While AUVs (autonomous underwater vehicles) are often used for scientific studies, they're sometimes also utilized in more secretive applications, such as surveillance and reconnaissance. A new system helps hide their location, by having them deploy a micro-AUV.
Even though some AUVs are capable of travelling deep underwater for days at a time, they still have to surface whenever it's time to transmit gathered data to their users – this is because radio waves don't travel well through the water. While the craft is floating at the surface, there's a chance that it could be spotted by the people who are being spied on.
That's where the micro-AUV comes in.
It was designed by British company ecoSUB Robotics, and has been experimentally installed on an existing hydrogen-fuel-cell-powered Solus-LR AUV, made by Canada's Cellula Robotics. The latter craft can descend to a depth of 3,000 m (9,843 ft), travel at a top speed of 2 meters (6.6 ft) per second, and cover a distance of up to 2,000 km (1,243 miles) without refuelling.
In a nutshell, the micro-AUV allows the Solus-LR to transmit data without surfacing, as the smaller craft can be deployed by the larger one while it's still submerged.
Instead of just popping straight to the surface like a buoy, the micro-AUV independently travels underwater for up to several miles – away from the Solus-LR – before surfacing. Because it's so much smaller than its host vehicle, it's much less likely to be spotted. Even if it is seen, however, its surface location won't give away the Solus-LR's current underwater location.
Additionally, it simply sinks to the seabed after making its transmission, so it can't be followed back to its host. And yes, that does mean it becomes a form of marine litter.
In a test of the system conducted last month at Indian Arm inlet in the city of Vancouver, the specially equipped Solus-LR successfully deployed its micro-AUV while submerged and underway. That micro-AUV proceeded to navigate to a different location, where it surfaced and transmitted a status message to an offsite command center via Iridium satellite communications.
The technology was developed by Cellula and ecoSUB as part of their work with the SeaWolf AUV Project, run by Australian defence company Trusted Autonomous Systems.
Source: Cellula Robotics