• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 4
  • 4
  • 1
  • Tagged with
  • 15
  • 9
  • 9
  • 6
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 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.
1

Commande événementielle : applications aux systèmes robotiques / Event-based control dedicated to robotic systems

Boisseau, Bruno 30 June 2017 (has links)
La théorie du contrôle a d'abord été conçue pour des contrôleurs analogiques. Il était alors pertinent de synthétiser un contrôleur dans une représentation continue. De nos jours, les systèmes numériques ont majoritairement remplacés les systèmes analogiques pour différentes raisons (coût, résistance au bruit, intégration,...). Les signaux sont alors maintenus constants entre le cadencement périodique fixé par une horloge numérique.La commande événementielle vise à améliorer l’échantillonnage périodique en proposant une méthode dans laquelle les mises à jour sont déclenchées par une fonction événement.Dans cette thèse, de nouvelles méthodes de synthèse de contrôleurs evenementiels sont présentés et testés sur des systèmes temps-réels.La contribution la plus originale étant l'utilisation d'une commande événementielle appliquée à un problème d'anticollision entre une quadrirotor et un environnement supposé connu. / Control system theory has first been built for analog controllers. In this context, it was relevant to use a continuous framework to design a control feedback function. Nowadays, digital technologies are supplanting analog solutions due to several advantages (cost, noise, resistance, integration...). Signal is held constant between periodic triggers given by a digital clock.Event-based (or event-triggered) control aims to improve the periodic sampling scheme by proposing a method in which updates are triggered by an event function.In this thesis new event-based designs are detailled and tested on real-time systems.The most original contribution of this thesis is the use of an event-triggered design for a problem of collision avoidance between a quadrotor and a known environment.
2

Projeto e controle de um UAV quadrirotor. / Project and control of a quadrotor UAV.

Pfeifer, Erick 07 June 2013 (has links)
Este trabalho dedica-se ao projeto e desenvolvimento de um veículo aéreo não tripulado. Tais veículos podem ser utilizados em diversas aplicações como monitoramento, vigilância, transporte, resgate, entre outros. Dentre os diversos tipos de veículos aéreos, este trabalho irá focar no modelo do quadrirotor, composto por quatro hélices contra-rotoras que estabilizam e movimentam o veículo. Para alcançar o objetivo de controlar este tipo de veículo, várias propostas e metodologias podem ser aplicadas, todas buscando contemplar o controle de todas ou parte das variáveis de estado presentes nesta planta. Neste texto serão descritas: as equações cinemáticas e dinâmicas que regem este sistema; o projeto e composição mecânica da aeronave; definição de sensores e atuadores juntamente com seus métodos de utilização; implementação de controlador linear por alocação direta de polos e Regulador Linear Quadrático juntamente com observador de estados de ordem plena e filtro de Kalman, para recuperação de estados não mensurados e filtragem de ruídos. Serão apresentados resultados em simulações para cada método de controle selecionado visando optar pelo melhor controlador para a aplicação da aeronave. O método selecionado será implementado para controlar a aeronave com os sensores e atuadores selecionados. Esta implementação será realizada a partir da técnica HIL Hardware in The Loop juntamente com o software MATLAB/Simulink visando validar o controlador em conjunto com a planta real, bem como o modelo dinâmico construído. / This work is dedicated to the project and development of an unmanned aerial vehicle. Such vehicles can be employed in various applications such as monitoring, surveillance, transportation, rescue and others. Among the types of aerial vehicles, this work is focused on the quadrotor, composed by four counter-rotating propellers which stabilize and displace the vehicle. In order to fulfill the objective of controlling this vehicle, many methodologies and propositions can be applied, seeking the control of all or a snippet of the state variables present in the system. There will be described in this work: the cinematic and dynamic equations that govern this system; the mechanical project and construction of the aircraft; sensors and actuators definition, along with its usage methods; linear control implementation of the pole placement and Linear Quadratic Regulator techniques along full order state observer and Kalman filtering in order to recover and filter non-measured states. Performance results in simulations will be presented on each control implementation to validate the best controller for the application and this implementation will be applied on the projected aircraft using the sensors and actuators selected. This implementation will be given through the HIL - Hardware in the Loop method using MATLAB/Simulink software to validate the control technique applied and the constructed dynamic model.
3

Projeto e controle de um UAV quadrirotor. / Project and control of a quadrotor UAV.

Erick Pfeifer 07 June 2013 (has links)
Este trabalho dedica-se ao projeto e desenvolvimento de um veículo aéreo não tripulado. Tais veículos podem ser utilizados em diversas aplicações como monitoramento, vigilância, transporte, resgate, entre outros. Dentre os diversos tipos de veículos aéreos, este trabalho irá focar no modelo do quadrirotor, composto por quatro hélices contra-rotoras que estabilizam e movimentam o veículo. Para alcançar o objetivo de controlar este tipo de veículo, várias propostas e metodologias podem ser aplicadas, todas buscando contemplar o controle de todas ou parte das variáveis de estado presentes nesta planta. Neste texto serão descritas: as equações cinemáticas e dinâmicas que regem este sistema; o projeto e composição mecânica da aeronave; definição de sensores e atuadores juntamente com seus métodos de utilização; implementação de controlador linear por alocação direta de polos e Regulador Linear Quadrático juntamente com observador de estados de ordem plena e filtro de Kalman, para recuperação de estados não mensurados e filtragem de ruídos. Serão apresentados resultados em simulações para cada método de controle selecionado visando optar pelo melhor controlador para a aplicação da aeronave. O método selecionado será implementado para controlar a aeronave com os sensores e atuadores selecionados. Esta implementação será realizada a partir da técnica HIL Hardware in The Loop juntamente com o software MATLAB/Simulink visando validar o controlador em conjunto com a planta real, bem como o modelo dinâmico construído. / This work is dedicated to the project and development of an unmanned aerial vehicle. Such vehicles can be employed in various applications such as monitoring, surveillance, transportation, rescue and others. Among the types of aerial vehicles, this work is focused on the quadrotor, composed by four counter-rotating propellers which stabilize and displace the vehicle. In order to fulfill the objective of controlling this vehicle, many methodologies and propositions can be applied, seeking the control of all or a snippet of the state variables present in the system. There will be described in this work: the cinematic and dynamic equations that govern this system; the mechanical project and construction of the aircraft; sensors and actuators definition, along with its usage methods; linear control implementation of the pole placement and Linear Quadratic Regulator techniques along full order state observer and Kalman filtering in order to recover and filter non-measured states. Performance results in simulations will be presented on each control implementation to validate the best controller for the application and this implementation will be applied on the projected aircraft using the sensors and actuators selected. This implementation will be given through the HIL - Hardware in the Loop method using MATLAB/Simulink software to validate the control technique applied and the constructed dynamic model.
4

Kinodynamic motion planning for quadrotor-like aerial robots / Planification kinodynamique de mouvements pour des systèmes aériens de type quadrirotor

Boeuf, Alexandre 05 July 2017 (has links)
La planification de mouvement est le domaine de l’informatique qui a trait au développement de techniques algorithmiques permettant la génération automatique de trajectoires pour un système mécanique. La nature d’un tel système varie selon les champs d’application. En animation par ordinateur il peut s’agir d’un avatar humanoïde. En biologie moléculaire cela peut être une protéine. Le domaine d’application de ces travaux étant la robotique aérienne, le système est ici un UAV (Unmanned Aerial Vehicle: véhicule aérien sans pilote) à quatre hélices appelé quadrirotor. Le problème de planification de mouvements consiste à calculer une série de mouvements qui amène le système d’une configuration initiale donnée à une configuration finale souhaitée sans générer de collisions avec son environnement, la plupart du temps connu à l’avance. Les méthodes habituelles explorent l’espace des configurations du système sans tenir compte de sa dynamique. Cependant, la force de poussée qui permet à un quadrirotor de voler est par construction parallèle aux axes de rotation des hélices, ce qui implique que certains mouvements ne peuvent pas être effectués. De plus, l’intensité de cette force de poussée, et donc l’accélération linéaire du centre de masse, sont limitées par les capacités physiques du robot. Pour toutes ces raisons, non seulement la position et l’orientation doivent être planifiées, mais les dérivées plus élevées doivent l’être également si l’on veut que le système physique soit en mesure de réellement exécuter le mouvement. Lorsque c’est le cas, on parle de planification kinodynamique de mouvements. Une distinction est faite entre le planificateur local et le planificateur global. Le premier est chargé de produire une trajectoire valide entre deux états du système sans nécessairement tenir compte des collisions. Le second est l’algorithme principal qui est chargé de résoudre le problème de planification de mouvement en explorant l’espace d’état du système. Il fait appel au planificateur local. Nous présentons un planificateur local qui interpole deux états comprenant un nombre arbitraire de degrés de liberté ainsi que leurs dérivées premières et secondes. Compte tenu d’un ensemble de limites sur les dérivées des degrés de liberté jusqu’au quatrième ordre (snap), il produit rapidement une trajectoire en temps minimal quasi optimale qui respecte ces limites. Dans la plupart des algorithmes modernes de planification de mouvements, l’exploration est guidée par une fonction de distance (ou métrique). Le meilleur choix pour celle-ci est le cost-to-go, c.a.d. le coût associé à la méthode locale. Dans le contexte de la planification kinodynamique de mouvements, il correspond à la durée de la trajectoire en temps minimal. Le problème dans ce cas est que calculer le cost-to-go est aussi difficile (et donc aussi coûteux) que de calculer la trajectoire optimale elle-même. Nous présentons une métrique qui est une bonne approximation du cost-to-go, mais dont le calcul est beaucoup moins coûteux. Le paradigme dominant en planification de mouvements aujourd’hui est l’échantillonnage aléatoire. Cette classe d’algorithmes repose sur un échantillonnage aléatoire de l’espace d’état afin de l’explorer rapidement. Une stratégie commune est l’échantillonnage uniforme. Il semble toutefois que, dans notre contexte, ce soit un choix assez médiocre. En effet, une grande majorité des états uniformément échantillonnés ne peuvent pas être interpolés. Nous présentons une stratégie d’échantillonnage incrémentale qui diminue considérablement la probabilité que cela ne se produise. / Motion planning is the field of computer science that aims at developing algorithmic techniques allowing the automatic computation of trajecto- ries for a mechanical system. The nature of such a system vary according to the fields of application. In computer animation it could be a humanoid avatar. In molecular biology it could be a protein. The field of application of this work being aerial robotics, the system is here a four-rotor UAV (Unmanned Aerial Vehicle) called quadrotor. The motion planning problem consists in computing a series of motions that brings the system from a given initial configuration to a desired final configuration without generating collisions with its environment, most of the time known in advance. Usual methods explore the system’s configuration space regardless of its dynamics. By construction the thrust force that allows a quadrotor to fly is tangential to its attitude which implies that not every motion can be performed. Furthermore, the magnitude of this thrust force and hence the linear acceleration of the center of mass are limited by the physical capabilities of the robot. For all these reasons, not only position and orientation must be planned, higher derivatives must be planned also if the motion is to be executed. When this is the case we talk of kinodynamic motion planning. A distinction is made between the local planner and the global planner. The former is in charge of producing a valid trajectory between two states of the system without necessarily taking collisions into account. The later is the overall algorithmic process that is in charge of solving the motion planning problem by exploring the state space of the system. It relies on multiple calls to the local planner. We present a local planner that interpolates two states consisting of an arbitrary number of degrees of freedom (dof) and their first and second derivatives. Given a set of bounds on the dof derivatives up to the fourth order (snap), it quickly produces a near-optimal minimum time trajectory that respects those bounds. In most of modern global motion planning algorithms, the exploration is guided by a distance function (or metric). The best choice is the cost-to-go, i.e. the cost associated to the local method. In the context of kinodynamic motion planning, it is the duration of the minimal-time trajectory. The problem in this case is that computing the cost-to-go is as hard (and thus as costly) as computing the optimal trajectory itself. We present a metric that is a good approximation of the cost-to-go but which computation is far less time consuming. The dominant paradigm nowadays is sampling-based motion planning. This class of algorithms relies on random sampling of the state space in order to quickly explore it. A common strategy is uniform sampling. It however appears that, in our context, it is a rather poor choice. Indeed, a great majority of uniformly sampled states cannot be interpolated. We present an incremental sampling strategy that significantly decreases the probability of this happening.
5

Vers un robot aérien autonome bio-inspiré à morphologie variable / Towards a new bio-inspired autonomous platform with morphing capabilities

Rivière, Valentin 31 January 2019 (has links)
Ce manuscrit traite de la conception d’un robot quadrirotor bio-inspiré. Ce robot, nommé QuadMorphing, s’inspire de l’oiseau et possède la capacité de se replier en vol afin de diminuer son envergure. Cette particularité est intéressante pour des problématiques d’évitement d’obstacles dans des milieux encombrés.Le travail présenté ici contient une présentation du robot où la plateforme mécatronique y est décrite en détails. Puis, des résultats expérimentaux sont présentés et commentés afin de quantifier les performances du prototype QuadMorphing durant des scénarios de franchissement d’obstacles.La deuxième partie de cette thèse traite de l’estimation de la taille d’obstacles en vol grâce à une perception visuelle monoculaire. Deux algorithmes d’estimation ont été simulés afin d’être validés pour être ensuite mis en place sur une nouvelle version du robot qui a été testée expérimentalement. Ces estimations permettent par la suite de rendre le robot plus autonome pour éviter les collisions avec son environnement et actionner son système de changement de forme si cela est nécessaire. / This paper describes a bio-inspired quadrotor design. This robot, called QuadMorphing, is inspired by birds and has the ability to fold its mechanical structure to reduce its wingspan during the flight. This feature could be useful for obstacle avoidance task in cluttered environments.The work presented here contains a full description of the mechatronic structure. Then, experimental results are presented and discussed in order to quantify the QuadMorphing performances during obstacle avoidance scenarios.The second part of this thesis deals with estimating obstacle size during flight using monocular visual perception. Two estimation algorithms were simulated in order to be validated and then implemented for experimental testing on a new version of the robot. In order to make the robot autonomous, the estimation of the size of the obstacle allows the robot to avoid collisions with its environment and to perform its morphological reduction if necessary.
6

Robust tracking of dynamic targets with aerial vehicles using quaternion-based techniques / Suivi robuste des cibles dynamiques avec véhicules aériens à l’aide de techniques basées en quaternions

Abaunza Gonzalez, Hernán 26 April 2019 (has links)
L'objectif de ce travail de thèse est de concevoir des algorithmes de commande et de navigation pour le suivi des cibles dynamiques au sol en utilisant des véhicules aériens. Les quaternions, qui fournissent une alternative aux représentations classiques de la dynamique des véhicules aériens, ont été choisis comme une base pour développer des contrôleurs robustes et des algorithmes de navigation agile, en raison de leurs avantages tels que l'absence de singularités et discontinuités, et leur simplicité mathématique lors de la manipulation des rotations. Les approches de commande explorées à l'aide de quaternions dans cette thèse commencent par le retour d'état, la passivité, et des contrôleurs basés sur l'énergie, jusqu'à des modes glissants, et des approches de saturation en trois dimensions. Ensuite, des stratégies de navigation autonomes et semi-autonomes pour quadrirotors ont été explorées. Un algorithme a été développé pour le pilotage d'un quadrirotor en utilisant des gestes d'un utilisateur portant un bracelet. Afin de faciliter le fonctionnement des multi rotors dans des scénarios défavorables, une stratégie de déploiement agressive a été proposée ou un quadrirotor est lancé à la main avec ses moteurs éteints. Finalement, des techniques de navigation autonomes pour le suivi des cibles dynamiques ont été conçues. Un algorithme de génération de trajectoire basée sur des équations différentielles a été introduit pour le suivi d'un véhicule terrestre tout en décrivant des cercles. Enfin un algorithme de planification de chemin distribué a été développé pour une flottille de drones, afin de suivre de façon autonome des cibles au sol, en résolvant un problème d'optimisation en ligne. / The objective of this thesis work is to design control and navigation algorithms for tracking of dynamic ground targets using aerial vehicles. Quaternions, which provide an alternative to the classical representations of aerial vehicle dynamics, have been chosen as a basement to develop robust controllers and agile navigation algorithm, due to their advantages such as the absence of singularities and discontinuities and their mathematical simplicity when handling rotations. The quaternion-based control approaches explored in this thesis range from state feedback, passivity, and energy-based controllers, up to sliding modes, and three-dimensional saturation approaches. Then, autonomous and semi-autonomous navigation strategies for quadrotors were explored. An algorithm has been developed for controlling a quadrotor using gestures from a user wearing an armband. To facilitate the operation of multirotors in adverse scenarios, an aggressive deployment strategy has been proposed where a quadrotor is launched by hand With its motors turned off. Finally, autonomous navigation techniques for tracking dynamic targets have been designed. A trajectory generation algorithm based on differential equations has been introduced to track a land vehicle while describing circles. Finally a distributed path planning algorithm has been developed for a fleet of drones to autonomously track ground targets by solving an online optimization problem.
7

Alocação de tarefas para a coordenação de robôs heterogêneos aplicados a agricultura de precisão / Task allocation for the coordination heterogeneous robots applied to precision agriculture

Fraccaroli, Eduardo Sacogne 05 December 2017 (has links)
O Brasil é uma referência mundial na produção e exportação de citros, entretanto esse cultivo pode sofrer diversos problemas e perdas de produtividade por motivos diversos, como por exemplo, pragas. Para reduzir os riscos e perdas, torna-se interessante o uso de sistemas automatizados de monitoramento, justificando a necessidade de realizar a coleta de dados para determinar diversos fatores. Determinadas plantações, como a de citros, não podem ser monitoradas somente via solo ou somente via imagens aéreas, tornando necessário mesclar ambas as abordagens de acordo com o parâmetro a ser monitorado. Para a realização desse monitoramento devem ser utilizados robôs com habilidades distintas, robôs aéreos e robôs terrestres. Assim, é preciso designar as tarefas que cada robô realizará e também coordenar todos os robôs durante a execução do sistema como um todo, visando otimizar o processo de coleta de dados. Esse problema pode ser analisado e modelado como um problema de alocação de tarefas para robôs (Multi-Robot Task Allocation (MRTA)). Para resolver esse problema propõe-se um framework baseado em técnicas de cobertura de conjuntos e em mecanismo de mercado baseado em leilão. Teste simulados são realizados e demonstram que a presente proposta cumpre o papel na alocação das tarefas aos robôs. Além disso, visando a aplicação da solução proposta é projetado e desenvolvido uma plataforma robótica aérea (quadrirotor) de baixo custo utilizando peças prototipadas. Para o controle de estabilidade dessa plataforma, propõe-se um modelo matemático de acordo com os parâmetros inerciais do quadrirotor. Esse quadrirotor é utilizado em diversas aplicações reais, mostrando que o projeto desenvolvido pode ser reproduzido e destinado a execução de tarefas reais, como por exemplo a coleta de dados na agricultura de precisão. / Brazil is a world reference in the production and export of citrus, although this crop can suffer several problems and losses of productivity for diverse reasons, as for example, pests. In order to reduce risks and losses, it is interesting to use automated monitoring systems, justifying the need to perform data collection to determine several factors. Certain plantations, such as citrus plantations, can not be monitored only via soil or only via aerial images, making it necessary to merge both approaches according to the parameter to be monitored. To perform this monitoring, robots with different abilities, such asunmanned aerial vehicle (UAV) and unmanned ground vehicle (UCV) should be used. Therefore, it is necessary to assign the tasks that each robot will perform and also to coordinate all the robots during the execution of the system as a whole, in order to optimize the process of data collection. The problem can be studied and modeled as a task allocation problem for robots (MRTA). To solve this problem we propose a framework based set covering techniques and auction-based market mechanism. Simulated tests are performed and demonstrate that the present proposal fulfills the role in assigning tasks to robots. In addition, aiming at the application of the proposed solution is designed and developed a low cost aerial robotic platform (quadrirotor) which use prototyped parts. This quadrirotor is used in several real applications, showing that the developed project can be reproduced and destined to perform real tasks, such as data collection in precision agriculture.
8

Formation control for a group of underactuated vehicles / Commande de vol en formation d'une flotte de véhicules sous-actionnés

Nguyen, Dang Hao 07 December 2015 (has links)
Le contrôle de vol en formation se rapporte au contrôle de la trajectoire de plusieurs véhicules pour accomplir une tâche commune. La motivation du contrôle du vol en formation réside dans le fait que l'utilisation de plusieurs drones permet de réaliser des tâches plus complexes et que ne peut accomplir un drone unique. Les stratégies de commande de flotte de véhicules peuvent être classées en trois groupes principaux : la stratégie de vol type meneur-suiveur, celle basée sur comportement et l'approche utilisant un meneur virtuel. Chaque groupe se compose de différents véhicules et on suppose que les véhicules communiquent entre eux pour échanger des informations. Le contrôle de position pour des quadrirotors sous-actionnés ou des UAV VTOL a retenu l'intérêt de plusieurs chercheurs de la communauté scientifique. En raison de la nature sous-actionnée des UAV VTOL, l'attitude du système doit être utilisée afin de commander la position et la vitesse. En effet, la prise en compte des perturbations externes, des incertitudes sur la dynamique du système ainsi que l'objectif d'obtenir des résultats globaux rendent la synthèse de lois de commande plus difficile. Nous proposons, dans ce travail, un algorithme permettant l'extraction de l'attitude et une nouvelle formulation de la poussée pour la commande d'un drone. Cet algorithme utilise cette formulation de la force de poussée pour atteindre les objectifs en translation et utilise le vecteur quaternion unitaire comme consigne du sous-système en rotation. Cet algorithme est ensuite étendu au cas de la commande de vol en formation. Cinq contrôleurs de vol en formation sont développés et séparés dans deux groupes : l'approche structure virtuelle et l'approche meneur-suiveur. Les trois premiers contrôleurs de vol en formation utilisent l'approche structure virtuelle. La vitesse, les perturbations et les incertitudes de modèle dans la dynamique sont estimées par le biais d'un observateur et la technique de commande "backstepping" adaptative. La synthèse des deux derniers contrôleurs de vol en formation de vol est obtenue en utilisant l'approche meneur-suiveur. La formation utilisant cette approche pour des quadrirotors et pour le système du second degré est construite. Le changement de la configuration de la formation de vol est également simulé pour ces deux derniers contrôleurs de vol en formation. Dans chacun des cinq contrôleurs de vol en formation, la fonction d'évitement de collision construite à partir d'une fonction indicielle "lisse" est incluse. Cette fonction produit une force de poussée quand un quadrirotor évolue près des autres et d'une force de traction quand un quadrirotor évolue hors de la zone de détection. Les résultats de simulation prouvent que cette fonction d'évitement de collision fonctionne tout à fait correctement et qu'aucune collision entre les quadrirotors ni avec les obstacles ne se produit. En résumé, l'utilisation de la poussée, de l'algorithme d'extraction d'attitude et de la fonction d'évitement de collision, rend la synthèse des lois de commande plus facile et les résultats obtenus pour le vol en formation sont globaux / Formation control relates with the motion control of multiple vehicles to accomplish a common task. The motivation of formation control is because of the advantages achieved by using a formation of vehicles instead of a single one. Cooperative control approach can be cataloged into three main groups: leader-follower, behavior-based and virtual structure. Each group consists of individual vehicles and the communication allows the information be exchanged among vehicles. Position control for under-actuated quadrotors or VTOL UAVs has been focused in several group in the research community. Due to the under-actuated nature of VTOL UAVs, the system attitude must be used in order to control the position and velocity of the system. Moreover, the effect of external disturbance, uncertainty of the dynamics and the requirement of achieving the global results make the control design process more difficult. Developing from a global controller for a single quadrotor, a new thrust and attitude extraction algorithm is proposed. This algorithm allows transferring an intermediate control force to a thrust force to achieve the translational objective and an unit quaternion vector as a reference for the rotational subsystem. This algorithm is also embedded in the formation controller. Five formation controllers are developed and separated into two groups, virtual structure and leader-follower approach. The first three formation controllers are constructed by using the virtual structure approach. The unmeasured linear velocity, disturbance and uncertainty in the dynamics are solved by employing observer design and adaptive backstepping control design technique. The last two formation controllers are built by using the leader-follower approach. The leader follower formation for quadrotors and for second order system are constructed. The changing of formation shape in working time also is simulated in these last two formation controllers. In all five formation controllers, collision avoidance function constructed from a smooth step function is embedded. This function generates a pushing force when a quadrotor goes close to the others and a pulling force when a quadrotor travels out of the sensing range. The simulation results show that this collision avoidance function works quite effectively and there is no collision among quadrotors and obstacles. It can be summarized that by using the thrust and attitude extraction algorithm and the collision avoidance function, the control design process becomes easier and all the formation controllers achieve the global results
9

Approches bornées pour la commande des drones

Hably, Ahmad 05 December 2007 (has links) (PDF)
Les drones et les micro-drones font actuellement l'objet de développements très rapides. L'objectif principal de ce sujet de recherche est le développement de lois de commande permettant de contrôler deux systèmes sous actionnés classiques : l'avion à décollage et à atterrissage verticaux et le "quadrirotor" ou hélicoptère à quatre rotors fixes. La spécificité des approches développées est que les limites des actionneurs sont prises en compte tout en assurant un coût de calcul compatible avec une implantation et une exécution en temps réel sur un système informatique embarqué. La commande de l'assiette et de la position sont abordées dans ce travail. Les commandes proposées sont basées sur la stabilisation globale des chaînes d'intégrateurs linéaires et sur les techniques de commande prédictive rapide.
10

Alocação de tarefas para a coordenação de robôs heterogêneos aplicados a agricultura de precisão / Task allocation for the coordination heterogeneous robots applied to precision agriculture

Eduardo Sacogne Fraccaroli 05 December 2017 (has links)
O Brasil é uma referência mundial na produção e exportação de citros, entretanto esse cultivo pode sofrer diversos problemas e perdas de produtividade por motivos diversos, como por exemplo, pragas. Para reduzir os riscos e perdas, torna-se interessante o uso de sistemas automatizados de monitoramento, justificando a necessidade de realizar a coleta de dados para determinar diversos fatores. Determinadas plantações, como a de citros, não podem ser monitoradas somente via solo ou somente via imagens aéreas, tornando necessário mesclar ambas as abordagens de acordo com o parâmetro a ser monitorado. Para a realização desse monitoramento devem ser utilizados robôs com habilidades distintas, robôs aéreos e robôs terrestres. Assim, é preciso designar as tarefas que cada robô realizará e também coordenar todos os robôs durante a execução do sistema como um todo, visando otimizar o processo de coleta de dados. Esse problema pode ser analisado e modelado como um problema de alocação de tarefas para robôs (Multi-Robot Task Allocation (MRTA)). Para resolver esse problema propõe-se um framework baseado em técnicas de cobertura de conjuntos e em mecanismo de mercado baseado em leilão. Teste simulados são realizados e demonstram que a presente proposta cumpre o papel na alocação das tarefas aos robôs. Além disso, visando a aplicação da solução proposta é projetado e desenvolvido uma plataforma robótica aérea (quadrirotor) de baixo custo utilizando peças prototipadas. Para o controle de estabilidade dessa plataforma, propõe-se um modelo matemático de acordo com os parâmetros inerciais do quadrirotor. Esse quadrirotor é utilizado em diversas aplicações reais, mostrando que o projeto desenvolvido pode ser reproduzido e destinado a execução de tarefas reais, como por exemplo a coleta de dados na agricultura de precisão. / Brazil is a world reference in the production and export of citrus, although this crop can suffer several problems and losses of productivity for diverse reasons, as for example, pests. In order to reduce risks and losses, it is interesting to use automated monitoring systems, justifying the need to perform data collection to determine several factors. Certain plantations, such as citrus plantations, can not be monitored only via soil or only via aerial images, making it necessary to merge both approaches according to the parameter to be monitored. To perform this monitoring, robots with different abilities, such asunmanned aerial vehicle (UAV) and unmanned ground vehicle (UCV) should be used. Therefore, it is necessary to assign the tasks that each robot will perform and also to coordinate all the robots during the execution of the system as a whole, in order to optimize the process of data collection. The problem can be studied and modeled as a task allocation problem for robots (MRTA). To solve this problem we propose a framework based set covering techniques and auction-based market mechanism. Simulated tests are performed and demonstrate that the present proposal fulfills the role in assigning tasks to robots. In addition, aiming at the application of the proposed solution is designed and developed a low cost aerial robotic platform (quadrirotor) which use prototyped parts. This quadrirotor is used in several real applications, showing that the developed project can be reproduced and destined to perform real tasks, such as data collection in precision agriculture.

Page generated in 0.4274 seconds