Multi-Dimensional Guidance System with Adaptive Algorithm and Lightweight Model for AUV Underwater Optical Docking

Underwater optical docking is essential for enabling autonomous underwater vehicles (AUVs) to maintain long-duration operations through standardized energy replenishment and data exchange. However, existing optical docking guidance still faces challenges including discontinuous guidance space, fluctuating beacon visibility, and limited real-time feasibility on resource-constrained AUV platforms. This study proposes a three-layer underwater optical guidance framework designed to enhance both stability and deployment feasibility. First, a multi-dimensional beacon configuration is developed to provide stage-based optical guidance, supported by a spatial simulation tool that evaluates beacon placement and effective detection regions. Second, an adaptive spatiotemporal guidance algorithm is introduced, integrating Kalman-based prediction and correction mechanisms to maintain consistent beacon tracking under dynamic underwater conditions. Third, a lightweight optical beacon detection model is implemented to reduce computational cost while preserving sufficient detection accuracy for real-time onboard processing. Pool and lake experiments demonstrate that the proposed framework achieves continuous optical guidance over a range of 0–35 m, significantly improving guidance stability and perception continuity compared with conventional approaches.