The underwater robot incorporates several standard environmental awareness sensors, such as DVL (Doppler Velocity Log), pressure sensors, USBL (ultra-short baseline), and Stereo Cameras, which are fed into the INS (inertial navigation system), where the information is fused to develop a state estimation for the AUV. As multiple AUVs begin to operate concurrently, a dynamic LBL (Long BaseLine) positioning approach will also be employed.
More information about subsea positioning
The state estimation accuracy for the AUV will be highest at the seafloor, where it is in proximity to other AUVs that have maintained a high accuracy, and near the surface, where it is close to the surface vessel-based USBL. When at the surface, the position will be based almost exclusively on USBL. When at the seafloor, the dynamic LBL combined with DVL and vision tracking of the seafloor will dominate. The stereo cameras on the front of the AUV map out the locations of any nodules and any macro life for the arm control algorithms to determine how to handle them.
