ABCUnloc: Acoustic Backscatter Communication-based Underwater Localization

As offshore industries and the Internet of underwater things continue to expand, autonomous underwater vehicles (AUVs) are expected to be in increasingly widespread use, carrying out various tasks in harsh marine environments. The autonomous operation of an AUV relies on accurately ascertaining its position along its route, but GPS does not work underwater.

AUV navigation is typically supported by underwater acoustic positioning systems, e.g., long baseline (LBL) systems. However, batteries of LBL nodes need to be replaced periodically, thereby being operationally demanding and costly and posing a great threat to the marine environment. Eco friendly, low-cost and low-maintenance underwater localization systems are urgently needed by industry and scientific communities to support AUV navigation.

Leveraging underwater acoustic backscatter communication (UABC) that allows a node to communicate at near-zero power by reflecting incident acoustic signals, this action will develop a novel acoustic backscatter communication-based underwater localization (ABCUnloc) system that deploys three or more multi-node subsurface buoys at known locations to backscatter localisation information to an AUV.

The R&I objectives of the action are: (1) To model the UABC channel between a subsurface buoy and an AUV. (2) To design a novel multi-node subsurface buoy (each node comprising a piezoelectric array and ultra-low-power control circuits) and assess its feasibility for UABC-based AUV localization. (3) To devise UABC-based 3D localization algorithms that can support AUV navigation in dynamic underwater environments. (4) To optimise the ABCUnloc system (i.e. the number of nodes and inter-node distance per subsurface buoy, the number and placement of buoys for covering an underwater region) regarding AUV localization power consumption, accuracy and robustness and impact on marine environment. (5) To prototype and test the ABCUnloc system in controllable wave tanks and in the North Sea.