New 'thinking' robotic sea turtle developed

Indian-origin researchers have developed a next-generation 'thinking' robotic sea turtle capable of performing complicated tasks such as surveillance and energy harvesting.
In the near future, it would be possible to produce a swarm of autonomous tiny robotic sea turtles and fishes for example, to perform hazardous missions such as detecting nuclear wastes underwater or other tasks too dangerous for humans, researchers said.
In the underwater robotic world, turtle robots are among the most manoeuvrable, researchers said.
The National University of Singapore (NUS) team's turtle robot, besides being manoeuvrable, can also go about determinedly performing what it is set out to do, while being able to react to exigencies and obstacles.

The team led by Associate Professor S K Panda is putting the final touches to a robotic sea turtle which could move about underwater, including diving to deeper depths vertically, like a real turtle, by just using its front and hind limb gait movements.
"Our turtle robot does not use a ballast system which is commonly used in underwater robots for diving or sinking functions," said Panda.

"Without this ballast system, it is much smaller and lighter, enabling it to carry bigger payloads so that it can perform more complicated tasks such as surveillance, water quality monitoring in Singapore reservoir or energy harvesting for long endurance.

"Being able to do a dynamic dive or sinking vertically means that it can also enter vertical tunnels or pipes in the seabed with very small diameters," said Panda.
Being smaller and lighter would also enhance its energy efficiency. The NUS turtle robot is also able to self-charge, further reducing the need for it to return to base station for recharging. It is agile and able to turn sharp corners with small radius, without losing speed.
Researcher Abhra Roy Chowdhury said the team has designed and developed four other underwater prototypes - a spherical robot that mimics a puffer fish in structure but uses a jet propulsion technique similar to jellyfishes and squids; and three robotic fishes of different morphologies.

These robots are scalable, modular and possess stealth (ability to avoid detection) features.
"If need be, we can actually combine all their merits in a single robot," Chowdhury added.
Another member of the team, Bhuneshwar Prasad, has also developed a spherical robot. This robot can be used for oceanic surveys, inspections of pipe and cable, inspection of a ship hull or a propeller's shaft, for example.