Underwater optical guiding and communication solution for the AUV andseafloor node

In this paper, an optical guiding and docking scheme is designed, and a node integrating laser positioning guidance and communication functions is developed. Through experiments, it is verified that the laser docking system has the function of guiding and communicating the autonomous underwater vehicle (AUV) with the support of the seabed observation network. It can provide two-dimensional position information for underwater platforms to navigate the media to sea network nodes and enable visual contact between them. The integrated terminals are small enough (6 cm in diameter) to be installed on small underwater platforms, such as AUVs. To safely work at a depth of thousands of meters, the devices have cylindrical shapes rather than spherical shapes. However, the cylindrical shell confines the view angle of the receiver. An optical system and a photodiode array are adopted to enlarge the cylindrical-shaped receiver's view angle. The positioning algorithm is designed based on the optical lens system and the photodiode array. In a small-pool experiment, this system is tested to achieve a data rate of 1 Mbit/s at a distance of 4 m. Positioning algorithms are also confirmed preliminarily in the small-pool experiment, and the error of the positioning algorithm is discussed.