On the Tracking Control of Differentially Steered Wheeled Mobile Robots

Abstract

Fundamental tracking control algorithms of a differentially steered wheeled mobile robot with two conventional driven wheels are studied through analyzing the robot’s inherent kinematics. This includes the tracking variable assignment as well as the tracking singularity and position-orientation tracking decoupling problems. Globally convergent tracking control algorithms are proposed, which can exactly track any differentiable reference path. A fundamental motion orientation equation under the condition of exact position tracking is developed, and it is shown that it is not possible to exactly track both position and orientation concurrently for this kind of mobile robot configuration if the tracking point is not on the baseline. Examples are provided illustrating the tracking ability of the developed control algorithms.