Leveraging passive acoustic identification AID tag for autonomous underwater vehicle docking

Accurate positioning is essential for the navigation of autonomous underwater vehicles (AUVs), especially during docking and homing. This presentation explores the feasibility of using passive Acoustic Identification (AID) tags for precise AUV localization at a docking station. As a proof of concept, scaled experiments used AID tags made of four concentric hemispherical acrylic layers, each creating a unique backscattered acoustic signature when ensonified by a broadband ultrasonic transducer in GaTech water tank. The tags in these tests have a 9-in. outer diameter and were tested at a frequency range of 700 kHz to 1.3 MHz over a distance of up to 6 m. To enhance detection in cluttered environments, a parameterized signal processing method was employed. Additionally, we will present analysis of long-range experiments to assess the tags' detectability at greater distances using larger AID tags with outer diameter of up to 24-in. outer diameter. These tests will operate at a frequency range of 100 to 600 kHz, aiming to reach distances of tens of meters. Implications for the performance of AID tags operating under real-life conditions will be discussed.