Development of a Compact Autonomous Underwater Vehicle for Hierarchical Multi-Agent Cooperation

We present the design of a compact autonomous underwater vehicle (AUV) as part of a testbed for hierarchical, multi-agent cooperation experiments. The new vehicle design, dubbed the daughter AUV, represents economy agents within a cooperative sensor network facilitated by a small number of well-equipped agents, called the mother AUVs, in missions including cooperative localization, distributed sensing, and multi-agent networking. In this article, we focus on a system-level description of the daughter AUV, design updates on both the mechanical structure and the embedded system based on preliminary testing results with the daughter AUV prototype, and the integration with the mother AUV and our indoor testing facilities. Tailored for a multi-vehicle testing setup in a confined water tank, the daughter AUV features novel, bio-inspired jet thrusters for agile vehicle maneuvers, a bio-inspired, semi-active buoyancy control system for depth adjustment, and a compact embedded system for thruster control, state estimation, and efficient information fusion with another vehicle or a base station. Particularly, we provide an in-depth discussion on the performance of an underwater optical communication system designed for fast transmission of large data sets within short distances to supplement the acoustic communication system.