An Active Perception Approach for Mid-Water Localization of Autonomous Underwater Vehicles

Mid-water localization is challenging for autonomous underwater vehicles (AUVs) due to limited communications and geo-referencing capabilities in the underwater environment, coupled with unknown complex and dynamic surroundings. Existing solutions typically utilize expensive sensors that may not be available to all AUVs. In this paper, we consider an AUV descending through the water column and propose an approach for mid-water localization using inertial and depth sensors only. During a descent of the vehicle, we leverage spiral motion, which allows for exploitation of vehicle dynamics along with associated inertial sensor measurements for localization. The spiral motion enables us to observe and estimate the influence of environmental flow (e.g., ocean currents) on the vehicle motion, thereby enhancing the understanding of the environment through active perception. The estimated flow together with inertial and depth sensor measurements are integrated in the vehicle motion model for localization. Comparing our approach with conventional dead-reckoning, the simulation results demonstrate its promising potential.