Practical Prescribed-Time Tracking Control for Underactuated WMR: A Fully Actuated System Approach

In this paper, a practical prescribed-time (PPT) tracking control method based on fully actuated system (FAS) approach is proposed for an underactuated wheeled mobile robot (WMR) with external disturbances and model uncertainties. Firstly, a FAS model is established for the WMR. Combined a time-varying constraining function and output-dependent universal barrier function, a new mapping FAS model is derived. Secondly, a distributed extended state observer (ESO) is presented to estimate the external disturbances and model uncertainties. For the new mapping FAS model, the controller via FAS approach is proposed to guarantee that the tracking error system is PPT stable. Finally, effectiveness of the proposed method is verified by trajectory tracking experiment of WMR.