SUMMARY

The oceans cover a majority of Earth’s surface, yet a vast ocean proportion remains unexplored due to the enormous physical scale and involved technical complexities. Ocean exploration and mapping offer immense returns through improved shipping routes, renewable energy generation, and accurate ocean modeling for better understanding Earth’s climate processes.
Autonomous Underwater Vehicles (AUVs) offer adaptability, compactness and power efficiency while minimizing human oversight, making them ideal for ocean exploration. However, operational AUV use in the GPS-denied oceans is limited by currently achievable undersea localization and navigation accuracy.
Conventional active transponders as navigation aids for AUVs are constrained by the active power supply requirement. This energy limitation can be overcome through development of underwater Acoustic Identification (AID) tags which utilize wireless ultrasonic power transfer from a remote acoustic source mounted on an interrogating AUV. Such tags can provide AUVs with precise positioning information and pass messages using backscatter communication. As a feasibility demonstration, this work develops AID tags using a custom piezoelectric transducer design for communication and concurrent efficient energy harvesting using a broadband acoustic and electric impedance matching technique.
The device incorporating broadband matched transducers and supporting electronic platform is experimentally tested for its viability in proposed applications. Further optimization of the design is proposed with the operational frequency selection to balance long range application with high data rates. Finally, experiments are proposed to demonstrate the device functionality for AUV routing and navigation, and short-range homing and docking applications.