ROBUST TRACKING CONTROL OF 2-DEGREES-OF-FREEDOM MOBILE ROBOTS

A robust tracking controller for a mobile robot with two degrees of fr eedom has been developed. It is implemented and tested on a real mobil e robot. Where other controllers show decreasing performance for low r eference velocities, the performance of this controller depends only o n the geometry of the reference trajectory. This allows accurate posit ioning at low speeds, close to obstacles. The dynamics of the velocity -controlled mobile robot are considered as a perturbed unity transfer from input velocity to actual velocity. It is shown that the tracking controller is robust with respect to the-se perturbations.