[pt] O medo de voar é um problema real que afeta entre 10 porcento e 25 porcento da população mundial. Aproximadamente 25 porcento da população adulta experimenta um aumento significativo nos níveis de ansiedade ao serem solicitados a usar algum meio de transporte aéreo, e destes, 10 porcento evitam a situação. O tratamento que se mostrou mais efetivo no tratamento de fobias é a exposição in vivo. Porém, a dificuldade e o custo, e muitas vezes até o perigo, de usar aviões e voos reais para expor pessoas com medo de voar a esses estímulos assustam muitos pesquisadores, terapeutas e pacientes apesar da prevalência e do impacto do medo de voar. Neste trabalho é apresentada uma aplicação de realidade virtual que visa prover uma exposição sistemática a estímulos causadores de ansiedade relacionados ao medo de voar através de ambientes gerados por computador. Esta aplicação utiliza o conceito de imersão através do Oculus Rift, para prover uma experiência praticamente real aos pacientes. Para avaliar a aplicação proposta, em especial o sentimento de presença causado por ela, foram obtidos dados qualitativos a partir de entrevistas e questionários com seus meta-usuários, i.e., os psiquiatras que aplicarão o tratamento nos pacientes. / [en] Fear of flying is a real problem that affects 10 percent to 25 percent of the world s population. Approximately 25 percent of adults experience a significant increase in their anxiety levels when required to take any type of air transport and 10 percent of them avoid the situation. The approach that has proven to be the most effective in the treatment of phobias is in vivo exposure. However, the difficulty and the cost, and sometimes even the danger, of using real airplanes and real flights to expose people with fear of flying to these stimuli have daunted many researchers, therapists, and patients despite the prevalence and the impact of the fear of flying. We present in this study a virtual reality application that promotes a systematic exposure to the stimuli that causes significant increase in anxiety levels related to fear of flying through computer generated environments. This application uses the concept of immersion through the Oculus Rift to promote an almost real experience to the patients. To evaluate the proposed application, in special the sense of presence caused by it, we obtained qualitative data from interviews and questionnaires with its meta-users, i.e., the psychiatrists that will apply the treatment to their patients.

Power-poles are one of the common massive conducting structures in cities and countryside. To fulfill the remarkable increased electric power demand nowadays, the number and the size of power-poles are also growing over the past few decades.  The influence of power-pole on electromagnetic  wave  propagation  is  a  potential  noise  source  for  nearby  radio  devices  like radars.   This master thesis project is aiming to analysis the interference of a case where an Amplitude Modulated (AM) signal emitted. We consider here the Stockholm Arlanda Airport’s Very High Frequency (VHF) Omnidirectional Range (VOR) radar scattering by a power-pole 2.6km away.A Method of Moment technique is used to solve the scattering problem.  We modeled the power-pole on a blueprint from Svenska Kraftnät. It is meshed in small triangles by AutoCAD and  GMSH  software,  and  on  that  mesh  the  Rao-Wilton-Glisson  (RWG)  basis  function  are formed.  A MoM code developed by Makarov determines the bi-static scattering pattern of the power-pole.  Four main models have been considered, a one-side power-pole model and the same model with the ground plane, as well as two sides power-pole model and the model with the ground plane.  We have assumed that the incident field on the power-pole is a plane wave and that the ground is an infinite PEC surface.  The result is presented by the Interference to Signal ratio (ISR) of an airplane receiver when it is flying toward the airport for landing.By the end of the project, we have shown for the considered model that a    50    15dB level of interference is estimated for the interference to signal ratio.  This result then suggests that a power-pole may have a little signal interference towards the VOR system radar wave emit awayfrom 2.6km. / Kraftstolpar är vanligt förekommande stora ledande strukturerna i stadsnära regioner.  Städer och regioner uppvisar idag en kraftigt ökad efterfrågan på elektricitet, vilket ställer krav på ett kraftnät som klarar av större effekt. Ett sätt att öka effekten är att introducera fler kraftledningar, och där med också öka antalet kraftledningsstolpar.  Kraftledningsstolparna kan påverka den elektromagnetiska vågutbredning och är en potentiell bruskälla för närliggande radioenheter som t.ex.  radar/signal-anläggningar.  Detta examensarbete syftar till att analysera eventuella störningar vid användandet av en amplitudmodulerad (AM) signal. Vi betraktar här Stockholm Arlanda Airport’s Very High Frequency (VHF) Omnidirectional Range (VOR) radarspridning med en kraftstolpe 2,6 km bort.I detta fall används Method of Moment (MoM)-tekniken för att lösa spridningsproblemet. Vi modellerade kraftstolpen baserad på data från Svenska Kraftnät.  Stolpen modelleras med små  sammankopplade  trianglar  med  hjälp  av  programvaran  AutoCAD  och  GMSH,  och  på det nätverket bildas Rao-Wilton-Glisson (RWG) -basisfunktionen.  En MoM-kod utvecklad av Makarov bestämmer det bi-statiska spridningsmönstret för kraftstolpen.  Fyra huvudmodeller har beaktats, en en-sidig modell av en kraftstolpe med och utan jordplan, liksom en två-sidig modell med och utan jordplan. Vi har antagit att det mot kraftstoplen infallande fältet är en plan våg och att marken är en oändlig prefekt ledande-yta. Resultatet presenteras som en kvot mellan störning i förhållande till signalen (ISR) hos en flygmottagare när den flyger mot flygplatsen för landning.Beräkningarna i projektet visar att för de betraktade modellerna har vi en ISR på -50±15dB. Detta resultat antyder att en kraftstolpe på ett avstånd 2,6 km från VOR-systemet har en lågstörning på VOR-systemets amplitudmodulerade signal.

Detta arbete har med hjälp av en antagen förbrukningsprofil för effekt samt energibehov för laddning av elflyg beräknat om det nuvarande elnätet på mellanspänningsnivå kommer att klara av en framtid där elflyg kommer att användas för kortare resor eller om det kommer behöva avhjälpas med ett batterilagringssystem. Arbetet kom fram till att oavsett räknad förbrukning kommer dagens elnät klara av detta vid normaldrift men inte vid reservdrift för de två fall med högre räknad förbrukning. Vidare kom arbetet fram till att vid användning av nuvarande nätstation kommer ett batterilagringssystem alltid att behövas både vid normaldrift och reservdrift. Arbetet kom även fram till att effekten som elflyg kommer att kräva för att ladda dessa är den begränsande faktorn för elnätet medan energin som dessa kräver för laddning under en hel dag inte är en begränsande faktor. / This work has, with the help of an assumed consumption profile for power and energy requirements for charging electric aircraft, calculated whether the current medium voltage power grid will be able to handle a future where electric aircraft will be used for shorter trips, or if it will need to be supplemented with a battery energy storage system. The work concluded that regardless of the calculated consumption, the current power grid will be able to handle this under normal operation but not under reserve operation for the two cases with higher calculated consumption. Furthermore, the work concluded that when using the current substation, a battery energy storage system will always be needed both under normal operation and reserve operation. The work also found that the power required to charge electric aircraft is the limiting factor for the power grid, while the energy they require for charging over a full day is not a limiting factor.

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In this thesis the problem of autonomous landing of an unmanned aerial vehicle named AE-2 is addressed. The guidance and control technique is developed and demonstrated through numerical simulation results. The complete work includes Mathematical modeling, Control design, Guidance and State estimation for AE-2, which is a fixed wing vehicle with 2m wing span and 6kg weight. The aerodynamic data for AE-2 is available from static wind tunnel tests. Functional fit is done on the wind tunnel data with least squares method to find static aerodynamic coefficients. The aerodynamic forces and moment coefficients are highly nonlinear some of them are partitioned in two zones based on the angle of attack. The dynamic derivatives are found with Athena Vortex Lattice software. For the validation of vortex lattice method the static derivatives obtained by the wind tunnel tests and vortex lattice method, are compared before finding dynamic derivatives. The dynamics of the servo actuators for the aerodynamic control surfaces is incorporated in the simulation. The nonlinear dynamic inversion technique has been used for the guidance and control design. The control is structured in two loops, outer and inner loop. The goal of outer loop is to track the guidance commands of altitude, roll angle and yaw angle by converting them into body rate commands through dynamic inversion. The inner loop than tracks these commanded roll rate, pitch rate and yaw rate by finding the required deflection of control surfaces. The forward velocity of the vehicle is controlled by varying the throttle. A controller for actuator is also designed to reduce the lag. The guidance for landing consists of three phases approach, glideslope and flare. During approach the vehicle is aligned with the runway and guided to a specified height from where the glideslope can begin. The glideslope is straight line path specified by a flight path angle which is restricted between 3 to 4 degree. At the end of glideslope which is marked by flare altitude the flare maneuver begins which is an exponential curve. The problem of transition between the glideslope and flare has addressed by ensuring continuity and smoothness at transition. The exponential curve of flare is designed to end below the ground so that it intersects the ground at a prespecified point. The sink rate at touchdown is also controlled along with the location of touchdown point. The state estimation has been done with Extended Kalman Filter in continuous discrete formulation. The external disturbances like wind shear and wind gust are accounted by appending them in state variables. Further the control design with guidance is tested from various initial conditions, in presence of wind disturbances. The designed filter has also been tested for parameter uncertainty.

Thesis (Ph. D.)--Miami University, Dept. of Political Science, 2008. / Title from first page of PDF document. Includes bibliographical references (p.112-118).

Cette thèse étudie certains problèmes plus importants dans le sens de guidage, navigation et contrôle présentés dans une catégorie particulière de mini véhicules aériens (MVA) : le MVA convertible avec des ailes fixes et disques pendulaires. Cet aéronef est capable de changer sa configuration de vol, du vol stationnaire au vol palier et vice versa, au moyen d’une manœuvre de transition. Motivé par des applications civiles, on étudie théoriquement et expérimentalement les principes de contrôle en fonction de Lyapunov pour les dynamiques présentées dans le MVA convertible. Des résultats de convergence asymptotique sont obtenus sur l’enveloppe de vol complet du véhicule : d’un vol vertical à basse vitesse à un vol vers l’avant à grande vitesse. Cette thèse est divisée en quatre parties principales : l’étude de 1) les aéronefs à voilure fixe ; 2) le quadrirotor (avion équipe de quatre moteurs) ; 3) l’aéronef convertible ; 4) les applications de vision en utilisant l’aéronef convertible. Dans la première partie, un principe de contrôle en fonction de Lyapunov est développé pour diriger un mini véhicule aérien à voilure fixe tout au long d’un chemin d’accès souhaité. En outre, un générateur de chemin d’accès est proposé. Le résultant de la stratégie du contrôle donne une convergence globale du chemin actuel du MVA au chemin d’accès souhaité. Dans la deuxième partie, un contrôle en fonction de Lyapunov à l’aide de la théorie de la perturbation du singulier est proposé et appliqué sur la dynamique du MVA. En effet, dans cette partie on a abordé le problème diagnostic et la détection de pannes fault detection and diagnosis (FDD) pour un quadrirotor. Dans la troisième partie une nouvelle stratégie de contrôle pour effectuer la transition d’un avion convertible entre le mode avion et le mode hélicoptère, et vice versa, est présenté. L’analyse est effectuée pour le modèle longitudinal du PVHAT (Planar Vertical Helicopter-Airplane Transition) aéronef, lequel est un avion ayant disques pendulaires afin de réaliser la manœuvre de transition. L’algorithme de contrôle de boucle fermée qui en résulte, est prouvé être globalement asymptotiquement stable. Finalement, dans la quatrième partie de cette thèse, le problème de l’estimation et suivi d’un chemin à l’aide de vision système embarqué dans l’avion PVHAT est résolu. La stabilité globale exponentielle de la position sous-système ainsi que le contrôleur de commutation est démontrée. Des simulations illustratives et résultats expérimentaux sont obtenus sur plusieurs plateformes expérimentales développées dans cette thèse, pour évaluer l’applicabilité des principes contrôle proposés et mettre en valeur les mérites de l’approche. / This thesis studies some of the most relevant problems in the sense of guidance,navigation and control presented in a particular class of mini aerial vehicles (MAV) : the convertible MAV with fixed wings and tilting rotors. This aircraft is able to change its flight configuration from hover to level flight and vice-versaby means of a transition maneuver. Motivated by civilian applications, we theoretically and experimentally study Lyapunov-based control laws for dynamics presented in the convertible MAV. Results of asymptotic convergence are obtained over the complete flight envelope of the vehicle : from low-speed vertical flight through high-speed forward flight. We have divided this thesis in four main parts : the study of 1) the fixed-wingaircraft; 2) the quadrotor; 3) the convertible aircraft and 4) vision applications by using the convertible aircraft. In a first part, a Lyapunov-based controllaw is developed to steer a fixed wing mini aerial vehicle along a desired path. Furthermore a path generator is proposed. The resulting control strategy yields global convergence of the current path of the MAV to the desired path. In a second part, a Lyapunov-based control using singular perturbation theory is proposed and applied on dynamics of the MAV. Furthermore, in this part we address the problem of fault detection and diagnosis (FDD) for a quad-rotor. In the third part a new control strategy for the transition between airplane and helicopter mode, and vice versa, in convertible planes is presented. The analysis is carried out for the longitudinal model of the PVHAT (Planar VerticalHelicopter-Airplane Transition) aircraft, which is an airplane having tilting rotors in order to achieve the transition maneuver. The resulting closed loop control algorithm is proved to be globally asymptotically stable. Finally in thefourth part of this thesis the problem of estimation and tracking of a road using avision embedded system in the PVHAT aircraft is solved. The global exponential stability of the position subsystem together with the switching controller is demonstrated. Illustrative simulations and experimental results obtained on several experimental platforms developed in this thesis, assess the implementability of the proposed control laws and highlight the merits of the approach.

This thesis addresses the problems of collision avoidance and coalition formation of multiple UAVs in high density traffic environments, proposes simple and efficient algorithms as solutions, and discusses their applications in multiple UAV missions. First, the problem of collision avoidance among UAVs is considered and deconfliction algorithms are proposed. The efficacy of the proposed algorithms is tested using simulations involving random flights in high density traffic. Further, the proposed collision avoidance algorithms are implemented using realistic six degree of freedom UAV models. The studies in this thesis show that implementation of the proposed collision avoidance algorithms leads to a safer and efficient operational airspace occupied by multiple UAVs. Next, coalition formation in a search and prosecute mission involving a large number of UAVs and targets is considered. This problem is shown to be NP-hard and a sub-optimal but polynomial time coalition formation strategy is proposed. Simulations are carried out to show that this coalition formation algorithm works well. The coalition formation algorithm is then extended to handle situations where the UAVs have limited communication ranges. Finally, this thesis considers some multiple UAV missions that require the application of collision avoidance and coalition formation techniques. The problem of multiple UAV rendezvous is tackled by using (i) a consensus among the UAVs to attain rendezvous and (ii) the collision avoidance algorithm previously developed for safety. The thesis also considers a search and prosecute mission where the UAVs also have to avoid collisions among one another. In summary, the main contributions of this thesis include (a) novel collision avoidance algorithms, which are conceptually simple and easy to implement, for resolving path conflicts – both planar and three dimensional – in a high density traffic airspace with UAVs in free flight and (b) efficient coalition formation algorithms for search and prosecute task with large number of UAVs and targets where UAVs have limited communication ranges and targets are maneuvering. Simulations to evaluate the performance of algorithms based on these concepts to carry out realistic tasks by UAV swarms are also given.

This master thesis deals with computational stress-strain analysis of the tailskid of airplane L410 NG with main focus firstly the check current design of the tailskid and then the design another design solution with the able to absorb as much as possible the deformation energy. Solution of this problem is performed using computational modeling utilizing numerical simulation of quasi-static and crash deformation load of the tailskid with using explicit Finite Element Method (FEM) in program ABAQUS v6.14. After the introduction with problem situation and tailskid assembly introductory part is devoted to the research study of various designs of the tailskid for different types of airplanes. There follows these theoretical general principles of thin-walled structures and buckling of them. Before the creating of the computational model itself, the explicit form of the Finite Element Method is better described. The conclusion of this thesis deals with the mutual comparison of the most advantageous design variants of the tailskid and the selection of the most suitable one of them for the airplane L410 NG.

This diploma thesis deals with navigation on airport surface. In thesis there are described main surveillance systems, which are used for navigation on airport surface and systems for prediction and avoiding collisions. For all systems is listed principle of action, their usage, advantages and disadvantages and informations, which are provided by these systems. In last chapter there are compared properties of main surveillance systems.