Adaptive Non-Singular Terminal Sliding Mode Tracking Control of an UUV Against Disturbances

A robust design of a trajectory tracker for an unmanned underwater vehicle under the influence of disturbances is addressed in this article. The controller policy is formulated upon an adaptive sliding mode approach, where a manifold of a non-singular terminal sliding mode ensures the tracking errors to converge to a locality close to zero in practical finite-time. Moreover, the adaptation dynamics allow no overestimation of control gains, reducing chattering as well as the control efforts, and maintain robustness against external perturbations with unknown boundaries. Simulation results conducted in a full mathematical model of the craft showcase the performance and feasibility of the suggested method to track the desired references, even with the vehicle subject to water currents. Copyright (C) 2022 The Authors.