenas aeronaves não-tripuladas podem ser de grande valia para pesquisas em agrometeorologia e meteorologia, pois se destacam por possibilitar a realização de sondagens atmosféricas em lugares de difícil acesso, tendo um baixo custo.
146

Symbolic and Geometric Planning for teams of Robots and Humans / Planification symbolique et géométrique pour des équipes de robots et d'Humains

Lallement, Raphael 08 September 2016 (has links)
La planification HTN (Hierarchical Task Network, ou Réseau Hiérarchique de Tâches) est une approche très souvent utilisée pour produire des séquences de tâches servant à contrôler des systèmes intelligents. Cette thèse présente le planificateur HATP (Hierarchical Agent-base Task Planner, ou Planificateur Hiérarchique centré Agent) qui étend la planification HTN classique en enrichissant la représentation des domaines et leur sémantique afin d'être plus adaptées à la robotique, tout en offrant aussi une prise en compte des humains. Quand on souhaite générer un plan pour des robots tout en prenant en compte les humains, il apparaît que les problèmes sont complexes et fortement interdépendants. Afin de faire face à cette complexité, nous avons intégré à HATP un planificateur géométrique apte à déduire l'effet réel des actions sur l'environnement et ainsi permettre de considérer la visibilité et l'accessibilité des éléments. Cette thèse se concentre sur l'intégration de ces deux planificateurs de nature différente et étudie comment par leur combinaison ils permettent de résoudre de nouvelles classes de problèmes de planification pour la robotique. / Hierarchical Task Network (HTN) planning is a popular approach to build task plans to control intelligent systems. This thesis presents the HATP (Hierarchical Agent-based Task Planner) planning framework which extends the traditional HTN planning domain representation and semantics by making them more suitable for roboticists, and by offering human-awareness capabilities. When computing human-aware robot plans, it appears that the problems are very complex and highly intricate. To deal with this complexity we have integrated a geometric planner to reason about the actual impact of actions on the environment and allow to take into account the affordances (reachability, visibility). This thesis presents in detail this integration between two heterogeneous planning layers and explores how they can be combined to solve new classes of robotic planning problems
147

Modelling and Real Deployment of C-ITS by Integrating Ground Vehicles and Unmanned Aerial Vehicles

Hadiwardoyo, Seilendria Ardityarama 27 March 2019 (has links)
[ES] Para proporcionar un entorno de tráfico vial más seguro y eficiente, los sistemas ITS o Sistemas Inteligentes de Transporte representan como una solución dotada de avances tecnológicos de vanguardia. La integración de elementos de transporte como automóviles junto con elementos de infraestructura como RoadSide Units (RSUs) ubicados a lo largo de la vía de comunicación permiten ofrecer un entorno de red conectado con múltiples servicios, incluida conectividad a Internet. Esta integración se conoce con el término C-ITS o Sistemas Inteligentes de Transporte Cooperativos. La conexión de automóviles con dispositivos de infraestructura permite crear redes vehiculares conectadas (V2X) vehículo a dispositivos, que ofrecen la posibilidad de nuevos despliegues en aplicaciones C-ITS como las relacionadas con la seguridad. Hoy en día, con el uso masivo de teléfonos inteligentes y debido a su flexibilidad y movilidad, existen varios esfuerzos para integrarlos con los automóviles. De hecho, con el soporte adecuado de unidad a bordo (OBU), los teléfonos inteligentes se pueden integrar perfectamente con las redes vehiculares, permitiendo a los conductores usar sus teléfonos inteligentes como dispositivos de bordo a que participan en los servicios C-ITS, con el objeto de mejorar la seguridad al volante entre otros. Tópico este, que hoy día representa un tema relevante de investigación. Un problema a solucionar surge cuando las comunicaciones vehiculares sufren inferencias y bloqueos de la señal debidos al escenario. De hecho, el impacto de la vegetación y los edificios, ya sea en áreas urbanas y rurales, puede afectar a la calidad de la señal. Algunas estrategias para mejorar la comunicación vehicular en este tipo de entorno consiste en desplegar UAVs o vehículo aéreo no tripulado (drones), los cuales actúan como enlaces de comunicación entre vehículos. De hecho, UAV ofrece importantes ventajas de implementación, ya que tienen una gran flexibilidad en términos de movilidad, además de un rango de comunicaciones mejorado. Para evaluar la calidad de las comunicaciones, debe realizarse un conjunto de mediciones. Sin embargo, debido al costo de las implementaciones reales de UAV y automóviles, los experimentos reales podrían no ser factibles para actividades de investigación con recursos limitados. Por lo tanto, los experimentos de simulación se convierten en la opción preferida para evaluar las comunicaciones entre UAV y vehículos terrestres. Lograr modelos de propagación de señal correctos y representativos que puedan importarse a los entornos de simulación se vuelve crucial para obtener un mayor grado de realismo, especialmente para simulaciones que involucran el movimiento de UAVs en cualquier lugar del espacio 3D. En particular, la información de elevación del terreno debe tenerse en cuenta al intentar caracterizar los efectos de propagación de la señal. En esta tesis doctoral, proponemos nuevos enfoques tanto teóricos como empíricos para estudiar la integración de redes vehiculares que combinan automóviles y UAVs, así mismo el impacto del entorno en la calidad de las comunicaciones. Esta tesis presenta una aplicación, una metodología de medición en escenarios reales y un nuevo modelo de simulación, los cuales contribuyen a modelar, desarrollar e implementar servicios C-ITS. Más específicamente, proponemos un modelo de simulación que tiene en cuenta las características del terreno en 3D, para lograr resultados confiables de comunicación entre UAV y vehículos terrestres. / [CAT] Per a proporcionar un entorn de trànsit viari més segur i eficient, els sistemes ITS o Sistemes Intel·ligents de Transport representen una solució dotada d'avanços tecnològics d'avantguarda. La integració d'elements de transport com auto móvils juntament amb elements d'infraestructura com Road Side Units (RSUs) situats al llarg de lav via de comunicació permeten oferir un entorn de xarxa connectat amb multiples serveis, inclusa connectivitat a Internet. Aquesta integració es connex amb el terme C-ITS o Sistemes Intel·ligents de Transport Cooperatius , com ara els automòbils, amb elements d'infraestructura, com ara les road side units (RSU) o pals situats al llarg de la carretera, per a aconseguir un entorn de xarxa que oferisca nous serveis a més de connectivitat a Internet. Aquesta integració s'expressa amb el terme C-ITS, o sistemes intel·ligents de transport cooperatius. La connexió d'automòbils amb dispositius d'infraestructura permet crear xarxes vehiculars connectades (V2X) vehicle a dispositiu, que ofreixen la possibilitat de nous desplegaments en aplicacions C-ITS, com ara les relacionades amb la seguretat. Avui dia, amb l'ús massiu dels telèfons intel·ligents, i a causa de la flexibilitat i mobilitat que presenten, es fan esforços per integrar-los amb els automòbils. De fet, amb el suport adequat d'unitat a bord (OBU), els telèfons intel·ligents es poden integrar perfectament amb les xarxes vehiculars, permetent als conductors usar els seus telèfons intel·ligents com a dispositius per a participar en els serveis de C-ITS, a fi de millorar la seguretat al volant entre altres. Tòpic est, que hui dia representa un tema rellevant d'investigació. Un problema a solucionar sorgeix quan les comunicacions vehiculars ateixen inferències i bloquejos del senyal deguts a l'escenari. De fet, l'impacte de la vegetació i els edificis, tant en àrees urbanes com rurals, pot afectar la qualitat del senyal. Algunes estratègies de millorar la comunicació vehicular en aquest tipus d'entorn consisteix a desplegar UAVs o vehicles aeris no tripulats (drones), els quals actuen com a enllaços de comunicació entre vehicles. De fet, l'ús d'UAVs ofereix importants avantatges d'implementació, ja que tenen una gran flexibilitat en termes de mobilitat, a més d'un rang de comunicacions millorat. Per a avaluar la qualitat de les comunicacions, s'han de realitzar mesures en escenaris reals. No obstant això, a causa del cost de les implementacions i desplegaments reals d'UAV i el seu ús combinat amb vehicles, aquests experiments reals podrien no ser factibles per a activitats d'investigació amb recursos limitats. Per tant, la metodologia basada en simulació es converteixen en l'opció preferida entre els investigadors per a avaluar les comunicacions entre UAV i vehicles terrestres. Aconseguir models de propagació de senyal correctes i representatius que puguen importar-se als entorns de simulació resulta crucial per a obtenir un major grau de realisme, especialment per a simulacions que involucren el moviment d'UAV en qualsevol lloc de l'espai 3D. En particular, cal tenir en compte la informació d'elevació del terreny per a intentar caracteritzar els efectes de propagació del senyal. En aquesta tesi doctoral proposem enfocaments tant teòrics com empírics per a estudiar la integració de xarxes vehiculars que combinen automòbils i UAV, així com l'impacte de l'entorn en la qualitat de les comunicacions. Aquesta tesi presenta una aplicació, una metodología de mesurament en escenaris reals i un nou model de simulació, els quals contribueixen a modelar, desenvolupar i implementar serveis C-ITS. Més específicament, proposem un model de simulació que té en compte les característiques del terreny en 3D, per a aconseguir resultats fiables de comunicació entre UAV i vehicles terrestres. / [EN] To provide a safer road traffic environment and make it more convenient, Intelligent Transport Systems (ITSs) are proposed as a solution endowed with cutting-edge technological advances. The integration of transportation elements like cars together with infrastructure elements like Road Side Units to achieve a networking environment offers new services in addition to Internet connectivity. This integration comes under the term Cooperative Intelligent Transport System (C-ITS). Connecting cars with surrounding devices forming vehicular networks in Vehicle-to-Everything (V2X) open new deployments in C-ITS applications like safety-related ones. With the massive use of smartphones nowadays, and due to their flexibility and mobility, several efforts exist to integrate them with cars. In fact, with the right support from the vehicle's On-Board Unit (OBU), smartphones can be seamlessly integrated with vehicular networks. Hence, drivers can use their smartphones as a device to participate in C-ITS services for safety purposes, among others, which is a quite interesting research topic. A significant problem arises when vehicular communications face signal obstructions caused by the environment. In fact, the impact of vegetation and buildings, whether in urban and rural areas, can result in a lower signal quality. One way to enhance vehicular communication networks is to deploy Unmanned Aerial Vehicles (UAVs) to act as relays for communication between cars, or ground vehicles. In fact, UAVs offer important deployment advantages, as they offer great flexibility in terms of mobility, in addition to an enhanced communications range. To assess the quality of the communications, a set of measurements must take place. However, due to the cost of real deployments of UAVs and cars, real experiments might not be feasible for research activities with limited resources. Hence, simulation experiments become the preferred option to assess UAV-to- car communications. Achieving correct and representative signal propagation models that can be imported to the simulation environments becomes crucial to obtain a higher degree of realism, especially for simulations involving UAVs moving anywhere throughout the 3D space. In particular, terrain elevation information must be taken into account when attempting to characterize signal propagation effects. In this research work, we propose both theoretical and empirical approaches to study the integration of vehicular networks combining cars and UAVs, and we study the impact of the surrounding environment on the communications quality. An application, a measurement framework, and a simulation model are presented in this thesis in an effort to model, develop, and deploy C-ITS services. More specifically, we propose a simulation model that takes into account 3D terrain features to achieve reliable UAV-to-car communication results. / I want to thank the Spanish government through the Ministry of Economy and Competitiveness (MINECO) and the European Union Commission through the European Social Fund (ESF) for co-financing and granting me the fellowship to fund my studies in Spain and my research stay in Russia. In addition, I would to thank the National Institute of Informatics for granting me the internship fund and the Japanese government through the Japan Society for the Promotion of Science (JSPS) for supporting my research work in Japan. / Hadiwardoyo, SA. (2019). Modelling and Real Deployment of C-ITS by Integrating Ground Vehicles and Unmanned Aerial Vehicles [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/118796 / TESIS
148

Dynamic Mission Planning for Unmanned Aerial Vehicles

Rennu, Samantha R. January 2020 (has links)
No description available.
149

Jamming Detection and Classification via Conventional Machine Learning and Deep Learning with Applications to UAVs

Yuchen Li (11831105) 13 December 2021 (has links)
<div>With the constant advancement of modern radio technology, the safety of radio communication has become a growing concern for us. Communication has become an essential component, particularly in the application of modern technology such as unmanned aerial vehicle (UAV). As a result, it is critical to ensure that a drone can fly safely and reliably while completing duties. Simultaneously, machine learning (ML) is rapidly developing in the twenty-first century. For example, ML is currently being used in social media and digital marking for predicting and addressing users' varies interests. This also serves as the impetus for this thesis. The goal of this thesis is to combine ML and radio communication to identify and classify UAV interference with high accuracy.</div><div>In this work, a ML approach is explored for detecting and classifying jamming attacks against orthogonal frequency division multiplexing (OFDM) receivers, with applicability to UAVs. Four types of jamming attacks, including barrage, protocol-aware, single-tone, and successive-pulse jamming, are launched and analyzed using software-defined radio (SDR). The jamming range, launch complexity, and attack severity are all considered qualitatively when evaluating each type. Then, a systematic testing procedure is established, where a SDR is placed in the vicinity of a drone to extract radiometric features before and after a jamming attack is launched. Traditional ML methods are used to create classification models with numerical features such as signal-to-noise ratio (SNR), energy threshold, and important OFDM parameters. Furthermore, deep learning method (i.e., convolutional neural networks) are used to develop classification models trained with spectrogram images filling in it. Quantitative indicators such as detection and false alarm rates are used to evaluate the performance of both methods. The spectrogram-based model correctly classifies jamming with a precision of 99.79% and a false-alarm rate of 0.03%, compared to 92.20% and 1.35% for the feature-based counterpart.</div>
150

Unmanned Aerial Vehicle Remote Sensing of Soil Moisture with I-Band Signals of Opportunity

Jared D Covert (8816072) 08 May 2020 (has links)
Measurements of root zone soil moisture play large roles in our understanding of the water cycle, weather, climate, land-heat exchanges, drought forecasting, and agriculture. Current measurements are made using a combination of ground-based sampling and active and passive microwave remote sensing. Signals of Opportunity (SoOp) has emerged as a promising method for sensing soil moisture, using satellite communication signals to make bi-static reflectometry measurements. The current combination of ground and satellite-based measurements for soil moisture results in a gap of useful spatial and temporal resolutions, as well as limited soil penetration depth. This thesis developed and constructed an Unmanned Aerial Vehicle (UAV) mountable, I-band SoOp instrument with calibration capabilities, along with supporting specular point mapping and mission planning software. This work advances the creation of a compact, mobile, root zone soil moisture (RZSM) remote sensing system.

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