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Project Manager

Lee Frey

Project Team

• Brian Ramos, Software Engineer
• William Spears (University of Wyoming)
• Diana Spears (University of Wyoming)
• Dimitri Zarzhitsky (US Air Force Academy)

Project Description

The DRONES project is intended to investigate the potential of cooperative autonomous surface vehicle (ASV) swarms to seek out and follow marine gradient plumes.  These plumes may be thermal, chemical, or bioluminescent in nature.   This project is funded by the Office of Naval Research.

Intellectual Merit

Autonomous swarms have inherent advantages over single AUVs or ASVs, such as:

Synoptic Sampling – A swarm of agents can take a simultaneous “snapshot” of a phenomenon over a large area, much like a distributed mobile sensor grid.  In a typical single-agent “mowing the lawn” scenario, many phenomena change over time, making it difficult to correlate data between the beginning and end of a mission.

Cooperative Tasking – Swarms work together to accomplish a goal faster and more reliably than a single agent can, sharing data, delegating tasks, and assisting each other in avoiding failure.

Large Area Coverage – Agents in the swarm can spread out to cover more area per pass than a single vehicle could “mowing the lawn.” 

Robustness – Cooperation and large numbers allow swarms to maintain robust, fault-tolerant formations.  If one or even several agents are lost, the mission can still continue, unlike with a single vehicle.  Redundancy within the group adds strength to this robustness.  Furthermore, economies of scale decrease per-vehicle cost, making lost assets less of an issue.

To this end, the RI Lab is developing a series of seven small test-bed ASVs to demonstrate swarm formation and gradient following.  Our control methodology is based on the Physicomimetics (Artificial Physics, or AP) framework, pioneered by researchers at the University of Wyoming and Harbor Branch.   Unlike other cooperative vehicle methodologies, AP does not rely on behavioral modeling, and is fully distributed (i.e. no leaders and no followers).  

Broader Impacts

This work has far-reaching impacts, both tactically and environmentally.  On the tactical side, bioluminescence is of major concern to the US Navy, as it has the potential to expose the position of forces during a covert insertion operation along a hostile coastline.

An autonomous swarm could be sent in prior to the operation to covertly assess the severity of the luminescence, as well as determine the best path through the luminescent “minefield."

On the environmental side, autonomous swarms could be used to seek-out the sources of nutrient and other pollutant plumes, such as sewage seeps and agricultural discharge.  These discharges contribute to the nutrification of our bays, estuaries, and coastal reefs, and are shown to cause Harmful Algal Blooms (HABs).

Publications

Frey, C.L., D. Zarzhitsky, W. Spears, et. al. (2008). A Physicomimetics Control Framework for Swarms of Autonomous Surface Vehicles. Marine Technology Society of the IEEE, Oceans 2008.