PID-Fixed Time Sliding Mode Control for Trajectory Tracking of AUVs under Disturbance

Abstract

A novel approach is proposed for the trajectory tracking control of Autonomous Underwater Vehicles (AUVs). Firstly, previous implementations of Proportional-Integral-Derivative (PID) and Sliding Mode Control (SMC) are discussed and their disadvantages are highlighted in terms of fixed time convergence and the chattering phenomenon. Secondly, to improve the stability of the tracking performance and convergence of the system, a controller combining PID and Fixed Time SMC (FTSMC) is proposed for AUVs. The proposed controller is then applied to simulate a 6 Degrees-of-Freedom (6DOF) BlueRov2 underwater robot and the results are analytically discussed. The simulation results show that the proposed PID-FTSMC controller can accurately control the BlueRov2 in trajectory tracking operations with faster convergence and no oscillations around the set reference, even under disturbance.