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Fuglaas, Simen. "Precision Airdrop from a Fixed-Wing Unmanned Aerial Vehicle." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25909.
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Accurate mapping of the polar regions requires reliable placement ofwireless transmitting sensors, also known as beacons, on icebergs anddrift ice. This thesis considers the use of a specific fixed-wing unmannedaerial vehicle, known as the Penguin B, to accurately deploysaid beacons from the air. An analysis of the possible precision airdropmethods was conducted and the decision was made to release thebeacon in free fall from the aircraft. The estimated trajectory was calculatedand used to decide the optimal release position and direction.Combined this is known as the release configuration. Moreover, twodifferent aircraft path planning algorithms were developed in order toachieve the desired configuration.The final system, including the necessary hardware and software, wasimplemented into the provided framework. This system was furthertested through simulations in the laboratory in addition to some fieldtesting. The simulations revealed that with the most advanced pathplanning algorithm, it was possible to achieve a close to optimal releaseconfiguration. This further resulted in an airdrop where the accuracyof the impact depended primarily on the altitude of release, in additionto the unpredictable environmental factors, such as wind gusts. Thefield tests displayed that the system was successfully implemented intothe provided framework. However, unforeseen technical difficultiesrelated to the aircraft, outside the control of this project, preventedin-air testing.Under the assumptions made throughout this thesis, the simulationsrevealed that the implemented system was able to reliably deploy thebeacon such that it landed within a relatively small perimeter aroundthe target.
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Hough, Willem J. "Autonomous aerobatic flight of a fixed wing unmanned aerial vehicle." Thesis, Link to online version, 2007. http://hdl.handle.net/10019/428.
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Alberts, Frederik Nicolaas. "Accurate autonomous landing of a fixed-wing unmanned aerial vehicle." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71672.
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Thesis (MScEng)-- Stellenbosch University, 2012.ENGLISH ABSTRACT: This thesis presents the analysis, design, simulation and practical implementation of a control system to achieve an accurate autonomous landing of a fixed-wing unmanned aerial vehicle in the presence of wind gust atmospheric disturbances. Controllers which incorporate the concept of direct-lift control were designed based on a study of the longitudinal dynamics of the UAV constructed as a testbed. Direct-lift control offers the prospect of an improvement in the precision with which aircraft height and vertical velocity can be controlled by utilising actuators which generate lift directly, instead of the conventional method whereby the moment produced by an actuator results in lift being indirectly generated. Two normal specific acceleration controllers were designed. The first being a conventional moment-based controller, and the second a direct-lift-augmented controller. The moment-based controller makes use of the aircraft’s elevator while the direct-lift augmented controller in addition makes use of the flaps of the aircraft which serve as the direct-lift actuator. Controllers were also designed to regulate the airspeed, altitude, climb rate, and roll angle of the aircraft as well as damp the Dutch roll mode. A guidance controller was implemented to allow for the following of waypoints. A landing procedure and methodology was developed which includes the circuit and landing approach paths and the concept of a glide path offset to calibrate the touchdown point of a landing. All controllers and the landing procedure were tested in a hardware-in-the-loop simulation environment as well as practically in a series of flight tests. Five fully autonomous landings were performed, three of these using the conventional NSA controller, and the final two the direct-lift-augmented NSA controller. The results obtained during the landing flight tests show that the project goal of a landing within five meters along the runway and three meters across the runway was achieved in both normal wind conditions as well as in conditions where wind gusts prevailed. The flight tests also showed that the direct-lift-augmented NSA controller appears to achieve a more accurate landing than the conventional NSA controller, especially in the presence of greater wind disturbances. The direct-lift augmented NSA controller also exhibited less pitch angle rotation during landing.
AFRIKAANSE OPSOMMING: Hierdie tesis verteenwoordig die analise, ontwerp, simulasie en praktiese implementering van ’n beheerstelsel wat ten doel het om ’n akkurate en outonome landing van ’n onbemande vastevlerk vliegtuig in rukwind atmosferiese toestande te bewerkstellig. Gegrond op ’n studie van die longitudinale dinamika van die vliegtuig wat as proeftuig gebruik is, is beheerders ontwerp wat die beginsel van direkte-lig insluit. Direkte-lig beheer hou die potensiaal in om die vliegtuig se hoogte en vertikale snelheid akkuraat te beheer deur gebruik te maak van aktueerders wat lig direk genereer in teenstelling met die konvensionele metode waar die moment van die aktueerder indirek lig genereer. Twee normaal-versnellings beheerders is ontwerp. Die eerste is ’n konvensionele moment-gebaseerde beheerder wat gebruik maak van die hys-aktueerder van die vliegtuig, en die tweede is ’n direkte-lig-bygestaande beheerder wat addisioneel gebruik maak van die flappe van die vliegtuig wat as die direkte-lig aktueerder dien. Vedere beheerders is ontwerp wat die lugspoed, hoogte, klimkoers, en rolhoek van die vliegtuig reguleer asook die “Dutch roll” gedrag afklam. ’n Leiding-beheerder wat die volg van vliegbakens hanteer, is ingestel. Die landingsprosedure en -metodologie is ontwikkel wat die landingspad sowel as die sweef-pad bepaal en wat terselfdertyd ’n metode daarstel om die posisie van die landingspunt te kalibreer. Die beheerders en landingsprosedure is in ’n hardeware-in-die-lus omgewing gesimuleer en deur middel van ’n reeks proefvlugte getoets. Vyf ten volle outonome landings is uitgevoer waarvan drie van die konvensionele normaal-versnellings beheerder gebruik gemaak het, en die laaste twee die direkte-lig-bygestaande normaal-versnellings beheerder. Die vlugtoetsuitslae bevestig dat die navorsingsdoel om ’n landing binne vyf meter in lyn met en drie meter dwarsoor die landingstrook te bewerkstellig, behaal is. Hierdie akkuraatheid is verkry in beide goeie atmosferiese toestande sowel as toestande met rukwinde. Volgens die vlugtoetse blyk dit dat die direkte-lig-bygestaande normaalversnellings beheerder ’n meer akkurate landing kan bewerkstellig as die konvensionele normaal-versnellings beheerder, veral dan in toestande met rukwinde. Die direkte-ligbygestaande normaal-versnellings beheerder het ook ’n laer hei-hoek rotasie tydens die landing vertoon.
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Oland, Espen. "Nonlinear Control of Fixed-Wing Unmanned Aerial Vehicles." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-27263.
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Gaum, Dunross Rudi. "Agressive flight control techniques for a fixed wing unmanned aerial vehicle." Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/3112.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009.This thesis investigates aggressive all-attitude flight control systems. These are flight controllers capable of controlling an aircraft at any attitude and will enable the autonomous execution of manoeuvres such as high bank angle turns, steep climbs and aerobatic flight manoeuvres. This class of autopilot could be applied to carry out evasive combat manoeuvres or to create more efficient and realistic target drones. A model for the aircraft’s dynamics is developed in such a way that its high bandwidth specific force and moment model is split from its lower bandwidth kinematic model. This split is done at the aircraft’s specific acceleration and roll rate, which enables the design of simple, decoupled, linear attitude independent inner loop controllers to regulate these states. Two outer loop kinematic controllers are then designed to interface with these inner loop controllers to guide the aircraft through predefined reference trajectories. The first method involves the design of a linear quadratic regulator (LQR) based on the successively linearised kinematics, to optimally control the system. The second method involves specific acceleration matching (SAM) and results in a linear guidance controller that makes use of position based trajectories. These position based trajectories allow the aircraft’s velocity magnitude to be regulated independently of the trajectory tracking. To this end, two velocity regulation algorithms were developed. These involved methods of optimal control, implemented using dynamic programming, and energy analysis to regulate the aircraft’s velocity in a predictive manner and thereby providing significantly improved velocity regulation during aggressive aerobatic type manoeuvres. Hardware in the loop simulations and practical flight test data verify the theoretical results of all controllers presented
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Mullen, Jon. "FILTERED-DYNAMIC-INVERSION CONTROL FOR FIXED-WING UNMANNED AERIAL SYSTEMS." UKnowledge, 2014. http://uknowledge.uky.edu/me_etds/45.
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Instrumented umanned aerial vehicles represent a new way of measuring turbulence in the atmospheric boundary layer. However, autonomous measurements require control methods with disturbance-rejection and altitude command-following capabilities. Filtered dynamic inversion is a control method with desirable disturbance-rejection and command-following properties, and this controller requires limited model information. We implement filtered dynamic inversion as the pitch controller in an altitude-hold autopilot. We design and numerically simulate the continuous-time and discrete-time filtered-dynamic-inversion controllers with anti-windup on a nonlinear aircraft model. Finally, we present results from a flight experiment comparing the filtered-dynamic-inversion controller to a classical proportional-integral controller. The experimental results show that the filtered-dynamic-inversion controller performs better than a proportional-integral controller at certain values of the parameter.
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Basson, Matthys Michaelse. "Stall prevention control of fixed-wing unmanned aerial vehicles." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4310.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: This thesis presents the development of a stall prevention flight control subsystem, which can easily be integrated into existing flight control architectures of fixed-wing unmanned aerial vehicles (UAV’s). This research forms an important part of faulttolerant flight control systems and will ensure that the aircraft continues to operate safely within its linear aerodynamic region. The focus of this thesis was the stall detection and prevention problem. After a thorough literature study on the topic of stall, a model based stall prevention control algorithm with feedback from an angle of attack sensor was developed. This algorithm takes into account the slew rate and saturation limits of the aircraft’s servos and is able to predict when the current flight condition will result in stall. The primary concern was stall during wings-level flight and involved the prevention of stall by utilising only the elevator control surface. A model predictive slew rate control algorithm was developed to override and dynamically limit the elevator command to ensure that the angle of attack does not exceed a predefined limit. The stall prevention control system was designed to operate as a switching control scheme, to minimise any restrictions imposed on the existing flight control system. Finally, software in the loop simulations were conducted using a nonlinear aircraft model and realistic sensor noise, to verify the theoretical results obtained during the development of this stall prevention control strategy. A worst-case performance analysis was also conducted to investigate the robustness of the control algorithms against model uncertainties.
AFRIKAANSE OPSOMMING: Hierdie tesis handel oor die ontwikkeling van ’n staak voorkomings-vlugbeheer substelsel wat maklik geïntegreer kan word in bestaande vlugbeheer argitektuur van onbemande vaste-vlerk lugvaartuie. Hierdie tesis vorm ’n belangrike deel van fouttolerante vlugbeheertegnieke en sal verseker dat die vliegtuig slegs binne sy lineêre aerodinamiese werksgebied bly. Die fokus van hierdie tesis is die staak opsporing en voorkomings probleem. Na afloop van ’n deeglike literatuurstudie oor die onderwerp van staak, is ’n model gebaseerde staak voorkomings-beheertegniek ontwikkel, wat terugvoer van ’n invalshoek sensor ontvang. Hierdie algoritme neem die sleur tempo en defleksie limiete van die vliegtuig se servos in ag en is in staat om staak te voorspel. Die primêre oorweging was staak tydens simmetriese vlugte en behels slegs die voorkoming van staak deur gebruik te maak van die hei beheer oppervlak. ’n Model voorspellings sleur tempo beheeralgoritme is ontwikkel om die hei-roer dinamies te beperk sodat die invalshoek nie ’n sekere vooraf bepaalde limiet oorskry nie. Die staak voorkomings beheerstelsel is ontwerp om te funksioneer as ’n skakel beheer skema om die beperkings op die bestaande vlugbeheerstelsel te minimaliseer. Laastens was sagteware-in-die-lus simulasies gebruik om die teoretiese resultate, wat verkry is tydens die ontwikkeling van hierdie staak voorkomings beheer-strategie, te kontroleer. Om die robuusthied van hierdie beheeralgoritmes teen model onsekerhede te ondersoek, is ’n ergste-geval prestasie analise ook uitgevoer.
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Persson, Linnea. "Cooperative Control for Landing a Fixed-Wing Unmanned Aerial Vehicle on a Ground Vehicle." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187667.
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High Altitude Long Endurance (HALE) platforms are a type of Unmanned Aerial Vehicle (UAV). With their relatively easy deployment and independence of a fixed orbit, HALE UAVs have the potential to replace satellites for certain tasks in the future. A challenge with this technology is that the current platforms are too heavy to fly for a long period of time. A suggested method for reducing the weight is to remove the landing gear to instead use alternative methods for take-off and landing. One such alternative method is to land the UAV on top of a cooperating ground vehicle. In this thesis, the cooperative controller and the experimental setup of such a landing have been investigated. The cooperation between the systems was analyzed and evaluated analytically, through simulations and with flight tests. Using a PID controller for the position alignment and a modified flare law for the descent, feasibility of the landing was verified by performing a landing of a Penguin BE fixed-wing UAV on top of a cooperating ground vehicle.Så kallade HALE - High Altitude Long Endurance -farkoster är en växande teknik inom området för autonoma flygplan. Med fördelar som exempelvis en möjlighet att röra sig oberoende av en omloppsbana samt en mer effektiv implementering– och utvecklingsprocess har de visat potential att i framtiden kunna ersätta satelliter inom vissa områden. Ett problem är i dagsläget svårigheten att bygga tillräckligt lätta farkoster för att kunna flyga under en längre tidsperiod. För att minska vikten har det bland annat föreslagits att landningsställ kan tas bort för att istället använda alternativa start- och landningsmetoder. I detta projekt har en metod undersökts där idén är att landa ett autonomt flygplan på en mobil plattform. Samarbetet mellan systemen har analyserats både analytiskt och genom tester. Slutligen verifieras att en kooperativ landning är genomförbar genom att en landning av ett obemannat flygplan på en samarbetande bil utförs.
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Smit, Samuel Jacobus Adriaan. "Autonomous landing of a fixed-wing unmanned aerial vehicle using differential GPS." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80122.
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Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: This dissertation presents the design and practical demonstration of a flight control system (FCS) that is capable of autonomously landing a fixed-wing, unmanned aerial vehicle (UAV) on a stationary platform aided by a high-precision differential global positioning system. This project forms part of on-going research with the end goal of landing a fixed-wing UAV on a moving platform (for example a ship’s deck) in windy conditions. The main aim of this project is to be able to land the UAV autonomously, safely and accurately on the runway. To this end, an airframe was selected and equipped with an avionics payload. The equipped airframe’s stability derivatives were analysed via AVL and the moment of inertia was determined by the double pendulum method. The aircraft model was developed in such a way that the specific force and moment model (high bandwidth) is split from the point-mass dynamics of the aircraft (low bandwidth) [1]. The advantage of modelling the aircraft according to this unique method, results in a design that has simple decoupled linear controllers. The inner-loop controllers control the high-bandwidth specific accelerations and roll-rate, while the outer-loop controllers control the low-bandwidth point-mass dynamics. The performance of the developed auto-landing flight control system was tested in software-in-the-loop (SIL) and hardware-in-the-loop (HIL) simulations. A Monte Carlo non-linear landing simulation analysis showed that the FCS is expected to land the aircraft 95% of the time within a circle with a diameter of 1.5m. Practical flight tests verified the theoretical results of the developed controllers and the project was concluded with five autonomous landings. The aircraft landed within a circle with a 7.5m radius with the aiming point at the centre of the circle. In the practical landings the longitudinal landing error dominated the landing performance of the autonomous landing system. The large longitudinal error resulted from a climb rate bias on the estimated climb rate and a shallow landing glide slope.
AFRIKAANSE OPSOMMING: Hierdie skripsie stel die ontwikkeling en praktiese demonstrasie van ʼn self-landdende onbemande vastevlerkvliegtuigstelsel voor, wat op ʼn stilstaande platform te lande kan kom met behulp van ʼn uiters akkurate globale posisionering stelsel. Die projek maak deel uit van ʼn groter projek, waarvan die doel is om ʼn onbemande vastevlerkvliegtuig op ʼn bewegende platform te laat land (bv. op ʼn boot se dek) in onstuimige windtoestande. Die hoofdoel van die projek was om die vliegtuig so akkuraat as moontlik op die aanloopbaan te laat land. ʼn Vliegtuigraamwerk is vir dié doel gekies wat met gepaste avionica uitgerus is. Die uitgeruste vliegtuig se aerodinamsie eienskappe was geanaliseer met AVL en die traagheidsmoment is deur die dubbelependulum metode bepaal. Die vliegtuigmodel is op so ‘n manier onwikkel om [1] die spesifieke krag en momentmodel (vinnige reaksie) te skei van die puntmassadinamiek (stadige reaksie). Die voordeel van hierdie wyse van modulering is dat eenvoudige ontkoppelde beheerders ontwerp kon word. Die binnelusbeheerders beheer die vinnige reaksie-spesifieke versnellings en die rol tempo van die vliegtuig. Die buitelusbeheerders beheer die stadige reaksie puntmassa dinamiek. Die vliegbeheerstelsel is in sagteware-in-die-lus en hardeware-in-die-lus simulasies getoets. Die vliegtuig se landingseienskappe is ondersoek deur die uitvoer van Monte Carlo simulasies, die simulasie resultate wys dat die vliegtuig 95% van die tyd binne in ʼn sirkel met ʼn diameter van 1.5m geland het. Praktiese vlugtoetse het bevestig dat die teoretiese uitslae en die prakties uitslae ooreenstem. Die vliegtuig het twee suksesvolle outomatiese landings uitgevoer, waar dit binne ʼn 7.5m-radius sirkel geland het, waarvan die gewenste landingspunt die middelpunt was. In die outomatiese landings is die longitudinale landingsfout die grootse. Die groot longitudinale landingsfout is as gevolg van ʼn afset op die afgeskatte afwaartse spoed en ʼn lae landings gradiënt.
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Alatorre, Sevilla Armando. "Landing of a fixed-wing unmanned aerial vehicle in a limited area." Electronic Thesis or Diss., Compiègne, 2024. http://www.theses.fr/2024COMP2801.
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Le projet de thèse consiste à développer une solution pour l'atterrissage d'un drone à voilure fixe de configuration classique dans une zone limitée. Le principal défi consiste à réduire la vitesse de l'avion à une phase minimale pendant le vol, à l'aide d'algorithmes de contrôle automatique. La réduction de la vitesse d'un drone à voilure fixe s'effectue en augmentant son angle d'attaque, ce qui implique un freinage par la force de traînée. Cependant, cette manœuvre est critique pour un avion conventionnel, parce que si son angle d'attaque augmente au-delà de l'angle de décrochage, le véhicule peut perdre sa contrôlabilité, c'est-à-dire qu'il est possible que le véhicule aérien s'effondre et que sa structure soit endommagée. Le modèle mathématique est une représentation d'équations qui décrit le comportement de la dynamique du système. En considérant plusieurs variables pour obtenir une meilleure approximation de la dynamique du système, dans notre cas le véhicule à voilure fixe, la conception des stratégies de contrôle sera plus difficile et plus complexe. Dans ce travail de recherche, nous utiliserons un modèle mathématique non linéaire car les effets de décrochage peuvent être inclus par des approximations mathématiques du moment de tangage, des forces de portance et de traînée. Cela nous permet d'obtenir une meilleure performance des lois de contrôle pour la navigation autonome du drone à voilure fixe. L'une des limites des véhicules à voilure fixe est qu'ils atterrissent dans des espaces de dimensions réduites et que le pourcentage de dommages subis par leur structure est élevé. En outre, les perturbations extérieures et l'inexpérience des pilotes augmentent le risque de dommages. Il est bien connu qu'il est très difficile de satisfaire aux conditions d'une piste d'atterrissage. Par conséquent, la communauté scientifique s'est efforcée de mettre au point des solutions pour l'atterrissage dans des zones limitées. Dans la littérature, on trouve quelques solutions basées sur des véhicules hybrides et des systèmes de récupération. Les véhicules hybrides consistent à modifier la structure d'un véhicule à voilure fixe. Les moteurs sont répartis stratégiquement pour obtenir une configuration de véhicule multirotor, offrant certaines caractéristiques telles que le décollage et l'atterrissage verticaux. Cependant, ces actionneurs augmentent la masse du véhicule, la consommation d'énergie (ce qui réduit la durabilité du vol), la probabilité de défaillance, le coût d'acquisition, de réparation et d'entretien. Notre objectif dans ce travail de recherche est de concevoir et de valider des stratégies de contrôle pour l'atterrissage d'un drone à voilure fixe dans un espace limité. Les stratégies de contrôle ont été conçues selon deux approches : la première est basée sur le développement de manœuvres pour un drone à voilure fixe afin de réduire la vitesse à une phase minimale pendant le vol. Dans la deuxième approche, nous avons travaillé sur les stratégies de contrôle pour l'atterrissage d'un drone à voilure fixe sur un véhicule terrestre en mouvement. Une stratégie de contrôle a été proposée pour réduire la vitesse du drone à voilure fixe au minimum afin d'être capturé par un système de récupération. La stratégie de contrôle a été divisée en trois étapes de vol : dans la première étape, l'avion s'aligne dans le plan x-y tandis qu'il est conduit à une altitude souhaitée pour effectuer un vol de croisière. L'étape suivante consiste en un vol ascendant, axé sur le suivi d'une référence angulaire basée sur une trajectoire phugoïde. Cette trajectoire implique une augmentation de l'angle d'attaque jusqu'à l'angle de décrochage de l'avion. Ainsi, la vitesse aérienne obtient une réduction maximale dans des conditions sûres, permettant au drone d'être capturé par le système de récupération. Toutefois, si le drone n'est pas capturé par le système de récupération, une stratégie de contrôle est appliquée pour rétablir le vol de l'aéronefThe development of this thesis consists of designing some control strategies that allow a fixedwing drone with classical configuration to perform a safe landing in a limited area. The main challenge is to reduce the aircraft’s airspeed avoiding stall conditions. The developed control strategies are focused on two approaches: the first approach consists of the designing airspeed reduction maneuvers for a fixed-wing vehicle to be captured by a recovery system and for a safe landing at a desired coordinate. The next approach is focused on landing a fixed-wing drone on a moving ground vehicle. A dynamic landing trajectory was designed to lead a fixedwing vehicle to the position of a ground vehicle, reaching its position in a defined distance. Moreover, this trajectory was used in a cooperative control design. The control strategy consists of the synchronization of both vehicles to reach the same position at a desired distance. The aerial vehicle tracks the dynamic landing trajectory, and the ground vehicle controls its speed. In addition, we will propose a control architecture with a different focus, where the ground vehicle performs the tracking task of the aerial vehicle’s position in order to be captured. And, the drone’s task is to track a descending flight until the top of the ground vehicle. However, considering the speed difference between both vehicles. Therefore, we propose a new control architecture defining that the aircraft performs an airspeed reduction strategy before beginning its landing stage. The aircraft will navigate to a minimum airspeed, thus, allowing the ground vehicle to reach the fixed-wing drone’s position by increasing its speed. The control laws of each strategy were determined by developing the Lyapunov stability analysis, thus, the stability is guaranteed in each flight stage. Finally, the control strategies were implemented on prototypes allowing us to validate their performance and obtain satisfactory results for safe landing of a fixed-wing drone with classical configuration
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Gundlach, John Frederick. "Multidisciplinary Design Optimization of Subsonic Fixed-Wing Unmanned Aerial Vehicles Projected Through 2025." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/26482.
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Through this research, a robust aircraft design methodology is developed for analysis and optimization of the Air Vehicle (AV) segment of Unmanned Aerial Vehicle (UAV) systems. The analysis functionality of the AV design is integrated with a Genetic Algorithm (GA) to form an integrated Multi-disciplinary Design Optimization (MDO) methodology for optimal AV design synthesis. This research fills the gap in integrated subsonic fixed-wing UAV AV MDO methods. No known single methodology captures all of the phenomena of interest over the wide range of UAV families considered here. Key advancements include: 1) parametric Low Reynolds Number (LRN) airfoil aerodynamics formulation, 2) UAV systems mass properties definition, 3) wing structural weight methods, 4) self-optimizing flight performance model, 5) automated geometry algorithms, and 6) optimizer integration. Multiple methods are provided for many disciplines to enable flexibility in functionality, level of detail, computational expediency, and accuracy.
The AV design methods are calibrated against the High-Altitude Long-Endurance (HALE) Global Hawk, Medium-Altitude Endurance (MAE) Predator, and Tactical Shadow 200 classes, which exhibit significant variations in mission performance requirements and scale from one another. Technology impacts on the design of the three UAV classes are evaluated from a representative system technology year through 2025. Avionics, subsystems, aerodynamics, design, payloads, propulsion, and structures technology trends are assembled or derived from a variety of sources. The technology investigation serves the purposes of validating the effectiveness of the integrated AV design methods and to highlight design implications of technology insertion through future years. Flight performance, payload performance, and other attributes within a vehicle family are fixed such that the changes in the AV designs represent technology differences alone, and not requirements evolution. The optimizer seeks to minimize AV design gross weight for a given mission requirement and technology set.
All three UAV families show significant design gross weight reductions as technology improves. The predicted design gross weight in 2025 for each class is: 1) 12.9% relative to the 1994 Global Hawk, 2) 6.26% relative to the 1994 Predator, and 3) 26.3% relative to the 2000 Shadow 200. The degree of technology improvement and ranking of contributing technologies differs among the vehicle families. The design gross weight is sensitive to technologies that directly affect the non-varying weights for all cases, especially payload and avionics/subsystems technologies. Additionally, the propulsion technology strongly affects the high performance Global Hawk and Predator families, which have high fuel mass fractions relative to the Tactical Shadow 200 family. The overall technology synergy experienced 10-11 years after the initial technology year is 6.68% for Global Hawk, 7.09% for Predator, and 4.22% for the Shadow 200, which means that the technology trends interact favorably in all cases. The Global Hawk and Shadow 200 families exhibited niche behavior, where some vehicles attained higher aerodynamic performance while others attained lower structural mass fractions. The high aerodynamic performance Global Hawk vehicles had high aspect ratio wings with sweep, while the low structural mass fraction vehicles had straight, relatively low aspect ratios and smaller wing spans. The high aerodynamic performance Shadow 200 vehicles had relatively low wing loadings and large wing spans, while the lower structural mass fraction counterparts sought to minimize physical size.Ph. D.
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Guthrie, Kyle Thomas. "Linear Parameter Varying Path Following Control of a Small Fixed Wing Unmanned Aerial Vehicle." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23740.
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A mathematical model of a small fixed-wing aircraft was developed through application of parameter estimation techniques to simulated flight test data. Multiple controllers were devised based on this model for path following, including a self-scheduled linear parameter-varying (LPV) controller with path curvature as a scheduling parameter. The robustness and performance of these controllers were tested in a rigorous MATLAB simulation environment that included steady winds and gusts, measurement noise, delays, and model uncertainties. The linear controllers designed within were found to be robust to the disturbances and uncertainties in the simulation environment, and had similar or better performance in comparison to a nonlinear control law operating in an inner-outer loop structure. Steps are being taken to implement the resulting controllers on the unmanned aerial vehicle (UAV) testbed in the Nonlinear Systems Laboratory at Virginia Tech.Master of Science
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McFarlane, Cormac. "An investigation of flying qualities for fixed wing unmanned aerial vehicles." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508060.
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Sakarya, Arzu. "Multidisciplinary Design Of An Unmanned Aerial Vehicle Wing." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613606/index.pdf.
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In this thesis, the structural design, structural analysis and producibility analysis of an unmanned aerial vehicle wing were performed. Three different wing models, made of different materials, were designed. The wings were aluminum wing model and composite wing modelsmade of prepreg and wet lay-up. All wings have the same aerodynamic geometry and structural configuration under the same flight conditions. The structural designs of three wings were done by using Unigraphics NX. The finite element modeling of the wings were built by using MSC Patran package program. After the application of the loads on models, structural analyses were performed by MSC Nastran. Finally, the producibility analysis of prepreg wing model was conducted by using FiberSIM package program. The prepreg wing model was selected as optimum design with studies conducted in the study considering weight, producibility, cruise and gust stress and displacement conditions.
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Casey, Julian L. "Analytical approach to multi-objective joint inference control for fixed wing unmanned aerial vehicles." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright160431245463856.
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Trittler, Martin [Verfasser]. "Automatic Landing for Fixed-Wing Unmanned Aerial Vehicles with Optical Sensors / Martin Trittler." Aachen : Shaker, 2018. http://d-nb.info/1162794321/34.
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De, Hart Ruan Dirk. "Advanced take-off and flight control algorithms for fixed wing unmanned aerial vehicles." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4179.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: This thesis presents the development and implementation of a position based kinematic guidance system, the derivation and testing of a Dynamic Pursuit Navigation algorithm and a thorough analysis of an aircraft’s runway interactions, which is used to implement automated take-off of a fixed wing UAV. The analysis of the runway is focussed on the aircraft’s lateral modes. Undercarriage and aerodynamic effects are first analysed individually, after which the combined system is analysed. The various types of feedback control are investigated and the best solution suggested. Supporting controllers are designed and combined to successfully implement autonomous take-off, with acceleration based guidance. A computationally efficient position based kinematic guidance architecture is designed and implemented that allows a large percentage of the flight envelope to be utilised. An airspeed controller that allows for aggressive flight is designed and implemented by applying Feedback Linearisation techniques. A Dynamic Pursuit Navigation algorithm is derived that allows following of a moving ground based object at a constant distance (radius). This algorithm is implemented and verified through non-linear simulation.
AFRIKAANSE OPSOMMING: Hierdie tesis handel oor die ontwikkeling en toepassing van posisie-afhanklike, kinematiese leidings-algoritmes, die ontwikkeling van ’n Dinamiese Volgings-navigasie-algoritme en ’n deeglike analise van die interaksie van ’n lugraam met ’n aanloopbaan sodat outonome opstygprosedure van ’n vastevlerk vliegtuig bewerkstellig kan word. Die bogenoemde analise het gefokus op die laterale modus van ’n vastevlerk vliegtuig en is tweeledig behartig. Die eerste gedeelte het gefokus op die analise van die onderstel, terwyl die lugraam en die aerodinamiese effekte in die tweede gedeelte ondersoek is. Verskillende tipes terugvoerbeheer vir die outonome opstygprosedure is ondersoek om die mees geskikte tegniek te bepaal. Addisionele beheerders, wat deur die versnellingsbeheer gebaseerde opstygprosedure benodig word, is ontwerp. ’n Posisie gebaseerde kinematiese leidingsbeheerstruktuur om ’n groot persentasie van die vlugvermoë te benut, is ontwikkel. Terugvoer linearisering is toegepas om ’n lugspoedbeheerder , wat in staat is tot aggressiewe vlug, te ontwerp. ’n Dinamiese Volgingsnavigasie-algoritme wat in staat is om ’n bewegende grondvoorwerp te volg, is ontwikkel. Hierdie algoritme is geïmplementeer en bevestig deur nie-lineêre simulasie.
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Silva, Natássya Barlate Floro da. "Development of an autonomous unmanned aerial vehicle specification of a fixed-wing vertical takeoff and landing aircraft." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-16102018-100220/.
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Several configurations of Unmanned Aerial Vehicles (UAVs) were proposed to support different applications. One of them is the tailsitter, a fixed-wing aircraft that takes off and lands on its own tail, with the high endurance advantage from fixed-wing aircraft and, as helicopters and multicopters, not requiring a runway during takeoff and landing. However, a tailsitter has a complex operation with multiple flight stages, each one with its own particularities and requirements, which emphasises the necessity of a reliable autopilot for its use as a UAV. The literature already introduces tailsitter UAVs with complex mechanisms or with multiple counter-rotating propellers, but not one with only one propeller and without auxiliary structures to assist in the takeoff and landing. This thesis presents a tailsitter UAV, named AVALON (Autonomous VerticAL takeOff and laNding), and its autopilot, composed of 3 main units: Sensor Unit, Navigation Unit and Control Unit. In order to choose the most appropriate techniques for the autopilot, different solutions are evaluated. For Sensor Unit, Extended Kalman Filter and Unscented Kalman Filter estimate spatial information from multiple sensors data. Lookahead, Pure Pursuit and Line-of-Sight, Nonlinear Guidance Law and Vector Field path-following algorithms are extended to incorporate altitude information for Navigation Unit. In addition, a structure based on classical methods with decoupled Proportional-Integral-Derivative controllers is compared to a new control structure based on dynamic inversion. Together, all these techniques show the efficacy of AVALONs autopilot. Therefore, AVALON results in a small electric tailsitter UAV with a simple design, with only one propeller and without auxiliary structures to assist in the takeoff and landing, capable of executing all flight stages.Diversas configurações de Veículos Aéreos Não Tripulados (VANTs) foram propostas para serem utilizadas em diferentes aplicações. Uma delas é o tailsitter, uma aeronave de asa fixa capaz de decolar e pousar sobre a própria cauda. Esse tipo de aeronave apresenta a vantagem de aeronaves de asa fixa de voar sobre grandes áreas com pouco tempo e bateria e, como helicópteros e multicópteros, não necessita de pista para decolar e pousar. Porém, um tailsitter possui uma operação complexa, com múltiplos estágios de voo, cada um com suas peculiaridades e requisitos, o que enfatiza a necessidade de um piloto automático confiável para seu uso como um VANT. A literatura já introduz VANTs tailsitters com mecanismos complexos ou múltiplos motores contra-rotativos, mas não com apenas um motor e sem estruturas para auxiliar no pouso e na decolagem. Essa tese apresenta um VANT tailsitter, chamado AVALON (Autonomous VerticAL takeOff and laNding), e seu piloto automático, composto por 3 unidades principais: Unidade Sensorial, Unidade de Navegação e Unidade de Controle. Diferentes soluções são avaliadas para a escolha das técnicas mais apropriadas para o piloto automático. Para a Unidade Sensorial, Extended Kalman Filter e Unscented Kalman Filter estimam a informação espacial de múltiplos dados de diversos sensores. Os algoritmos de seguimento de trajetória Lookahead, Pure Pursuit and Line-of-Sight, Nonlinear Guidance Law e Vector Field são estendidos para considerar a informação da altitude para a Unidade de Navegação. Além do mais, uma estrutura baseada em métodos clássicos com controladores Proporcional- Integral-Derivativo desacoplados é comparada a uma nova estrutura de controle baseada em dinâmica inversa. Juntas, todas essas técnicas demonstram a eficácia do piloto automático do AVALON. Portanto, AVALON resulta em um VANT tailsitter pequeno e elétrico, com um design simples, apenas um motor e sem estruturas para auxiliar o pouso e a decolagem, capaz de executar todos os estágios de voo.
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Fridén, Tobias. "Robust Autonomous Landing of Fixed-Wing UAVs in Wind." Thesis, Linköpings universitet, Reglerteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-165136.
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Fixed-wing UAVs are today used in many different areas, from agriculture to search and rescue operations. Through various research efforts, they are becoming more and more autonomous. However, the procedure of landing a fixed-wing UAV remains a challenging task, which requires manual input from an experienced pilot. This work proposes a novel method which autonomously performs such landings. The main focus is on small and light-weight UAVs, for which the wind acts as a major disturbance and has to be taken into account. Robustness to other disturbances, such as variations in environmental factors or measurement errors, has also been prioritized during the development of this method.The main contribution of this work consists of a framework in which der\-iva\-tive-free optimization is used to calculate a set of waypoints, which are feasible to use in different wind speeds and directions, for a selected UAV model. These waypoints are then combined online using motion planning techniques, to create a trajectory which safely brings the UAV to a position where the landing descent can be initiated. To ensure a safe descent in a predefined area, another nonlinear optimization problem is formulated and solved. Finally, the proposed method is implemented on a real UAV platform. A number of simulations in different wind conditions are performed, and data from a real flight experiment is presented. The results indicate that the method successfully calculates feasible landing sequences in different scenarios, and that it is applicable in a real-world landing.
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Greer, Daniel S. "Avionics System development for a Rotary Wing Unmanned Aerial Vehicle." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA350437.
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Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, June 1998."June 1998." Thesis advisor(s): Russ W. Duren. Includes bibliographical references (p. 79). Also available online. Mode of access: World Wide Web.
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Venter, Jacob. "Development of an experimental tilt-wing VTOL unmanned aerial vehicle." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/225.
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Puttige, Vishwas Ramadas Engineering & Information Technology Australian Defence Force Academy UNSW. "Neural network based adaptive control for autonomous flight of fixed wing unmanned aerial vehicles." Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43736.
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This thesis presents the development of small, inexpensive unmanned aerial vehicles (UAVs) to achieve autonomous fight. Fixed wing hobby model planes are modified and instrumented to form experimental platforms. Different sensors employed to collect the flight data are discussed along with their calibrations. The time constant and delay for the servo-actuators for the platform are estimated. Two different data collection and processing units based on micro-controller and PC104 architectures are developed and discussed. These units are also used to program the identification and control algorithms. Flight control of fixed wing UAVs is a challenging task due to the coupled, time-varying, nonlinear dynamic behaviour. One of the possible alternatives for the flight control system is to use the intelligent adaptive control techniques that provide online learning capability to cope with varying dynamics and disturbances. Neural network based indirect adaptive control strategy is applied for the current work. The two main components of the adaptive control technique are the identification block and the control block. Identification provides a mathematical model for the controller to adapt to varying dynamics. Neural network based identification provides a black-box identification technique wherein a suitable network provides prediction capability based upon the past inputs and outputs. Auto-regressive neural networks are employed for this to ensure good retention capabilities for the model that uses the past outputs and inputs along with the present inputs. Online and offline identification of UAV platforms are discussed based upon the flight data. Suitable modifications to the Levenberg-Marquardt training algorithm for online training are proposed. The effect of varying the different network parameters on the performance of the network are numerically tested out. A new performance index is proposed that is shown to improve the accuracy of prediction and also reduces the training time for these networks. The identification algorithms are validated both numerically and flight tested. A hardware-in-loop simulation system has been developed to test the identification and control algorithms before flight testing to identify the problems in real time implementation on the UAVs. This is developed to keep the validation process simple and a graphical user interface is provided to visualise the UAV flight during simulations. A dual neural network controller is proposed as the adaptive controller based upon the identification models. This has two neural networks collated together. One of the neural networks is trained online to adapt to changes in the dynamics. Two feedback loops are provided as part of the overall structure that is seen to improve the accuracy. Proofs for stability analysis in the form of convergence of the identifier and controller networks based on Lyapunov's technique are presented. In this analysis suitable bounds on the rate of learning for the networks are imposed. Numerical results are presented to validate the adaptive controller for single-input single-output as well as multi-input multi-output subsystems of the UAV. Real time validation results and various flight test results confirm the feasibility of the proposed adaptive technique as a reliable tool to achieve autonomous flight. The comparison of the proposed technique with a baseline gain scheduled controller both in numerical simulations as well as test flights bring out the salient adaptive feature of the proposed technique to the time-varying, nonlinear dynamics of the UAV platforms under different flying conditions.
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SARTORI, DANIELE. "Design, Implementation and Testing of Advanced Control Laws for Fixed-wing UAVs." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2571146.
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The present PhD thesis addresses the problem of the control of small fixed-wing Unmanned
Aerial Vehicles (UAVs). In the scientific community much research is dedicated to the study
of suitable control laws for this category of aircraft. This interest is motivated by the several
applications that these platforms can perform and by their peculiarities as dynamical systems.
In fact, small UAVs are characterized by highly nonlinear behavior, strong coupling between
longitudinal and latero-directional planes, and high sensitivity to external disturbances and
to parametric uncertainties. Furthermore, the challenge is increased by the limited space
and weight available for the onboard electronics. The aim of this PhD thesis is to provide a
valid confrontation among three different control techniques and to introduce an innovative
autopilot configuration suitable for the unmanned aircraft field.
Three advanced controllers for fixed-wing unmanned aircraft vehicles are designed and
implemented: PID with H1 robust approach, L1 adaptive controller and nonlinear backstepping
controller. All of them are analyzed from the theoretical point of view and validated
through numerical simulations with a mathematical UAV model. One is implemented on a
microcontroller board, validated through hardware simulations and tested in
flight.
The PID with H1 robust approach is used for the definition of the gains of a commercial
autopilot. The proposed technique combines traditional PID control with an H1 loop
shaping method to assess the robustness characteristics achievable with simple PID gains.
It is demonstrated that this hybrid approach provides a promising solution to the problem
of tuning commercial autopilots for UAVs. Nevertheless, it is clear that a tradeoff between
robustness and performance is necessary when dealing with this standard control technique.
The robustness problem is effectively solved by the adoption of an L1 adaptive controller
for complete aircraft control. In particular, the L1 logic here adopted is based on piecewise
constant adaptive laws with an adaptation rate compatible with the sampling rate of an autopilot
board CPU. The control scheme includes an L1 adaptive controller for the inner loop,
while PID gains take care of the outer loop. The global controller is tuned on a linear decoupled
aircraft model. It is demonstrated that the achieved configuration guarantees satisfying
performance also when applied to a complete nonlinear model affected by uncertainties and parametric perturbations.
The third controller implemented is based on an existing nonlinear backstepping technique.
A scheme for longitudinal and latero-directional control based on the combination of
PID for the outer loop and backstepping for the inner loop is proposed. Satisfying results are
achieved also when the nonlinear aircraft model is perturbed by parametric uncertainties. A
confrontation among the three controllers shows that L1 and backstepping are comparable
in terms of nominal and robust performance, with an advantage for L1, while the PID is
always inferior.
The backstepping controller is chosen for being implemented and tested on a real fixed-wing
RC aircraft. Hardware-in-the-loop simulations validate its real-time control capability
on the complete nonlinear model of the aircraft adopted for the tests, inclusive of sensors
noise. An innovative microcontroller technology is employed as core of the autopilot system,
it interfaces with sensors and servos in order to handle input/output operations and it
performs the control law computation. Preliminary ground tests validate the suitability of
the autopilot configuration. A limited number of flight tests is performed. Promising results
are obtained for the control of longitudinal states, while latero-directional control still needs
major improvements.
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Simmons, Benjamin Mason. "System Identification of a Nonlinear Flight Dynamics Model for a Small, Fixed-Wing UAV." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/95324.
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This thesis describes the development of a nonlinear flight dynamics model for a small, fixed-wing unmanned aerial vehicle (UAV). Models developed for UAVs can be used for many applications including risk analysis, controls system design and flight simulators. Several challenges exist for system identification of small, low-cost aircraft including an increased sensitivity to atmospheric disturbances and decreased data quality from a cost-appropriate instrumentation system. These challenges result in difficulties in development of the model structure and parameter estimation. The small size may also limit the scope of flight test experiments and the consequent information content of the data from which the model is developed. Methods are presented to improve the accuracy of system identification which include data selection, data conditioning, incorporation of information from computational aerodynamics and synthesis of information from different flight test maneuvers. The final parameter estimation and uncertainty analysis was developed from the time domain formulation of the output-error method using the fully nonlinear aircraft equations of motion and a nonlinear aerodynamic model structure. The methods discussed increased the accuracy of parameter estimates and lowered the uncertainty in estimates compared to standard procedures for parameter estimation from flight test data. The significant contributions of this thesis are a detailed explanation of the entire system identification process tailored to the needs of a small UAV and incorporation of unique procedures to enhance identification results. This work may be used as a guide and list of recommendations for future system identification efforts of small, low-cost, minimally instrumented, fixed-wing UAVs.MS
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Mills, Steven John. "Visual guidance for fixed-wing unmanned aerial vehicles using feature tracking : application to power line inspection." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/62558/4/62558%28updated_version%29.pdf.
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This thesis presents novel vision based control solutions that enable fixed-wing Unmanned Aerial Vehicles to perform tasks of inspection over infrastructure including power lines, pipe lines and roads. This is achieved through the development of techniques that combine visual servoing with alternate manoeuvres that assist the UAV in both following and observing the feature from a downward facing camera. Control designs are developed through techniques of Image Based Visual Servoing to utilise sideslip through Skid-to-Turn and Forward-Slip manoeuvres. This allows the UAV to simultaneously track and collect data over the length of infrastructure, including straight segments and the transition where these meet.
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Obenchain, Matthew Bridger 1978. "Shape memory alloy induced wing warping for a small unmanned aerial vehicle." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/7983.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2003.Includes bibliographical references (p. 135-137).
The Wide Area Surveillance Projectile (WASP) is a gun-launched unmanned aerial vehicle designed to be carried as payload in an artillery shell. Due to the 15000 g shock sustained during gun launch, conventional ailerons are too fragile to be a reliable means of roll control for the aircraft. For this reason, the possibility of using shape memory alloys (SMA) to control the vehicle is investigated. A conceptual design is introduced in which pre-strained Nitinol wires are attached to the surface of the wing. When the resistively heated wires pass a transition temperature, a phase change occurs in the wires and they contract to recover the pre-strain. As the wires contract, they twist the wing in what is known as wing warping. This conceptual design is refined through extensive modeling and finite element analysis. Thermal analysis is used to determine how fast the wires heat and cool, which determines how fast the vehicle can be controlled. Structural analysis is used to determine the amount of twist induced in the wing when the wires contract. A preliminary performance analysis illustrates what bank angles and roll rates the WASP could achieve when the actuator is used. Tensile testing of the Nitinol wire is conducted to determine its modulus of elasticity in both its martensite and austenite phases. In addition, cycle tests are performed in which the wire is heated and cooled at constant stress to determine the transition temperatures of the material. Tests are conducted on prototype wings with Nitinol wires attached to determine the actual performance of the actuator. Using epoxy to attach the Nitinol to the wing is found to be problematic, since the epoxy degrades as the wires are heated. Using mechanical means to attach the wires is shown to be much more effective. This thesis shows that an SMA actuator can repeatedly twist the wing of a small UAV to angles in excess of one degree. Analytical results show that the wing can be actuated every 3.2 seconds. Performance analysis predicts that roll rates of over 25 degrees/second can be achieved. These results indicate that an SMA actuator has the ability to control the aircraft during slow, banking turns while the aircraft follows a racetrack pattern.
by Matthew Bridger Obenchain.
S.M.
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Masango, Thubalakhe Patrick. "Condition monitoring of a wing structure for an unmanned aerial vehicle (UAV)." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2384.
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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2015.Currently non-destructive testing techniques for composite aircraft structures are disadvantaged when compared to online Structural Health Monitoring (SHM) systems that monitor the structure while in-service and give real time data. The present research work looks at developing a protocol for online structural health monitoring of a UAV wing structure using PVDF film sensors, especially including the monitoring of structural changes caused by defects. Different types of SHM techniques were studied in relation to carbon fibre composites. Laminate composite make-up and manufacturing process was investigated and vacuum infusion process was used to manufacture the samples that resemble the Guardian II wing structure, then the three-point bending test was used to determine the material properties. Digital Shearography was employed as a stationery non-destructive technique to determine the sensor to structure attachment, type and position of defects that affect the state of performance. Finite Element Analysis (FEA) was done using ANSYS Workbench which served as a modelling tool using a drawing imported from Solid-works. Experimental investigation was done using PVDF sensor embedded on the surface of the sample in a cantilever setup and a vertical Vernier scale to measure the deflection due to impact and vibration loading. A Fluke-View oscilloscope was used as a data logger when the measurement of the output voltage and the natural frequency were recorded. The techniques of using FEA and experimental investigation were then compared. The findings of this study showed that the PVDF sensor is suitable for condition monitoring of a UAV wing structure.
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Blaauw, Deon. "Flight control system for a variable stability blended-wing-body unmanned aerial vehicle." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2297.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009.This thesis presents the analysis, design, simulation and practical implementation of a novel control system for a variable stability blended-wing-body unmanned aerial vehicle. The aircraft has a moveable centre of mass that allows it to operate in an aerodynamically optimised minimum drag configuration during cruise flight. The primary purpose of the control system is thus to regain nominal static stability for all centre of mass positions, and then to further regulate motion variables for autonomous way point navigation. A thorough analysis of the parameters affected by the varying centre of mass position leads to the identification of the main control problem. It is shown that a recently published acceleration based control methodology can be used with minor modification to elegantly solve the variable stability control problem. After providing the details of the control system design, the customised avionics used for their practical implementation are presented. The results of extensive hardware in the loop simulations verify the functionality of the controllers. Finally, flight test results illustrate the practical success of the autopilot and clearly show how the control system is capable of controlling the variable stability aircraft at centre of mass locations where a human pilot could not.
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Knijnenburg, Gerard Franciscus. "Development of a vibration isolation system for a rotary wing unmanned aerial vehicle." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62777.
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Antiresonance vibration isolation has long been a well known, studied and applied method for alleviating vibrations in stiff structures where small static deflection and a low transmissibility is needed, making it ideal for use in the rotor-craft industry. Most prior arts focus on passive single frequency antiresonance vibration isolation, while some, most notably liquid inertia vibration isolators, are adapted to actively isolate vibrations at more than one frequency. Very little literature is found on the adaptation of mechanical pendulum antiresonance vibration isolators for in-flight tunable multiple frequency isolation, and although these systems predate the more modern liquid inertia type isolator, there is merit in their further development and use as low cost, robust and low maintenance isolators. A feasibility study on the performance of changing each fundamental design variable to achieve antiresonance tuning concludes, that for the antiresonance frequency shift range of interest in this dissertation, no specific design variable change quantifiably outperforms another with respect to tuning the antiresonance. Concept designs are created and investigated, finding the superior method of tuning the vibration isolator based on other criteria like overall weight, design simplicity, practicality, robustness and reliability. Shifting the tuning mass on the pendulum arm is deemed to be the superior concept, with respect to the helicopter being developed, and a tunable multi-frequency pendulum antiresonance vibration isolation system with a sliding concentrated mass is developed with ADAMS multi-body dynamics software and SolidWorks. The isolation system along with a full scale dummy fuselage and transmission-rotor assembly is manufactured and experimentally tested. Initial experimental results show antiresonance frequencies 10Hz higher than the design targets, this phenomenon is later discovered to be related to friction in the pin joints of the pendulum hinges, increasing the system overall stiffness. Needle roller bearings are inserted to eliminate the friction, and experimental and ADAMS model results are again compared showing good correlation, with experimental results isolating close to the three target frequencies within 3% error. An astonishing level of vibration isolation is observed with the largest transmissibility obtained at the three frequencies being 0:5%. This dissertation proves the concept of a tunable mechanical pendulum vibration isolator, and its design methodology, particularly with respect to shifting the position of the tuning mass. Suggestions for further work are: to implement this system with an actuation mechanism, further research on the effects of friction in isolators and the use of said phenomenon as a tuning method, development of isolators implementing the other concept of changing the design variables and a comparison between the effect of normal damping and friction damping on vibration isolation.Dissertation (MEng)--University of Pretoria, 2017.
Mechanical and Aeronautical Engineering
MEng
Unrestricted
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Bagheri, Shahriar. "Modeling, Simulation and Control System Design for Civil Unmanned Aerial Vehicle (UAV)." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96458.
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Unmanned aerial systems have been widely used for variety of civilian applications over the past few years. Some of these applications require accurate guidance and control. Consequently, Unmanned Aerial Vehicle (UAV) guidance and control attracted many researchers in both control theory and aerospace engineering. Flying wings, as a particular type of UAV, are considered to have one of the most efficient aerodynamic structures. It is however difficult to design robust controller for such systems. This is due to the fact that flying wings are highly sensitive to control inputs. The focus of this thesis is on modeling and control design for a UAV system. The platform understudy is a flying wing developed by SmartPlanes Co. located in Skellefteå, Sweden. This UAV is particularly used for topological mapping and aerial photography. The novel approach suggested in this thesis is to use two controllers in sequence. More precisely, Linear Quadratic Regulator (LQR) is suggested to provide robust stability, and Proportional, Integral, Derivative (PID) controller is suggested to provide reference signal regulation. The idea behind this approach is that with LQR in the loop, the system becomes more stable and less sensitive to control signals. Thus, PID controller has an easier task to do, and is only used to provide the required transient response. The closed-loop system containing the developed controller and a UAV non-linear dynamic model was simulated in Simulink. Simulated controller was then tested for stability and robustness with respect to some parametric uncertainty. Obtained results revealed that the LQR successfully managed to provide robust stability, and PID provided reference signal regulation.
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Assel, Timothy William. "Computational study of flow over elliptic airfoils for rotor/wing unmanned aerial vehicle applications." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/Tim_Assel_Thesis_Final_09007dcc804c796b.pdf.
Full textAbstract:
Thesis (M.S.)--University of Missouri--Rolla, 2007.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed March 26, 2008) Includes bibliographical references (p. 102-104).
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Hwangbo, Myung. "Vision-Based Navigation for a Small Fixed-Wing Airplane in Urban Environment." Research Showcase @ CMU, 2012. http://repository.cmu.edu/dissertations/201.
Full textAbstract:
An urban operation of unmanned aerial vehicles (UAVs) demands a high level of autonomy for tasks presented in a cluttered environment. While fixed-wing UAVs are well suited for long-endurance missions at a high altitude, enabling them to navigate inside an urban area brings another level of challenges. Their inability to hover and low agility in motion cause more difficulties on finding a feasible path to move safely in a compact region, and the limited payload allows only low-grade sensors for state estimation and control.
We address the problem of achieving vision-based autonomous navigation for a small fixed-wing in an urban area with contributions to the following several key topics. Firstly, for robust attitude estimation during dynamic maneuvering, we take advantage of the line regularity in an urban scene, which features vertical and horizontal edges of man-made structures. The sensor fusion with gravity-related line segments and gyroscopes in a Kalman filter can provide driftless and realtime attitude for ight stabilization. Secondly, as a prerequisite to sensor fusion, we present a convenient self-calibration scheme based on the factorization method. Natural references such as gravity, vertical edges, and distant scene points, available in urban fields, are sufficient to find intrinsic and extrinsic parameters of inertial and vision sensors. Lastly, to generate a dynamically feasible motion plan, we propose a discrete planning method that encodes a path into interconnections of finite trim states, which allow a significant dimension reduction of a search space and result in naturally implementable paths integrated with ight controllers. The most probable path to reach a target is computed by the Markov Decision Process with motion uncertainty due to wind, and a minimum target observation time is imposed on the final motion plan to consider a camera's limited field-of-view.
In this thesis, the effectiveness of our vision-based navigation system is demonstrated by what we call an "air slalom" task in which the UAV must autonomously search and localize multiple gates, and pass through them sequentially. Experiment results with a 1m wing-span airplane show essential navigation capabilities demanded in urban operations such as maneuvering passageways between buildings.
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Small, Elias. "Modelling, Control, and Experimental Evaluation of the Hovering Characteristics of a Tilt-Wing Unmanned Aerial Vehicle." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-61531.
Full textAbstract:
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.
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Insuyu, Erdogan Tolga. "Aero-structural Design And Analysis Of An Unmanned Aerial Vehicle And Its Mission Adaptive Wing." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611657/index.pdf.
Full textAbstract:
This thesis investigates the effects of camber change on the mission adaptive wing of a structurally designed unmanned aerial vehicle (UAV). The commercial computational fluid dynamics (CFD) software ANSYS/FLUENT is employed for the aerodynamic analyses. Several cambered airfoils are compared in terms of their aerodynamic coefficients and the effects of the camber change formed in specific sections of the wing on the spanwise pressure distribution are investigated. The mission adaptive wing is modeled structurally to observe the effect of spanwise pressure distribution on the wing structure. For the structural design and analysis of the UAV under this study, commercial software MSC/PATRAN and MSC/NASTRAN are used. The structural static and dynamic analyses of the unmanned aerial vehicle are also performed under specified flight conditions. The results of these analyses show that the designed structure is safe within the flight envelope. Having completed aero-structural design and analysis, the designed unmanned aerial vehicle is manufactured by TUSAS Aerospace Industries (TAI).
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Rowe, Johnathan. "FINITE ELEMENT MODELING OF AN INFLATABLE WING." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/475.
Full textAbstract:
Inflatable wings provide an innovative solution to unmanned aerial vehicles requiring small packed volumes, such as those used for military reconnaissance or extra-planetary exploration. There is desire to implement warping actuation forces to change the shape of the wing during flight to allow for greater control of the aircraft. In order to quickly and effectively analyze the effects of wing warping strategies on an inflatable wing, a finite element model is desired. Development of a finite element model which includes woven fabric material properties, internal pressure loading, and external wing loading is presented. Testing was performed to determine material properties of the woven fabric, and to determine wing response to static loadings. The modeling process was validated through comparison of simplified inflatable cylinder models to experimental test data. Wing model response was compared to experimental response, and modeling changes including varying material property models and mesh density studies are presented, along with qualitative wing warping simulations. Finally, experimental and finite element modal analyses were conducted, and comparisons of natural frequencies and mode shapes are presented.
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Marchini, Brian Decimo. "Adaptive Control Techniques for Transition-to-Hover Flight of Fixed-Wing UAVs." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1108.
Full textAbstract:
Fixed-wing unmanned aerial vehicles (UAVs) with the ability to hover combine the speed and endurance of traditional fixed-wing fight with the stable hovering and vertical takeoff and landing (VTOL) capabilities of helicopters and quadrotors. This combination of abilities can provide strategic advantages for UAV operators, especially when operating in urban environments where the airspace may be crowded with obstacles. Traditionally, fixed-wing UAVs with hovering capabilities had to be custom designed for specific payloads and missions, often requiring custom autopilots and unconventional airframe configurations. With recent government spending cuts, UAV operators like the military and law enforcement agencies have been urging UAV developers to make their aircraft cheaper, more versatile, and easier to repair. This thesis discusses the use of the commercially available ArduPilot open source autopilot, to autonomously transition a fixed-wing UAV to and from hover flight. Software modifications were made to the ArduPilot firmware to add hover flight modes using both Proportional, Integral, Derivative (PID) Control and Model Reference Adaptive Control (MRAC) with the goal of making the controllers robust enough so that anyone in the ArduPilot community could use their own ArduPilot board and their own fixed-wing airframe (as long as it has enough power to maintain stable hover) to achieve autonomous hover after some simple gain tuning. Three new hover flight modes were developed and tested first in simulation and then in flight using an E-Flight Carbon Z Yak 54 RC aircraft model, which was equipped with an ArduPilot 2.5 autopilot board. Results from both the simulations and flight test experiments where the airplane transitions both to and from autonomous hover flight are presented.
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Smith, David Everett. "Modelling and controlling a bio-inspired flapping-wing micro aerial vehicle." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43577.
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The objective of this research is to verify the three degree of freedom capabilities of a bio-inspired quad flapping-wing micro aerial vehicle in simulation and in hardware. The simulation employs a nonlinear plant model and input-output feedback linearization controller to verify the three degree of freedom capabilities of the vehicle. The hardware is a carbon fiber test bench with four flapping wings and an embedded avionics system which is controlled via a PD linear controller. Verification of the three degree of freedom capabilities of the quad flapping-wing concept is achieved by analyzing the response of both the simulation and test bench to pitch, roll, and yaw attitude commands.
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Garnand-Royo, Jeffrey Samuel. "Design and Evaluation of Geometric Nonlinearities using Joined-Wing SensorCraft Flight Test Article." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23234.
Full textAbstract:
The Boeing Joined-Wing SenorCraft is a novel aircraft design that has many potential benefits, especially for surveillance missions. However, computational studies have shown the potential for nonlinear structural responses in the joined-wing configuration due to aerodynamic loading that could result in aft wing buckling. The design, construction, and flight testing of a 1/9th scale, aeroelastically tuned model of the Joined-Wing SensorCraft has been the subject of an ongoing international collaboration aimed at experimentally demonstrating the nonlinear aeroelastic response in flight. To accurately measure and capture the configuration\'s potential for structural nonlinearity, the test article must exhibit equivalent structural flexibility and be designed to meet airworthiness standards. Previous work has demonstrated airworthiness through the successful flight of a Geometrically Scaled Remotely Piloted Vehicle. The work presented in this thesis involves evaluation of an aeroelastically tuned design through ground-based experimentation. The result of these experimental investigations has led to the conclusion that a full redesign of the forward and aft wings must be completed to demonstrate sufficient geometric nonlinearity for the follow-on Aeorelastically Tuned Remotely Piloted Vehicle. This thesis also presents flight test plans for the aeroelastically tuned RPV.Master of Science
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Gleeson, Jeremy Information Technology & Electrical Engineering Australian Defence Force Academy UNSW. "Finding the shipboard relative position of a rotary wing unmanned aerial vehicle (UAV) with ultasonic ranging." Awarded by:University of New South Wales - Australian Defence Force Academy, 2008. http://handle.unsw.edu.au/1959.4/38978.
Full textAbstract:
Simple, cheap and reliable echo-based ultrasonic ranging systems such as the Polaroid ranging unit are easily applied to indoor applications. However, to measure the range between an unmanned helicopter and a moving ship deck at sea using ultrasound requires a more robust ranging system, because rushing air and breaking water are known ultrasound noise sources. The work of designing, constructing and testing such a system is described in this dissertation. The compact, UAV ready ultrasound transmitter module provides high power, broadband arbitrary signal generation. The separate field-ready receiver is based on a modern embedded Digital Signal Processor (DSP), providing high speed matched-filter correlation processing. Large time-bandwidth signalling is employed to maximise the signal to noise ratio of the ranging system. Synthesised experiments demonstrate the ability of the correlation processing to reliably recover timing from signals buried in noise. Real world experiments demonstrate decimetre accuracy with two centimetre resolution, ten metre range and 32Hz refresh rate. A maximum boresight range of up to 38m is supported.
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Rathore, Ankush, and ankushrathore@yahoo com. "A systems approach to model the conceptual design process of vertical take-off unmanned aerial vehicle." RMIT University. School of Aerospace, Mechanical and Manufacturing Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20061114.103443.
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The development and induction in-service of Unmanned Air Vehicles (UAV) systems in a variety of civil, paramilitary and military roles have proven valuable on high-risk missions. These UAVs based on fixed wing configuration concept have demonstrated their operational effectiveness in recent operations. New UAVs based on rotary wing configuration concept have received major attention worldwide, with major resources committed for its research and development. In this thesis, the design process of a rotary-wing aircraft was re-visualised from an unmanned perspective to address the requirements of rotary-wing UAVs - Vertical Take-off UAVs (VTUAV). It investigates the conventional helicopter design methodology for application in UAV design. It further develops a modified design process for VTUAV addressing the requirements of unmanned missions by providing remote command-and-control capabilities. The modified design methodology is automated to address the complex design evaluations and optimisation process. An illustration of the automated design process developed for VTUAVs is provided through a series of inputs of the requirements and specifications, resulting in an output of a proposed VTUAV design configuration for
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Harris, Turner John. "CONSTRAINED VOLUME PACKING OF DEPLOYABLE WINGS FOR UNMANNED AIRCRAFT." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_theses/129.
Full textAbstract:
UAVs are becoming an accepted tool for sensing. The benefits of deployable wings allow smaller transportation enclosures such as soldier back packs up to large rocket launched extraterrestrial UAVs. The packing of soft inflatable wings and Hybrid inflatable with rigid section wings is being studied at the University of Kentucky. Rigid wings are volume limited while inflatable wings are mass limited. The expected optimal wing design is a hybrid approach. Previous wing designs have been packed into different configurations in an attempt to determine the optimal stowed configurations. A comparison of rigid, hybrid, and inflatable wings will be presented. Also a method for simulating optimally packed wings with respect to geometric constraints will be presented. A code has been written to study soft wing packing and verified the soft wing packing results. This code can be used during initial wing design to help predict wing size and packing configurations. In this thesis, an over view of the packing configurations as well as packing observations will be covered such , packing inefficiencies, wing mounting limits, long term storage, and scaling of packing.
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Unlusoy, Levent. "Structural Design And Analysis Of The Mission Adaptive Wings Of An Unmanned Aerial Vehicle." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611515/index.pdf.
Full textAbstract:
In this study, the structural design and analysis of a wing having mission-adaptive control surfaces were conducted. The wing structure was designed in order to withstand a maximum aerodynamic loading of 5 g due to maneuver. The structural model of the wing was developed by using MSC/PATRAN package program and that structural model was analyzed by using MSC/NASTRAN package program. The designed wing was then manufactured by Turkish Aerospace Industries Inc. (TUSAS-TAI). The finite element analysis results were verified by conducting ground vibration tests on the manufactured wing. The comparative results were used to tune the finite element model and the results obtained showed that the modeling was very successful.
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Aarons, Tyler David. "Development and Implementation of a Flight Test Program for a Geometrically Scaled Joined Wing SensorCraft Remotely Piloted Vehicle." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/36383.
Full textAbstract:
The development and implementation of a flight test program for an unmanned
aircraft is a multidisciplinary challenge. This thesis presents the development and
implementation of a rigorous test program for the flight test of a Geometrically
Scaled Joined Wing SensorCraft Remotely Piloted Vehicle from concept through
successful flight test. The design methodology utilized in the development of the
test program is presented, along with the extensive formal review process required
for the approval of the test plan by the Air Force Research Laboratory. The
design, development and calibration of a custom instrumentation package is also
presented along with the setup, procedure and results from all testing. Results are
presented for a wind tunnel test for air data boom calibration, propulsion system
static thrust testing, a bifilar pendulum test for experimental calculation of mass
moments of inertia, a static structural loading test for structural design validation,
a full taxi test and a successful first flight.Master of Science
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Doepke, Edward Brady. "DESIGN AND FLIGHT TESTING OF A WARPING WING FOR AUTONOMOUS FLIGHT CONTROL." UKnowledge, 2012. http://uknowledge.uky.edu/me_etds/20.
Full textAbstract:
Inflatable-wing Unmanned Aerial Vehicles (UAVs) have the ability to be packed in a fraction of their deployed volume. This makes them ideal for many deployable UAV designs, but inflatable wings can be flexible and don’t have conventional control surfaces. This thesis will investigate the use of wing warping as a means of autonomous control for inflatable wings. Due to complexities associated with manufacturing inflatable structures a new method of rapid prototyping deformable wings is used in place of inflatables to decrease cost and design-cycle time. A UAV testbed was developed and integrated with the warping wings and flown in a series of flight tests. The warping wing flew both under manual control and autopilot stabilization.
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Jung, Dongwon Jung. "Hierarchical Path Planning and Control of a Small Fixed-wing UAV: Theory and Experimental Validation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19781.
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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2008.Committee Chair: Tsiotras, Panagiotis; Committee Member: Corban, Eric; Committee Member: Feron, Eric; Committee Member: Johnson, Eric; Committee Member: Vachtsevanos, George.
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Beyers, Coenraad Johannes. "Motion planning algorithms for autonomous navigation for a rotary-wing UAV." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80231.
Full textAbstract:
Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: This project concerns motion planning for a rotary wing UAV, where vehicle controllers are already in place, and map data is readily available to a collision detection module. In broad terms, the goal of the motion planning algorithm is to provide a safe (i.e. obstacle free) flight path between an initial- and goal waypoint. This project looks at two specific motion planning algorithms, the Rapidly Exploring Random Tree (or RRT*), and the Probabilistic Roadmap Method (or PRM). The primary focus of this project is learning how these algorithms behave in specific environments and an in depth analysis is done on their differences. A secondary focus is the execution of planned paths via a Simulink simulation and lastly, this project also looks at the effect of path replanning. The work done in this project enables a rotary wing UAV to autonomously navigate an uncertain, dynamic and cluttered environment. The work also provides insight into the choice of an algorithm for a given environment: knowing which algorithm performs better can save valuable processing time and will make the entire system more responsive.
AFRIKAANSE OPSOMMING: ’n Tipiese vliegstuuroutomaat is daartoe in staat om ’n onbemande lugvaartvoertuig (UAV) so te stuur dat ’n stel gedefinieerde punte gevolg word. Die punte moet egter vooraf beplan word, en indien enige verandering nodig is (bv. as gevolg van veranderinge in die omgewing) is dit nodig dat ’n menslike operateur betrokke moet raak. Vir voertuie om ten volle outonoom te kan navigeer, moet die voertuig in staat wees om te kan reageer op veranderende situasies. Vir hierdie doel word kinodinamiese beplanningsalgoritmes en konflikdeteksiemetodes gebruik. Hierdie projek behels kinodinamiese beplanningsalgoritmes vir ’n onbemande helikopter, waar die beheerders vir die voertuig reeds in plek is, en omgewingsdata beskikbaar is vir ’n konflikdeteksie-module. In breë terme is die doel van die kinodinamiese beplanningsalgoritme om ’n veilige (d.w.s ’n konflikvrye) vlugpad tussen ’n begin- en eindpunt te vind. Hierdie projek kyk na twee spesifieke kinodinamiese beplanningsalgoritmes, die “Rapidly exploring Random Tree*” (of RRT*), en die “Probabilistic Roadmap Method” (of PRM). Die primêre fokus van hierdie projek is om die gedrag van hierdie algoritmes in spesifieke omgewings te analiseer en ’n volledige analise te doen op hul verskille. ’n Sekondêre fokus is die uitvoering van ’n beplande vlugpad d.m.v ’n Simulink-simulasie, en laastens kyk hierdie projek ook na die effek van padherbeplanning. Die werk wat gedoen is in hierdie projek stel ’n onbemande helikopter in staat om outonoom te navigeer in ’n onsekere, dinamiese en besige omgewing. Die werk bied ook insig in die keuse van ’n algoritme vir ’n gegewe omgewing: om te weet watter algoritme beter uitvoertye het kan waardevolle verwerkingstyd bespaar, en verseker dat die hele stelsel vinniger kan reageer.
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Thamann, Michael. "AERODYNAMICS AND CONTROL OF A DEPLOYABLE WING UAV FOR AUTONOMOUS FLIGHT." UKnowledge, 2012. http://uknowledge.uky.edu/me_etds/18.
Full textAbstract:
UAV development and usage has increased dramatically in the last 15 years. In this time frame the potential has been realized for deployable UAVs to the extent that a new class of UAV was defined for these systems. Inflatable wing UAVs provide a unique solution for deployable UAVs because they are highly packable (some collapsing to 5-10% of their deployed volume) and have the potential for the incorporation of wing shaping. In this thesis, aerodynamic coefficients and aileron effectiveness were derived from the equations of motion of aircraft as necessary parameters for autonomous flight. A wind tunnel experiment was performed to determine the aerodynamic performance of a bumpy inflatable wing airfoil for comparison with the baseline smooth airfoil from which it was derived. Results showed that the bumpy airfoil has improved aerodynamics over the smooth airfoil at low-Re. The results were also used to create aerodynamic performance curves to supplement results of aerodynamic modeling with a smooth airfoil. A modeling process was then developed to calculate the aileron effectiveness of a wing shaping demonstrator aircraft. Successful autonomous flight tests were then performed with the demonstrator aircraft including in-flight aileron doublets to validate the predicted aileron effectiveness, which matched within 8%.
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Miranda, Ricardo E. "Development of a nonlinear 6-degree of freedom miniature rotary-wing unmanned aerial vehicle software model and PID flight path controller using Mathworks Simulink simulation environment." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FMiranda.pdf.
Full textAbstract:
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 2009.Thesis Advisor(s): Hutchins, Robert G. ; Dobrokhodov, Vladimir ; Kitsios, Ioannis. "September 2009." Description based on title screen as viewed on November 5, 2009. Author(s) subject terms: Hardware in the Loop (HIL), Software in the Loop (SIL) Simulation Environment, 6-Degree of Freedom (6-DOF) Rotary-wing Unmanned Aerial Vehicle (RW UAV) model , PID Flight Path Controllers Includes bibliographical references (p. 111). Also available in print.
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Samal, Mahendra Engineering & Information Technology Australian Defence Force Academy UNSW. "Neural network based identification and control of an unmanned helicopter." Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43917.
Full textAbstract:
This research work provides the development of an Adaptive Flight Control System (AFCS) for autonomous hover of a Rotary-wing Unmanned Aerial Vehicle (RUAV). Due to the complex, nonlinear and time-varying dynamics of the RUAV, indirect adaptive control using the Model Predictive Control (MPC) is utilised. The performance of the MPC mainly depends on the model of the RUAV used for predicting the future behaviour. Due to the complexities associated with the RUAV dynamics, a neural network based black box identification technique is used for modelling the behaviour of the RUAV. Auto-regressive neural network architecture is developed for offline and online modelling purposes. A hybrid modelling technique that exploits the advantages of both the offline and the online models is proposed. In the hybrid modelling technique, the predictions from the offline trained model are corrected by using the error predictions from the online model at every sample time. To reduce the computational time for training the neural networks, a principal component analysis based algorithm that reduces the dimension of the input training data is also proposed. This approach is shown to reduce the computational time significantly. These identification techniques are validated in numerical simulations before flight testing in the Eagle and RMAX helicopter platforms. Using the successfully validated models of the RUAVs, Neural Network based Model Predictive Controller (NN-MPC) is developed taking into account the non-linearity of the RUAVs and constraints into consideration. The parameters of the MPC are chosen to satisfy the performance requirements imposed on the flight controller. The optimisation problem is solved numerically using nonlinear optimisation techniques. The performance of the controller is extensively validated using numerical simulation models before flight testing. The effects of actuator and sensor delays and noises along with the wind gusts are taken into account during these numerical simulations. In addition, the robustness of the controller is validated numerically for possible parameter variations. The numerical simulation results are compared with a base-line PID controller. Finally, the NN-MPCs are flight tested for height control and autonomous hover. For these, SISO as well as multiple SISO controllers are used. The flight tests are conducted in varying weather conditions to validate the utility of the control technique. The NN-MPC in conjunction with the proposed hybrid modelling technique is shown to handle additional disturbances successfully. Extensive flight test results provide justification for the use of the NN-MPC technique as a reliable technique for control of non-linear complex dynamic systems such as RUAVs.
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Gameiro, Gonçalo. "Design modifications of a UAV wing for optimal integration of a magnetic anomaly detection sensor." Master's thesis, Academia da Força Aérea; Instituto Superior Técnico, 2018. http://hdl.handle.net/10400.26/40254.
Full textAbstract:
Supervisors: Prof. Afzal Suleman.
Examination Committee:
Chairperson: Prof. Filipe Szolnoky Ramos Pinto Cunha;
Supervisor: Prof. Afzal Suleman;
Member of the Committee: Major Dr. Luís Filipe da Silva FélixThis work describes the conceptual design of a Unmanned Air Vehicle (UAV) wing with a Magnetic Anomaly Detection (MAD) sensor for submarine detection operations. Nowadays, underwater marine vessels are able to evade conventional detection methods such as sonar. Therefore, it is necessary to integrate MAD sensors in modern Anti-Submarine Warfare theatres. UAVs typically generate a magnetic field due to the electrical systems on board, causing interference noise on the MAD sensor data analysis and compromising its performance. To address these issues, a characterization of the aircraft’s magnetic signature was conducted, and it was found that the wing tip and a tail stinger boom are the best options to minimize the magnetic noise. A structural and aerodynamic analysis of the aircraft showed the wing tip configuration was the best option since the amount of mass required to counter the moment of a tail stinger boom would require major modifications on the UAV. Also, the aircraft magnetic signature is minimum at the wing tip, with an intensity of -2.9nT. An aerodynamic characterization of the aircraft was carried to evaluate the effect of the MAD pods on the wingtips. A parametric optimization of the wing was conducted. Given the dimensional constraints on the wing structure and a target magnetic noise of 2nT at the wing tip, the optimizer objective function was to minimize the total fuel consumption. The optimum solution allowed a decrease of 30% on the magnetic noise and a fuel consumption of 8.71 kg of fuel for an 8-hour search operation.
Este trabalho descreve o processo de projeto conceptual de uma asa de um Veículo Aéreo Não-Tripulado (VANT) com um sensor de anomalias magnéticas (AM) para ser usado em deteção de submarinos. Atualmente, estes veículos estão dotados com capacidades que diminuem as hipóteses de detecão por métodos convencionais, como o sonar. Assim, torna-se necessário integrar sensores de AM em cenários atuais de Guerra Anti-Submarina. Os sistemas aviónicos destas aeronaves geram um campo magnético que causa interferência no sensor de AM, causando ruído nos dados da análise e comprometendo a sua eficiência. Para evitar este problema, realizou-se uma caracterização da assinatura magnética da aeronave, concluindo que as pontas das asas e uma configuração de arpão na cauda seriam as melhores soluções para colocar o sensor, a fim de minimizar a interferência magnética. Estudos estruturais e aerodinâmicos revelaram que a primeira seria a melhor opção, pois a massa necessária para anular o momento gerado na segunda requeria alterações substanciais na estrutura da aeronave. A ponta da asa era também o local com menor nível de assinatura magnética. Realizou-se uma otimização paramétrica da asa da aeronave, considerando os efeitos aerodinâmicos dos invólucros do sensor. Atendendo às restrições no dimensionamento da estrutura da asa e a um valor de interferência magnética, o otimizador teria como objetivo minimizar o consumo total de combustível. A solução ótima permitiu reduzir em 30% o valor da assinatura magnética na ponta da asa e obter uma configuração que, numa missão de patrulha de 8 horas, consome 8.71 kg de combustível.
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