Target Following and Close Monitoring Using an Unmanned Surface Vehicle

We consider an unmanned surface vehicle (USV) whose mission is to approach a maneuvering target ship as fast as possible followed by monitoring the target closely. The USV is equipped with sensors to detect the relative position of the target ship. Also, we assume that the USV is faster than the target and is localized using global positioning system. To achieve the mission, we develop a control law to make the USV approach the designated point (e.g., stern, left side, or right side, etc.) of the target as fast as possible. Once the USV reaches the designated point of the target, the USV checks whether the speed of the USV is fast enough to circle around the target. In the case where the circling maneuver is not feasible, the USV keeps following the designated point of the target. Once the USV determines that the circling maneuver is feasible, then we make the USV circle around the target for close monitoring, while maintaining a designated distance from the target. We present MATLAB simulations to verify our approach.