Improved adaptive twisting sliding mode control for trajectory tracking of an AUV subject to uncertainties

During various marine activities, autonomous underwater vehicles (AUVs) suffer from uncertainties while tracking the trajectory, including external disturbances and parameter perturbations. Such issues make it difficult to design robust trajectory-tracking controllers for accurate trajectory-tracking for AUVs. This study presents an improved adaptive twisting controller (IATC) design that can tackle the chattering effect and prior knowledge problems simultaneously for trajectory tracking, making practical application more convenient. By using a threshold parameter with respect to the Lyapunov function in the adaptive law, the trajectory of the closed-loop tracking system is guaranteed to be practical finite-time stable. Simulation results, including comparisons with an adaptive-gain twisting controller (ATC) and a super-twisting integral sliding mode control (STISMC), demonstrate the superior performance of the IATC.