Extended State Observer Based Robust Friction Compensation for Tracking Control of an Omnidirectional Mobile Robot

This paper presents an extended state observer (ESO) based robust friction compensation scheme for trajectory tracking control of a three-wheeled omnidirectional mobile robot. The proposed approach is practical in implementation, with no friction model required and only three parameters to be tuned. First, a dynamic model with unknown friction forces is given for the robot. Then, the controller is designed, consisting of two parts. One part of the control effort is to compensate the friction effects, which are estimated by ESO without using any friction model. The other part of the control effort is designed based on traditional resolved acceleration control to achieve the trajectory tracking goals. In addition, stability analysis of the designed control system is presented. Extensive simulations and experiments are conducted to validate the proposed control system design in compensating different friction forces.