Trajectory tracking control of a wheeled mobile robot with unmeasurable velocity based on a super-twisting algorithm

In this paper, a trajectory tracking control problem is investigated for a wheeled mobile robot (WMR) under unmeasurable velocity. A trajectory tracking strategy is proposed based on a dual closed-loop control architecture with a linear extended state observer (LESO). The LESO is developed to estimate the unmeasurable velocity to obtain an estimated velocity which is subsequently utilized in an inner-loop dynamic controller. A nonlinear extended state observer (NESO) is designed to estimate total disturbances on the WMR. A dynamic controller is designed based on a super-twisting algorithm such that finite-time convergence is established based on Lyapunov theory. Experiment results show effectiveness of the trajectory tracking strategy for demonstrating control accurate and robust performance.