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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

Task and motion planning for mobile manipulators

January 2012 (has links)
This thesis introduces new concepts and algorithms that can be used to solve the simultaneous task and motion planning (STAMP) problem. Given a set of actions a robot could perform, the STAMP problem asks for a sequence of actions that takes the robot to its goal and for motion plans that correspond to the actions in that sequence. This thesis shows how to solve the STAMP problem more efficiently and obtain more robust solutions, when compared to previous work. A solution to the STAMP problem is a prerequisite for most operations complex robots such as mobile manipulators are asked to perform. Solving the STAMP problem efficiently thus expands the range of capabilities for mobile manipulators, and the increased robustness of computed solutions can improve safety. A basic sub-problem of the STAMP problem is motion planning. This thesis generalizes KPIECE, a sampling-based motion planning algorithm designed specifically for planning in high-dimensional spaces. KPIECE offers computational advantages by employing projections from the searched space to lower-dimensional Euclidean spaces for estimating exploration coverage. This thesis further develops the original KPIECE algorithm by introducing a means to automatically generate projections to lower-dimensional Euclidean spaces. KPIECE and other state-of-the-art algorithms are implemented as part the Open Motion Planning Library (OMPL), and the practical applicability of KPIECE and OMPL is demonstrated on the PR2 hardware platform. To solve the STAMP problem, this thesis introduces the concept of a task motion multigraph (TMM), a data structure that can express the ability of mobile manipulators to perform specific tasks using different hardware components. The choice of hardware components determines the state space for motion planning. An algorithm that prioritizes the state spaces for motion planning using TMMs is presented and evaluated. Experimental results show that planning times are reduced by a factor of up to six and solution paths are shortened by a factor of up to four, when considering the available planning options. Finally, an algorithm that considers uncertainty at the task planning level based on generating Markov Decision Process (MDP) problems from TMMs is introduced.
2

Modelagem e implementação no ros de um controlador para manipuladores móveis

Barros, Taiser Tadeu Teixeira January 2014 (has links)
Este trabalho apresenta a modelagem matemática para um manipulador móvel composto por uma base móvel (o robô móvel Twil) e um manipulador (o manipulador WAM da Barrett). Os modelos cinemático e dinâmico para a base móvel, manipulador e manipulador móvel são apresentados. Como o manipulador móvel é um sistema não linear, uma estratégia de controle baseada em linearização por realimentação da dinâmica da plataforma seguida por uma transformação não suave para tratar a não holonomicidade do modelo cinemático é proposta. Então o método de backstepping é utilizado para obter as entradas do modelo dinâmico. Um controlador de torque calculado é proposto para o manipulador, Estas técnicas de controle são utilizadas simultaneamente para controlar o manipulador móvel. A implementação dos controladores propostos, na forma de plugins para o gerenciador de controladores é feita no ROS, assim os controladores são executados em tempo real. A maioria dos controladores existentes no ROS são do tipo SISO baseados em controle PID e independentes para cada junta, sendo que neste trabalho controladores MIMO não lineares são implementados. / This work presents a mathematical modelling for a mobile manipulator composed by a mobile base (the Twil mobile robot) and a manipulator (the Barrett WAM manipulator). The kinematic and dynamic models for the mobile base, the manipulator and the mobile manipulator are presented. As the the mobilie manipulator is a non-linear system, a control strategy based on feedback linearization of the platform dynamics followed by a non-smooth transform to handle the non-holonomicity of its kinematic model is proposed. Then, the backstepping method is used to obtain the inputs for the dynamic model. A computed torque controller is proposed for the manipulador. These control techniques are used simultaneously to control the mobile manipulator. The implementation of the proposed controllers is done in ROS as plugins for the controller manager so that the controllers run in real-time. Most controllers existing in ROS are independent joint SISO controllers based on the PID control law while in this work MIMO non-linear controllers are implemented.
3

Modelagem e implementação no ros de um controlador para manipuladores móveis

Barros, Taiser Tadeu Teixeira January 2014 (has links)
Este trabalho apresenta a modelagem matemática para um manipulador móvel composto por uma base móvel (o robô móvel Twil) e um manipulador (o manipulador WAM da Barrett). Os modelos cinemático e dinâmico para a base móvel, manipulador e manipulador móvel são apresentados. Como o manipulador móvel é um sistema não linear, uma estratégia de controle baseada em linearização por realimentação da dinâmica da plataforma seguida por uma transformação não suave para tratar a não holonomicidade do modelo cinemático é proposta. Então o método de backstepping é utilizado para obter as entradas do modelo dinâmico. Um controlador de torque calculado é proposto para o manipulador, Estas técnicas de controle são utilizadas simultaneamente para controlar o manipulador móvel. A implementação dos controladores propostos, na forma de plugins para o gerenciador de controladores é feita no ROS, assim os controladores são executados em tempo real. A maioria dos controladores existentes no ROS são do tipo SISO baseados em controle PID e independentes para cada junta, sendo que neste trabalho controladores MIMO não lineares são implementados. / This work presents a mathematical modelling for a mobile manipulator composed by a mobile base (the Twil mobile robot) and a manipulator (the Barrett WAM manipulator). The kinematic and dynamic models for the mobile base, the manipulator and the mobile manipulator are presented. As the the mobilie manipulator is a non-linear system, a control strategy based on feedback linearization of the platform dynamics followed by a non-smooth transform to handle the non-holonomicity of its kinematic model is proposed. Then, the backstepping method is used to obtain the inputs for the dynamic model. A computed torque controller is proposed for the manipulador. These control techniques are used simultaneously to control the mobile manipulator. The implementation of the proposed controllers is done in ROS as plugins for the controller manager so that the controllers run in real-time. Most controllers existing in ROS are independent joint SISO controllers based on the PID control law while in this work MIMO non-linear controllers are implemented.
4

Modelagem e implementação no ros de um controlador para manipuladores móveis

Barros, Taiser Tadeu Teixeira January 2014 (has links)
Este trabalho apresenta a modelagem matemática para um manipulador móvel composto por uma base móvel (o robô móvel Twil) e um manipulador (o manipulador WAM da Barrett). Os modelos cinemático e dinâmico para a base móvel, manipulador e manipulador móvel são apresentados. Como o manipulador móvel é um sistema não linear, uma estratégia de controle baseada em linearização por realimentação da dinâmica da plataforma seguida por uma transformação não suave para tratar a não holonomicidade do modelo cinemático é proposta. Então o método de backstepping é utilizado para obter as entradas do modelo dinâmico. Um controlador de torque calculado é proposto para o manipulador, Estas técnicas de controle são utilizadas simultaneamente para controlar o manipulador móvel. A implementação dos controladores propostos, na forma de plugins para o gerenciador de controladores é feita no ROS, assim os controladores são executados em tempo real. A maioria dos controladores existentes no ROS são do tipo SISO baseados em controle PID e independentes para cada junta, sendo que neste trabalho controladores MIMO não lineares são implementados. / This work presents a mathematical modelling for a mobile manipulator composed by a mobile base (the Twil mobile robot) and a manipulator (the Barrett WAM manipulator). The kinematic and dynamic models for the mobile base, the manipulator and the mobile manipulator are presented. As the the mobilie manipulator is a non-linear system, a control strategy based on feedback linearization of the platform dynamics followed by a non-smooth transform to handle the non-holonomicity of its kinematic model is proposed. Then, the backstepping method is used to obtain the inputs for the dynamic model. A computed torque controller is proposed for the manipulador. These control techniques are used simultaneously to control the mobile manipulator. The implementation of the proposed controllers is done in ROS as plugins for the controller manager so that the controllers run in real-time. Most controllers existing in ROS are independent joint SISO controllers based on the PID control law while in this work MIMO non-linear controllers are implemented.
5

Conception et commande collaborative de manipulateurs mobiles modulaires (C3M3) / Design and collaborative control of modular mobile manipulators

Chebab, Zine Elabidine 11 December 2018 (has links)
Dans un contexte d’Industrie 4.0, on perçoit de nouveaux usages possibles des manipulateurs mobiles (MMs), des robots généralement obtenus par l’association d’un bras manipulateur et d’une plate-forme mobile. Ce travail de thèse se focalise sur la synthèse et la commande de nouveaux MMs coopératifs en définissant trois défis à relever. Le premier défi concerne l’élargissement des domaines d’utilisation des robots par la possibilité de leur utilisation coopérative. Nous définissons ainsi un système robotique modulaire basé sur l’utilisation d’entités robotiques appelés mono-robots (m-bots). Ceux-ci sont des MMs qui peuvent se réarranger sous forme de poly-robot (p-bot) pour réaliser une tâche en collaboration. Le deuxième défi se focalise sur la définition de l’architecture cinématique élémentaire de ces robots. Ainsi, nous proposons une démarche générique de synthèse structurale qui permet l’obtention de plusieurs architectures de m-bots respectant les cahiers des charges relatifs à la tâche en tant que m-bot, mais aussi en tant que p-bot pour un environnement considéré. Cette démarche est basée sur l’analyse structurale des MMs à l’aide des paramètres structuraux des mécanismes (connectivité, mobilité, redondance et hyperstatisme). Le troisième défi proposé est d’arriver à modéliser et contrôler les architectures de MMs synthétisées pour la tâche. Deux lois de commande (PID et hybride force-position) sont proposées pour la réalisation de la tâche considérée. Leur validation a été réalisée grâce à des simulations avancées. / In recent years, the concept of Industry 4.0 has led to new possibilities of use for mobile manipulators (MMs) that are generally made of a manipulator arm mounted on a mobile base. The current Ph.D. is focused on the synthesis and control of new cooperative MMs by defining three challenges. The first challenge concerns the widening of the fields of application of robots. Therefore, we define a modular robotic system based on the use of multiple MMs (mono robots or m-bots) that can be used as a global system (poly-robot or p-bot) for collaborative tasks. The second challenge concerns the definition of the kinematic structure of the MMs. We propose a new generic method of structural synthesis that allows to obtain multiple kinematic architectures for m-bots that respect the constraints imposed by the task and the workspace. This method is based on structural analysis of MMs by the evaluation of the structural parameters (connectivity, mobility, redundancy and overconstraint). The last challenge concerns the modelling and control of the new architectures for the new fields of application. Two control laws (PID control and hybrid force-position control) are proposed in order to realise the considered task. Their validation is done with advanced simulations.
6

Control of robotic mobile manipulators : application to civil engineering / Commande de manipulateurs mobiles robotisés : application au génie civil

Mohy El Dine, Kamal 23 May 2019 (has links)
Malgré le progrès de l'automatisation industrielle, les solutions robotiques ne sont pas encore couramment utilisées dans le secteur du génie civil. Plus spécifiquement, les tâches de ponçage, telles que le désamiantage, sont toujours effectuées par des opérateurs humains utilisant des outils électriques et hydrauliques classiques. Cependant, avec la diminution du coût relatif des machines par rapport au travail humain et les réglementations sanitaires strictes applicables à des travaux aussi risqués, les robots deviennent progressivement des alternatives crédibles pour automatiser ces tâches et remplacer les humains.Dans cette thèse, des nouvelles approches de contrôle de ponçage de surface sont élaborées. Le premier contrôleur est un contrôleur hybride position-force avec poignet conforme. Il est composé de 3 boucles de commande, force, position et admittance. La commutation entre les commandes pourrait créer des discontinuités, ce qui a été résolu en proposant une commande de transition. Dans ce contrôleur, la force de choc est réduite par la commande de transition proposée entre les modes espace libre et contact. Le second contrôleur est basé sur un modèle de ponçage développé et un contrôleur hybride adaptatif position-vitesse-force. Les contrôleurs sont validés expérimentalement sur un bras robotique à 7 degrés de liberté équipé d'une caméra et d'un capteur de force-couple. Les résultats expérimentaux montrent de bonnes performances et les contrôleurs sont prometteurs. De plus, une nouvelle approche pour contrôler la stabilité des manipulateurs mobiles en temps réel est présentée. Le contrôleur est basé sur le « zero moment point », il a été testé dans des simulations et il a été capable de maintenir activement la stabilité de basculement du manipulateur mobile tout en se déplaçant. En outre, les incertitudes liées à la modélisation et aux capteurs sont prises en compte dans les contrôleurs mentionnés où des observateurs sont proposés.Les détails du développement et de l'évaluation des différents contrôleurs proposés sont présentés, leurs mérites et leurs limites sont discutés et des travaux futurs sont suggérés. / Despite the advancements in industrial automation, robotic solutions are not yet commonly used in the civil engineering sector. More specifically, grinding tasks such as asbestos removal, are still performed by human operators using conventional electrical and hydraulic tools. However, with the decrease in the relative cost of machinery with respect to human labor and with the strict health regulations on such risky jobs, robots are progressively becoming credible alternatives to automate these tasks and replace humans.In this thesis, novel surface grinding control approaches are elaborated. The first controller is based on hybrid position-force controller with compliant wrist and a smooth switching strategy. In this controller, the impact force is reduced by the proposed smooth switching between free space and contact modes. The second controller is based on a developed grinding model and an adaptive hybrid position-velocity-force controller. The controllers are validated experimentally on a 7-degrees-of-freedom robotic arm equipped with a camera and a force-torque sensor. The experimental results show good performances and the controllers are promising. Additionally, a new approach for controlling the stability of mobile manipulators in real time is presented. The controller is based on zero moment point, it is tested in simulations and it was able to actively maintain the tip-over stability of the mobile manipulator while moving. Moreover, the modeling and sensors uncertainties are taken into account in the mentioned controllers where observers are proposed. The details of the development and evaluation of the several proposed controllers are presented, their merits and limitations are discussed and future works are suggested.

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