Lake George Multiple Vehicle Testing
May 30 - June 9, 2006
The Lake George tests are being conducted by the Autonomous Undersea Systems Institute, Technology Systems Inc., and Falmouth Scientific Inc. in collaboration with Rensselaer Polytechnic Institute's Darrin Fresh Water Institute research center and the Naval Undersea Warfare Center.
These tests are part of a broader program to research and develop technology and systems to enable multiple cooperating AUVs, and is funded through ONR and NSF.
The principle objectives of the Lake George testing are to:
- Provide a dress rehearsal for the July 2006 Monterey Bay exercise where multiple SAUV vehicles will cooperate to acquire scientific data to be utilized by the LOCO (Layered Organization in the Coastal Ocean) scientific team
- Support the NSF-sponsored RiverNet project through a SAUV mission to sample the Hudson River
- Demonstrate technology development efforts which support multiple cooperating AUVs
Results
During operations at the DFWI, the team of AUSI, NUWC, FSI and TSI successfully completed a series of cooperative survey in-water tests. The mission consisted of defining a watch circle area for each vehicle and a survey box depicted below in the snapshot from the MMPT.
The set-up process consisted of the operations boat towing each vehicle to its designated watch circle and the operators at the command center located on the third floor of the DFWI lodge issuing a watch circle mission to each vehicle (SAUV-3 and SAUV-5). Once all systems were ready and the operations boat was positioned at safe stand-off, the cooperative box survey mission (cobox) was broadcast to the SAUVs. The cooperative behavior allows the vehicle with the highest energy to perform a survey box and the vehicle with the lower energy is allowed to re-charge in its assigned watch circle area. This is determined real-time based on messages passed acoustically between vehicles. The messages contain the energy level and the current task each vehicle is running.
During the in-water testing the scenario proceeded as follows: SAUV-5 and SAUV-3 were initially tied with respect to energy level so SAUV-3, the vehicle with the lower ID, started the survey box running at the surface. Following a complete survey, SAUV-3's energy level was lower than SAUV-5, which had been sitting in its watch circle so the vehicles swapped roles. When SAUV-5 completed its first survey, it was still higher in energy so it continued to perform the survey box. It was determined that because of the overcast conditions and the voltage levels of SAUV-3, it would never be able to charge enough to surpass SAUV-5, so the energy level of SAUV-3 was re-set to its maximum level. At the next decision point, SAUV-5 had the lower energy so the vehicles swapped successfully once again.
This test met our goal of running a two vehicle cooperative survey. We used the new Modular Mission Planning Toolkit (MMPT) as the interface at the command center. We also used the Macromedia Breeze tool to provide a virtual observation room for personnel from the team that were not at Lake George. Team members from TSI in Maine and from NUWC in Rhode Island were observing the MMPT display plotting vehicle position and status messages real-time and providing comments and feedback through a chat pod in the Breeze environment.