Differential-Flatness-Based Planning and Control of a Wheeled Mobile Manipulator—Theory and Experiment

This paper presents a differential-flatness-based integrated point-to-point trajectory planning and control method for a class of nonholonomic wheeled mobile manipulator (WMM). We demonstrate that its kinematic model possesses a feedback-linearizable description due to the flatness property, which allows for full-state controllability. Trajectory planning can then be simplified and achieved by polynomial fitting method in the flat output space to satisfy the terminal conditions, while control design reduces to a pole-placement problem for a linear system. The method is then deployed on our custom-constructed WMM hardware to evaluate its effectiveness and to highlight various aspects of the hardware implementation.