Contributions à la planification et à la commande pour les robots mobiles coopératifs

Abstract

This thesis concerns the autonomous navigation of a formation of nonholonomic mobile robots. Our objective is to equip a multi-robot system at the same time of a flexible motion planner and of an efficient and robust trajectory tracking controller.<br />The first chapter deals with the presentation of the context.<br />The second chapter is devolved to the design of a feasible collision-free trajectory planner for a mobile robot enough flexible in order to be extended to the multi-robot framework.<br />In the third chapter, two coordination mechanisms are developed. For the first one, the conflicts are solved via a supervisor. The second one allows the on-line optimal trajectory generation for every robot in a decentralized way from available information.<br />The fourth chapter concerns the higher order sliding mode control. The efficiency of the algorithm is highlighted through experimental results on a stepper motor.<br />In the fifth chapter, two integral sliding mode controllers are designed and implemented on the Pekee mobile robot. These control laws ensure the stabilization and/or the trajectory tracking in spite of the presence of disturbances and uncertainties.<br />The last chapter describes a decentralized coordination mechanism based on a ``leader/follower'' approach. It allows to eliminate the knowledge of the absolute position of all the robots and to avoid the inter-robot collisions. Finally, we present experimental results on a formation of three Miabot robots.