Research on Passive Positioning Algorithm for AUVs Based on Single Mobile Surface Beacon and Inverted USBL

Single beacon passive positioning is crucial for the covert and rapid navigation of autonomous underwater vehicles (AUVs). Traditional methods, which assume a fixed beacon position, known sound speed, and error-free AUV heading, limit the applicability and accuracy of passive positioning systems. In this article, we proposed an angle-based passive positioning algorithm, underwater moving bearing angle of arrival (U-MBAOA), to solve the above problems. First, we replace the bottom-anchored fixed beacon with a mobile surface beacon and develop a dynamic positioning model to accommodate its movement. Then, to enhance the positioning accuracy, we parameterized the sound speed and derived a weighted least squares method to estimate the sound speed. Finally, we constructed an error model for heading errors and positioning under a straight-line trajectory and combined this model with U-MBAOA, achieving the estimation of heading errors in passive positioning for the first time. Through simulation analysis and sea tests, we confirmed that our algorithms outperform the existing algorithms.