Adaptive Finite-Time Trajectory Tracking Control for Wheeled Mobile Robots Based on Event-Triggered and Time-Varying Functions

Abstract

Nonholonomic wheeled mobile robots (WMRs) are typical multiinput, multioutput, coupled, and underactuated nonlinear systems, and their motion control, especially trajectory tracking, is highly challenging. However, due to the complexity of the control, it is difficult to ensure that the system converges within a finite time, let alone quickly complete various tracking tasks without consuming excessive computational resources. Therefore, this paper proposes a novel improved finite-time control scheme. Firstly, the incorporation of a smooth time-varying function enables the system to achieve a better and smoother tracking performance. Secondly, finite-time control allows the system to converge rapidly within a finite time, and its stability is proven through the Lyapunov function. Moreover, the adaptive control method makes the controller more flexible and applicable to various situations. Additionally, due to the introduction of the time-varying function, the controller’s input coupling complicates the solution of the event-triggered mechanism (ETM). To address this issue, this paper employs an extended Barbalat’s lemma to decouple the system and derive an appropriate ETM. This mechanism significantly reduces the update frequency of control signals, thereby conserving system resources. It is also proven that the designed controller can avoid Zeno behavior. Finally, the effectiveness of the proposed control scheme is verified through simulation studies.