ACOUSTIC LOCALIZATION AND COMMUNICATION OF AUTONOMOUS UNDERWATER VEHICLES IN SHALLOWENVIRONMENTS

This thesis lays the groundwork for multi-robot underwater operations by addressing key challenges in shallow-water environments, acoustic navigation, inter-robot communication, and automated performance evaluation in simulations. Using the Research-Oriented Underwater Glider for Hands-on Investigative Engineering (ROUGHIE) as a testbed, advancements were made to improve hardware reliability, maneuverability, and acoustic communication under multipath effects, propagation delays, and environmental noise. A comprehensive simulation environment, developed with ROS and Gazebo, was used to evaluate and optimize localization strategies. Notably, the Weighted Average with Dead Reckoning (WADR) method was introduced, merging dead reckoning with weighted average techniques to significantly reduce localization error and mitigate the impact of acoustic delays.

To validate these solutions, experiments were conducted using SeaTrac X110 and X150 acoustic modems, demonstrating the feasibility of surface-deployed acoustic beacons for energy-efficient localization without frequent resurfacing. Additionally, acoustic communication protocols were enhanced to support mission monitoring and control via standardized IMC messages. The developed data manager addressed payload limitations by implementing efficient packet management and error correction mechanisms.

Finally, the thesis introduced an automated performance evaluation framework, enabling real-time metric analysis and feedback for ROS-based simulations. This framework reduces manual labor for performance testing and grading, streamlining future development processes. Overall, this work provides a robust foundation for scalable multi-robot underwater systems and highlights opportunities for further advancements in autonomy, communication, and mission planning for Autonomous Underwater Vehicles (AUVs).