Localization and trajectory following for multi-body wheeled mobile robots

Autonomous navigation for wheeled mobile robots generally requires to plan a trajectory and to follow it while performing localization in the environment. In order to execute long-range motion, dead-reckoning localization is not precise enough and the robot must use landmark-based localization. Landmark-based localization can produce discontinuities in the robot position estimation, as it is well known with GPS systems, and perturb the trajectory following. If the robot is able to converge smoothly towards the trajectory, then these perturbations are easily managed. Otherwise, if the robot is more complex (for instance a multi-body mobile robot subject to several nonholonomic constraints) and navigates in a cluttered environment, we show that these perturbations can lead to collisions. The contribution of this paper is to state theoretically the problem and to propose a practical solution to trajectory following for multi-body wheeled mobile robots using landmark-based localization. This solution has been tested on a real robot towing a trailer.