Monocular Vision Guided Lamp Array Tracking Method for the UUV Recovery Process

An unmanned undersea vehicle(UUV) is restricted by its carrying load and environment during underwater operation, reducing the maximum operation time and distance. As a result, periodical UUV recovery is necessary to supply it with energy, obtain data, and arrange new tasks. Further study on UUV vision tracking is important to realize a rapid, accurate, and safe UUV recovery. In this study, problems caused by the monocular visual multi-target tracking for UUV recovery are investigated. A recovery tracking method of UUVs based on the nonlinear Kalman filter and asymmetric light array is proposed. First, underwater images collected by the monocular camera are preprocessed to extract characteristic information of the light source array. Afterward, the target trajectory is determined through a method based on the asymmetric L-shaped light source array. The optimal cost matrix is thereafter established by weighing the observer and the filter, and the detection is matched to the target trajectory using the improved Hungarian algorithm. Prior results of the Kalman filter are modified according to these results. Finally, the engineering effectiveness of the proposed method is verified through underwater target tracking experiments.