AbstracI-This paper presents a vision-based localization approach for an underwater robot in a ~t~e t u r r d environment. The system is based on a coded pattern placed on the bottom of a water tank and an onhoard downlooking camera. Main features are, absolute and map-based localization, landmark detection and tracking, and real-time computation (12.5 Hz). The proposed system provides threedimensional position and orientation of the vehicle along with its velocity. Accuracy of the drift-free estimates is very high, allowing them to he used as feedback measures of a velocity-based low level controller. The paper details the localization algorithm, by showing some graphical results, and the accuracy of the system.
Carreras proposed a vision-based localization technique REF , using a coded pattern placed on the bottom of a water tank and an onboard downward looking camera.