Bearing-Only Circumnavigation of a Varying Velocity Target for AUV Based on Fully Actuated System Approach

This paper investigates the target circumnavigation problem of an Autonomous Underwater Vehicle (AUV) using bearing-only measurements. Existing works most focus on the target which is static or moves at a constant velocity, and in this work, we consider the target moving at an unknown varying velocity. The fully actuated system approach is adopted to deal with the AUV dynamics. An estimator-based controller is designed and the control strategy addresses second-order system behaviors to ensure smooth and stable tracking of the moving target. It is rigorously proved that the tracking error is ultimately uniformly bounded under the proposed integrated method. Simulation results demonstrate the feasibility and effectiveness of the proposed method in practical scenarios.