NOAA, Navy swimming with the SHARCs
When I wrote a column recently about DARPA’s AlphaDog, and how the mule-like robot could one day help Marines carry and even recharge their gear in the field, a lot of people were impressed.
But agencies whose focus is a little bit more aquatic in nature, such as the National Oceanic and Atmospheric Administration and the Navy, countered with information about a more advanced robot they are already using in the field. While the Marines work with their mules, the Navy and NOAA are swimming with SHARCs.
SHARCs are Sensor Hosting Autonomous Research Craft created by Liquid Robotics. Whereas the AlphaDog can travel 20 miles on its own with limited user intervention, SHARC Wave Gliders are now routinely swimming the world’s oceans, traveling hundreds of miles and going for up to a year without personal human contact.
NOAA launched its first Wave Glider in April 2011 and has since found plenty of other uses for them, including one deployed to monitor Hurricane Isaac.
The Naval Postgraduate School recently acquired two Wave Gliders and opened its Sea Web and Wave Glider Laboratory.
The secret of the SHARC — actually, the Navy calls them SHARCs; NOAA refers to them as Wave Gliders — is that it has two power systems. The first is an array of solar panels that floats above the water on a surfboard-size keel and is used to power instruments below that can measure just about anything from ocean salinity to the strength of whale songs.
But the second part of the setup is what makes the Wave Gliders so amazing. The surface part of the robot that floats is tethered to a submersible that hangs seven meters into the water. When the top part of the robot rises on a swell, it pulls the lower part up too. Fins on the submersible direct the water and force the craft forward, somewhat like the way an airplane moves through the air. Then when the float comes off the wave, the lower part of the robot sinks down, but its fins rotate in the opposite direction, and it gets pushed forward once again.
So it can always move forward as long as there is wave action. The solar power system at the top of the robot powers navigation control and can direct its movements and hold a true course, or its path can be changed remotely by a human operator if needed.
Right now the Wave Gliders are mostly being used for research, but the possibility of more dangerous work, such as scanning for minefields or even espionage tasks, could be in the cards for an always-on, always moving, low profile craft that can operate independently anywhere in the world without any risk to human life.