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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Autonomous take-off and landing for a fixed wing UAV / Décollage et atterrissage autonome pour un UAV d’aile fixe

Lugo Cárdenas, Israel 06 June 2017 (has links)
Ce travail étudie certains des problèmes les plus pertinents dans le sens de la navigation et contrôle présentés dans une classe particulière de mini-véhicules aériens. L'un des principaux objectifs c'est à réaliser un véhicule léger et facile à déployer dans un court laps de temps, un véhicule sans pilote drone capable de suivre une mission complète, du décollage aux points de cheminement suivants et de terminer la mission avec un atterrissage autonome à l'intérieur d'une zone délimitée en utilisant une interface graphique dans un ordinateur ou une tablette. La génération de trajectoire II est la partie qui dit le drone où il doit voyager et sont générés par un algorithme intégré sur le drone. Le résultat classique de Dubins est utilisé comme base pour la génération de trajectoire en 2D et nous avons étendu à la génération de trajectoire 3D. Une stratégie de suivi de trajectoire développée en utilisant l'approche de Lyapunov, est présentée pour piloter un drone à voilure fixe à travers tout le chemin désiré. Le concept clé derrière le contrôleur de suivi de trajectoire s'appuie sur la réduction de la distance entre le centre de masse de l'avion p et le point sur la trajectoire q à zéro, ainsi que l'angle entre le vecteur vitesse et la tangente à la trajectoire. Afin de tester les techniques mises au point au cours de la thèse une application C# -Net personnalisée a été développé nommé MAV3DSim (Multi-Aerial Vehicle 3D Simulator). Le MAV3DSim permet une opération de lecture/écriture de/vers le moteur de simulation à partir de laquelle nous pourrions recevoir toutes les informations de capteurs émulés et envoyés par le simulateur. Le système complet est capable d'effectuer un décollage et d'atterrissage autonome, à travers des points de suivi. Ceci est accompli en utilisant chacune des stratégies développées au cours de la thèse. Nous avons une stratégie pour le décollage et l'atterrissage, ce qui est généré par la partie de navigation qui est le générateur de trajectoire. Une fois que nous avons généré le chemin, il est utilisé par la stratégie de suivi de trajectoire et avec ce que nous avons l'atterrissage et le décollage autonome. / This work studies some of the most relevant problems in the direction of navigation and control presented in a particular class of mini‐aircraft. One of the main objectives is to build a lightweight and easy to deploy vehicle in a short period of time, an unmanned aerial vehicle capable of following a complete mission from take‐o⁄ to the following waypoints and complete the mission with an autonomous landing within a delimitated area using a graphical interface in a computer. The Trajectory Generation It is the part that tells the drone where it must travel and are generated by an algorithm built into the drone. The classic result of Dubins is used as a basis for the trajectory generation in 2D and we have extended it to the 3D trajectory generation. A path following strategy developed using the Lyapunov approach is presented to pilot a fixed wing drone across the desired path. The key concept behind the tracking controller is the reduction of the distance between the center of mass of the aircraft p and the point q on the path to zero, as well as the angle between the velocity vector and the vector tangent to the path. In order to test the techniques developed during the thesis a customized C # .Net application was developed called MAV3DSim (Multi‐Aerial Vehicle 3D Simulator). The MAV3DSim allows a read / write operation from / to the simulation engine from which we could receive all emulated sensor information and sent to the simulator. The MAV3DSim consists of three main elements, the simulation engine, the computation of the control law and the visualization interface. The simulation engine is in charge of the numeric integration of the dynamic equations of the vehicle, we can choose between a quadrotor and a xed wing drone for use in simulation. The visualization interface resembles a ground station type of application, where all variables of the vehicle s state vector can be represented on the same screen. The experimental platform functions as a test bed for the control law prototyping. The platform consists of a xed wing aircraft with a PX4 which has the autopilot function as well as a Raspberry PI mini‐computer which to the implementation of the generation and trajectory tracking. The complete system is capable of performing an autonomous take‐o⁄and landing, through waypoints. This is accomplished by using each of the strategies developed during the thesis. We have a strategy for take‐o⁄ and landing, which is generated by the navigationon part that is the trajectory generator. Once we have generated the path, it is used by the trajectory tracking strategy and withthat we have landing and take‐o⁄ autonomously.
22

Vision-Based Navigation for a Small Fixed-Wing Airplane in Urban Environment

Hwangbo, Myung 01 May 2012 (has links)
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.
23

Robust Visual-Inertial Navigation and Control of Fixed-Wing and Multirotor Aircraft

Nielsen, Jerel Bendt 01 June 2019 (has links)
With the increased performance and reduced cost of cameras, the robotics community has taken great interest in estimation and control algorithms that fuse camera data with other sensor data.In response to this interest, this dissertation investigates the algorithms needed for robust guidance, navigation, and control of fixed-wing and multirotor aircraft applied to target estimation and circumnavigation.This work begins with the development of a method to estimate target position relative to static landmarks, deriving and using a state-of-the-art EKF that estimates static landmarks in its state.Following this estimator, improvements are made to a nonlinear observer solving part of the SLAM problem.These improvements include a moving origin process to keep the coordinate origin within the camera field of view and a sliding window iteration algorithm to drastically improve convergence speed of the observer.Next, observers to directly estimate relative target position are created with a circumnavigation guidance law for a multirotor aircraft.Taking a look at fixed-wing aircraft, a state-dependent LQR controller with inputs based on vector fields is developed, in addition to an EKF derived from error state and Lie group theory to estimate aircraft state and inertial wind velocity.The robustness of this controller/estimator combination is demonstrated through Monte Carlo simulations.Next, the accuracy, robustness, and consistency of a state-of-the-art EKF are improved for multirotors by augmenting the filter with a drag coefficient, partial updates, and keyframe resets.Monte Carlo simulations demonstrate the improved accuracy and consistency of the augmented filter.Lastly, a visual-inertial EKF using image coordinates is derived, as well as an offline calibration tool to estimate the transforms needed for accurate, visual-inertial estimation algorithms.The imaged-based EKF and calibrator are also shown to be robust under various conditions through numerical simulation.
24

Small-Target Detection and Observation with Vision-Enabled Fixed-Wing Unmanned Aircraft Systems

Morgan, Hayden Matthew 27 May 2021 (has links)
This thesis focuses on vision-based detection and observation of small, slow-moving targets using a gimballed fixed-wing unmanned aircraft system (UAS). Generally, visual tracking algorithms are tuned to detect motion of relatively large objects in the scene with noticeably significant motion; therefore, applications such as high-altitude visual searches for human motion often ignore target motion as noise. Furthermore, after a target is identified, arbitrary maneuvers for transitioning to overhead orbits for better observation may result in temporary or permanent loss of target visibility. We present guidelines for tuning parameters of the Visual Multiple Target Tracking (Visual MTT) algorithm to enhance its detection capabilities for very small, slow-moving targets in high-resolution images. We show that the tuning approach is able to detect walking motion of a human described by 10-15 pixels from high altitudes. An algorithm is then presented for defining rotational bounds on the controllable degrees of freedom of an aircraft and gimballed camera system for maintaining visibility of a known ground target. Critical rotations associated with the fastest loss or acquisition of target visibility are also defined. The accuracy of these bounds are demonstrated in simulation and simple applications of the algorithm are described for UAS. We also present a path planning and control framework for defining and following both dynamically and visually feasibly transition trajectories from an arbitrary point to an orbit over a known target for further observation. We demonstrate the effectiveness of this framework in maintaining constant target visibility while transitioning to the intended orbit as well as in transitioning to a lower altitude orbit for more detailed visual analysis of the intended target.
25

Application of Randomized Algorithms in Path Planning and Control of a Micro Air Vehicle

Bera, Titas January 2015 (has links) (PDF)
This thesis focuses on the design and development of a fixed wing micro air vehicle (MAV) and on the development of randomized sampling based motion planning and control algorithms for path planning and stabilization of the MAV. In addition, the thesis also contains probabilis-tic analyses of the algorithmic properties of randomized sampling based algorithms, such as completeness and asymptotic optimality. The thesis begins with a detailed discussion on aerodynamic design, computational fluid dy-namic simulations of propeller wake, wind tunnel tests of a 150mm fixed wing micro air ve-hicle. The vehicle is designed in such a way that in spite of the various adverse effects of low Reynolds number aerodynamics and the complex propeller wake interactions with the airframe, the vehicle shows a balance of external forces and moments at most of the operating conditions. This is supported by various CFD analysis and wind tunnel tests and is shown in this thesis. The thesis also contains a reasonably accurate longitudinal and lateral dynamical model of the MAV, which are verified by numerous flight trials. However, there still exists a considerable amount of model uncertainties in the system descrip-tion of the MAV. A robust feedback stabilized close loop flight control law, is designed to attenuate the effects of modelling uncertainties, discrete vertical and head-on wind gusts, and to maintain flight stability and performance requirements at all allowable operating conditions. The controller is implemented in the MAV autopilot hardware with successful close loop flight trials. The flight controller is designed based on the probabilistic robust control approach. The approach is based on statistical average case analysis and synthesis techniques. It removes the conservatism present in the classical robust feedback design (which is based the worst case de-sign techniques) and associated sluggish system response characteristics. Instead of minimizing the effect of the worst case disturbance, a randomized techniques synthesizes a controller for which some performance index is minimized in an empirical average sense. In this thesis it is shown that the degree of conservatism in the design and the number of samples used to by the randomized sampling based techniques has a direct relationship. In particular, it is shown that, as the lower bound on the number of samples reduces, the degree of conservatism increases in the design. Classical motion planning and obstacle avoidance methodologies are computationally expen-sive with the number of degrees of freedom of the vehicle, and therefore, these methodologies are largely inapplicable for MAVs with 6 degrees of freedom. The problem of computational complexity can be avoided using randomized sampling based motion planning algorithms such as probabilistic roadmap method or PRM. However, as a pay-off these algorithms lack algorith-mic completeness properties. In this thesis, it is established that the algorithmic completeness properties are dependent on the choice of the sampling sequences. The thesis contains analy-sis of algorithmic features such as probabilistic completeness and asymptotic optimality of the PRM algorithm and its many variants, under the incremental and independent problem model framework. It is shown in this thesis that the structure of the random sample sequence affects the solution of the sampling based algorithms. The problem of capturing the connectivity of the configuration space in the presence of ob-stacles, which is a central problem in randomized motion planning, is also discussed in this thesis. In particular, the success probability of one such randomized algorithm, named Obsta-cle based Probabilistic Roadmap Method or OBPRM is estimated using geometric probability theory. A direct relationship between the weak upper bound of the success probability and the obstacle geometric features is established. The thesis also contains a new sampling based algorithm which is based on geometric random walk theory, which addresses the problem of capturing the connectivity of the configuration space. The algorithm shows better performance when compared with other similar algorithm such as the Randomized Bridge Builder method for identical benchmark problems. Numerical simulation shows that the algorithm shows en-hanced performance as the dimension of the motion planning problem increases. As one of the central objectives, the thesis proposes a pre-processing technique of the state space of the system to enhance the performance of sampling based kino-dynamic motion plan-ner such as rapidly exploring random tree or RRT. This pre-processing technique can not only be applied for the motion planning of the MAV, but can also be applied for a wide class of vehicle and complex systems with large number of degrees of freedom. The pre-processing techniques identifies the sequence of regions, to be searched for a solution, in order to do mo-tion planning and obstacle avoidance for an MAV, by an RRT planner. Numerical simulation shows significant improvement over the basic RRT planner with a small additional computa-tional overhead. The probabilistic analysis of RRT algorithm and an approximate asymptotic optimality analysis of the solution returned by the algorithm, is also presented in this thesis. In particular, it is shown that the RRT algorithm is not asymptotically optimal. An integral part of the motion planning algorithm is the capability of fast collision detection between various geometric objects. Image space based methods, which uses Graphics Pro-cessing Unit or GPU hardware, and do not use object geometry explicitly, are found to be fast and accurate for this purpose. In this thesis, a new collision detection method between two convex/non-convex objects using GPU, is provided. The performance of the algorithm, which is an extension of an existing algorithm, is verified with numerous collision detection scenarios.
26

Diagnóstico de processos erosivos em solos agrícolas mediante análise de modelos numéricos do terreno

Rosa, Joel Zubek 10 August 2018 (has links)
Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-11-26T20:27:20Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Joel Zubek.pdf: 7864320 bytes, checksum: f2e6f06e6ec1c27abd616c5e845d97f8 (MD5) / Made available in DSpace on 2018-11-26T20:27:20Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Joel Zubek.pdf: 7864320 bytes, checksum: f2e6f06e6ec1c27abd616c5e845d97f8 (MD5) Previous issue date: 2018-08-10 / Entre os principais problemas relacionados à conservação ambiental em áreas agrícolas está a degradação dos solos por meio da erosão hídrica que ocasiona a remoção das camadas mais férteis de solo e o transporte de partículas de solo para as partes mais baixas do relevo, o que contribui para o assoreamento dos recursos hídricos. Portanto, o presente estudo teve como objetivo diagnosticar processos erosivos em uma área de produção agrícola localizada na Fazenda Escola Capão da Onça – FESCON – UEPG, mediante análise de dados obtidos por Sistema de Navegação Global por Satélite (Global Navigation Satellite System - GNSS) e Aeronaves Remotamente Pilotadas (Remotely Piloted Aircraft - RPA). Para a realização do trabalho foi implantada uma grade regular com pontos de 45 x 45 metros de distância, totalizando 140 pontos em uma área de aproximadamente 26 hectares. Foram realizados georreferenciamento dos pontos da grade regular por meio de receptores de sinal GNSS Geodésico pós-processado e a coleta de atributos do solo (textura do solo). Os dados de textura do solo levantados na grade regular proporcionaram gerar modelos para o cálculo do fator de erodibilidade do solo para área de estudo. Com os valores altimétricos das coordenadas levantadas nos pontos da grade regular foi possível avaliar a precisão vertical de Modelos Numéricos do Terreno - MNT gerados por meio de dados obtidos com RPA. Foram avaliados os modelos gerados com dados obtidos por meio de equipamentos de RPA de asa fixa e multirotor com a distribuição de diferentes números de pontos de controle e sem pontos de controle. Mediante a análise estatística aplicada em relação entre a dispersão das diferenças altimétricas geradas nos MNT e os pontos da grade regular usados como referência, o MNT gerado com os dados de RPA asa fixa com pontos de controle apresentou o melhor resultado. Diante da constatação do melhor MNT foi modelado o fator topográfico para a área de estudo. A utilização de Sistema de Informação Geográfica - SIG proporcionou integrar todos os dados em um único ambiente computacional; gerar modelos por meio de interpolação; analisar a precisão dos modelos; implementar as equações para o cálculo dos fatores de erodibilidade e topográfico e também a Equação Universal de Perda de Solo Revisada (Revised Universal Soil Loss Equation – RUSLE); além das representações das informações. O resultado obtido com o modelo gerado mediante o cálculo da RUSLE apresentou a estimativa que mais de 70 % da área de estudo está com baixa suscetibilidade à erosão ou ligeira perda de solo. O restante da área de estudo apresentou perda de solos acima de 10 tonelada/ha.ano, indicando média e alta suscetibilidade à erosão. / Among the major problems related to environmental conservation in agricultural areas is soil degradation through water erosion, which causes the removal of the most fertile soil layers and the transport of soil particles to the lower parts of the relief, which contributes to the silting up of water resources. Therefore, the present study aimed to diagnose erosive processes in an area of agricultural production located at Fazenda Escola Capão da Onça - FESCON - UEPG, by analyzing data obtained by the Global Navigation Satellite System (GNSS) and Remotely Piloted Aircraft (RPA).For the accomplishment of the work a regular grid with points of 45 x 45 meters of distance was implanted, totaling 140 points in an area of approximately 26 hectares. Georeferencing of the regular grid points was carried out by means of post-processed GNSS signal receivers and the soil attributes collection (soil texture). The soil texture data collected in the regular grid provided the model for calculating the soil erodibility factor for the study area. With the altimetric values of the coordinates raised at the points of the regular grid it was possible to evaluate the vertical accuracy of Numerical Terrain Models generated through data obtained with RPA. The models generated with data obtained by means of fixed-wing and multirotor RPA equipment with the distribution of different numbers of control points and without control points were evaluated. by means of the statistical analysis applied in relation between the dispersion of the altimetric differences generated in the Numerical Terrain Model and the points of the regular grid used as reference, the Numerical Terrain Model generated with the fixed wing RPA data with control points presented the best result. In view of the finding of the best NTM, the topographic factor was modeled for the study area. The use of Geographic Information System GIS provided to integrate all the data in a unique computational environment; generate models through interpolation; analyze the accuracy of the models; implement the equations for the calculation of the erodibility and topographic factors and also the Revised Universal Soil Loss Equation (RUSLE); beyond the representations of the information. The result obtained with the model generated by RUSLE calculation showed that more than 70% of the study area is low susceptibility to erosion or slight soil loss. The rest of the study area presented soil loss above 10 ton / ha.year, indicating medium and high susceptibility to erosion.
27

Vers une stratégie unifiée pour la commande des véhicules aériens / Towards a unified approach for the control of aerial vehicles

Pucci, Daniele 11 April 2013 (has links)
Au cours du siècle dernier, la communauté scientifique a traité le contrôle des véhicules aériens principalement par l'élaboration de stratégies ad hoc, mais aucune approche unifiée n'a été développé jusqu'à présent. Cette thèse participe à l'élaboration d'une approche unifiée pour le contrôle des véhicules aériens en prenant en compte les forces aérodynamiques dans la conception de la commande. Nous supposons les effets aérodynamiques de rotation et les effets non stationnaires négligeables. Les actionneurs du véhicule sont supposés être composés d'une force de poussé fixée au corps pour le mouvement en translation, et d'un couple de contrôle pour la régulation d'attitude. Cette thèse se concentre ensuite sur la boucle de guidage, traitant du contrôle de la vitesse linéaire. L'un des principaux objectifs a été de déterminer la façon de réguler la force de poussée et l'orientation du véhicule pour compenser les forces extérieures. Tout d'abord nous abordons la modélisation, l'analyse et le contrôle de la dynamique longitudinale de l'avion. Ensuite nous étendons certaines de ces études aux mouvements tridimensionnels d'avions au corps symétrique, tels que les missiles. Un résultat original de cette thèse est de préciser les conditions sur la force aérodynamique permettant de reformuler le problème du contrôle dans celui de la commande d'un corps sphérique, pour lequel des résultats de stabilité peuvent être démontrés. Les lois de commande proposées intègrent des termes intégraux et anti-wind up sans reposer sur une politique de commutation entre plusieurs lois de commande. / Over the last century, the scientific community has dealt with the control of flying machines by mainly developing different strategies in relation to different classes of aircraft, and no unified control approach has been developed so far. The present thesis contributes towards the development of a unified control approach for aerial vehicles by maintaining aerodynamic forces in the control design. It is assumed, however, that the aerodynamic effects of rotational and unsteady motions are negligible, and that the means of actuation for an aerial vehicle consist of a body-fixed thrust force for translational motion and a control torque for attitude monitoring. This thesis then focuses on the guidance loop of the control problem. One of the main objectives has been to determine how to regulate the thrust intensity and the vehicle orientation to compensate for the orientation-dependent external forces. In particular, the modeling, analysis, and control of the longitudinal aircraft dynamics is first addressed. Then, some of these studies are extended to three-dimensional motions of symmetric aircraft, such as missile-like bodies. An original outcome of this thesis is to state conditions on the aerodynamic force that allow the control problem to be recasted into that of controlling a spherical body. In this case, strong stability results can be shown. The proposed control laws incorporate integral and anti-wind up terms and do not rely on a switching policy between several control laws.
28

Projeto e implementação de um piloto automático aplicado a aeromodelos de asa fixa e asa móvel / Design and implementation of a autopilot aplied a model airplane

Alves, Rubens Antônio 30 September 2015 (has links)
Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-03-21T18:01:54Z No. of bitstreams: 2 Dissertação - Rubens Antônio Alves - 2015.pdf: 7966348 bytes, checksum: 5a95a9ee436c444d586451331b40e5a0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-22T12:33:33Z (GMT) No. of bitstreams: 2 Dissertação - Rubens Antônio Alves - 2015.pdf: 7966348 bytes, checksum: 5a95a9ee436c444d586451331b40e5a0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-22T12:33:33Z (GMT). No. of bitstreams: 2 Dissertação - Rubens Antônio Alves - 2015.pdf: 7966348 bytes, checksum: 5a95a9ee436c444d586451331b40e5a0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-30 / Outro / This Project, in the electrical engineering area, consists in the development of a complete control system, hardware and software, for controlling model airplanes of the fixedwing and rotary-wing types, aiming the implementation of an automatic control system compatible with the necessity of autonomous and aided flights, applied to critical systems monitoring.The final system consists of a controller, or automatic pilot, with specific hardware and software, capable of controlling a model airplane using GPS coordinates, in a way that allows the airplane to go through a planned route and go back to the starting point in an autonomous way. The controller should receive, in ground, the programmed route; the model should answer to the pilot commands, within a visual range when operating in the aided mode, and should go through the programmed route in the autonomous mode, after confirmation of the pilot. After reaching the end of the programmed route, the model airplane should return to the starting point, keeping the maximum flight level of the route as the reference height. The model airplane will carry in a communication system to allow the monitoring process from a ground station, able to keep updated the airworthy conditions, as well as the level of accuracy between the actual and the planned route. The communication may be carried out directly using a radio link, with the receiver allocated in a mobile ground station, monitored by a pilot, to make higher the security level. However, the model airplane may transfer the data through a GPRS link, connected to the web system, which transfers the data to the ground station. In this case, the ground station must be connected to the web.The route saved in the model control system is built based on online maps directly linked by the software for the mission programming and monitoring, which can carry out the treatment and storage of the model data and parameters. The programming of the stability control and route, with primary data of latitude, longitude and height allows the real time monitoring of the model, related to the planned route and throught images captured by embedded video cameras. All data are storage following a timeline process, such that they can be recovered for futher analysis. / Esta disertação da área de engenharia elétrica consiste na construção de um sistema de controle completo de hardware e software para controle de um aeromodelo de asa fixa e/ou asa móvel, de maneira a implementar um piloto automático compatível com as necessidades de voo autônomo ou assistido, sendo que tal sistema deverá ser compatível com a precisão de voo aplicada a monitoramento de sistemas críticos.O sistema é constituído por uma placa controladora composta por hardware e firmware específicos, capaz de controlar um modelo orientado por coordenadas GPS, para que o mesmo percorra uma rota predeterminada e retorne ao ponto de partida de forma autônoma. A placa recebe, ainda em solo, a programação da rota a ser percorrida; o aeromodelo deve responder normalmente aos comandos do controle remoto do piloto em solo, respeitando o raio de alcance visual do piloto no modo assistido e segue a rota programada no modo autônomo após confirmação de comando do piloto. No final do percurso o aermodelo volta em trajetória reta para o ponto de partida, respeitando a maior altura do trajeto. O aeromodelo deve ser munido de sistema de comunicação para o devido acompanhamento em solo das condições de aeronavegabilidade do aeromodelo em voo, bem como a verificação dos níveis de precisão em relação à rota programada. A comunicação pode ser feita diretamente por sistema de link de rádio, direcionada a um terminal móvel em solo, que é acompanhado pelo piloto, para aumentar o nível de segurança, mas o aeromodelo também pode comunicar por rede de celular GPRS, conectado à internet, que direciona os dados ao terminal em solo. Nesse caso, o terminal, também deverá estar conectado à internet. A rota programada no aeromodelo é construída com base em mapas online conectados diretamente ao software de programação e acompanhamento de missão, que faz o tratamento e armazenamento dos dados e parâmetros do aermodelo. Tanto a programação de controle de estabilidade, quanto de rota, com dados primários relativos a latitude, longitude e altura, permitem o acompanhamento em tempo real do aeromodelo junto à rota programada e também através da imagem da câmera de gravação embarcada no aeromodelo. Todos os dados são gravados com base em processo de linha do tempo, que podem ser recuperados em conjunto para análise posterior.
29

Navigation d'un avion miniature de surveillance aérienne en présence de vent / Small lightweight aircraft navigation in the presence of wind

Brezoescu, Cornel-Alexandru 28 October 2013 (has links)
Ce travail de thèse porte sur le comportement en vol de drones légers à voilure fixe en présence de vent. Ces dispositifs aériens offrent une transition en douceur de la théorie à la pratique dans le domaine de la commande autonome. En outre, ils fournissent une solution appropriée dans des environnements inaccessibles ou dangereux pour les êtres humains. Cependant, ne pas avoir un pilote humain à bord implique que les UAV reposent sur l'automatisation pour naviguer ou pour éviter les obstacles. De plus, leur vitesse de fonctionnement relativement faible les rend particulièrement affectés par le vent. Motivé par ces considérations, les objectifs de ce travail de recherche visent des résultats théoriques et expérimentaux dans le domaine de la conception de contrôleurs de vol pour les petits drones à voilure fixe de configuration classique permettant le vol stable dans les conditions de vent. Pour atteindre ces objectifs, plusieurs domaines de recherche sont abordés dans cette thèse comme il suit.Tout d'abord, une étude approfondie sur l'aspect aérodynamique de l'avion est menée afin d'obtenir le modèle mathématique du véhicule en présence de vent. En outre, des modèles qui reproduisent le comportement essentiel du système dans un contexte simplifié sont analysés. Par conséquent, des modèles non linéaires de complexité réduite, qui sont plus simples à analyser et simuler et plus adaptés à la conception de stratégies de contrôle, sont présentés. Deuxièmement, le problème à résoudre est formulé comme un problème de suivi de trajectoire dans lequel le dispositif de commande de vol doit être en mesure de diriger le véhicule le long d'un chemin. Des stratégies de navigation sont élaborées dans le but d'éliminer la déviation de l'avion par rapport à la trajectoire de référence. Le vent est considéré d'abord mesurable par une station au sol et, ensuite, estimé en utilisant une navigation adaptative basée sur la théorie de Lyapunov. La performance de l'algorithme d'estimation est améliorée en utilisant la stratégie de commande basée sur la méthode des fonctions de réglage. Le troisième axe de recherche est la conception et la mise en œuvre d'un dispositif expérimental qui se compose d'une station au sol utilisée pour la visualisation et la commande à distance du drone et d'un pilote automatique embarqué contenant la plate-forme de vol munie d'avionique appropriée. / This research work addresses the flight behavior of lightweight fixed-wing UAVs in windy conditions. Such aerial devices offer a smooth transition of autonomous flight control design from theory to practice in addition to providing a proper solution in environments inaccessible or dangerous to human beings. However, not having a human pilot onboard implies that UAVs rely on automation to navigate or to avoidobstacles. In addition, their relatively low operating speed makes them particularly affected by the wind field.Motivated by theses considerations, the objectives of the current research aim theoretical and experimental results in designing flight controllers for small fixed-wing UAVs of conventional configuration allowing for stable flight in windy conditions. In order to achieve these objectives, several research areas are being addresses in this thesis as it follows. First, a comprehensive study on the aerodynamic aspect of the aiplane in conducted in order to obtain the mathematical model of the aircraft in presence of wind. Further, models thet reproduce the essential behavior of the system in a simplified context are analyzed. consequently, nonlinear models of reduced complexity, that are easier to analyze and simulate and more adapted to the design of control strategies, are presented. Secondly, the problem to be solved is formulated as a trajectory following problem in which the flight controller must be able to steer the vehicle along a path. Navigation strategies are developed in order to minimize the airplane deviation relative to the reference trajectory. the wind is considered initially measurable by a ground station and, then, estimated using adaptative navigation based on the theory of Lyapunov. The performance of the estimation algorithm is improved using control design based on thr tuning functions method. The third axis of research is the design and the implementation of an experimental setup which consists of a ground station used for visualization and control purposes and an embedded autopilot architecture containing the airframe platform equipped with appropriate avionics.
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Design, modeling and control of a convertible mini airplane having four tiliting rotors / Conception, modélisation et commande d'un drone convertible à quatre hélices pivotantes

Flores Colunga, Gerardo Ramón 31 October 2014 (has links)
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.

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