Dissertations / Theses on the topic 'Drone controllers'

Le GPR (Ground Penetrating Radar) ou géoradar est utilisé pour la prospection des sous-sols. Par ailleurs, le marché des drones a rapidement évolué ces dernières années et la performance des solutions volantes actuelles vient offrir de nouvelles perspectives quant à leur utilisation. L’association des technologies du drone et du géoradar est alors une idée très attractive. De nombreux défis et incertitudes sont liés au rayonnement des basses fréquences, utiles pour une meilleure pénétration, et qui impliquent une taille conséquente du système antennaire. De plus, une maîtrise du coût et de la consommation du système est requise. Pour répondre aux contraintes d’encombrement et de poids, des solutions d’aiguillage des signaux pour n’utiliser qu’une seule antenne ont été développées. Dans le but de permettre la génération reconfigurable et bas coût des fréquences du radar, l’utilisation de VCO (Voltage-Controlled Oscillator) couplé à une méthode de correction analogique de la non-linéarité de fréquence a été mise en place. Un démonstrateur radar a été mis en œuvre et des expérimentations sur site ont été réalisées. Enfin, l’exploration de solutions pour l’augmentation de la résolution en distance du radar est présentée et une méthode alternative basée sur les réseaux de neurones a été développée<br>The GPR (Ground Penetrating Radar) is designed for underground imaging. In addition, the UAV market has evolved rapidly in recent years, and the performance of today's flying solutions offers new concepts for their use. The pairing of UAV and ground-penetrating radar technologies is a very attractive idea. Many challenges and uncertainties are related to low-frequency radiation, which is useful for better penetration, and which imply a consequent size of the antenna system. In addition, a reduction in the cost and consumption of the system is required. To meet compactness and weight constraints, switching solutions for using only one antenna have been developed. Toallow the reconfigurable and low-cost generation of waveform from a VCO (Voltage-Controlled Oscillator), an analog frequency non-linearity correction method has been implemented. A radar demonstrator has been developed and on-site experiments have been carried out. Finally, the exploration of solutions for increasing the range resolution of the radar is presented and a method based on neural networks has been developed

Cette thèse propose des solutions aux problématiques inhérentes au contrôle de formations aériennes de type leader­-suiveur pour des flottes de quadrirotors. Au regard des travaux existants, les stratégies qui sont proposés dans notre travail, considère que le(s) leader{s) a une interaction avec les suiveurs. En outre, les rôles de leader et de suiveur sont interchangeables lors de la formation. Dans un premier temps, la modélisation mathématique d'un seul quadrirotor et celle de la formation de quadrirotors est développée. Ensuite, le problème de suivi de trajectoire pour un seul quadrirotor est étudié. Au travers de l'analyse de 1, dynamique du système pour la conception d'une commande par platitude, il apparait que le suivi de trajectoire pour chaque quadrirotor équivaut à déterminer les sorties plates désirées. Un contrôleur pour système plats permettant l'asservissement des drones pour le suivi de trajectoire est donc proposé. Étant donné la propriété de double-boucle de la dynamique du quadrirotor en boucle fermée, un contrôleur d'attitude avec des grands gains est conçu, selon la théorie « singular perturbation system ». Puisque la dynamique du quadrirotor en boucle fermée fonctionne sur deux échelles de temps, la dynamique de rotation (boundary-layer mode) est contrôlée sur l'échelle de temps la plus rapide. La conception du contrôleur de formation dépend seulement de la dynamique de translation (modèle réduit dans une échelle de temps lente). Ce résultat a simplifié la conception du contrôleur de formation, de telle sorte que le modèle réduit du quadrirotor est utilisé au lieu du modèle complet. Étant donné que le modèle réduit du quadrirotor a une caractéristique de double-intégrateur, un algorithme de consensus pour des systèmes caractérisés par de multiple double-intégrateurs est proposé. Pour traiter le problème de la formation leader-suiveur, une matrice d'interaction est initialement proposée basée sur la matrice de Laplacienne. Nous montrons que la condition de convergence et la vitesse de convergence de l'erreur de formation dépendent de la plus petite valeur propre de la matrice d'interaction. Trois stratégies de contrôle de la formation avec une topologie fixe sont ensuite proposées. Le contrôle de formation par platitude est proposé pour obtenir une formation agressive, tandis que les dérivées de grands ordres de la trajectoire désirée pour chaque UAV sont estimées en utilisant un observateur; la méthode Lyapunov redesign est implémentée pour traiter les non-linéarités de la dynamique de la translation des quadrotors; une loi de commande bornée par l'utilisation, entre autre, de la fonction tangente hyperbolique est développée avec un feedback composite non linéaire, afin d'améliorer les performances de la formation. De plus, une commande de commutation saturée de la formation est étudiée, car la topologie de la formation est variable. La stabilité du système est obtenue grâce aux théories “convex hull » et « common Lyapunov function ». Cette stratégie de commande de commutation permet le changement des leaders dans la formation. Inspirée par certains travaux existants, tels que le contrôle de la formation avec des voisins anonymes, nous proposons, finalement, une loi de commande avec des voisins pondérés, qui montre une meilleure robustesse que le contrôle avec des voisins anonymes. Les résultats de simulation obtenus avec Matlab illustrent premièrement nos stratégies de contrôle que nous proposons De plus, en utilisant le langage de programmation C ++, nos stratégies sont mises en œuvre dans un framework de simulation et d'expérimentation développé au laboratoire Heudiasyc. Grâce aux nombreux tests variés que nous avons réalisés en simulation et en temps-réel, l'efficacité et les avantages de nos stratégies de contrôle de la formation proposées sont présentés<br>In this thesis, we address a leader-follower (L-F) formation control problem for multiple UAVs, especially quadrotors. Different from existing works, the strategies, which are proposed in our work, consider that the leader(s) have interaction with the followers. Additionally, the leader(s) are changeable during the formation. First, the mathematical modeling of a single quadrotor and of the formation of quadrotors is developed. The trajectory tracking problem for a single quadrotor is investigated. Through the analysis of the flatness of the quadrotor dynamical model, the desired trajectory for each quadrotor is transferred to the design of the desired at outputs. A flatness-based trajectory tracking controller is, then, proposed. Considering the double-loop property of the closed-loop quadrotor dynamics, a high-gain attitude controller is designed, according to the singular perturbation system theory. Since the closed-loop quadrotor dynamics performs in two time scales, the rotational dynamics (boundary-layer model) is controlled in a fast time scale. The formation controller design is then only considered for the translational dynamics: reduced model in a slow time scale. This result has simplified the formation controller design such that the reduced model of the quadrotor is considered instead of the complete model. Since the reduced model of the quadrotor has a double-integrator characteristic, consensus algorithm for multiple double-integrator systems is proposed. Dealing with the leader-follower formation problem, an interaction matrix is originally proposed based on the Laplacian matrix. We prove that the convergence condition and convergence speed of the formation error are in terms of the smallest eigenvalue of the interaction matrix. Three formation control strategies with fixed formation topology are then proposed. The flatness-based formation control is proposed to deal with the aggressive formation problem, while the high-order derivatives of the desired trajectory for each UAV are estimated by using an observer; the Lyapunov redesign is developed to deal with the nonlinearities of the translational dynamics of the quadrotors; the hyperbolic tangent-based bounded control with composite nonlinear feedback is developed in order to improve the performance of the formation. In an additional way, a saturated switching control of the formation is investigated, where the formation topology is switching. The stability of the system is obtained by introducing the convex hull theory and the common Lyapunov function. This switching control strategy permits the change of the leaders in the formation. Inspired by some existing works, such as the anonymous neighbor-based formation control, we finally propose a weighted neighbor-based control, which shows better robustness than the anonymous neighbor-based control. Simulation results using Matlab primarily illustrate our proposed formation control strategies. Furthermore, using C++ programming, our strategies are implemented on the simulator-experiment framework, developed at Heudiasyc laboratory. Through a variety of tests on the simulator and real-time experiments, the efficiency and the advantages of our proposed formation control strategies are shown. Finally, a vision-based inter-distance detection system is developed. This system is composed by an on-board camera, infrared LEDs and an infrared filter. The idea is to detect the UAVs and calculate the inter-distance by calculating the area of the special LEDs patterns. This algorithm is validated on a PC, with a webcam and primarily implemented on a real quadrotor

Dans cette thèse, nous étudions la conception d’un contrôleur décentralisé pour un ensemble de quadrotors. Les quadrotors sont organisés en leader et suiveurs. Le leader est piloté par l’homme, tandis que les suiveurs utilisent le contrôleur décentralisé pour suivre le leader. Les suiveurs sont autonomes et n’ont pas conscience du comportement du leader. La nouveauté de cette thèse est de s’appuyer sur des capteurs peu coûteux tels que des modules WiFi pour estimer les distances vers les quadrotors voisins. Afin de concevoir le contrôleur décentralisé, l’apprentissage itératif est utilisé et combiné à un apprentissage supervisé et par imitation, à travers plusieurs phases, notamment la collecte de journaux, la formation de modèles avancés et la conception d’un contrôleur sur celui-ci. Ensuite, le contrôleur est intégré dans les suiveurs, les rendant autonomes. Le principal avantage des méthodes d’apprentissage est de déplacer le fardeau de l’optimisation de l’étape des tests en ligne à l’étape de la collecte des données. Par conséquent, cette approche convient aux robots Commerical Of The Shelf (COTS) tels que les micro et nano quadrotors qui ne disposent pas de ressources de calcul considérables à bord. Nos méthodes ont été validées à l’aide de MagicFlock, un framework de construction maison pour essaim de quadrotors qui étend RotorS, un framework de simulation Software In The Loop (SITL) construit sur le simulateur basé sur la physique Gazebo. Nos résultats ont démontré que le comportement de l’essaim est obtenu lorsqu’il est intégré à un ensemble de quadrotors à l’intérieur de Gazebo en utilisant les méthodes d’apprentissage itératif proposées avec une performance similaire à un modèle d’essaim qui utilise les positions absolues des robots<br>In this thesis, we study designing a decentralized controller for a set of quadrotors. The quadrotors are organized as a leader and followers. The leader is human-piloted, while the followers use the decentralized controller to follow the leader. The followers are autonomous and not aware of the leader’s behavior. The novelty of this thesis is to rely on inexpensive sensors such as WiFi modules to estimate the distances toward neighbors’ quadrotors. In order to design the decentralized controller, iterative learning is used and combined with supervised and imitation learning, through several phases, including logs gathering, training forward models, and designing a controller upon it. Then the controller is embedded in the followers, rendering them autonomous. The main advantage of learning methods is to shift the burden of optimization from the online tests step to the data gathering step. Therefore, making this approach is suitable for Commerical Of The Shelf (COTS) robots such as micro and nano quadrotors that do not have considerable computational resources on board. Our methods have been validated using MagicFlock, a home build framework for quadrotors swarm that extends RotorS, a Software In The Loop (SITL) simulation framework built on the top of the physics-based simulator Gazebo. Our results demonstrated that the swarm behavior is achieved when embedded on a set of quadrotors inside Gazebo using the proposed iterative learning methods with a performance similar to a flocking model that uses the absolute positions of the robots

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-03-21T18:01:54Z No. of bitstreams: 2 Dissertação - Rubens Antônio Alves - 2015.pdf: 7966348 bytes, checksum: 5a95a9ee436c444d586451331b40e5a0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-22T12:33:33Z (GMT) No. of bitstreams: 2 Dissertação - Rubens Antônio Alves - 2015.pdf: 7966348 bytes, checksum: 5a95a9ee436c444d586451331b40e5a0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Made available in DSpace on 2017-03-22T12:33:33Z (GMT). No. of bitstreams: 2 Dissertação - Rubens Antônio Alves - 2015.pdf: 7966348 bytes, checksum: 5a95a9ee436c444d586451331b40e5a0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-30<br>Outro<br>This Project, in the electrical engineering area, consists in the development of a complete control system, hardware and software, for controlling model airplanes of the fixedwing and rotary-wing types, aiming the implementation of an automatic control system compatible with the necessity of autonomous and aided flights, applied to critical systems monitoring.The final system consists of a controller, or automatic pilot, with specific hardware and software, capable of controlling a model airplane using GPS coordinates, in a way that allows the airplane to go through a planned route and go back to the starting point in an autonomous way. The controller should receive, in ground, the programmed route; the model should answer to the pilot commands, within a visual range when operating in the aided mode, and should go through the programmed route in the autonomous mode, after confirmation of the pilot. After reaching the end of the programmed route, the model airplane should return to the starting point, keeping the maximum flight level of the route as the reference height. The model airplane will carry in a communication system to allow the monitoring process from a ground station, able to keep updated the airworthy conditions, as well as the level of accuracy between the actual and the planned route. The communication may be carried out directly using a radio link, with the receiver allocated in a mobile ground station, monitored by a pilot, to make higher the security level. However, the model airplane may transfer the data through a GPRS link, connected to the web system, which transfers the data to the ground station. In this case, the ground station must be connected to the web.The route saved in the model control system is built based on online maps directly linked by the software for the mission programming and monitoring, which can carry out the treatment and storage of the model data and parameters. The programming of the stability control and route, with primary data of latitude, longitude and height allows the real time monitoring of the model, related to the planned route and throught images captured by embedded video cameras. All data are storage following a timeline process, such that they can be recovered for futher analysis.<br>Esta disertação da área de engenharia elétrica consiste na construção de um sistema de controle completo de hardware e software para controle de um aeromodelo de asa fixa e/ou asa móvel, de maneira a implementar um piloto automático compatível com as necessidades de voo autônomo ou assistido, sendo que tal sistema deverá ser compatível com a precisão de voo aplicada a monitoramento de sistemas críticos.O sistema é constituído por uma placa controladora composta por hardware e firmware específicos, capaz de controlar um modelo orientado por coordenadas GPS, para que o mesmo percorra uma rota predeterminada e retorne ao ponto de partida de forma autônoma. A placa recebe, ainda em solo, a programação da rota a ser percorrida; o aeromodelo deve responder normalmente aos comandos do controle remoto do piloto em solo, respeitando o raio de alcance visual do piloto no modo assistido e segue a rota programada no modo autônomo após confirmação de comando do piloto. No final do percurso o aermodelo volta em trajetória reta para o ponto de partida, respeitando a maior altura do trajeto. O aeromodelo deve ser munido de sistema de comunicação para o devido acompanhamento em solo das condições de aeronavegabilidade do aeromodelo em voo, bem como a verificação dos níveis de precisão em relação à rota programada. A comunicação pode ser feita diretamente por sistema de link de rádio, direcionada a um terminal móvel em solo, que é acompanhado pelo piloto, para aumentar o nível de segurança, mas o aeromodelo também pode comunicar por rede de celular GPRS, conectado à internet, que direciona os dados ao terminal em solo. Nesse caso, o terminal, também deverá estar conectado à internet. A rota programada no aeromodelo é construída com base em mapas online conectados diretamente ao software de programação e acompanhamento de missão, que faz o tratamento e armazenamento dos dados e parâmetros do aermodelo. Tanto a programação de controle de estabilidade, quanto de rota, com dados primários relativos a latitude, longitude e altura, permitem o acompanhamento em tempo real do aeromodelo junto à rota programada e também através da imagem da câmera de gravação embarcada no aeromodelo. Todos os dados são gravados com base em processo de linha do tempo, que podem ser recuperados em conjunto para análise posterior.

Negli ultimi anni, tra le varie tecnologie che hanno acquisito una sempre maggiore popolarità e diffusione, una di particolare rilevanza è quella degli Unmanned Aerial Vehicles. Di questi velivoli, quelli che stanno riscuotendo maggiore successo sono i multirotori, alimentati esclusivamente da azionamenti elettrici disposti in opportune posizioni della struttura. Particolari sforzi sono stati recentemente dedicati al miglioramento di questa tecnologia in termini di efficienza e precisione, tuttavia quasi sempre si trascura la vitale importanza dello sfruttamento efficiente dei motori elettrici. La tecnica di pilotaggio adottata nella quasi totalità dei casi per questi componenti è il BLDC sensorless, anche se la struttura si dimostra spesso essere PMSM, dunque inadatta all’uso di questa strategia. Il controllo ideale per i PMSM risulterebbe essere FOC, tuttavia per l'implementazione sensorless molti aspetti scontati nel BLDC devono essere affrontati, in particolare bisogna risolvere problemi di osservazione e identificazione. Durante la procedura di avviamento, efficienti strategie di self-commissioning vengono adottate per l’identificazione dei parametri elettrici. Per la fase di funzionamento nominale viene proposto un osservatore composto da diversi componenti interfacciati tra loro tramite un filtro complementare, il tutto al fine di ottenere una stima di posizione e velocità depurata dai disturbi. In merito al funzionamento in catena chiusa, vengono esposte valutazioni preliminari sulla stabilità e sulla qualità del controllo. Infine, per provare la validità degli algoritmi proposti, vengono mostrati i risultati delle prove sperimentali condotte su un tipico azionamento per UAV, pilotato da una scheda elettronica progettata appositamente per l’applicazione in questione. Vengono fornite inoltre indicazioni sull’implementazione degli algoritmi studiati, in particolare considerazioni sull’uso delle operazioni a virgola fissa per velocizzare l'esecuzione.

Finding missing people and obtaining an overview of complex emergencies is very demanding and requires costly resources. I have on a few occasions sought after my grandfather, who, when he got Alzheimer, liked to go for a stroll at night (!) when my grandmother was sleeping. Those kind of situations are very stressful, especially a cold winter night. During my first 25 years I was part of a dedicated outdoor culture with countless ski trips, mountain hikes, mountain bike trips and many hours in primarily Swedish nature. It happened on a few occasions that we came in contact with people who worked with rescue operations in this type of environment. It could be about hikers who strayed away or been injured in the inaccessible nature, lost skiers in the mountain massifs around Riksgränsen, berry pickers in the Västerbotten forests etc. There are many examples of this type of situations and it's reflections on these scenarios and similar current problem which is the basis for this project.   Every year, about 7000 people are reported missing in Sweden. Of these remains about 30-35 vanished. Globally, the figure is huge. Earthquakes, floods and other hit by natural occurs despite various preventive measures. There are many occasions where the search, reconnaissance and location of individuals as well as physical problems play a critical role, but where human capacity seldom is sufficient. Search party chains (organized by organisations like Missing People) requires significant human resources and costs precious time, police helicopter reconnaissance is economically very costly, not environmentally friendly and involves a significant margin of error. With these statements as background, I would look at the possibility of creating a thorough design solution that contributes to people in need can be located, provided security and helped significantly faster than today without requiring significant resources. With this as a backdrop, I wanted to create a concept that would contribute to that more people were found and could be saved. Through an extensive research of how a rescue operation is conducted, interviews with police and Missing People, as well as observations during actual operations, I identified a few main problem areas that my concept generation would center around. Together with my sponsor, we wanted to create something that can best be described as a robotic eagle with hyper vision, long flight time and a positive association for the victim. The result is Aetos (Greek for eagle). A modular drone-system with innovative features to handle with long flights and demanding rescue missions. Thanks to an aerodynamic shape and a remote-controlled system Aetos requires minimal resources to create overview and help in locating the missing person. We want to save lives, and it can Aetos that.

Les travaux de recherches sur la commande, le diagnostic et la tolérance aux défauts appliqués aux drones deviennent de plus en plus populaires. Il est judicieux de concevoir des lois de commande qui garantissent la stabilité et les performances du drone, non seulement dans le cas nominal, mais également en présence de fortes perturbations et de défauts.Dans cette thèse, un nouvel algorithme bio-inspiré adapté pour la recherche de solutions dans des problèmes d’optimisation est développé. Cet algorithme est utilisé pour trouver les gains des différents contrôleurs conçus pour les drones. La commande par mode glissant est utilisée pour développer deux contrôleurs passifs tolérants aux défauts pour les quadrirotors: un contrôleur par mode glissant augmentée avec un intégrateur, et un contrôleur par mode glissant implémenté en cascade. Parce que les commandes passives ont une robustesse réduite, une commande active par mode glissant est développée. Pour traiter les défauts extrêmes, un contrôleur d’urgence basé sur la conversion du quadrirotor en trirotor est développé. Les commandes actives, passives, et le contrôleur d’urgences sont ensuite intégrés pour former un contrôleur tolérant aux défauts capable de gérer un grand nombre de défaillances tout en garantissant les ressources actionneur et en limitant la charge de calcul du processeur. Finalement, des contrôleurs tolérants aux défauts, actifs et passifs, basés sur des méthodes par mode glissant du premier et deuxième ordre sont développées pour les octorotors. La commande active utilise des méthodes d’allocation de contrôles pour redistribuer les efforts sur les actionneurs sains, réduisant ainsi l’effet du défaut<br>Unmanned Aerial Vehicles (UAV) are more and more popular for their civil and military applications. Classical control laws usually show weaknesses in the presence of parameter uncertainties, environmental disturbances, and actuator and sensor faults. Therefore, it is judicious to design a control law capable of stabilizing the UAV not only in the fault-free nominal cases, but also in the presence of disturbances and faults. In this thesis, a new bio-inspired search algorithm called Ecological Systems Algorithm (ESA) suitable for engineering optimization problems is developed. The algorithm is used over the thesis to find optimal gains for the fault tolerant controllers. Sliding Mode Control theory is used to develop two Passive Fault Tolerant Controllers for quadrotor UAVs: Regular and Cascaded SMC. Because Passive Controllers handle a few numbers of faults, an Active Sliding Mode Fault Tolerant Controller using Kalman Filter is developed. To overcome severe faults and failures, an emergency controller based on the Quadrotor-to-Trirotor conversion maneuver is developed. The Controllers developed so far (Passive, Active, and emergency controllers) are then integrated to form the Integrated Fault Tolerant Controller (IFTC). The IFTC is a powerful controller that is able to handle a wide number of faults, and save actuator resources as well as processor computational effort. Finally, Passive and Active Fault Tolerant Controllers are designed for octorotor UAVs based on First Order and Second Order Sliding Mode Control. The AFTC uses Dynamic and Pseudo-Inverse Control Allocation methods to redistribute the control effort among healthy actuators reducing the effect of fault

Robotic aerial vehicles (RAVs) have been increasingly deployed in various areas (e.g., commercial, military, scientific, and entertainment). However, RAVs’ security and safety issues could not only arise from either of the “cyber” domain (e.g., control software) and “physical” domain (e.g., vehicle control model) but also stem in their interplay. Unfortunately, existing work had focused mainly on either the “cyber-centric” or “control-centric” approaches. However, such a single-domain focus could overlook the security threats caused by the interplay between the cyber and physical domains. <br>In this thesis, we present cyber-physical analysis and hardening to secure RAV controllers. Through a combination of program analysis and vehicle control modeling, we first developed novel techniques to (1) connect both cyber and physical domains and then (2) analyze individual domains and their interplay. Specifically, we describe how to detect bugs after RAV accidents using provenance (Mayday), how to proactively find bugs using fuzzing (RVFuzzer), and how to patch vulnerable firmware using binary patching (DisPatch). As a result, we have found 91 new bugs in modern RAV control programs, and their developers confirmed 32 cases and patch 11 cases.

This thesis describes the functional principle of FARN, a novel flight controller for Unmanned Aerial Vehicles (UAVs) designed for mission scenarios that require highly accurate and reliable navigation. The required precision is achieved by combining low-cost inertial sensors and Ultra-Wide Band (UWB) radio ranging with raw and carrier phase observations from the Global Navigation Satellite System (GNSS). The flight controller is developed within the scope of this work regarding the mission requirements of two research projects, and successfully applied under real conditions. FARN includes a GNSS compass that allows a precise heading estimation even in environments where the conventional heading estimation based on a magnetic compass is not reliable. The GNSS compass combines the raw observations of two GNSS receivers with FARN’s real-time capable attitude determination. Thus, especially the deployment of UAVs in Arctic environments within the project for ROBEX is possible despite the weak horizontal component of the Earth’s magnetic field. Additionally, FARN allows centimeter-accurate relative positioning of multiple UAVs in real-time. This enables precise flight maneuvers within a swarm, but also the execution of cooperative tasks in which several UAVs have a common goal or are physically coupled. A drone defense system based on two cooperative drones that act in a coordinated manner and carry a commonly suspended net to capture a potentially dangerous drone in mid-air was developed in conjunction with the project MIDRAS. Within this thesis, both theoretical and practical aspects are covered regarding UAV development with an emphasis on the fields of signal processing, guidance and control, electrical engineering, robotics, computer science, and programming of embedded systems. Furthermore, this work aims to provide a condensed reference for further research in the field of UAVs. The work describes and models the utilized UAV platform, the propulsion system, the electronic design, and the utilized sensors. After establishing mathematical conventions for attitude representation, the actual core of the flight controller, namely the embedded ego-motion estimation and the principle control architecture are outlined. Subsequently, based on basic GNSS navigation algorithms, advanced carrier phase-based methods and their coupling to the ego-motion estimation framework are derived. Additionally, various implementation details and optimization steps of the system are described. The system is successfully deployed and tested within the two projects. After a critical examination and evaluation of the developed system, existing limitations and possible improvements are outlined<br>Diese Arbeit beschreibt das Funktionsprinzip von FARN, einer neuartigen Flugsteuerung für unbemannte Luftfahrzeuge (UAVs), die für Missionsszenarien entwickelt wurde, die eine hochgenaue und zuverlässige Navigation erfordern. Die erforderliche Präzision wird erreicht, indem kostengünstige Inertialsensoren und Ultra-Breitband (UWB) basierte Funkreichweitenmessungen mit Roh- und Trägerphasenbeobachtungen des globalen Navigationssatellitensystems (GNSS) kombiniert werden. Die Flugsteuerung wird im Rahmen dieser Arbeit unter Berücksichtigung der Missionsanforderungen zweier Forschungsprojekte entwickelt und unter realen Bedingungen erfolgreich eingesetzt. FARN verfügt über einen GNSS-Kompass, der eine präzise Schätzung des Steuerkurses auch in Umgebungen erlaubt, in denen eine konventionelle Schätzung mit Hilfe eines Magnetkompasses nicht zuverlässig ist. Der GNSS-Kompass kombiniert die Messungen von zwei GNSS-Empfängern mit der echtzeitfähigen Lagebestimmung von FARN. Damit ist insbesondere der Einsatz von UAVs in arktischen Umgebungen im Rahmen des Projektes ROBEX trotz der schwachen horizontalen Komponente des Erdmagnetfeldes möglich. Zusätzlich erlaubt FARN eine zentimetergenaue relative Positionierung mehrerer UAVs in Echtzeit. Dies ermöglicht präzise Flugmanöver innerhalb eines Schwarms, aber auch die Ausführung kooperativer Aufgaben, bei denen mehrere UAVs ein gemeinsames Ziel haben oder physikalisch gekoppelt sind. In Verbindung mit dem Projekt MIDRAS wurde ein Drohnenabwehrsystem entwickelt, das auf zwei kooperativen Drohnen basiert, die koordiniert agieren und ein gemeinsam aufgehängtes Netz tragen, um eine potenziell gefährliche Drohne in der Luft einzufangen. Im Rahmen dieser Arbeit werden sowohl theoretische als auch praktische Aspekte der UAV-Entwicklung behandelt, wobei der Schwerpunkt auf den Bereichen der Signalverarbeitung, der Navigation und der Steuerung, der Elektrotechnik, der Robotik sowie der Informatik und der Programmierung eingebetteter Systeme liegt. Darüber hinaus soll diese Arbeit eine zusammengefasste Referenz für die weitere Drohnenforschung darstellen. Die Arbeit erläutert und modelliert die verwendete UAV-Plattform, das Antriebssystem, das elektronische Design und die eingesetzten Sensoren. Nach der Ausarbeitung mathematischer Konventionen zur Lagedarstellung, wird der eigentliche Kern des Flugreglers erläutert, nämlich die eingebettete Schätzung der Eigenbewegung und die prinzipielle Regelungsarchitektur. Anschließend werden, basierend auf grundlegenden Navigationsalgorithmen, fortgeschrittene trägerphasenbasierte Methoden und deren Zusammenhang mit der Schätzung der Eigenbewegung abgeleitet. Zusätzlich werden verschiedene Implementierungsdetails und Optimierungsschritte des Systems beschrieben. Das System wird innerhalb der beiden Projekte erfolgreich verwendet und getestet. Nach einer kritischen Untersuchung und Bewertung des entwickelten Systems werden bestehende Einschränkungen und mögliche Verbesserungen aufgezeigt

How do technologies that remove warfighters from the front lines affect the frequency and intensity of military confrontations between states? Many scholars and policymakers fear that weapons that reduce the risks and costs of war – in blood and treasure – will lead states to resort to force more frequently during crises, destabilizing the international security environment. These concerns have featured prominently in debates surrounding the proliferation and use of remote warfighting technologies, such as drones. This project sets out to evaluate whether and how drones affect crisis escalation. Specifically, do drones allow decisionmakers to deploy military forces more frequently during interstate crises? Once deployed, how do these systems affect escalation dynamics? I argue that drones can help control escalation, raising questions about scholarly theories that suggest the world is more dangerous and less stable when technology makes conflict cheaper and less risky. At the core of this project is a theory of technology-enabled escalation control. The central argument is that technologies like drones that remove friendly forces from the battlefield may lead states to use force more frequently, but decrease the likelihood of escalation when used in lieu of inhabited platforms. More specifically, these technologies lower the political barriers to initiating military operations during crises, primarily by eliminating the risk of friendly force casualties and the associated domestic political consequences for launching military operations. At the same time, removing personnel from harm’s way may reduce demand for escalatory reprisals after remotely operated systems are lost to hostile action. Drones can also help to mitigate escalatory spirals by collecting intelligence that overcomes information asymmetries that often contribute to armed conflict, helping facilitate more measured decision-making and tailored targeting of enemy forces. By more fully considering how technology affects escalatory dynamics after the initial use of force, technology-enabled escalation control theory advances our understanding of the link between technology and conflict. I test the theory using a multi-method approach that combines case studies with original experiments embedded in surveys fielded on public and military samples. The dissertation also introduces a new research method for international relations research: experimental manipulations embedded in wargames with military participants. In Chapter 1 and 2, I define the concept of crisis escalation and review the literature that examines the effect of technology on escalation and conflict dynamics. I then introduce the theory of technology-enabled escalation control and outline four mechanisms that undergird the theory – increased initiation, tempered/tailored targeting, restrained retaliation, and amplified aggression. Each of these hypothesized mechanisms describes ways in which emerging technologies can prevent crises from escalating into broader or more intense conflicts. Chapter 3 describes each component of the multi-method research design that I use to test the theory in Chapters 4 through 7. Chapter 4 uses experiments embedded in surveys and wargames to assess whether and how drones allow states to more frequently initiate military operations. Chapter 5 tests whether drones enable decisionmakers to control escalation by restraining retaliation after attacks on a state’s drones. Chapter 6 and 7 test the theory in the context of U.S drone use during the Cold War and Israeli drone use from the 1960s through late-2010s. The findings of these empirical tests provide strong support for technology-enabled escalation control. In Chapter 8, I conclude with a summary of the analysis and test the generalizability of the theory beyond the state use of drones. I find that tenets of technology-enabled escalation control explain escalation dynamics associated with U.S. cyber operations against North Korea and Hezbollah’s use of drones against Israel and during the Syrian Civil War. The chapter also maps out pathways for future research and identifies policy implications. My findings suggest the growing proliferation of drones will increase the frequency of military confrontations during crises, yet these confrontations are unlikely to escalate. Even though drones may help control escalation, clearer doctrine, rules of engagement, and international agreements to govern their use will help to further avoid crisis escalation and conflict.