  Since the end of the 1980's, the development of self-driven autonomous
vehicles is an intensive research area in most major industrial countries.
Positive socio-economic potential impacts include a decrease of crashes, a
reduction of travel times, energy efficiency improvements, and a reduced need
of costly physical infrastructure. Some form of vehicle-to-vehicle and/or
vehicle-to-infrastructure cooperation is required to ensure a safe and
efficient global transportation system. This thesis deals with a particular
form of cooperation by studying the problem of coordinating multiple mobile
robots at an intersection area. Most of coordination systems proposed in
previous work consist in planning a trajectory and to control the robots along
the planned trajectory: that is the plan-as-program paradigm where planning is
considered as a generative mechanism of action. The approach of the thesis is
to plan priorities -- the relative order of robots to go through the
intersection -- which is much weaker as many trajectories respect the same
priorities. More precisely, priorities encode the homotopy classes of solutions
to the coordination problem. Priority assignment is equivalent to the choice of
some homotopy class to solve the coordination problem instead of a particular
trajectory. Once priorities are assigned, robots are controlled through a
control law preserving the assigned priorities, i.e., ensuring the described
trajectory belongs to the chosen homotopy class. It results in a more robust
coordination system -- able to handle a large class of unexpected events in a
reactive manner -- particularly well adapted for an application to the
coordination of autonomous vehicles at intersections where cars, public
transport and pedestrians share the road.
