Free will arbitrary time sliding mode control of autonomous underwater vehicle with external disturbances

Abstract This study addresses the trajectory tracking control problem for autonomous underwater vehicles (AUVs) under the influence of external environmental disturbances. To tackle this challenge, a novel free-will arbitrary-time sliding mode controller (FWATSMC) is proposed, which is irrespective of the system’s initial state and ensures that the AUVs can track a given reference trajectory within arbitrary time. Specifically, the method guarantees that the tracking error converges rapidly to a small neighborhood of the origin within the specified time, while maintaining high tracking accuracy. Moreover to further enhance the system’s robustness against time-varying external disturbances, a free will arbitrary sliding mode disturbance observer (FWATSMDO) is designed to effectively estimate and compensate for external disturbances, thereby improving the overall robustness of the AUVs system. Finally, simulation results are presented to validate the effectiveness and superiority of the proposed method.