Fully-Actuated System Approach Based Trajectory Tracking Control of Wheeled Mobile Robots

This paper investigates the trajectory tracking control problem for wheeled mobile robots (WMRs) with external disturbances, and nonlinear dynamics. Firstly, an auxiliary generalized velocity control law is designed for the kinematic model of the WMRs to achieve trajectory tracking. A reference angular velocity signal for the system's dynamic model is derived from a transformation matrix. Secondly, a differential decomposition is performed on the dynamic model of the system (left and right wheels) to obtain a full-actuated system (FAS) model that satisfies the full-actuated condition, while the external disturbances, and nonlinear dynamics are treated as a lumped disturbance of the system. Furthermore, a linear closed-loop system is given by the designed FAS controller, in which the parameters of the system are determined by a parametric approach. Subsequently, a generalized extended state observer (GESO) is designed to estimate the system state as well as the lumped disturbances. Next, an output feedback controller with disturbance compensation is designed for the WMRs, and system stability analysis is provided to ensure that the angular velocity of the WMR can quickly and stably track the reference angular velocity signal. Finally, the effectiveness and superior performance of the proposed method are verified by simulation experiments.