Nolinear tracking differentiator based practical prescribed time tracking control for perturbed wheeled mobile robot

This paper addresses the tracking problem of a perturbed wheeled mobile robot by considering both the kinematic and dynamic models. A modified model is built based on the heading position. Through extracting fundamental elements from the combined disturbance, it becomes possible to estimate and remove the impact of the disturbance using a specific adaptive compensation term. Concurrent learning is integrated into the adaptive law to ease the requirement for persistent excitation. A practical prescribed time-tracking controller is designed based on a time-varying scaling function. Both the settling time and tracking precision are user-defined. What's more, a sigmoid function-based tracking differentiator is utilized to avoid the complex differentiation of the virtual controller. A Lyapunov-based approach is employed to guarantee globally uniformly ultimately bounded stable tracking. The effectiveness of the proposed control strategy is validated through numerical simulation.