Purdue Researchers Create A Cheap Underwater Glider

Autonomous submersible probes and drones are of use to scientists all around the world for exploring the oceans. There are challenges with designing underwater drones and other autonomous underwater vehicles because they can be intrusive to the environment and have trouble fitting through confined spaces. Researchers at Purdue University have created a new underwater drone that's highly maneuverable and low cost.

The underwater glider can operate silently, and its components and sensors can be swapped out or added to, allowing it to meet a wide range of mission profiles. Researchers say their underwater glider can travel for weeks or months between charges allow it to be a benefit for deployment in high-risk areas. Underwater gliders differ from other Marine robots, in that they have no propeller or active propulsion system.

Rather, the glider makes changes to its buoyancy to sink down and rise up to propel itself forward. The up-and-down approach allows for highly energy-efficient vehicles, but also presents problems. Typically underwater gliders are expensive, slow, and not maneuverable. The vehicle the researchers created is called ROUGHIE, standing for Research Oriented Underwater Glider for Hands on Investigative Engineering, and is shaped like a torpedo.

It's about four-feet long and has no outward propulsion or control surfaces other than a static wing. When the craft is deployed from shore or a boat, it pumps water into ballast tanks to change its buoyancy and provide that initial glide path angle. Pitch is controlled by the vehicle's battery subtly shifting weight forward and backward.

Steering is provided by a suite of inner components mounted on a rail that rotates precisely to control the vehicle's role. ROUGHIE has a turning radius of only 10 feet compared to 33 feet for other gliders. The device can also be fitted with various sensors for gathering temperature, pressure, and conductivity data.