New undersea robot is ‘fast, hovers and carries several instruments’

WASHINGTON - MBARI engineers recently demonstrated a new super-efficient autonomous underwater vehicles (AUV) that can travel rapidly for hundreds of kilometres, “hover” in the water for weeks at a time, and carry a wide variety of instruments.

Called Tethys, it can travel up to one meter per second (2.25 miles an hour) - about four times faster than most underwater gliders. However, it can also travel long distances at around half this speed.

“In designing this AUV, we were actually trying to make a fundamental change in how we do oceanography. Tethys can travel to a spot in the ocean and ‘park’ there until something interesting happens. Once a bloom occurs, Tethys can move fast enough to follow the bloom and watch it evolve, the way a biologist on land might follow and study a herd of deer,” said MBARI’s Chief Technologist, Jim Bellingham, who has been designing cutting-edge AUVs for almost 20 years.

Like a fish, it can control its buoyancy and the angle at which it “swims” through the water. It also incorporates sophisticated power-saving software like that found in some laptop computers, which monitors what systems are being used, and turns off those systems that are not in use.

The engineers also designed numerous fail-safe systems into the robot, some of which have their own independent power supplies.

Tethys can make some decisions without human intervention. Such internal decision-making becomes increasingly important when robots operate for weeks or months at a time.

But having such sophisticated internal control software carries certain risks.

“You cannot predict exactly how the AUV will behave-that’s the whole point. But you still want to make sure that whatever it decides to do, nothing bad is going to happen to the vehicle,” said Bellingham.

Bellingham hopes that this new AUV design will be small and inexpensive enough so that it can be used for a variety of ocean research and monitoring.

“Ultimately we’d like to Tethys to be a vehicle that is broadly accessible to scientists-a vehicle that can be launched from a small boat, at relatively low cost,” he said.

Bellingham also hopes to use two LRAUVs with different instruments in a single experiment, so that they can monitor different types of marine organisms simultaneously. (ANI)