Commande d’un robot mobile rapide à roues non directionnelles sur sol naturel

摘要

A mobile robot traveling over a natural terrain at high speed is subject to slipping and skidding phenomena. The control of the movement at high speed in natural environment may become an important challenge for robotic applications in terrestrial or planetary exploration and in agriculture. In this thesis, we developed a semi-empirical model of the interaction between wheels and soil, which has been integrated into a new control scheme. The overall objective is to design a control architecture for path following or trajectory tracking, while taking into account dynamics and slippage. This control architecture has been validated in a dynamic simulation environment, which was enhanced to include the contact model. A robotic platform was built and instrumented in order to demonstrate experimentally the relevance and the benefits of this approach. In particular, a ground speed sensor, based on Doppler effect, has been developed. Thus, it is possible to measure and regulate the slippage of wheels with respect to the ground. An in situ estimation procedure of the contact model parameters has also been validated.