Swiss students are collaborating on a project to create a nautical swimming robot would make it ideal for approaching fish to study them without scaring them away -- because it looks and swims like a fish, too.
The device dubbed Sepios, built at the Swiss Federal Institute of Technology in Zürich, is a four-finned robot inspired by a cuttlefish.
Although when it comes to maneuverability, it goes a cuttlefish one better, the students say; cuttlefish are highly agile sea creatures but Sepios uses its four separate fins "to maximize our goal of omnidirectionality."
"These qualities combined with its fishlike appearance and low disturbance are ideal for closing in on fish, making it the ideal device for marine life filming," the student say on the Sepios project website.
The four fins, each individually controllable, give the undersea robot the capability of rotating around any axis and moving in any direction.
In trials last year in the ocean off the coast of France, Sepios had no trouble navigating through thick sea grass, and fish were attracted to the natural rhythms of its undulating fins.
"Sepios has no trouble moving through dense patches of seagrass, even in surge, which would be a tangled nightmare for any underwater vehicle relying on propulsion systems that produce thrust by spinning," the student team reported. "It also generates a minimal amount of turbulence."
Sepios, at about 28 inches long with a wingspan -- or "fin span" -- of around 37 inches, can move through the water at a speed of approximately a mile per hour.
Powered by a battery that can last for an hour and a half, Sepios can operate down to a depth of 30 feet.
As befits any underwater research vehicle, Sepios is equipped with an array of sensors, a camera, a laser for collision detection, and instruments to report its accelerations and velocities back to its controllers.
That creates a level of complexity that introduces a number of challenges, the student designers say.
"Sepios has many different sensors which have to be coordinated, including a pressure and a humidity sensor," they write on their website.
