A concept design for the naro-tartaruga looks like a sea turtle. (Image courtesy ETH Zurich)In 2008, students at the Swiss Federal Institute of Technology Zurich (ETH Zurich) developed the 'naro' — a robotic tuna — while studying how autonomous underwater vehicles (AUVs) could be more successful if they were patterned after nature. Similar to the BIOSwimmer being developed for the US Department of Homeland Security, the naro robot was designed after the tuna because the configuration of that species' tail, dorsal and pectoral fins gives it exceptional speed and maneuverability.
Students at ETH Zurich are continuing the naro project with their new naro-tartaruga robot. This new AUV continues the concept of using fin propulsion, but rather than continue to work off fish designs, with the tail-fin propulsion and the rest for steering, they switched to a different ocean-dwelling species — the sea turtle.
With two longer pairs of fins at the front of the robot, and two shorter fins in the back — all of which can be used both as steering and propulsion — this AUV will be highly maneuverable. Additionally, the larger and more rigid body of this robot will allow for more sensors and electronics to be installed, and will allow for more versatility in its missions, due to its ability to use more standardized equipment — unlike the tuna-shaped naro, which needs specially designed electronics to work in its thin, flexible body.
The naro-tartaruga team has a working model at the moment, in the form of a 1 metre-long red cylinder with four fins, and a camera on the front. They plan on using the robot to test the energy consumption of flapping-fin propulsion, in an effort to determine which is more efficient — man-made propeller technology, or technology mimicking natural mechanisms that have evolved over millions of years, specifically for the marine environment.
Originally scheduled for test runs during this past summer, the naro-tartaruga will instead be making its first dives in the next few weeks.