Three-dimensional trajectory tracking control of underactuated autonomous underwater vehicles

This study proposes a three-dimensional (3D) trajectory-tracking control scheme for an underactuated autonomous underwater vehicle (AUV). Given the 3D reference trajectory, the reference velocities, angles, angular velocities, force, and torques were planned first. These reference variables were used to obtain the error dynamics. The backstepping technique was used to design the trajectory-tracking controller for tracking the AUVs reference trajectory. According to the Lyapunov stability theory, the trajectory-tracking system was stable and bounded, and the tracking errors converged close to a small neighbourhood of zero. Finally, the effectiveness of the developed control method was demonstrated using simulations.