Dynamic modeling and adaptive dynamic compensation for unicycle-like mobile robots

Abstract

This paper develops a new representation for the dynamic model of unicycle-like mobile robots, discusses some properties of it, and proposes an adaptive dynamic compensation controller based on such model. The proposed dynamic model has linear and angular velocities as inputs, which is usual in commercial mobile robots but not in the literature, thus increasing the significance of the model itself. Important properties of such model are summarized, and some of those are considered in the design of the dynamic compensation controller and in the stability analysis of the equilibrium of the closed-loop system. A robust updating law is applied to avoid parameter drifting and it is shown that the system can deal with bounded parameter variations, keeping the control errors inside a bounded region. Performance comparison shows that the proposed dynamic compensation scheme improves robot's performance in trajectory tracking, compared to the case in which only a kinematic controller is used. Finally, experimental results illustrate the performance of the proposed scheme when applied to a commercial mobile robot.