Advances in Integrating Autonomy with Acoustic Communications for Intelligent Networks of Marine Robots.

摘要

Autonomous marine vehicles are increasingly used in clusters; the effectiveness of this collaboration is often limited by communications. This thesis argues that improved communication can be gained by acting on knowledge from improved awareness of the physical acoustic link and higher network layers by the autonomous underwater vehicle's (AUV's) decision making software. This thesis presents a modular acoustic networking framework called Goby-Acomms which provides underwater vehicles with an efficient short-range single-hop network. Goby-Acomms is comprised of short message serialization, queuing which prioritizes based both on importance and time sensitivity, medium access control with passive automatic discovery, and an abstract modem driver. Also, two approaches that use the vehicle's 'intelligence' to improve communications are presented. The first is a 'non-disruptive' approach which uses state observers in conjunction with an entropy source encoder to enable highly compressed telemetry of AUV position vectors. The second approach is 'disruptive,' as it changes the vehicle's course to effect an improvement in the communications channel. This technique is an autonomous environmental adaptation framework which allows AUVs to follow a path which optimizes their ability to maintain connectivity with an acoustic contact for optimal sensing or communication.