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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Unmanned Aerial Manipulators in Construction - Opportunities and Challenges

Nagori, Chinmay 23 December 2020 (has links)
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.
2

Novel morphologies on flying robots: design for field application / Novas morfologias para robôs aéreos: projeto e controle para aplicações de campo

Sampaio, Rafael Coronel Bueno 27 March 2015 (has links)
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.
3

Novel morphologies on flying robots: design for field application / Novas morfologias para robôs aéreos: projeto e controle para aplicações de campo

Rafael Coronel Bueno Sampaio 27 March 2015 (has links)
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.
4

Decoupled Controllers for Mobile Manipulation with Aerial Robots : Design, Implementation and Test

Riccardo Zanella, Riccardo January 2016 (has links)
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.
5

Learning to Land on Flexible Structures / Lära sig att landa på flexibla strukturer

Wang, Ziqiao January 2022 (has links)
Forests cover 30% of the Earth’s surface area, but most of the tree canopy reaches up to tens of meters above the ground, making it challenging to explore, and thus our knowledge of it is very limited. To help scientists further grasp the biological information in the tree canopy and sample the tree branches, we need a control algorithm that can land drones on branches with different flexibility. Because the flexibility of branches is unpredictable before landing, conventional model-based control methods are not up to the task. For this reason, we developed a reinforcement learning-based landing strategy. By controlling the UAV, interacting with different flexible branches in the simulation to collect data, and then applying the PPO and SAC algorithms for training, we obtained a control strategy that can land the UAV on arbitrarily flexible branches. Finally, the control algorithm is verified in the simulation. / Skogarna täcker 30% av jordens yta, men det mesta av trädkronorna når upp till tiotals meter över marken, vilket gör det svårt att utforska dem, och därför är vår kunskap om dem mycket begränsad. För att hjälpa forskarna att ytterligare förstå den biologiska informationen i trädkronorna och ta prover från trädgrenarna behöver vi en kontrollalgoritm som kan landa drönare på grenar med olika flexibilitet. Eftersom grenarnas flexibilitet är oförutsägbar före landning klarar konventionella modellbaserade styrmetoder inte uppgiften. Därför har vi utvecklat en förstärkningsinlärningsbaserad landningsstrategi. Genom att styra drönaren, interagera med olika flexibla grenar i simuleringen för att samla in data och sedan tillämpa PPO- och SAC-algoritmerna för träning fick vi en kontrollstrategi som kan landa drönaren på godtyckligt flexibla grenar. Slutligen verifieras kontrollalgoritmen i simuleringen.
6

Optimal control and machine learning for humanoid and aerial robots / Contrôle optimal et apprentissage automatique pour robots humanoïdes et aériens

Geisert, Mathieu 23 April 2018 (has links)
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 calcul. / What 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.
7

Theory and Applications for Control and Motion Planning of Aerial Robots in Physical Interaction with particular focus on Tethered Aerial Vehicles / Commande et Planification de Mouvement pour des Robots Aériens en Interaction Physique avec leur Environnement : Théorie et Applications

Tognon, Marco 13 July 2018 (has links)
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 aériens. / This 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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