High-Accuracy Localization of an Underwater Robot in a~Structured Environment Using Computer Vision

This paper presents a vision-based localization approach for an underwater robot in a structured environment. The system is based on a coded pattern placed on the bottom of a water tank and an onboard down-looking camera. Main features are, absolute and map-based localization, landmark detection and tracking, and real-time computation (12.5 Hz). The proposed system provides three-dimensional position and orientation of the vehicle. The paper details the codification used in the pattern and the localization algorithm, which is illustrated with some images. Finally, the paper shows results about the accuracy of the system.