Agradecimentos À todos os membros do Laboratório de Robótica Movel da USP -São Carlos pelo apoio e suporte durante todo o tempo em que realizei meu mestrado. Ao meu orientador, Prof. Dr. Denis Fernando Wolf, pelas sugestões, ensinamentos e esforços dedicados a me ajudar na conclusão deste trabalho. À FAPESP pela bolsa de estudos me que foi concedida. i Palavras-chave: Visão estéreo, navegação autônoma, método estéreo semi-global, robótica móvel, unidade de processamento gráfico. iii Abstract A

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... tonomous navigation is a broad topic that has received increasing attention from the community of mobile robots over the years. The problem is to guide a robot in a smart way for a certain route without human help. This dissertation presents a navigation system for open environments based on stereo vision. A stereo camera is used to capture images of the environment and based on the disparity map generated by a semi-global stereo method, two obstacle detection methods are used to segment the images into navigable and non-navigable regions. Subsequently, this classification is employed in conjunction with a obstacle avoidance method, resulting in a complete autonomous navigation system. The results include an evaluation two stereo methods, this being favorable to the employed stereo method (semi-global). Tests were performed to evaluate the quality and computational cost of two methods for obstacle detection, a plane based one and a cone based. Such tests have left clear the limitations of both methods and led to a parallel implementation of the cone based method. Using a graphics processing unit, a parallel version of the cone based method reached a gain in computational time of approximately ten times. Finally, the results demonstrate the complete system in operation, where the robotic platform used, an electric vehicle, was able to dodge people and cones reaching its goal safely.