Avant de pouvoir interagir avec l'homme, les robots humanoïdes doivent encore être largement améliorés, tant au niveau de leur modélisation, de leur commande que de leur conception. Contrairement aux robots manipulateurs la notion de centre de masse est prédominante chez les robots humanoïdes et sera au centre de la gestion de leur équilibre. C'est donc dans ce cadre que s'inscrit cette thèse dont le but est de proposer une modélisation précise du centre de masse des robots humanoïdes dont la complexité ne cesse d'augmenter. En effet les modèles utilisés aujourd'hui pour définir la trajectoire du centre de masse sont des modèles simplifiés des robots humanoïdes. Les travaux de cette thèse s'articulent autour de trois contributions majeures : la modélisation cinématique et dynamique ainsi que l'estimation du centre de masse de robots humanoïdes. La première contribution propose une transformation de la structure arborescente de l'humanoïde en une chaîne virtuelle série localisant son centre de masse et permettant une commande cinématique adaptée de ce dernier. La dynamique du robot est ensuite exprimée en son centre de masse permettant ainsi une description exacte de ses accélérations. À ce titre, le concept de manipulabilité dynamique du centre de masse est introduit. Enfin grâce à la modélisation sous forme de chaîne virtuelle, une méthodologie qui s'impose aujourd'hui comme référence dans le domaine de l'estimation du centre de masse chez l'humain est proposée. De nombreuses expérimentations illustrent tout au long de cette thèse l'application et l'utilité de ces travaux. / Before they can interact with men, humanoid robots must be strongly enhanced in their modeling, their control and their design. Contrary to manipulator robots, the notion of center of mass is predominant in humanoid robots and will be central to the management of their balance. In this context, this thesis aims to provide accurate modeling of the center of mass of humanoid robots, whose complexity is increasing. Indeed, the models used today to determine the trajectory of center of mass are simplified models of humanoid robots. The works of this thesis revolve around three major contributions : kinematics and dynamics modeling as well as the estimation of the center of mass of humanoid robots. The first part proposes a transformation of the tree structure of the humanoid in a virtual serial chain locating its center of mass and allowing an adapted control of the latter. The dynamics of the robot is then expressed in the center of mass space allowing an accurate description of its acceleration. As such, the concept of dynamic manipulability of the center of mass is introduced. Finally, through the modeling in a virtual chain, a methodology that is today a reference in the field of center of mass estimation in humans is proposed. Many experiments show throughout this thesis the application and usefulness of this work.

Made available in DSpace on 2014-12-17T14:56:13Z (GMT). No. of bitstreams: 1 IvoAON_DISSERT.pdf: 3534559 bytes, checksum: 4a686a0bd15089c1b9710cf531e7beda (MD5) Previous issue date: 2013-01-31 / Universidade Federal do Rio Grande do Norte / The objective of the dissertation was the realization of kinematic modeling of a robotic wheelchair using virtual chains, allowing the wheelchair modeling as a set of robotic manipulator arms forming a cooperative parallel kinematic chain. This document presents the development of a robotic wheelchair to transport people with special needs who overcomes obstacles like a street curb and barriers to accessibility in streets and avenues, including the study of assistive technology, parallel architecture, kinematics modeling, construction and assembly of the prototype robot with the completion of a checklist of problems and barriers to accessibility in several pathways, based on rules, ordinances and existing laws. As a result, simulations were performed on the chair in various states of operation to accomplish the task of going up and down stair with different measures, making the proportional control based on kinematics. To verify the simulated results we developed a prototype robotic wheelchair. This project was developed to provide a better quality of life for people with disabilities / O objetivo da disserta??o foi a realiza??o da modelagem cinem?tica de uma cadeira de rodas rob?tica usando cadeias virtuais, que permitiu modelar a cadeira como um conjunto de bra?os manipuladores cooperativos formando uma cadeia cinem?tica paralela. Foi desenvolvida uma cadeira de rodas rob?tica para transporte de portador de necessidades especiais que supera obst?culos como desn?veis e barreiras existentes ? acessibilidade em ruas e avenidas, incluindo o estudo sobre tecnologia assistiva, arquitetura paralela, modelagem cinem?tica, constru??o e montagem do prot?tipo do rob? com a realiza??o de uma lista de verifica??o de problemas e barreiras ? acessibilidade em diversos percursos, tomando como base normas, decretos e leis existentes. Como resultado, foram realizadas simula??es da cadeira em v?rios estados de opera??o para realizar a tarefa de subir e descer desn?veis com diferentes alturas, realizando o controle proporcional baseado na cinem?tica. Para comprovar os resultados simulados foi desenvolvido um prot?tipo do rob?. Este projeto foi desenvolvido visando proporcionar uma melhor qualidade de vida ?s pessoas portadoras de necessidades especiais