A nonsingular fast terminal sliding mode control for autonomous underwater vehicle

Purpose This paper proposes a novel non-singular fast terminal sliding mode (NFTSM) control approach to address challenges in autonomous underwater vehicles (AUVs) caused by external disturbances and modeling uncertainties. The goal is to achieve finite-time convergence and avoid singular problems in control systems. Design/methodology/approach A NFTSM control is designed to ensure finite-time stability. A control law is derived based on the sliding mode control rate obtained from the sliding mode surface. Lyapunov stability analysis is conducted to verify the convergence of tracking errors to a range near zero within a finite time period. Findings Simulation results demonstrate the effectiveness of the proposed control scheme. The approach achieves faster convergence and improved performance than two other finite-time tracking controllers, validating its suitability for AUV applications. Originality/value The proposed control scheme introduces a NFTSM approach, which avoids singular problems and ensures finite-time convergence. This innovation enhances the robustness and efficiency of control systems for AUVs, offering significant contributions to underwater vehicle control research.