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1
Manzi, Fraga Matías Jesús. „Involvement of aerial organs on the ABA accumulation in roots of Citrus plants under water deficit“. Doctoral thesis, Universitat Jaume I, 2016. http://hdl.handle.net/10803/387227.
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La sequía es una de las situaciones más perjudiciales para el crecimiento y la supervivencia de las plantas. Sin
embargo, las plantas han desarrollado estrategias para afrontar dichas condiciones, incluyendo el rápido incremento
de ácido abscísico (ABA). Se ha popularizado que las raíces son el órgano capaz de detectar la deshidratación en el
substrato, aumentando los niveles de ABA. En esta tesis se ha estudiado la capacidad de las raíces en sintetizar ABA
y la implicación del transporte desde tejidos aéreos. La evidencia presentada en esta tesis sugiere que las raíces de las
plantas cítricas no constituyen una fuente relevante de ABA y por el contrario, siendo las hojas responsables de
mantener la acumulación de ABA en las raíces deshidratas. Además, se sugiere que las hojas juegan un papel clave en
detectar el déficit hídrico y por tanto en desencadenar la acumulación de ABA en hojas y en raíces.Water deficit is one of the most detrimental conditions for plant growth and survival. However, plants have developed several strategies to cope with this condition including the rapid accumulation of abscisic acid (ABA). For years, it has been assumed that dehydration is perceived by roots which stimulate the ABA increase which is further transported to leaves to regulate the stomatal aperture. In this thesis, this model is questioned since several lines of evidence indicate that roots could not sustain larger increases of ABA. Here it is provided evidence that roots of Citrus plants are not an important source of ABA under water deficit and conversely, leaves sustain the accumulation of ABA in those dehydrated roots. Furthermore, data present here suggest that leaves are key not only in providing ABA to roots but also in triggering the water stress responses which lead to the ABA accumulation in both, leaves and roots.
2
Risante, Ana Paula de Oliveira. „Biodiversidade e estoques de carbono de um Cerrado stricto sensu na Reserva Biológica de Mogi Guaçu-SP“. Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-17072017-121713/.
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O desmatamento para uso agrícola é uma das principais causas da devastação dos biomas brasileiros como a floresta amazônica, o cerrado e a mata atlântica. A grande extensão do desmatamento com a derrubada e a queima das vegetações é a principal fonte de emissão de gases do efeito estufa do Brasil - quarto maior emissor mundial. Uma grande porcentagem do carbono estocado encontra-se na biomassa aérea das fisionomias florestais, enquanto que, nas vegetações de cerrado, a biomassa subterrânea corresponde à maior parte. São ainda poucos os estudos realizados a respeito de estimativas de carbono na biomassa subterrânea, ou mesmo na biomassa aérea, de vegetações de cerrado. O objetivo desta pesquisa foi relacionar os estoques de carbono aéreos e subterrâneos de um cerrado stricto sensu existente na Reserva Biológica de Mogi Guaçu (Martinho Prado - SP) com sua biodiversidade. Para isso estabeleceu-se, de modo sistemático, 10 parcelas de 10x50m subdivididas a cada 10m. Todas as plantas com diâmetros à altura do peito (DAPs) dos troncos maiores que 5 cm foram medidas e identificadas ao nível de espécie calculando-se posteriormente os índices de: diversidade de Shannon-Wiener, equitabilidade de Pielou e riqueza. A biomassa e o carbono aéreo destas árvores foram calculados com o auxílio de equações estabelecidas pela literatura. Foram coletadas amostras de raízes utilizando-se uma cavadeira manual para determinar seus estoques de biomassa e de carbono. Também se retirou amostras indeformadas de solo em diferentes profundidades (0-30cm) para cálculo de densidade do solo e determinação do carbono orgânico. A área de estudo apresentou um total de 64 espécies distintas e 773 indivíduos. A espécies vegetais mais recorrentes foram: Xylopia aromatica (pimenta de macaco) (10,9%), seguida por Syagrus flexuosa (coco babão) (8,8%), Copaifera langsdorffii (pau de óleo) (8,67%), Qualea grandiflora (pau-terra) (8,41%). Houve uma correlação positiva e significativa entre diversidade de Shannon e biomassa e carbono aéreos. Os maiores índices de diversidade de Shannon apresentados foram 2,966 e 2,927. A biomassa área média de foi 37,412 Mg.ha-1 e o carbono aéreo médio foi de 19,65 Mg.ha-1. Já a biomassa média de raízes foi de 3,20 Mg.ha-1 com um teor de carbono variando de 48 a 54%. O estoque médio de carbono do solo foi de 8,51 Mg.ha-1. A porção do solo nas profundidades de 0-10cm apresentaram as maiores concentrações de carbono orgânico. Por outro lado, a densidade do solo apresentou os maiores valores nas camadas de 20-30 cm de profundidade. Houve uma relação negativa significativa entre a densidade e o carbono orgânico do solo.Deforestation for agricultural use is one of the main causes of the devastation of Brazilian biomes such as the Amazon forest, the cerrado and the Atlantic forest. The big extension of the deforestation with the felling and burning of vegetation is the main cause of the greenhouse gas emissions in Brazil - 4th largest worldwide issuer. A large percentage of the stored carbon is found in the aerial biomass of the vegetable physiognomy, while, in the cerrado vegetation, the underground biomass corresponds the most of part. There are few studies carried out about the carbon stimates in the underground biomass, or even in the aerial biomass, of the cerrado vegetation. The purpose of this research was to relate aerial and underground carbon stocks of a stricto sensu cerrado existing in the Mogi Guaçu- SP Biological Reserve (Martinho Prado Junior-SP) with your biodiversity. For this has been established, systematically, ten plots of 10X50 meters subdivided every 10 meters. All the plants with breast height diameters (DAPs) of the trunks larger than 5 centimeters were measured and identified at the species level calculating the indices of: Shannon-Wiener diversity, Pielou equitability and species richness. The aerial biomass and carbon of these trees were calculated with the aid of equations established in the literature. Root samples were collected with the use of a manual digger for to determine their biomass and carbon stocks. Undisturbed soil samples were collected in different depths for calculating of the soil density and the determination of the soil organic carbon. The study area presented 65 different species and 773 trees. The most recurrent plant species were: Xylopia aromatica (monkey pepper) (10,9%), seguida por Syagrus flexuosa (coconut baboon) (8,8%), Copaifera langsdorffii (oil dick) (8,67%), Qualea grandiflora (dick-sand) (8,41%). There was a significant positive correlation between Shannon diversity and aerial biomass and carbon. The highest indices of the Shannon diversity presented were 2,966 and 2,927. The medium aerial biomass was 37,412 Mg.ha-1 and the medium aerial carbon was 19,65 Mg.ha-1. The medium roots biomass was 3,20 Mg.ha-1 with a carbon content is varying from 48 to 54%.The medium soil carbon was 8,51 Mg.ha-1. The portion of the soil in the depths of the 0-10 centimeters presented the highest organic carbon concentration. On the other side, the soil density presented the higher values in layers of 20-30 cm depth. There was a significant negative correlation between soil density and the soil organic carbon.
3
Boeuf, Alexandre. „Kinodynamic motion planning for quadrotor-like aerial robots“. Phd thesis, Toulouse, INPT, 2017. http://oatao.univ-toulouse.fr/20169/1/Boeuf.pdf.
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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.
4
Nagori, Chinmay. „Unmanned Aerial Manipulators in Construction - Opportunities and Challenges“. Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/101663.
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Unmanned Aerial Vehicles (UAVs) have now been accepted as an alternative medium to human workers for data collection processes in various industries. The capabilities of UAVs are now being extended from passive tasks of data collection to active tasks of interacting with the environment by equipping them with robotic arms and function as Unmanned Aerial Manipulators (UAMs).
Research on Unmanned Aerial Manipulators has been growing in the last few years. The applications of UAMs in terms of sensor installation, inspections, door opening, valve turning, pick and drop, etc. have been studied for the oil and gas industry, and civil applications, etc. However, there is a lack of studies in understanding applications of UAMs and their capabilities in construction and in advancing construction activities. The goal of this research is to identify potential opportunities and challenges of the application of UAM in construction projects. The study will undertake an extensive literature review and semi-structured interviews with industry experts to address research questions. This study will have a significant contribution to the introduction and development of new contact-based UAV-guided technologies in construction.Master of Science
Drones or Unmanned Aerial Manipulators have been used in the construction industry to collect visual data in form of images, videos, or to map surveys, and visually inspect the structures. However, if equipped with a robotic arm, they attain the capability of touching and interacting with the environment to effectively function as an Unmanned Aerial Manipulator (UAM). UAMs have researched for various applications such as sensor installation, touch-based sensor inspections, door opening, and closing, and pick up and drop, etc. However, there is a lack of study for their opportunities and challenges in the construction industry. This research focuses on understanding the opportunities and challenges associated with the application of UAMs in the construction industry.
5
Dierks, Travis. „Formation control of mobile robots and unmanned aerial vehicles“. Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Dierks_09007dcc806d7f16.pdf.
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Thesis (Ph. D.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed January 13, 2009) Includes bibliographical references.
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Cowlagi, Raghvendra V. „Hierarchical motion planning for autonomous aerial and terrestrial vehicles“. Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41066.
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Autonomous mobile robots - both aerial and terrestrial vehicles - have gained immense importance due to the broad spectrum of their potential military and civilian applications. One of the indispensable requirements for the autonomy of a mobile vehicle is the vehicle's capability of planning and executing its motion, that is, finding appropriate control inputs for the vehicle such that the resulting vehicle motion satisfies the requirements of the vehicular task. The motion planning and control problem is inherently complex because it involves two disparate sub-problems: (1) satisfaction of the vehicular task requirements, which requires tools from combinatorics and/or formal methods, and (2) design of the vehicle control laws, which requires tools from dynamical systems and control theory.
Accordingly, this problem is usually decomposed and solved over two levels of hierarchy. The higher level, called the geometric path planning level, finds a geometric path that satisfies the vehicular task requirements, e.g., obstacle avoidance. The lower level, called the trajectory planning level, involves sufficient smoothening of this geometric path followed by a suitable time parametrization to obtain a reference trajectory for the vehicle.
Although simple and efficient, such hierarchical separation suffers a serious drawback: the geometric path planner has no information of the kinematic and dynamic constraints of the vehicle. Consequently, the geometric planner may produce paths that the trajectory planner cannot transform into a feasible reference trajectory. Two main ideas appear in the literature to remedy this problem: (a) randomized sampling-based planning, which eliminates altogether the geometric planner by planning in the vehicle state space, and (b) geometric planning supported by feedback control laws. The former class of methods suffer from a lack of optimality of the resultant trajectory, while the latter class of methods makes a restrictive assumption concerning the vehicle kinematic model.
In this thesis, we propose a hierarchical motion planning framework based on a novel mode of interaction between these two levels of planning. This interaction rests on the solution of a special shortest-path problem on graphs, namely, one using costs defined on multiple edge transitions in the path instead of the usual single edge transition costs. These costs are provided by a local trajectory generation algorithm, which we implement using model predictive control and the concept of effective target sets for simplifying the non-convex constraints involved in the problem. The proposed motion planner ensures "consistency" between the two levels of planning, i.e., a guarantee that the higher level geometric path is always associated with a kinematically and dynamically feasible trajectory. We show that the proposed motion planning approach offers distinct advantages in comparison with the competing approaches of discretization of the state space, of randomized sampling-based motion planning, and of local feedback-based, decoupled hierarchical motion planning. Finally, we propose a multi-resolution implementation of the proposed motion planner, which requires accurate descriptions of the environment and the vehicle only for short-term, local motion planning in the immediate vicinity of the vehicle.
7
Shah, Syed Irtiza Ali. „Single camera based vision systems for ground and; aerial robots“. Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37143.
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Efficient and effective vision systems are proposed in this work for object detection for ground&aerial robots venturing into unknown environments with minimum vision aids, i.e. a single camera. The first problem attempted is that of object search and identification in a situation similar to a disaster site. Based on image analysis, typical pixel-based characteristics of a visual marker have been established to search for, using a block based search algorithm, along with a noise and interference filter. The proposed algorithm has been successfully utilized for the International Aerial Robotics competition 2009. The second problem deals with object detection for collision avoidance in 3D environments. It has been shown that a 3D model of the scene can be generated from 2D image information from a single camera flying through a very small arc of lateral flight around the object, without the need of capturing images from all sides. The forward flight simulations show that the depth extracted from forward motion is usable for large part of the image. After analyzing various constraints associated with this and other existing approaches, Motion Estimation has been proposed. Implementation of motion estimation on videos from onboard cameras resulted in various undesirable and noisy vectors. An in depth analysis of such vectors is presented and solutions are proposed and implemented, demonstrating desirable motion estimation for collision avoidance task.
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Selvatici, Luca. „Distributed cooperative MPC for aerial robots: a ROS 2 implementation“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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The significant decrease in manufacturing costs of hardware components for quadrotors has greatly encouraged research into the design of flight control algorithm for quadrotors, which has seen great growth in recent years. One of the key aspects of the research is the communication between the quadrotors. Nowadays it is considered essential that the quadrotors can communicate with each other. This feature allows numerous advantages: it is possible to generate a network capable of collaborating to solve complex tasks that single quadrotors would not be able to perform, or complete them in a shorter time.
The objective of this thesis is the design of a distributed algorithm to control the navigation of a set of quadrotors flying through the same navigation space. A surveillance task has been chosen as a case study, where quadrotors are in charge of arranging themselves in order to protect a target from intruders. Each quadrotor needs to complete both a specific task assigned to it (prevent a certain intruders from reaching the target) and a task in common with the other quadrotors (make sure that the center of the drones coincides with the target and the quadrotors do not collide). With this goal in mind, the project starts with the design of the quadrotor model, controller and trajectories from scratch. Then a Distributed Model Predictive Control algorithm is designed ad hoc to control the navigation of quadrotors. One of the challenges in the creation of this algorithm is the adaptation of the control algorithm to the simultaneous use of Model Predictive Control (MPC) and Online Distributed Gradient Tracking (O-DGT). Indeed, the speed required for the optimization calculations led us to reformulate the MPC in order to make the calculations faster and thus satisfy the limits imposed by the chosen time-step. The proposed model is tested with numerical examples, analyzing a series of cases that allowed us to test different combinations of the developed algorithms.
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Chamberlain, Caleb H. „System Identification, State Estimation, and Control of Unmanned Aerial Robots“. BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2605.
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This thesis describes work in a variety of topics related to aerial robotics, including system identification, state estimation, control, and path planning. The path planners described in this thesis are used to guide a fixed-wing UAV along paths that optimize the aircraft's ability to track a ground target. Existing path planners in the literature either ignore occlusions entirely, or they have limited capability to handle different types of paths. The planners described in this thesis are novel in that they specifically account for the effect of occlusions in urban environments, and they can produce a much richer set of paths than existing planners that account for occlusions. A 3D camera positioning system from Motion Analysis is also described in the context of state estimation, system identification, and control of small unmanned rotorcraft. Specifically, the camera positioning system is integrated inside a control architecture that allows a quadrotor helicopter to fly autonomously using truth data from the positioning system. This thesis describes the system architecture in addition to experiments in state estimation, control, and system identification. There are subtleties involved in using accelerometers for state estimation onboard flying rotorcraft that are often ignored even by researchers well-acquainted with the UAV field. In this thesis, accelerometer-rotorcraft behavior is described in detail. The consequences of ignoring accelerometer-rotorcraft behavior are evaluated, and an observer is presented that achieves better performance by specifically modeling actual accelerometer behavior. The observer is implemented in hardware and results are presented.
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Geisert, Mathieu. „Optimal control and machine learning for humanoid and aerial robots“. Thesis, Toulouse, INSA, 2018. http://www.theses.fr/2018ISAT0011/document.
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Quelle sont les points communs entre un robot humanoïde et un quadrimoteur ? Et bien, pas grand-chose… Cette thèse est donc dédiée au développement d’algorithmes permettant de contrôler un robot de manière dynamique tout en restant générique par rapport au model du robot et à la tâche que l’on cherche à résoudre. Le contrôle optimal numérique est pour cela un bon candidat. Cependant il souffre de plusieurs difficultés comme un nombre important de paramètres à ajuster et des temps de calcul relativement élevés. Ce document présente alors plusieurs améliorations permettant d’atténuer ces difficultés. D’un côté, l’ordonnancement des différentes tâches sous la forme d’une hiérarchie et sa résolution avec un algorithme adapté permet de réduire le nombre de paramètres à ajuster. D’un autre côté, l’utilisation de l’apprentissage automatique afin d’initialiser l’algorithme d’optimisation ou de générer un modèle simplifié du robot permet de fortement diminuer les temps de calculWhat are the common characteristics of humanoid robots and quadrotors? Well, not many… Therefore, this thesis focuses on the development of algorithms allowing to dynamically control a robot while staying generic with respect to the model of the robot and the task that needs to be solved. Numerical optimal control is good candidate to achieve such objective. However, it suffers from several difficulties such as a high number of parameters to tune and a relatively important computation time. This document presents several ameliorations allowing to reduce these problems. On one hand, the tasks can be ordered according to a hierarchy and solved with an appropriate algorithm to lower the number of parameters to tune. On the other hand, machine learning can be used to initialize the optimization solver or to generate a simplified model of the robot, and therefore can be used to decrease the computation time
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Ahmad, Iftikhar. „Attitude estimation of accelerated aerial vehicles using IMU/GPS“. Versailles-St Quentin en Yvelines, 2013. http://www.theses.fr/2013VERS0062.
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Ce travail de recherche porte sur l’estimation de l’attitude d’un corps rigide se déplaçant dans l’espace 3D avec une accélération qui n’est ni constante, ni négligeable par rapport à la gravité. Les capteurs utilisés sont une centrale inertielle (IMU) et un GPS qui fournissent respectivement les mesures de vecteurs accélération linéaire, champ magnétique terrestre et vitesse angulaire (données IMU) et la vitesse linéaire absolue (données GPS) du corps en mouvement. Nous avons proposé, dans un premier temps, un observateur par mode glissant d’ordre deux assurant la convergence exponentielle, capable d’estimer d’une manière exacte une entrée inconnue supposée bornée et variant dans le temps d’un système dynamique non linéaire. Cet observateur utilise la mesure de tout son état. Celui-ci a ensuite été appliqué à l’estimation de l’accélération linéaire inconnue dans le repère inertiel nécessaire dans la plupart des algorithmes d’estimation d’attitude connus (méthode algébrique ou dynamique). A partir de ce résultat, un observateur à deux étapes a été proposé pour estimer l’attitude du corps rigide en mouvement accéléré, où l’estimation de l’accélération linéaire constitue la première étape, tandis que la deuxième étape se résume à l’utilisation de cette accélération dans un algorithme d’estimation dynamique. En utilisant, le principe de séparation, nous arrivons à montrer la convergence asymptotique presque globale (almost global) de l’erreur d’estimation. Afin de prendre en compte les imperfections des capteurs de la centrale inertielle telles que le bruit et les biais, et par conséquent améliorer l’estimation de l’attitude, un filtre complémentaire non linéaire a été proposéThis research work addresses the problems of attitude estimation of rigid bodies moving in 3D-space with an acceleration which is neither constant, nor negligible as compared to the gravity, using IMU and GPS. We propose an observer based on proportional-integral type second order sliding mode to estimate unknown bounded time-varying input to a nonlinear dynamical system. Exponential convergence on the observed is demonstrated using Lyapunov theory in a general case. This observer has been applied to estimate the unknown linear acceleration in the inertial frame from the equations of rigid bodies translational dynamics. We then propose a two-step observer for which the estimation of linear acceleration is the first step which is then used in the equations of rigid bodies rotational dynamics at second step. The exponentially convergence at first step is sufficient excuse to study the convergence analysis of the rigid bodies rotational dynamics separately. The combined system is found to be almost global asymptotic convergent by using separation principle. We also propose a complementary filter to filter raw measurements of two non-collinear vectors in the body frame, for which we get global asymptotic convergence. Note that we get global exponential convergence if gyro-bias is not considered. After filtering these directions, the doors of attitude estimation through using some algebraic algorithm, are open. The performance of the proposed observers is illustrated by simulation results as well
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Naldi, Roberto <1980>. „Prototyping, modelling and control of a class of VTOL aerial robots“. Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/636/.
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Bicego, Davide. „Design and Control of Multi-Directional Thrust Multi-Rotor Aerial Vehicles with applications to Aerial Physical Interaction Tasks“. Thesis, Toulouse, INSA, 2019. http://www.theses.fr/2019ISAT0025.
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Cette thèse aborde l’étude de véhicules aériens autonomes interagissant d’une façon active avec l’environnement, en portant une attention particulière au développement des techniques de modélisation, de conception, et de stratégies de commande appropriées pour ces systèmes. L’étude de ces systèmes étant intrinsèquement complexe et relativement récente, de nouvelles techniques sont nécessaires pour : i) mieux décrire la dynamique du véhicule aérien et ses contraintes d’actionnement ; ii) concevoir efficacement de nouveaux prototypes aériens dotés de propriétés particulières de dextérité et de résilience ; iii) garantir un contrôle stable pendant les opérations sans contact malgré les contraintes d’actionnement ; et iv) préserver la stabilité du système pendant la phase de contact avec l’environnement tout en garantissant l’accomplissement de la tâche de manipulation. Cette thèse explore de nouvelles stratégies pour surmonter, dans une certaine mesure, les problèmes de sous-actionnement des véhicules traditionnels, conçus avec les hélices orientées dans une même direction. L’objectif de cette thèse est d’enrichir les résultats théoriques préliminaires sur de nouvelles plateformes et, en outre, de contribuer au développement de systèmes robotiques aériens réels plus appropriés aux moyens de manipulation améliorés et adaptés aux tâches d’interaction physique aérienne. Cette thèse s’inscrit dans le cadre du projet européen H2020 AeroArms, dont le but est de développer des systèmes robotiques aériens dotés de capacités de manipulation avancées à appliquer dans les domaines de l’inspection et de la maintenance industrielles. Par conséquent, l’impact sur l’industrie joue ici un rôle important.629.8This thesis addresses the study of autonomous Aerial Vehicles (AVs) actively interacting with the surrounding environment, with particular attention to the development of modeling and design techniques, and suitable control strategies for these systems. Due to the intrinsic difficulty and the novelty associated with the study of these systems, new techniques are needed to: i) better describe the aerial vehicle dynamics and its actuation limits; ii) effectively design new aerial prototypes with particular properties of dexterity and resilience; iii) guarantee a stable control during contact-less operations despite the actuation limits; and iv) preserve the system stability also during the contact phase with the environment while guaranteeing the fulfillment of the sought manipulation task. This thesis explores new strategies to overcome, to a certain extent, the under-actuation problem of classical multi-rotor platforms, conceived with the propellers aligned towards a common direction. The goal of this thesis is to contribute to a wise growth of the preliminary theoretical results on multi-directional thrust aerial vehicles laid by the state of the art and, furthermore, to the development of more suitable real aerial robotic systems with enhanced manipulation means, tailored for aerial physical interaction tasks. This thesis takes place inside the context of the European H2020 AeroArms project, whose goal is to develop aerial robotic systems with advanced manipulation capabilities to be applied in industrial inspection and maintenance. Hence, also the technology transfer and the impact on the industry plays here an important role
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Sharma, Rajnikant. „Bearing-Only Cooperative-Localization and Path-Planning of Ground and Aerial Robots“. BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2884.
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In this dissertation, we focus on two fundamental problems related to the navigation of ground robots and small Unmanned Aerial Vehicle (UAVs): cooperative localization and path planning. The theme running through in all of the work is the use of bearing only sensors, with a focus on monocular video cameras mounted on ground robots and UAVs. To begin with, we derive the conditions for the complete observability of the bearing-only cooperative localization problem. The key element of this analysis is the Relative Position Measurement Graph (RPMG). The nodes of an RPMG represent vehicle states and the edges represent bearing measurements between nodes. We show that graph theoretic properties like the connectivity and the existence of a path between two nodes can be used to explain the observability of the system. We obtain the maximum rank of the observability matrix without global information and derive conditions under which the maximum rank can be achieved. Furthermore, we show that for the complete observability, all of the nodes in the graph must have a path to at least two different landmarks of known location. The complete observability can also be obtained without landmarks if the RPMG is connected and at least one of the robots has a sensor which can measure its global pose, for example a GPS receiver. We validate these conditions by simulation and experimental results. The theoretical conditions to attain complete observability in a localization system is an important step towards reliable and efficient design of localization and path planning algorithms. With such conditions, a designer does not need to resort to exhaustive simulations and/or experimentation to verify whether a given selection of a control strategy, topology of the sensor network, and sensor measurements meets the observability requirements of the system. In turn, this leads to decreased requirements of time, cost, and effort for designing a localization algorithms. We use these observability conditions to develop a technique, for camera equipped UAVs, to cooperatively geo-localize a ground target in an urban terrain. We show that the bearing-only cooperative geo-localization technique overcomes the limitation of requiring a low-flying UAV to maintain line-of-sight while flying high enough to maintain GPS lock. We design a distributed path planning algorithm using receding horizon control that improves the localization accuracy of the target and of all of the UAVs while satisfying the observability conditions. Next, we use the observability analysis to explicitly design an active local path planning algorithm for UAVs. The algorithm minimizes the uncertainties in the time-to-collision (TTC) and bearing estimates while simultaneously avoiding obstacles. Using observability analysis we show that maximizing the observability and collision avoidance are complementary tasks. We provide sufficient conditions of the environment which maximizes the chances obstacle avoidance and UAV reaching the goal. Finally, we develop a reactive path planner for UAVs using sliding mode control such that it does not require range from the obstacle, and uses bearing to obstacle to avoid cylindrical obstacles and follow straight and curved walls. The reactive guidance strategy is fast, computationally inexpensive, and guarantees collision avoidance.
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Riccardo, Zanella Riccardo. „Decoupled Controllers for Mobile Manipulation with Aerial Robots : Design, Implementation and Test“. Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187649.
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This work considers an aerial robot system composed of an Unmanned Aerial Vehicle (UAV) and a rigid manipulator, to be employed in mobile manipulation tasks. The strategy adopted for accomplishing the aerial manipulation is a decomposition of the previous system in two decoupled subsystems: one concerning the center of mass of the aerial robot; and another concerning the manipulator's orientation. Two Lyapunov-based controllers are developed, using a back stepping procedure, for solving the trajectory tracking problems related to the two subsystems. In the controller design, three inputs are assumed available: a translational acceleration along a body direction of the UAV; an angular velocity vector of this body rotation; and, finally, a torque at the spherical, or revolute, joint connecting the UAV and the manipulator. The first two inputs are generated by the same controller in order to drive the center of mass on a desired trajectory; while a second controller drives, through the third input, the manipulator's orientation to track a desired orientation. Formal stability proofs are provided that guarantee asymptotic trajectory tracking. Finally, the proposed control strategy is experimentally tested and validated.
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Staub, Nicolas. „Models, algorithms and architectures for cooperative manipulation with aerial and ground robots“. Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30169/document.
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Les dernières années ont vu le développement de recherches portant sur l'interaction physique entre les robots aériens et leur environnement, accompagné de l'apparition de nombreux nouveaux systèmes mécaniques et approches de régulation. La communauté centrée autour de la robotique aérienne observe actuellement un déplacement de paradigmes des approches classiques de guidage, de navigation et de régulation vers des tâches moins triviales, telle le développement de l'interaction physique entre robots aériens et leur environnement. Ceci correspond à une extension des tâches dites de manipulation, du sol vers les airs. Cette thèse contribue au domaine de la manipulation aérienne en proposant un nouveau concept appelé MAGMaS, pour " Multiple Aerial Ground Manipulator System ". Les motivations qui ont conduites à l'association de manipulateurs terrestres et aériens pour effectuer des tâches de manipulation coopérative, résident dans une volonté d'exploiter leurs particularités respectives. Les manipulateurs terrestres apportant leur importante force et les manipulateurs aériens apportant leur vaste espace de travail. La première contribution de cette thèse présente une modélisation rigoureuse des MAGMaS. Les propriétés du système ainsi que ses possibles extensions sont discutées. Les méthodes de planning, d'estimation et de régulation nécessaire à l'exploitation des MAGMaS pour des tâches de manipulation collaborative sont dérivées. Ce travail propose d'exploiter les redondances des MAGMaS grâce à un algorithme optimal d'allocation de forces entre les manipulateurs. De plus, une méthode générale d'estimation de forces pour robots aériens est introduite. Toutes les techniques et les algorithmes présentés dans cette thèse sont intégrés dans une architecture globale, utilisée à la fois pour la simulation et la validation expérimentale. Cette architecture est en outre augmentée par l'addition d'une structure de télé-présence, afin de permettre l'opération à distances des MAGMaS. L'architecture générale est validée par une démonstration de levage de barre, qui est une application représentative des potentiels usages des MAGMaS. Une autre contribution relative au développement des MAGMaS consiste en une étude exploratoire de la flexibilité dans les objets manipulés par un MAGMaS. Un modèle du phénomène vibratoire est dérivé afin de mettre en exergue ses propriétés en termes de contrôle. La dernière contribution de cette thèse consiste en une étude exploratoire sur l'usage des actionneurs à raideur variable dans les robots aériens, dotant ces systèmes d'une compliance mécanique intrinsèque et de capacité de stockage d'énergie. Les fondements théoriques sont associés à la synthèse d'un contrôleur non-linéaire. L'approche proposée est validée par le biais d'expériences reposant sur l'intégration d'un actionneur à raideur variable léger sur un robot aérienIn recent years, the subject of physical interaction for aerial robots has been a popular research area with many new mechanical designs and control approaches being proposed. The aerial robotics community is currently observing a paradigm shift from classic guidance, navigation, and control tasks towards more unusual tasks, for example requesting aerial robots to physically interact with the environment, thus extending the manipulation task from the ground into the air. This thesis contributes to the field of aerial manipulation by proposing a novel concept known has Multiple Aerial-Ground Manipulator System or MAGMaS, including what appears to be the first experimental demonstration of a MAGMaS and opening a new route of research. The motivation behind associating ground and aerial robots for cooperative manipulation is to leverage their respective particularities, ground robots bring strength while aerial robots widen the workspace of the system. The first contribution of this work introduces a meticulous system model for MAGMaS. The system model's properties and potential extensions are discussed in this work. The planning, estimation and control methods which are necessary to exploit MAGMaS in a cooperative manipulation tasks are derived. This works proposes an optimal control allocation scheme to exploit the MAGMaS redundancies and a general model-based force estimation method is presented. All of the proposed techniques reported in this thesis are integrated in a global architecture used for simulations and experimental validation. This architecture is extended by the addition of a tele-presence framework to allow remote operations of MAGMaS. The global architecture is validated by robust demonstrations of bar lifting, an application that gives an outlook of the prospective use of the proposed concept of MAGMaS. Another contribution in the development of MAGMaS consists of an exploratory study on the flexibility of manipulated loads. A vibration model is derived and exploited to showcase vibration properties in terms of control. The last contribution of this thesis consists of an exploratory study on the use of elastic joints in aerial robots, endowing these systems with mechanical compliance and energy storage capabilities. Theoretical groundings are associated with a nonlinear controller synthesis. The proposed approach is validated by experimental work which relies on the integration of a lightweight variable stiffness actuator on an aerial robot
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Simões, Mauro André Oliveira. „Development of an aerial robot for inspection and surveillance“. Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/2515.
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Mestrado em Engenharia MecânicaOs veículos aéreos não tripulados são cada vez mais procurados para desempenhar diversas tarefas do quotidiano. Estes sistemas são, no entanto, caros e necessitam de equipas grandes para serem operados. O controlo de veículos aéreos autónomos num ambiente parcialmente conhecido é uma tarefa complexa. Os sistemas actuais são baseados em sensores e sistemas de controlo relativamente dispendiosos, e são frequentemente pesados, necessitando de uma grande quantidade de energia. O principal objectivo deste projecto é desenvolver um sistema aéreo não tripulado, fácil de operar, para inspecção e monitorização. Integrados neste sistema encontram-se a plataforma do robô aéreo, o sistema de controlo e a estação de controlo remoto. A plataforma desenvolvida é baseada em veículos mais leves que o ar. Pretende-se que esta plataforma seja capaz de navegar por espaços confinados e também em ambientes fechados. A esta plataforma foram incorporados sensores e sistemas de controlo leves e de baixo consumo de energia. Para a estação de supervisão foi desenvolvido um programa que permite o controlo do robô e supervisão dos objectivos da missão. A interface gráfica permite de uma forma intuitiva efectuar o controlo do robô. Os testes iniciais permitiram demonstrar as capacidades dos sistemas desenvolvidos para atingir os objectivos propostos. ABSTRACT: Unmanned aerial vehicles are being increasingly sought to perform every days tasks. But these systems are still costly and require a large crew of mission controllers and pilots to adequately manoeuvre the UAV. Managing and control an autonomous air vehicle in a partially known and uncontrolled environment is a complex problem. Current UAVs are based on costly sensors and control systems. These control systems are also usually heavy and demand large amounts of power. This thesis aims to develop an easy to operate unmanned aerial system for surveillance and monitoring missions. As part of this system will be developed an aerial platform, the embedded control system, the ground station with a graphical interface. The platform designed is based on a small lighter-than-air vehicle. To successfully complete the mission objectives the UAV must be capable of navigate through constrained areas and endow indoor flights. The UAV is equipped with low power consumption sensors and processors. For the ground station will be developed an application to control and monitor the UAV status. The graphical user interface application provide an easy to use interface to control and monitor the mission objectives. The initial tests allowed to validate the feasibility of the systems developed to achieve the proposed goals.
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Tognon, Marco. „Theory and Applications for Control and Motion Planning of Aerial Robots in Physical Interaction with particular focus on Tethered Aerial Vehicles“. Thesis, Toulouse, INSA, 2018. http://www.theses.fr/2018ISAT0030.
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Cette thèse se concentre sur les robots aériens autonomes qui interagissent avec l’environnement et en particulier sur la conception de nouvelles méthodes de commande et de planification de mouvement pour tels systèmes. De nos jours, les véhicules aériens autonomes sont de plus en plus utilisés dans des nombreux domaines d’application, mais ils viennent utilisés surtout comme des simples capteurs. Au vu de ça, les défis majeurs dans le domaine de l’interaction physique aérienne, est aujourd’hui d’aller au-delà de cette application limitée, et d’exploiter entièrement les capacités des robots aériens afin d’interagir avec l’environnement. Dans le but de réaliser cet objectif, cette thèse considère l’analyse d’une classe spécifique de systèmes aériens interagissant avec l’environnement : les véhicules aériens attachés avec des câbles ou des bars. Ce travail se concentre sur l’analyse formelle et minutieuse de véhicules aériens attachés, en allant du contrôle et l’évaluation d’état à la planification du mouvement. Nous avons examiné notamment la platitude différentielle du système, trouvant deux sorties plate possibles qui révèlent des nouvelles capacités de tel système pour l’interaction physiques. En plus, poussé par l’intérêt pour l’interaction physique aérienne d’A à Z, nous avons abordés des problèmes supplémentaires liés à la conception, au contrôle et à la planification du mouvement pour des manipulateurs aériensThis thesis focuses on the study of autonomous aerial robots interacting with the surrounding environment, and in particular on the design of new control and motion planning methods for such systems. Nowadays, autonomous aerial vehicles are extensively employed in many fields of application but mostly as autonomously moving sensors. On the other hand, in the recent field of aerial physical interaction, the goal is to go beyond sensing-only applications and fully exploit the aerial robots capabilities in order to interact with the environment. With the aim of achieving this goal, this thesis considers the analysis of a particular class of aerial robots interacting with the environment: tethered aerial vehicles. This work focuses on the thorough formal analysis of tethered aerial vehicles ranging from control and state estimation to motion planning. In particular, the differential flatness property of the system is investigated, finding two possible flat outputs that reveal new capabilities of such system for the physical interaction. The theoretical results were finally employed to solve the challenging problem of landing and takeoff on/from a sloped surface. In addition, moved by the interest on aerial physical interaction from A to Z, we addressed supplementary problems related to the design, control and motion planning for aerial manipulators
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Ait, Jellal Radouane [Verfasser], und Andreas [Akademischer Betreuer] Zell. „Stereo vision and mapping with aerial robots / Radouane Ait Jellal ; Betreuer: Andreas Zell“. Tübingen : Universitätsbibliothek Tübingen, 2020. http://d-nb.info/1212025172/34.
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Yang, Jian. „Real-time trajectory planning for ground and aerial vehicles in a dynamic environment“. Orlando, Fla. : University of Central Florida, 2008. http://purl.fcla.edu/fcla/etd/CFE0002031.
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Archontakis, Andreas. „Assessing the flight quality of a large UAV for sensors/ground robots aerial delivery“. Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5116.
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Approved for public release; distribution is unlimitedThe new goal for unmanned aerial systems will be to find creative methods of keeping the cost low and still maintain effectiveness. This thesis discusses the importance of UAVs over the last few years, suggests the development of a low-cost, large UAV, and evaluates the results. We also examine the idea of a platform for deploying multiple aerial-delivery, parafoil-based systems and discuss scenarios for the improvement of the collaboration of the large UAV with the Snowflake project.
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Fan, Jiankun. „Optimal Path Planning and Control of Quadrotor Unmanned Aerial Vehicle for Area Coverage“. University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1417345596.
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Nieuwenhuisen, Matthias [Verfasser]. „Planning and Navigation in Dynamic Environments for Mobile Robots and Micro Aerial Vehicles / Matthias Nieuwenhuisen“. Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1198933445/34.
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Moletta, Marco. „Path planning for autonomous aerial robots in unknown underground zones optimized for vertical tunnels exploration“. Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-285574.
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Robotics is revolutionizing the work in dangerous environments like mines and tunnels, making life easier and safer for the workers. The specific case considered in this thesis regards UAVs used for 3D mapping of these zones. However, the use of UAVs in underground mines can be challenging for many reasons, such as reduced visibility, no GPS localization available and limited wireless communication, challenges that can be partially solved by using au- tonomous robots. Precisely for these reasons, this work aims to contribute on this application with the implementation of an autonomous path planning algorithm for aerial vehicles in underground zones.However, the peculiar contribution of this work regards shaft mines, which are vertical or near-vertical tunnels with access from the top and the bottom. This particular scenario is extremely challenging for UAVs, since the length of these tunnels (typically 100-200 m) cause the lost of signal from the con- trol station during the mission. Hence, the implemented algorithm is chosen in order to succeed in shaft scenarios. Then, an optimization of the algorithm has been made in order to decrease the time of the mission, thus increasing the chances of success by saving the battery of the robot.Robotik revolutionerar arbetet i farliga miljöer som gruvor och tunnlar, vilket gör livet enklare och säkrare för arbetarna. Det specifika fallet som behandlas i denna avhandling gäller UAV: er som används för 3D-kartläggning av dessa zoner. Användningen av UAV i underjordiska gruvor kan dock vara utmanan- de av många anledningar, till exempel minskad sikt, ingen GPS-lokalisering tillgänglig och begränsad trådlös kommunikation, utmaningar som delvis kan lösas genom att göra roboten autonom. Just av dessa skäl syftar detta arbe- te till att bidra till denna applikation med implementeringen av en autonom vägplaneringsalgoritm för flygfordon i underjordiska zoner. Det relaterade ar- betet har utvecklats med stöd av Inkonova AB, ett robotföretag i Stockholm. Emellertid gäller det speciella bidraget till detta arbete axelminor, som är ver- tikala eller nästan vertikala tunnlar med åtkomst från toppen och botten. Det- ta speciella scenario är extremt utmanande för UAV: er, eftersom längden på dessa tunnlar (vanligtvis 100-200 m) orsakar förlorad signal från kontroll- stationen under uppdraget. Därför väljs den implementerade algoritmen för att lyckas i axelscenarier. Sedan har en optimering av algoritmen gjorts för att minska uppdragstiden och därmed öka chanserna för framgång genom att spara i robotens batteri.
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Sevcik, Keith Wayne Oh Paul Yu. „A hardware-in-the-loop testing facility for unmanned aerial vehicle sensor suites and control algorithms /“. Philadelphia, Pa. : Drexel University, 2010. http://hdl.handle.net/1860/3262.
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Hayajneh, Mohammad Radi Mohammad <1987>. „Nonlinear State Estimation and Control of Autonomous Aerial Robots: Design and Experimental Validation of Smartphone Based Quadrotor“. Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7297/.
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This work presents developments of Guidance, Navigation and Control (GNC) systems with application to autonomous Unmanned Aerial Vehicle (UAV). Precisely, this work shows the development of navigation system based on nonlinear complementary filters for position, velocity and attitude estimation using low-cost sensors. The proposed filtering method provides attitude estimates in quaternion representations and position and velocity estimates by fusing measurements from Inertial Measurement Unit (IMU), GPS, and a barometer. Least Square Method (LSM) was used in gains tuning to find the best-fitting of the estimated states with precise measurements obtained by a vision based motion capture system. A complete navigation system was produced by integrating both the attitude and the position filters. The integration of the filtering approach based primarily on the ease of design and computational load. Furthermore, the structure of the filtering design allow for straightforward implementation without a need of high performance signal processing. Moreover, the filters can be tuned totally independent of each other. This work also introduces a nonlinear flight controller for stability and trajectory tracking that is practical for real-time implementation. This controller is also demonstrated the ability of a supervisory controller to provide effective waypoint navigation capabilities in autonomous UAV. The implementation of the guidance, navigation, and control algorithms were adopted in the design of a novel smartphone based autopilot for particular quadrotor aerial platforms. The performances of the proposed work are then evaluated by means of several flight tests. The work also includes a design of advanced navigation and guidance systems based on Robot Operating System (ROS) for Search And Rescue (SAR) missions. Primarily, the performance of the navigation and guidance systems were tested in laboratory by simulating GPS measurements in Linux computer mounted on the top of a quadrotor. This activity facilitates moving by the experiments from indoor to outdoor.
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Tadiello, Matteo. „Deep reinforcement learning method for autonomous exploration of unknown underground zones using aerial robots with 3D LIDAR“. Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289156.
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The capability of robots to works in dangerous environments like underground mines can allow workers to work in a safer environment. In particular mapping and explore mines and tunnels can save lives and money. For this kind of missions, UAVs are often chosen, thanks to their high mobility in 3D spaces. However, to do that, the robot needs to work in a complex environment with reduced visibility and poor connections. Artificial intelligence and in particular Deep Reinforcement Learning (DRL) is becoming a more popular approach to solve this kind of problems, but the implementation of this techniques is still difficult and limited, especially when treating with 3D data. For these reasons, the aim of this work is to provide a new approach to solve the problem of autonomous exploration of 3D underground environments using DRL. We present and explain the approaches which has worked and why other approaches have not, with particular attention in the resources used. Moreover, we implement the new technique paying attention to provide a system which can be easily transferred in a real UAV. Hence, we test the new approach with the actual state of the art in the field, explaining which technique use today and why DRL is a valuable alternative to more analytical approaches used nowadays.Roboternas förmåga att arbeta i farliga miljöer som underjordiska gruvor kan göra det möjligt för arbetare att arbeta i en säkrare miljö. I synnerhet kan kartläggning och utforska gruvor och tunnlar spara liv och pengar. För denna typ av uppdrag väljs ofta UAV: er tack vare deras höga rörlighet i 3D-utrymmen. Men för att göra det måste roboten arbeta i en komplex miljö med nedsatt synlighet och dåliga anslutningar. Artificiell intelligens och särskilt Deep Reinforcement Learning (DRL) blir ett mer populärt tillvägagångssätt för att lösa denna typ av problem, men implementeringen av denna teknik är fortfarande svår och begränsad, särskilt vid behandling med 3D-data. Av dessa skäl är syftet med detta arbete att tillhandahålla ett nytt tillvägagångssätt för att lösa problemet med autonom utforskning av 3D-underjordiska miljöer med hjälp av DRL. Vi presenterar och förklarar de metoder som har fungerat och varför andra metoder inte har, med särskild uppmärksamhet i de resurser som används. Dessutom implementerar vi den nya tekniken med uppmärksamhet åt att tillhandahålla ett system som enkelt kan överföras i en riktig UAV. Därför testar vi det nya tillvägagångssättet med det faktiska tillståndet i fältet och förklarar vilken teknik som används idag och varför DRL är ett värdefullt alternativ till mer analytiska tillvägagångssätt som används idag.
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Yu, Kevin L. „Persistent Monitoring with Energy-Limited Unmanned Aerial Vehicles Assisted by Mobile Recharging Stations“. Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/83493.
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We study the problem of planning a tour for an energy-limited Unmanned Aerial Vehicle (UAV) to visit a set of sites in the least amount of time. We envision scenarios where the UAV can be recharged along the way either by landing on stationary recharging stations or on Unmanned Ground Vehicles (UGVs) acting as mobile recharging stations. This leads to a new variant of the Traveling Salesperson Problem (TSP) with mobile recharging stations. We present an algorithm that finds not only the order in which to visit the sites but also when and where to land on the charging stations to recharge. Our algorithm plans tours for the UGVs as well as determines the best locations to place stationary charging stations. While the problems we study are NP-Hard, we present a practical solution using Generalized TSP that finds the optimal solution. If the UGVs are slower, the algorithm also finds the minimum number of UGVs required to support the UAV mission such that the UAV is not required to wait for the UGV. We present a calibration routine to identify parameters that are needed for our algorithm as well as simulation results that show the running time is acceptable for reasonably sized instances in practice. We evaluate the performance of our algorithm through simulations and proof-of-concept experiments with a fully autonomous system of one UAV and UGV.Master of Science
Commercially available Unmanned Aerial Vehicles (UAVs), especially multi-rotor aircrafts, have a flight time of less than 30 minutes. However many UAV applications, such as surveillance, package delivery, and infrastructure monitoring, require much longer flight times. To address this problem, we present a system in which an Unmanned Ground Vehicle (UGV) can recharge the UAV during deployments. This thesis studies the problem of finding when, where, and how much to recharge the battery. We also allow for the UGV to recharge while moving from one site to another. We present an algorithm that finds the paths for the UAV and UGV to visit a set of points of interest in the least time possible. We also present algorithms for cases when the UGV is slower than the UAV, and more than one UGV may be required. We evaluate our algorithms through simulations and proof-of-concept experiments.
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Six, Damien. „Conception et commande de robots parallèles volants“. Thesis, Ecole centrale de Nantes, 2018. http://www.theses.fr/2018ECDN0046/document.
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La manipulation aérienne est l’un des défis de la robotique au cours de cette dernière décennie. L’un des freins au développement des manipulateurs aériens est l’autonomie limitée des drones, réduite par la charge et la consommation électrique du manipulateur embarqué. Une solution pour dépasser cette limite passe par la collaboration de plusieurs drones dans une tâche de manipulation. Cette thèse porte sur la conception et la commande d’un nouveau type de véhicule autonome aérien destiné à la manipulation. Le concept consiste à faire collaborer plusieurs drones, en particulier des quadricoptères, au travers d’une architecture passive polyarticulée. Le robot ainsi obtenu est une fusion entre l’architecture passive d’un robot parallèle et plusieurs drones. L’étude du modèle dynamique de cette classe de robots met en avant un découplage dans le modèle dynamique. Ce découplage permet la conception d’une commande en cascade qui assure la stabilisation et le suivi de trajectoire pour ces robots. Deux cas d’étude sont ensuite déclinés dans cette thèse : un robot parallèle volant à deux drones et un robot parallèle volant à trois drones. Pour ces deux robots, une simulation numérique est effectuée afin de valider le fonctionnement de la commande. Ces simulations ont également permis de valider la possibilité de changer la configuration de l’architecture passive en vol. Les travaux ont été portés avec succès jusqu’au stade expérimental pour le robot volant à deux dronesAerial manipulation is one of the challenges of robotics over the last decade. One of the constraints on the development of aerial manipulators is the limited autonomy of drones, reduced by the load and energy consumption of the on-board manipulator. One way to overcome this limit is to have several drones collaborate on a manipulation task. This thesis deals with the design and control of a new type of autonomous aerial vehicle for manipulation tasks. The concept consists in the collaboration of several drones, in particular quadrotors, through a polyarticulated passive architecture. The robot thus obtained is a fusion between the passive architecture of a parallel robot and several drones. The study of the dynamic model of this robot class highlights a decoupling in the dynamic model. This decoupling allows the design of a cascade control law. This controller provides stabilization and trajectory tracking for these robots. Two study cases are then presented in this thesis: a flying parallel robot with two drones and a flying parallel robot with three drones. For these two robots, a numerical simulation is performed to validate the controller performances. These simulations also allowed to validate the reconfiguration abilities of passive architecture in flight. The work was successfully carried to the experimental stage for the flying robot with two drones
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Pfeil, Kevin. „An Exploration of Unmanned Aerial Vehicle Direct Manipulation Through 3D Spatial Interaction“. Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5836.
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We present an exploration that surveys the strengths and weaknesses of various 3D spatial interaction techniques, in the context of directly manipulating an Unmanned Aerial Vehicle (UAV). Particularly, a study of touch- and device- free interfaces in this domain is provided. 3D spatial interaction can be achieved using hand-held motion control devices such as the NintendoWiimote, but computer vision systems offer a different and perhaps more natural method. In general, 3D user interfaces (3DUI) enable a user to interact with a system on a more robust and potentially more meaningful scale. We discuss the design and development of various 3D interaction techniques using commercially available computer vision systems, and provide an exploration of the effects that these techniques have on an overall user experience in the UAV domain. Specific qualities of the user experience are targeted, including the perceived intuition, ease of use, comfort, and others. We present a complete user study for upper-body gesture, and preliminary reactions towards 3DUI using hand-and-finger gestures are also discussed. The results provide evidence that supports the use of 3DUI in this domain, as well as the use of certain styles of techniques over others.M.S.
Masters
Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Science
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Polakowski, Matthew Ryan. „An Improved Lightweight Micro Scale Vehicle Capable of Aerial and Terrestrial Locomotion“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1334600182.
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Sampaio, Rafael Coronel Bueno. „Novel morphologies on flying robots: design for field application“. Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-21072016-223549/.
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Energetic limitations in low scale Unmanned Aerial Vehicles (UAVs) sometimes turns outdoor field applications impractical, which restricts the realization of several tasks that could potentially be improved or benefited from its sounding characteristics. Depending on the mission, Mini Aerial Vehicles (MAVs) energetic resources may be mostly wasted during the round trip from launching base and target point around which a given mission must be accomplished. In this sense, the initial deployment problem becomes prominent, raising new opportunities on how aerial robots may be launched/deployed. This work presents a novel perspective in morphological adaptations for aerial robotics that may potentially minimize initial deployment problem issues. From that perspective, we present three novel morphologies. First refers to a hybrid fixed-wing/quadrotor aiming in-flight launching possibilities. Still looking at in-flight launching, second MAV regards to a new morphology for a quadrotor whose center of gravity is shifted in order to improve passive static stability. Third one relates to a hybrid MAV that combines a watercraft and a quadrotor. The aircraft may navigate on water with low energetic cost through a specially designed structure. It also presents static stability in air and over the ground. We present all details concerning new concepts, development, analysis, design and flight simulation for all three novel platforms. A concise and robust validation of stability control is firstly performed with the ©VICON vision system. Finally, on-the-field evaluation for all three morphologies are extensively carried out, presenting optimistic experimental results of our findings.As limitações energéticas em robótica aérea de campo muitas vezes levam à sua não utilização em tarefas que poderiam se beneficiar substancialmente de suas inúmeras vantagens. Dependendo da complexidade da missão, os recursos energéticos podem ser despendidos prematuramente ainda durante o traslado ao ponto de interesse. Nesse contexto, se evidencia o problema do lançamento inicial de robôs, o que faz surgir novas possibilidades para o desenvolvimento de novas maneiras de lançá-los. Este trabalho propõe uma nova perspectiva para adaptações morfológicas para robótica aérea as quais podem significativamente minimizar os efeitos das limitações energéticas. Sob essa ótica, são propostas três novas morfologias. A primeira consiste de um robô aéreo híbrido asa fixa/quadrotor visando a possibilidade do lançamento em voo. A segunda consiste de uma aeronave de asa rotativa na configuração quadrotora morfologicamente adaptada para reposicionamento do seu centro de gravidade. O aumento da estabilidade estática passiva da aeronave também visa o seu lançamento durante o voo. A terceira se refere a um veículo aéreo híbrido que combina uma estrutura naval e um quadrotor, capaz de navegar em cenários aquáticos com baixo custo energético. O desenho mecânico resultante permite sua operação no ponto ótimo tanto para a navegação aérea quanto aquática, oferecendo estabilidade estática em todos os cenários (terra, ar e água). São apresentados todos os detalhes de conceito, concepção, análise, projeto e simulação em voo das três novas plataformas. Uma validação robusta dos sistemas de controle e estabilidade é realizada por sistema de visão ©VICON. Por fim, ensaios em campo são realizados, apresentando resultados experimentais otimistas para a aplicação das três novas morfologias.
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Hoffman, Bruce. „Biology and use of nibbi heteropsis flexuosa (ARACEAE) the source of an aerial root fiber product in Guyana“. FIU Digital Commons, 1997. http://digitalcommons.fiu.edu/etd/2716.
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The aerial roots of Heteropsis flexuosa (Kunth) Bunting, a hemi-epiphyte, are harvested by indigenous communities in Guyana for a developing wicker furniture market. Nibbi roots have potential as a sustainably harvested product, but there is little data to guide management. I examined nibbi biology, harvest response, product yield and use at several forest sites. H. flexuosa is a relatively abundant plant and 35% of trees (≥ 10 cm dbh) in plots were hosts. Stems exhibited mean growth rates of 1-3 cm per month. Aerial roots grew a mean 156 cm per month and some reached maturity within 6 months. With present methods, harvest does not decimate populations because 97% of colonized trees possess few harvestable roots. But, only 28% of cut roots re-generated in experiments. For indigenous harvesters at Manawarin village, nibbi harvesting is a primary source of cash income and is important in daily subsistence.
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Lallement, Raphael. „Symbolic and Geometric Planning for teams of Robots and Humans“. Thesis, Toulouse, INSA, 2016. http://www.theses.fr/2016ISAT0010/document.
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La planification HTN (Hierarchical Task Network, ou Réseau Hiérarchique de Tâches) est une approche très souvent utilisée pour produire des séquences de tâches servant à contrôler des systèmes intelligents. Cette thèse présente le planificateur HATP (Hierarchical Agent-base Task Planner, ou Planificateur Hiérarchique centré Agent) qui étend la planification HTN classique en enrichissant la représentation des domaines et leur sémantique afin d'être plus adaptées à la robotique, tout en offrant aussi une prise en compte des humains. Quand on souhaite générer un plan pour des robots tout en prenant en compte les humains, il apparaît que les problèmes sont complexes et fortement interdépendants. Afin de faire face à cette complexité, nous avons intégré à HATP un planificateur géométrique apte à déduire l'effet réel des actions sur l'environnement et ainsi permettre de considérer la visibilité et l'accessibilité des éléments. Cette thèse se concentre sur l'intégration de ces deux planificateurs de nature différente et étudie comment par leur combinaison ils permettent de résoudre de nouvelles classes de problèmes de planification pour la robotiqueHierarchical Task Network (HTN) planning is a popular approach to build task plans to control intelligent systems. This thesis presents the HATP (Hierarchical Agent-based Task Planner) planning framework which extends the traditional HTN planning domain representation and semantics by making them more suitable for roboticists, and by offering human-awareness capabilities. When computing human-aware robot plans, it appears that the problems are very complex and highly intricate. To deal with this complexity we have integrated a geometric planner to reason about the actual impact of actions on the environment and allow to take into account the affordances (reachability, visibility). This thesis presents in detail this integration between two heterogeneous planning layers and explores how they can be combined to solve new classes of robotic planning problems
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Tabatabaei, Seyed Jalal. „Yield, quality and nutritional status of tomato (Lycopersicon esculentum) fruits as affected by aerial environment and nutrition distribution in the root zone“. Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250733.
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Fernandes, Vanessa Jordão Marcato [UNESP]. „Extração de contornos de telhados de edifícios a partir da integração de imagem aérea de alta-resolução e dados LASER, utilizando campos aleatórios de Markov“. Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/148686.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Esse trabalho propõe o desenvolvimento de um método para a extração automática de contornos de telhados de edifícios com a combinação de dados de Varredura a LASER Aerotransportado (VLA) e dados fotogramétricos e campos aleatórios de Markov (MRF). Inicialmente, um Modelo Digital de Superfície normalizado (MDSn) é gerado através da diferença entre o Modelo Digital de Superfície (MDS) e o Modelo Digital de Terreno (MDT), obtidos a partir da nuvem de pontos LASER. Em seguida, o MDSn é segmentado para a obtenção dos polígonos que representam objetos altos da cena. Esses polígonos são projetados na imagem para restringir o espaço de busca para a segmentação da imagem em regiões. Esse processo possibilita a extração de polígonos na imagem que representem objetos altos. O processo de identificação de contornos de telhados, em meio aos objetos altos detectados na imagem, na etapa anterior, é realizado através da otimização de uma função de energia estabelecida com base em MRF que modela propriedades específicas de contornos de telhados de edifícios. No modelo MRF são utilizados tanto os polígonos extraídos da imagem quanto os extraídos dos dados VLA. A função de energia é otimizada pelo método Algoritmo Genético (AG). O método proposto nesse trabalho foi avaliado com base em dados reais - imagens aéreas de alta resolução e dados VLA. Os resultados obtidos na avaliação experimental mostraram que a metodologia funciona adequadamente na tarefa de extrair os contornos de telhados de edifícios. A função de energia proposta associada ao método de otimização AG diferenciou corretamente os contornos de telhados de edifícios dos demais objetos altos presentes nas cenas. Os contornos de telhados extraídos apresentam boa qualidade, o que é evidenciado por meio dos índices de completeza e correção obtidos pela avaliação numérica. Com base nos índices médios obtidos para cada experimento, têm-se as médias de completeza e correção para os experimentos iguais a 90,96% e 98,99%, respectivamente. Os valores máximos de completeza e correção são de 99,19% e 99,94%, respectivamente, e os valores mínimos de 78,08% e 97,46%, respectivamente. Os menores valores de completeza estão associados às áreas de oclusão por vegetação e presença de sombras.
This paper proposes a method for the automatic extraction of building roof contours through a combination of Airborne Laser Scanner (ALS) and photogrammetric data, and Markov Random Field (MRF). Initially, a normalized digital surface model (nDSM) is generated on the basis of the difference between the digital surface model and the digital terrain model, obtained from the LiDAR point cloud. Then the nDSM is segmented to obtain the polygons representing aboveground objects. These polygons are projected onto image to restrict the search space for image segmentation into regions. This process enables the extraction of polygons in the image representing aboveground objects. Building roof contours are identified from among the aboveground objects in the image by optimizing a Markov-random-field-based energy function that embodies roof contour specific properties. In the MRF model are used both polygons extracted from image and from ALS data. The energy function is optimized by the Genetic Algorithm (GA) method. The method proposed in this work was evaluated based on real data - high-resolution aerial images and ALS data. The results obtained in the experimental evaluation showed that the methodology works adequately in the task of extracting the contours of building roofs. The proposed energy function associated with the GA optimization method correctly differentiated the building roof contours from the other high objects present in the scenes. The extracted roof contours show good quality, which is evidenced by the indexes of completeness and correctness obtained by numerical evaluation. Based on the mean indexes obtained for each experiment, the average completeness and correctness for the experiments were equal to 90.96% and 98.99%, respectively. The maximum completeness and correctness values are 99.19% and 99.94%, respectively, and the minimum values are 78.08% and 97.46%, respectively. The lowest values of completeness are associated to the vegetation occlusion areas and presence of shadows.
FAPESP: 2012/22332-2
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Troiani, Chiara. „Vision-Aided Inertial Navigation : low computational complexity algorithms with applications to Micro Aerial Vehicles“. Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENM021/document.
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L'estimation précise du mouvement 3D d'une caméra relativement à une scène rigideest essentielle pour tous les systèmes de navigation visuels. Aujourd'hui différentstypes de capteurs sont adoptés pour se localiser et naviguer dans des environnementsinconnus : GPS, capteurs de distance, caméras, capteurs magnétiques, centralesinertielles (IMU, Inertial Measurement Unit). Afin d'avoir une estimation robuste, lesmesures de plusieurs capteurs sont fusionnées. Même si le progrès technologiquepermet d'avoir des capteurs de plus en plus précis, et si la communauté de robotiquemobile développe algorithmes de navigation de plus en plus performantes, il y aencore des défis ouverts. De plus, l'intérêt croissant des la communauté de robotiquepour les micro robots et essaim de robots pousse vers l'emploi de capteurs à bas poids,bas coût et vers l'étude d'algorithmes à faible complexité. Dans ce contexte, capteursinertiels et caméras monoculaires, grâce à leurs caractéristiques complémentaires,faible poids, bas coût et utilisation généralisée, représentent une combinaison decapteur intéressante.Cette thèse présente une contribution dans le cadre de la navigation inertielle assistéepar vision et aborde les problèmes de fusion de données et estimation de la pose, envisant des algorithmes à faible complexité appliqués à des micro-véhicules aériens.Pour ce qui concerne l'association de données, une nouvelle méthode pour estimer lemouvement relatif entre deux vues de caméra consécutifs est proposée.Celle-ci ne nécessite l'observation que d'un seul point caractéristique de la scène et laconnaissance des vitesses angulaires fournies par la centrale inertielle, sousl'hypothèse que le mouvement de la caméra appartient localement à un planperpendiculaire à la direction de la gravité. Deux algorithmes très efficaces pouréliminer les fausses associations de données (outliers) sont proposés sur la base decette hypothèse de mouvement.Afin de généraliser l'approche pour des mouvements à six degrés de liberté, deuxpoints caracteristiques et les données gyroscopiques correspondantes sont nécessaires.Dans ce cas, deux algorithmes sont proposés pour éliminer les outliers.Nous montrons que dans le cas d'une caméra monoculaire montée sur un quadrotor,les informations de mouvement fournies par l'IMU peuvent être utilisées pouréliminer de mauvaises estimations.Pour ce qui concerne le problème d'estimation de la pose, cette thèse fournit unesolution analytique pour exprimer la pose du système à partir de l'observation de troispoints caractéristiques naturels dans une seule image, une fois que le roulis et letangage sont obtenus par les données inertielles sous l'hypothèse de terrain plan.Afin d'aborder le problème d'estimation de la pose dans des environnements sombresou manquant de points caractéristiques, un système équipé d'une caméra monoculaire,d'une centrale inertielle et d'un pointeur laser est considéré. Grace à une analysed'observabilité il est démontré que les grandeurs physiques qui peuvent êtredéterminées par l'exploitation des mesures fourni par ce systeme de capteurs pendantun court intervalle de temps sont : la distance entre le système et la surface plane ;la composante de la vitesse du système qui est orthogonale à la surface ; l'orientationrelative du système par rapport à la surface et l'orientation de la surface par rapport àla gravité. Une méthode récursive simple a été proposée pour l'estimation de toutesces quantités observables.Toutes les contributions de cette thèse sont validées par des expérimentations à l'aidedes données réelles et simulées. Grace à leur faible complexité de calcul, lesalgorithmes proposés sont très appropriés pour la mise en oeuvre en temps réel surdes systèmes ayant des ressources de calcul limitées. La suite de capteur considéréeest monté sur un quadrotor, mais les contributions de cette thèse peuvent êtreappliquées à n'importe quel appareil mobileAccurate egomotion estimation is of utmost importance for any navigation system.Nowadays di_erent sensors are adopted to localize and navigate in unknownenvironments such as GPS, range sensors, cameras, magnetic field sensors, inertialsensors (IMU). In order to have a robust egomotion estimation, the information ofmultiple sensors is fused. Although the improvements of technology in providingmore accurate sensors, and the efforts of the mobile robotics community in thedevelopment of more performant navigation algorithms, there are still openchallenges. Furthermore, the growing interest of the robotics community in microrobots and swarm of robots pushes towards the employment of low weight, low costsensors and low computational complexity algorithms. In this context inertial sensorsand monocular cameras, thanks to their complementary characteristics, low weight,low cost and widespread use, represent an interesting sensor suite.This dissertation represents a contribution in the framework of vision-aided inertialnavigation and tackles the problems of data association and pose estimation aimingfor low computational complexity algorithms applied to MAVs.For what concerns the data association, a novel method to estimate the relative motionbetween two consecutive camera views is proposed. It only requires the observationof a single feature in the scene and the knowledge of the angular rates from an IMU,under the assumption that the local camera motion lies in a plane perpendicular to thegravity vector. Two very efficient algorithms to remove the outliers of the featurematchingprocess are provided under the abovementioned motion assumption. Inorder to generalize the approach to a 6DoF motion, two feature correspondences andgyroscopic data from IMU measurements are necessary. In this case, two algorithmsare provided to remove wrong data associations in the feature-matching process. Inthe case of a monocular camera mounted on a quadrotor vehicle, motion priors fromIMU are used to discard wrong estimations.For what concerns the pose estimation problem, this thesis provides a closed formsolution which gives the system pose from three natural features observed in a singlecamera image, once the roll and the pitch angles are obtained by the inertialmeasurements under the planar ground assumption.In order to tackle the pose estimation problem in dark or featureless environments, asystem equipped with a monocular camera, inertial sensors and a laser pointer isconsidered. The system moves in the surrounding of a planar surface and the laserpointer produces a laser spot on the abovementioned surface. The laser spot isobserved by the monocular camera and represents the only point feature considered.Through an observability analysis it is demonstrated that the physical quantities whichcan be determined by exploiting the measurements provided by the aforementionedsensor suite during a short time interval are: the distance of the system from the planarsurface; the component of the system speed that is orthogonal to the planar surface;the relative orientation of the system with respect to the planar surface; the orientationof the planar surface with respect to the gravity. A simple recursive method toperform the estimation of all the aforementioned observable quantities is provided.All the contributions of this thesis are validated through experimental results usingboth simulated and real data. Thanks to their low computational complexity, theproposed algorithms are very suitable for real time implementation on systems withlimited on-board computation resources. The considered sensor suite is mounted on aquadrotor vehicle but the contributions of this dissertations can be applied to anymobile device
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Frigeri, Renita Betero Correa. „Relação entre raiz e parte aerea de plantulas de especies arboreas tropicais sob diferentes niveis de radiação solar“. [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315143.
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Orientador: Ivany Ferraz Marques ValioTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O crescimento de plântulas de espécies arbóreas tropicais, em ambientes com disponibilidade luminosa contrastante, depende de interações entre características morfológicas e fisiológicas. Dentre as várias alterações morfológicas que ocorrem em condições de baixa irradiância, uma é a razão de crescimento entre a raiz e a parte aérea. A razão raiz:parte aérea de plântulas pode ser indicativa de especialização a diferentes ambientes. No geral, quanto mais sombreado o ambiente, maior a alocação de biomassa para as folhas. O aumento da biomassa da parte aérea (folhas e caules) se faz em detrimento da biomassa das raízes. Com o objetivo de verificar os efeitos de diferentes níveis de irradiância na alocação diferencial de fotossintatos, entre a parte aérea e subterrânea de plântulas de algumas espécies arbóreas tropicais, foram analisados o papel dos cotilédones e da região apical do caule e raiz na alocação, o teor de amido e a translocação de compostos de carbono. Plântulas de Copaifera langsdorfii, Dalbergia nigra, Hymenaea courbaril, Myroxylon peruiferum, Peltophorum dubium e Poecilanthe parviflora, consideradas tolerantes ao sombreamento e Bauhinia longifolia, Enterolobium contortisiliquum, Erythrina speciosa, Piptadenia gonoacantha, Senna macranthera e Schizolobium parahyba, consideradas pioneiras, foram crescidas por aproximadamente 2 meses sob 4, 18, 50 e 100 % da irradiância total. O acúmulo de biomassa de todas as espécies estudadas aumentou em resposta ao aumento da disponibilidade luminosa, bem como as taxas de crescimento relativo e a assimilação líquida. Verificou-se, em geral, redução na razão raiz: parte aérea das plântulas sob baixa irradiância. Apesar deste padrão geral, as espécies estudadas variaram quanto à razão raiz:parte aérea. Plântulas de espécies consideradas tolerantes ao sombreamento como Myroxylon peruiferum, Poecilanthe parviflora e Hymenaea courbaril apresentaram pouca alteração na razão raiz:parte aérea entre os diferentes tratamentos. Bauhinia longifolia, Copaifera langsdorfii, Erythrina speciosa, Enterolobium contortisiliquum e Piptadenia gonoacantha destacaram-se pelas altas razões raiz:parte aérea sob altas irradiâncias. A remoção dos cotilédones das plântulas, da maioria das espécies estudadas, resultou em redução da biomassa total. No geral, não houve diferença significativa na fração de biomassa alocada ao caule, às raízes e às folhas e na razão raiz:parte aérea, com a remoção dos cotilédones. O acúmulo relativo de amido nas folhas não pareceu associado ao decréscimo na partição de biomassa para as raízes, nas plântulas das espécies analisadas. Plântulas de Erythrina speciosa, que pouco diferiram neste aspecto quando mantidas a 2 e 50 % da irradiância, apresentaram a maior alteração na razão raiz:parte aérea. Plântulas de Poecilanthe parviflora, que não alteraram significativamente a distribuição de massa seca entre raiz e parte aérea, diferiram significativamente quanto ao acúmulo relativo de amido nas duas irradiâncias. Aparentemente, a remoção parcial dos diferentes órgãos contribuiu pouco para a redução da biomassa total. No geral, as plântulas das espécies analisadas revelaram um crescimento compensatório em resposta à remoção, tanto sob baixa quanto alta irradiância. A razão raiz:parte aérea não foi alterada em relação às plântulas intactas. A avaliação da distribuição de compostos com carbono radioativamente marcados demonstrou que a direção do movimento dos assimilados nas plântulas de Erythrina speciosa, Poecilanthe parviflora e Enterolobium contortisiliquum, após 48 horas de aplicação, deu-se no sentido da folha aplicada para o caule e em menor proporção para a raiz, exceto em plântulas de Hymenaea courbaril que retiveram quase a totalidade de assimilados na folha aplicada. No geral, não se observou uma diferença marcante em termos de movimento de assimilados, em plântulas mantidas a 2 e 50 % da irradiância. Em resumo, as espécies consideradas pioneiras apresentaram mudanças morfológicas e fisiológicas mais amplas, revelando grande plasticidade e habilidade em adaptar-se às variadas intensidades luminosas a que foram submetidas, em relação às espécies secundárias que revelaram baixa plasticidade fenotípica, a qual geralmente está associada à tolerância ao sombreamento. Entretanto, verificou-se a existência de espécies com respostas intermediárias e variáveis em relação aos parâmetros analisados
Abstract: The growth of seedlings of rain-forest tree species, in environments with contrasting light availability depends on the interaction between morphological and physiological characteristics. Among the various morphological alterations which occur in low-irradiance conditions, one of them is the ratio of growth between the root and shoot. The root: shoot ratio of seedlings can be suggestive to specialization to different environments. In general, the more shadowed the environment is, bigger is the biomass allocation on the leaves. The increase of biomass on the leaf area (leaves and stalk) occurs due to biomass detriment on the roots. Aiming to verify the different radiation level effects in the differential allocation of photosynthates between the root and the shoot of seedlings from some rain-forest tree species, the role of cotyledons and the apical region in the stalk and root in the allocation, the starch tenor and the translocation of carbon compounds radiolabelled. Seedlings of Copaifera langsdorfii, Dalbergia nigra, Hymenaea courbaril, Myroxylon peruiferum, Peltophorum dubium e Poecilanthe parviflora, considered shade tolerant and Bauhinia longifolia, Enterolobium contortisiliquum, Erythrina speciosa, Piptadenia gonoacantha,, Senna macranthera e Schizolobium parahyba, considered pioneers, were grown for approximately two months under 4, 18, 50 and 100 % of total irradiance. The biomass accumulation increased in all the studied species in response to light availability increase as well as the relative growth rate and net assimilation rate. In general, it was observed a reduction in the root:shoot ratio of seedlings under low irradiance. Despite this general pattern, the studied species varied regarding the root:shoot ratio. Seedlings of species considered shading tolerant as Myroxylon peruiferum, Poecilanthe parviflora e Hymenaea courbaril did not present a significant change in the root: shoot ratio. Bauhinia longifolia, Copaifera langsdorfii, Erythrina speciosa, Enterolobium contortisiliquum e Piptadenia gonoacantha contrasted due to high root: shoot ratio under high irradiance. The removal of cotyledons from the seedlings, in most of the studied species, resulted in reduction of the total biomass. Generally, there was not significant difference in the biomass portion allocated in the stalk, in the root and in the leaves and in the root:shoot ratio, with the removal of cotyledons. The accumulation of starch in the leaves did not seem associated to the decrease of biomass partitioning to the seedlings roots in the analyzed species. Seedlings of Erythrina speciosa which little differed in this aspect when put under 2 and 50% of irradiance, presented a higher alteration in the root: shoot ratio. Seedlings of Poecilanthe parviflora, which did not alter significantly the distribution of dry mass between root and shoot, differed significantly in the relative accumulate of starch in both irradiance. Apparently, the partial removal of these different organs little contributed for the total biomass reduction. In general, the analyzed seedling species, revealed compensatory growth in response to removal, either under low or high irradiance. The root:shoot ratio was not altered compared to the intact seedlings. The analyses of distribution of carbon compounds radioactively marked, showed that the moving direction of the assimilate in the seedlings of Erythrina speciosa, Poecilanthe parviflora e Enterolobium contortisiliquum, after 48 hours of application, occurred in the application leaf to stalk way also in lower portion to the root except in seedlings of Hymenaea courbaril which retained almost all the assimilate in the applied leaf. In an overall, a distinct difference was not observed in assimilates flow in seedlings put under 2 to 50 % of irradiance. Altogether, the species considered pioneers presented more ample morphological and physiological changes, revealing great plasticity and ability in adapting to various light intensities which they were submitted. In relation to the secondary species which revealed low phenotypical plasticity to which is generally associated with shadow tolerating therefore, there was found the existence of species with intermediate variable according to the analyzed parameters
Doutorado
Doutor em Biologia Vegetal
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Moses, Kenneth C. „Biomimicry of the Hawk Moth, Manduca sexta (L.): Forewing and Thorax Emulation for Flapping-Wing Micro Aerial Vehicle Development“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case158687503705972.
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Delamare, Quentin. „Algorithmes d’estimation et de commande pour des quadrirotors en interaction physique avec l’environnement“. Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S099.
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Le champ de la robotique aérienne pour l’interaction physique permet aujourd’hui à un robot aérien d’appliquer un effort maîtrisé sur un objet ou sur l’environnement alors qu’il vole. En s’inspirant de l’utilisation des contacts faite en robotique humanoïde, nous proposons dans cette thèse de s’appuyer sur ces approches pour dépasser l’idée que l’environnement est une contrainte, en exploitant le contact physique avec celui-ci dans le but de réaliser de la locomotion aérienne. Cette idée est étudiée et démontrée au travers de simulations et expérimentations d’une nouvelle plateforme robotique aérienne consistant en un quadrirotor équipé d’un bras robotique a 1 degré de liberté. D’autre part, nous avons aussi étudié le problème de la génération de trajectoires dont la sensibilité aux paramètres du modèle est minimale. Ce problème est généralisé à n’importe quel robot, et se révèle particulièrement approprié dans le cas du quadrirotor du fait de l’incertitude importante concernant ses paramètres inertiels et d’actionnement. Pour traiter ce problème, nous définissons et utilisons la ''sensibilité de l’état aux paramètres'' afin de générer des trajectoires dont la sensibilité aux paramètres est minimale, garantissant une forte robustesseIn recent years, the field of aerial robotics has been improved, allowing the UAVs to apply a controlled wrench on their environment or on an object while flying.Inspired by the use of contacts in legged robots, in this Thesis, we propose the idea of exploiting physical contact with the environment for the purpose of ‘locomotion’ during flight, with the goal of going beyond the common thought that the surrounding environment is a constraint to avoid. These ideas are studied and demonstrated in simulations and experiments on a novel aerial platform consisting of a quadrotor with a 1-dof arm that realizes maneuvers by leveraging contacts with pivot points. Additionally, we also study the problem of generating trajectories that are most insensitive to variations in the model parameters.This problem has a general validity for any robot, and it is particularly relevant for UAVs because of the high uncertainty in their inertial parameters and actuation. In order to address these issues, we define and leverage the novel notion of "closed-loop state sensitivity" for generating trajectories that are minimally-sensitive to parameters with high robustness guarantees
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Clem, Garrett Stuart. „An Optimized Circulating Vector Field Obstacle Avoidance Guidance for UnmannedAerial Vehicles“. Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1530874969780028.
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Moses, Kenneth C. „A Durable Terrestrial Drive Train for a Small Air Vehicle“. Cleveland, Ohio : Case Western Reserve University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1270233578.
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Thesis (Master of Sciences (Engineering))--Case Western Reserve University, 2010Department of EMC - Mechanical Engineering Title from PDF (viewed on 2010-05-25) Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center
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Mundim, Gabriel Borges. „Genetic diversity, path analysis and association mapping for nitrogen use efficiency in popcorn“. Universidade Federal de Viçosa, 2013. http://locus.ufv.br/handle/123456789/4780.
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Os objetivos deste estudo foram (i) identificar linhagens de milho-pipoca eficientes no uso de nitrogênio; (ii) avaliar a diversidade genética entre linhagens de milhopipoca em alto e baixo N; (iii) investigar os efeitos causais de vários caracteres sobre a eficiência no uso de nitrogênio (NUE) e (iv) identificar marcadores SSR associados com caracteres relacionados à NUE. Foram avaliadas 25 linhagens-elite de milhopipoca pertencentes às populações 'Viçosa' e 'Beija-Flor', em alto e baixo N. Foram mensurados os seguintes caracteres: crescimento diário (DG, cm), massa de parte aérea (SDW, mg), de raiz (RDW, mg), e da planta total seca (TDW, mg), razão parte aérea:raiz seca (RSR), eficiência no uso (NUE, mg mg-¹), na absorção (NUpE, mg mg-¹) e na utilização (NUtE, mg mg-¹) de nitrogênio, diâmetro médio (RAD, mm), comprimento total (TRL, cm), área superficial (RSA, cm²) e volume (RV, cm³) de raízes. Foram identificadas linhagens eficientes em cada nível de N. A avaliação da diversidade genética pelo método de agrupamento UPGMA baseado no quadrado da Distância Euclidiana Média resultou em quatro grupos de linhagens para cada nível de N e a análise de componentes principais mostrou que as linhagens poderiam ser agrupadas predominantemente pelos seus caracteres de parte aérea. A eficiência na absorção de N (NUpE) foi a característica mais importante para a NUE em estádios precoces de desenvolvimento da planta em ambos os níveis de N, por apresentar alta correlação e alto efeito direto sobre a variável principal (NUE) na análise de trilha. Em baixo N, a eficiência na utilização de N (NUtE) também apresentou alta correlação e alto efeito direto sobre a variável NUE, mostrando ser uma característica importante para esta condição nesses estádios. Contudo, a seleção direta ainda parece ser o melhor método para aumentar a eficiência de seleção para NUE em estádios precoces. Três marcadores SSR foram validados como associados com os caracteres relacionados à NUE pela análise de mapeamento associativo baseada em ANOVA.
The objectives of this study were to (i) identify efficient inbred lines in nitrogen use; (ii) assess the genetic diversity among popcorn inbred lines under high and low N; (iii) investigate the causal effects of several traits in nitrogen use efficiency (NUE) and (iv) identify SSR markers associated with the traits related to NUE. Twenty-five elite popcorn inbred lines belonging to the 'Viçosa' and 'Beija-Flor' populations were evaluated under high and low N. The following traits were assessed: daily growth (DG, cm), shoot dry weight (SDW, mg), root dry weight (RDW, mg), total plant dry weight (TDW, mg), root:shoot ratio (RSR), nitrogen use efficiency (NUE, mg mg-¹), nitrogen uptake efficiency (NUpE, mg mg-¹), nitrogen utilization efficiency (NUtE, mg mg-¹), root average diameter (RAD, mm), total root length (TRL, cm), root surface area (RSA, cm²) and root volume (RV, cm³). Efficient inbred lines were identified under each N level. The genetic diversity assessment using the UPGMA method based on the squared Mean Euclidean distance grouped the inbred lines into four clusters for each N level and the principal component analysis revealed that the inbred lines could be categorized predominantly by their shoot traits. Nitrogen uptake efficiency (NUpE) was the most important trait for NUE in the early stages of plant development under both N levels, due its high correlation with and high direct effect on NUE obtained in the path analysis. Under low N, nitrogen utilization efficiency (NUtE) also showed high correlation with and direct effect on NUE, demonstrating its importance in this N level in these early stages. Notwithstanding, the direct selection still seems to be the best method to increase the selection efficiency for NUE in these early stages. Furthermore, three SSR markers were identified as true associations with the traits related to NUE, through the association mapping analysis based on ANOVA.
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Schiano, Fabrizio. „Bearing-based localization and control for multiple quadrotor UAVs“. Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S009/document.
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Le but de cette thèse est d'étendre l'état de l'art par des contributions sur le comportement collectif d'un groupe de robots volants, à savoir des quadrirotors UAV. Afin de pouvoir sûrement naviguer dans un environnement, ces derniers peuvent se reposer uniquement sur leurs capacités à bord et non sur des systèmes centralisés (e.g., Vicon ou GPS). Nous réalisons cet objectif en offrant une possible solution aux problèmes de contrôle en formation et de localisation à partir de mesures à bord et via une communication locale. Nous abordons ces problèmes exploitant différents concepts provenant de la théorie des graphes algébriques et de la théorie de la rigidité. Cela nous permet de résoudre ces problèmes de façon décentralisée et de proposer des algorithmes décentralisés capables de prendre en compte également des limites sensorielles classiques. Les capacités embarquées que nous avons mentionnées plus tôt sont représentées par une caméra monoculaire et une centrale inertielle (IMU) auxquelles s'ajoute la capacité de chaque robot à communiquer (par RF) avec certains de ses voisins. Cela est dû au fait que l'IMU et la caméra représentent une possible configuration économique et légère pour la navigation et la localisation autonome d'un quadrirotor UAVThe aim of this Thesis is to give contributions to the state of the art on the collective behavior of a group of flying robots, specifically quadrotor UAVs, which can only rely on their onboard capabilities and not on a centralized system (e.g., Vicon or GPS) in order to safely navigate in the environment. We achieve this goal by giving a possible solution to the problems of formation control and localization from onboard sensing and local communication. We tackle these problems exploiting mainly concepts from algebraic graph theory and the so-called theory of rigidity. This allows us to solve these problems in a decentralized fashion, and propose decentralized algorithms able to also take into account some typical sensory limitations. The onboard capabilities we referred to above are represented by an onboard monocular camera and an inertial measurement unit (IMU) in addition to the capability of each robot to communicate (through RF) with some of its neighbors. This is due to the fact that an IMU and a camera represent a possible minimal, lightweight and inexpensive configuration for the autonomous localization and navigation of a quadrotor UAV
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Tang, Zhiqi. „Commande référencée vision de drones aériens“. Thesis, Université Côte d'Azur, 2021. http://www.theses.fr/2021COAZ4018.
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Cette thèse propose de nouvelles commandes basées sur un retour visuel pour le guidage de drones. Elle considère à la fois des scénarios impliquant un seul ou plusieurs véhicules. Pour le cas du guidage d'un seul véhicule, de nouvelles approches d'asservissement visuel basées image (IBVS) sont proposées pour les drones de type avion (fixed-wing) et les drones de type VTOL (Vertical Take-Off and Landing) opérant en environnements urbains ou encombrés. Des tâches de navigation dans un environnement complexe avec des capacités d'évitement d'obstacle sont considérées. Il s'agit en particulier de l'atterrissage de drones de type fixed-wing sur une piste d'atterrissage et l'atterrissage de drones de type VTOL-UAV en incluant une stratégie d'évitement d'obstacle. L'originalité de l'étude réside dans l'exploitation directe de la centroïde de l'image du motif observé et du flux optique permettant ainsi d'éliminer la nécessité l'estimation de la position et la vitesse du drone. Pour le cas du contrôle de plusieurs véhicules en formation, de nouveaux contrôleurs à base de la mesure de direction entre véhicules sont également proposés pour des formations ayant une interaction topologique orientées ou non orientées. Le flux optique est également exploité dans certains cas afin d'éviter les collisions entre différents agents pendant l'évolution de la formation. Afin d'assouplir les conditions classiques requises par la théorie de la rigidité d'une formation à partir de l'information de direction et lever par la même occasion l'ambiguïté du facteur d'échelle causée par les mesures de directions, la notion de la persistance de l'excitation associée à la formation de référence est explorée. La méthodologie proposée est soutenue par des outils mathématiques rigoureux (impliquant des systèmes dynamiques non linéaires et analysés à l'aide de la théorie de Lyapunov afin de prouver formellement la stabilité asymptotique (ou exponentielle) du système, de garantir la robustesse et enfin d'assurer le bon fonctionnement du système en boucle fermée) et par des expériences réelles et/ou des résultats de simulationThis thesis proposes novel vision-based controllers for the guidance of Unmanned Aerial Vehicles (UAVs). It considers scenarios involving both single and multiple vehicles. For the case of a single-vehicle, novel Image-based visual servo control (IBVS) approaches are proposed for both fixed-wing and vertical take-off and landing (VTOL) UAVs operating in urban or congested environments. Navigation tasks in a complex environment with obstacle avoidance capabilities are considered. In particular, the landing of fixed-wing UAVs on an airstrip and the landing of VTOL-UAVs that includes an obstacle avoidance strategy are considered. The originality of the study lies in the direct exploitation of the centroid of the image of the observed pattern together with the optical flow, thereby eliminating the need to estimate the position and the velocity of the UAV.For multiple vehicles, novel bearing formation controllers are designed for formations under both directed and undirected interaction topologies. Optical flow is explored in the bearing formation control laws in order to achieve collision avoidance between different agents during the formation progression.In order to relax the classical conditions required by bearing rigidity theory and to lift the scale ambiguity caused by bearings, persistence of excitation of the desired bearing reference is explored. The proposed methodology is supported by rigorous mathematical tools (This involves nonlinear dynamical systems and analysis using Lyapunov theory to formally prove the asymptotic (or exponential) stability of the system, guarantee robustness, and finally ensure good performance of the closed-loop system). Further support is provided by real experiments and/or simulation results
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Li, Zhongmou. „Theoretical developments and experimental evaluation of a novel collaborative multi-drones grasping and manipulation system Zof large objects“. Thesis, Ecole centrale de Nantes, 2021. http://www.theses.fr/2021ECDN0019.
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Cette thèse propose un nouveau concept de robot de manipulation aérienne appelé Flying Gripper. Ce robot est un manipulateur aérien, destiné à la saisie, la manipulation et le transport de grands objets de manière autonome. Le robot Flying Gripper est composé de quatre quadrotors, de quatre doigts auto-adaptatifs et d'un châssis. Les principaux apports de ces travaux sont: (1) un concept mécanique original reposant sur l'utilisation de plusieurs quadrotors et tirant parti de la rotation en lacet des quadrotors pour actionner un mécanisme de préhension auto-adaptatif et intrinsèquement sûr (2) une méthode pour analyser des torseurs disponibles en tenant compte des contraintes d'égalité et d'inégalité imposées par les limites d'actionnement, les butées mécaniques et les relations d'équilibre; (3) une commande prédictive permettant de manipuler l'objet saisie avec une masse, des inerties et un centre de masse inconnus; (4) un algorithme d'allocation de contrôle dynamique pour la distribution de l'effort de contrôle, de manière à optimiser l'efficacité énergétique et à assurer la continuité de la commande, en considérant les limites mécaniques du robot.Des simulations numériques et des tests expérimentaux ont été effectués pour valider les performances du contrôleurThis thesis proposes a new concept of aerial manipulation robot named Flying Gripper that is intended to perform grasping, manipulating, and transporting of large objects autonomously. The Flying Gripper robot is composed of four quadrotors, four self-adaptive fingers and a body structure. The main contributions of these works are: (1) an original mechanical concept using multiple quadrotors to obtain full manipulability in SE(3) and taking advantage of their yaw rotations to actuate a self-adaptive and intrinsically safe grasping mechanism; (2) a wrench capability analysis method taking into account the equality and inequality constraints imposed by actuation limits, mechanical stops and equilibrium relations; (3) a model predictive controller to deal with unknown mass, inertia and center of mass due to the grasped object; (4) a Dynamic Control Allocation algorithm to distribute the control output in a way that guarantees the continuity of actuator's velocity, improves the energy efficiency and satisfies the robot mechanical limits.Numerical simulations and experimental tests have been carried out to validate the controller performances
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Khannoussi, Arwa. „Intégration des préférences d'un opérateur dans les décisions d'un drone autonome et élicitation incrémentale de ces préférences“. Thesis, Brest, 2019. http://www.theses.fr/2019BRES0080.
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Un drone totalement autonome est un aéronef sans pilote humain à bord. Il est donc capable d'accomplir une mission sans l'intervention d'un opérateur humain et de prendre des décisions de façon totalement autonome. Cela sous-entend que l'opérateur au sol doit avoir une confiance élevée dans les décisions prises par le drone. L'objectif principal de cette thèse est donc de proposer un moteur de décisions à embarquer dans le drone autonome qui garantit un niveau de confiance élevé de l'opérateur dans la capacité du drone à prendre les "bonnes" décisions. Pour cela nous proposons un moteur de décisions multi-niveaux composé de deux niveaux de décisions principaux. Le premier permet de surveiller l'état du drone et de son environnement pour détecter les événements qui peuvent perturber la réalisation de la mission et déclencher la prise de décision du second niveau. Celui-ci une fois déclenché permet de choisir une action de haut niveau (atterrir, continuer, ...) la mieux adaptée à la situation courante parmi un ensemble d'actions possibles. Ce moteur intègre aussi les préférences d'un opérateur en utilisant des modèles d'Aide Multi-Critère à la Décision. Ces modèles nécessitent une phase en amont de la mission, où les préférences de l'opérateur sont élicitées, avant d'être intégrées dans le drone. Pour réduire l'effort cognitif de l'opérateur pendant cette phase, nous proposons un processus d'élicitation incrémental pendant lequel les questions soumises à l'opérateur sont déduites des réponses précédentes. Cela nous permet de déterminer un modèle représentant fidèlement ses préférences, tout en minimisant le nombre de questionsA fully autonomous unmanned aerial vehicle (UAV) is an aircraft without a human pilot on board. It is consequently able to accomplish a mission without the intervention of a human operator and to make decisions in a totally autonomous way. This implies that the ground operator must have a high level of confidence in the decisions made by the UAV.The main objective of this thesis is therefore to propose a decision engine to be embedded in the autonomous UAV that guarantees a high level of operator confidence in the UAV's ability to make the "right" decisions. For this purpose, we propose a multi-level decision engine composed of two main decision levels. The first one monitors the state of the UAV and its environment to detect events that can disrupt the mission’s execution and trigger the second level. Once triggered, it allows to choose a highlevel action (landing, continuing,...) best adapted to the current situation from a set of possible actions. This engine also integrates the operator's preferences by using Multi-Criteria Decision Aiding models. They require a preliminary phase before the mission, where the operator's preferences are elicited, before being integrated into the UAV. To reduce the operator's effort during this phase, we propose an incremental elicitation process during which the questions submitted to the operator are deduced from the previous answers. This allows us to determine a model that accurately represents his or her preferences, while minimizing the number of questions
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Tezenas, du montcel Thibaut. „Évitement d'obstacles pour quadrirotors en utilisant un capteur de profondeur“. Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT077.
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La sécurité est l'une des préoccupations majeures en robotique et ce autant dans le but de protéger le robot que dans le but de protéger son environnement. Parmi les fonctionnalités relevant de la sécurité, l'évitement d'obstacles est prisée car elle permet de faire évoluer un robot de manière autonome dans un environnement non contrôlé. Cette thèse s'articule autour de cette fonctionnalité d'évitement d'obstacles pour un type de robot spécifique, le quadrirotor. Deux algorithmes d'évitement d'obstacles seront ainsi présentés. Le premier sera quasiment exclusivement l'agrégat d'éléments présentés indépendamment les uns des autres dans la littérature récente dédiée aux quadrirotors. Le deuxième algorithme présentera une nouveauté, un filtrage spatial sur les coûts associés aux différentes trajectoires générées, qui permet d'améliorer les performances d'évitement. Ces deux algorithmes utiliseront un unique capteur de profondeur et se baseront, notamment, sur la platitude des quadrirotors et sur l'utilisation d'une carte de profondeur locale donnant une information sur 360degree.L'autre contribution de cette thèse réside dans la création du benchmark BOARR qui a été développé pour effectuer des tests d'évitement d'obstacles en simulation. Ce benchmark a été construit pour tenter de simuler au mieux un des problèmes présent à de multiples reprises dans la littérature : la navigation dans une forêt dense avec un quadrirotor d'environ SI{500}{g}. Ce benchmark est disponible en open-source et l'auteur de cette thèse espère, grâce à cet outil, augmenter la qualité des tests effectués sur la capacité d'évitement d'obstacles qui est, on le rappelle, une fonctionnalité de sécurité et qui nécessite donc des tests rigoureuxSafety is a major concern in robotics to protect both the robot and its environment. Among the fonctionalities related to safety, obstacle avoidance is looked for since it allows autonomous navigation in unknown environments. This thesis is built around this obstacle avoidance functionnality for a specific type of robots, quadrotors. Two obstacle avoidance algorithms are presented. The first one is the aggregation of recent researchs dedicated to quadrotors but presented in various contexts. The second algorithm includes a novel feature, a spatial filter on costs associated to generated trajectories, which improves the overall performances in avoiding obstacles. Both algorithms use a single RGBD sensor et are based, among other things, on differential flatness and on a representation of the environment that we call an egocubemap. During the thesis, the quality of the tests there were used to cheracterize the algorithms was one of the major concern. It led to the creation of the BOARR benchmark. This benchmark has been developped as an attempt to simulate the most common test environment for quadrotor obstacle avoidance : a forest. This benchmark is available online and is open source. It aims at increasing the quality of the tests used when characterizing the performances of obstacle avoidance algorithms which are related to safety and therefore deserve extended testings
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Juston, Raphael. „De l'oeil élémentaire à l'oeil composé artificiel : application à la stabilisation visuelle en vol stationnaire“. Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4118.
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La stratégie de l'équipe biorobotique est de s'inspirer de découvertes faites en biologie chez l'insecte ailé dont la vision est adaptée à la navigation autonome dans un environnement 3D inconnu. Cette inspiration donne naissance la réalisation de capteurs visuels minimalistes permettant de rendre autonomes des robots volants, pour des tâches complexes telles que : le décollage et l'atterrissage automatiques, l'évitement d'obstacles et, dans le cas de cette thèse, le vol stationnaire.Cette thèse présente la mise en œuvre des capteurs visuels minimalistes bio-inspirés qui, grâce à des algorithmes de traitement que nous avons réalisés, sont capables de localiser la position d'objets visuels en tirant partie de propriétés souvent bannies en optique : un flou, obtenu par défocalisation, associé à un micro-mouvement rétinien actif. Nous montrons que la précision en localisation ainsi obtenue est considérablement améliorée par rapport à la résolution statique définie par l'échantillonnage spatial : ces capteurs optiques bio-inspirés sont donc dotés d'hyperacuité.Cette thèse présente aussi l'œil composé artificiel miniature CurvACE (de 2,2cm3 pour 1,75g) doté d'une vision panoramique (180x60°). Cette thèse décrit la caractérisation et la mise en œuvre du capteur CurvACE sur le robot HyperRob. En fusionnant les mesures de position données par une quarantaine de pixels couvrant un grand champ visuel, l'œil CurvACE mesure sa position par rapport à un environnement visuel texturé complexe. Nous montrons aussi que le robot volant HyperRob, attaché au bout d'un bras, stabilise son roulis et sa position, dans le plan azimutal, grâce à son œil composé artificiel doté d'hyperacuitéThe biorobotics team from the Institute of Movement Sciences (Marseille, France) takes its inspiration from biological studies on flying insects which are able to navigate into unknown 3D environments with a high maneuverability. These studies led us to build minimalist optical sensors to make aerial robots autonomous for achieving complex tasks such as automatic landing and take-off, obstacle avoidance and very accurate hovering flight depicted in this doctoral thesis. This work presents several bio-inspired visual sensors implemented with different visual processing algorithms. All these sensors are able to locate visual objects (contrasting edges and bars) with unusual properties for optical sensing devices: a blur obtained by defocusing optics related with active retinal micro-movements to improve the sensor resolution. We showed that the resolution in locating contrasting objects can be improved up to 160 fold better than the static resolution defined by the pixel pitch, which means that these bio-inspired optical sensors are endowed with hyperacuity.The thesis presents a miniature artificial compound eye CurvACE (of 1.75g for 2.2cm3) with a panoramic field of view (180x60°). This thesis describes thoroughly the characterization and the implementation of the CurvACE sensor onboard an aerial robot named HyperRob. This artificial compound eye acts as a position sensing device able to measure its position relative to a complex textured scene by fusing the position measurements obtained by 40 pixels. The tethered flying robot HyperRob (a 150-g bi-rotor with a 23-cm wingspan) stabilizes its roll and its position thanks to its hyperacute artificial compound eye
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Belkhiri, Ayman. „Modélisation dynamique de la locomotion compliante : Application au vol battant bio-inspiré de l'insecte“. Phd thesis, Ecole des Mines de Nantes, 2013. http://tel.archives-ouvertes.fr/tel-00874497.
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Le travail présenté dans cette thèse est consacré à la modélisation de la dynamique de locomotion des "soft robots", i.e. les systèmes multi-corps mobiles compliants. Ces compliances peuvent être localisées et considérées comme des liaisons passives du système,ou bien introduites par des flexibilités distribuées le long des corps. La dynamique de ces systèmes est modélisée en adoptant une approche Lagrangienne basée sur les outils mathématiques développés par l'école américaine de mécanique géométrique. Du point de vue algorithmique, le calcul de ces modèles dynamiques s'appuie sur un algorithme récursif et efficace de type Newton-Euler, ici étendu aux robots locomoteurs munis d'organes compliants. Poursuivant des objectifs de commande et de simulation rapide pour la robotique, l'algorithme proposé est capable de résoudre la dynamique externe directe ainsi que la dynamique inverse des couples internes. Afin de mettre en pratique l'ensemble de ces outils de modélisation, nous avons pris le vol battant des insectes comme exemple illustratif. Les équations non-linéaires qui régissent les déformations passives de l'aile sont établies en appliquant deux méthodes différentes. La première consiste à séparer le mouvement de l'aile en une composante rigide dite de "repère flottant" et une composante de déformation. Cette dernière est paramétrée dans le repère flottant par la méthode des modes supposés ici appliquée à l'aile vue comme une poutre d'Euler-Bernoulli soumise à la flexion et à la torsion. Quant à la seconde approche, les mouvements de l'aile n'y sont pas séparés mais directement paramétrés par les transformations finies rigides et absolues d'une poutre Cosserat. Cette approche est dite Galiléenne ou "géométriquement exacte" en raison du fait qu'elle ne requiert aucune approximation en dehors des inévitables discrétisations spatiale et temporelle imposées parla résolution numérique de la dynamique du vol. Dans les deux cas,les forces aérodynamiques sont prises en compte via un modèle analytique simplifié de type Dickinson. Les modèles et algorithmes résultants sont appliqués à la conception d'un simulateur du vol, ainsi qu'à la conception d'un prototype d'aile, dans le contexte du projet coopératif (ANR) EVA.