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Résumé

Les travaux de recherche présentés dans ce mémoire s'articulent autour de la problématique du mouvement en robotique mobile. Il s'agit de développer des outils algorithmiques permettant à un robot mobile non holonome de planifier puis exécuter des mouvements dans un environnement encombré d'obstacles. L'originalité de ces travaux réside dans deux préoccupations omniprésentes : la généricité des approches proposées et l'applicabilité dans les conditions réelles de l'expérimentation. La plus grande partie de ces travaux sont d'ailleurs intégrés dans diverses plate-formes robotiques.

Abstract

The work presented in this document is concerned with the problem of automatic motion planning and control for mobile robots. The goal is the develop algorithmic tools that will enable a nonholonomic mobile robot to navigate autonomously in a partially known environment cluttered with obstacles. The originality of the work presented in this document resides in the genericity of the approaches proposed for each type of problem and in the applicability to real sized experimental mobile robots.

Mots-Clés / Keywords

Robots mobiles; Planification de mouvements; Navigation autonome; Evitement réactif d'obstacles; Mobile robot; Motion planning; Sensor based motion; Motion control; Autonomous navigation; Reactive obstacle avoidance;

Abstract

This paper presents a novel and generic approach of path optimization for nonholonomic systems. The approach is applied to the problem of reactive navigation for nonholonomic mobile robots in highly cluttered environments. This is a collision-free initial path being given for a robot, and obstacles detected while following this path can make it in collision. The current path is iteratively deformed in order to get away from obstacles and satisfy the nonholonomic constraints. The core idea of the approach is to perturb the input functions of the system along the current path in order to modify this path, making an optimization criterion decrease.

Abstract

The robust execution of a planned trajectory is a critical issue in robotics. In this paper, we set the formal basis for a sensor-landmark-based motion planning approach. Our approach deals with inaccuracy of the map of the environment by producing motion features composed of a reference trajectory and of a set of pair sensor landmark over which the robot would control its motion. These motion features define along the trajectory closed-loop motion strategies for the robot. This approach enables us to produce secure motions by putting emphasis on landmarks that can represent a danger of collision. Our contribution is to state the problem in a generic formalism and to propose some simulations that show the relevance of our resolution approach.