Light Beacon-Aided AUV Electromagnetic Localization for Landing on a Planar Docking Station

Autonomous underwater vehicles (AUVs) play an increasingly important role in underwater missions. However, traditional visual localization methods struggle to meet the accuracy requirements for AUV terminal docking in strong-illumination or turbid water conditions. This work proposes a universal navigation system using electromagnetic (EM) and light beacons for nontorpedo AUVs to be recovered using a planar docking station. The major challenge in designing this system is to deal with the incomplete sensing of the light and EM beacons. To solve this problem, a two-step fusion method of EM localization information is given first. The kinematic model of the AUV and visual information are also utilized to improve the robustness of the navigation system. Based on the localization result, a comprehensive docking strategy is proposed to address the time-varying sensing conditions. Localization and docking experiments were conducted in a pool. The test results show that the maximum EM localization error is less than 20 cm in both static and dynamic tests. The AUV completed all six docking attempts.