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Monday, 29 December 2014

Turtle robots could help with underwater tasks..............

Turtle robots could help with underwater tasks
From left: Bhuneshwar Prasad, Associate Professor S K Panda and Abhra Roy Chowdhury
Engineers from Singapore have created a smart turtle robot that could aid humans with underwater tasks such as oceanic surveys and inspections of cables, the ship hull or a propeller's shaft

Robots in the shapes of turtles and fish may soon lend humans a hand in performing underwater tasks such as water- quality testing in reservoirs and deep-sea cable inspection. These intriguing solutions developed by National University of Singapore (NUS) engineering researchers look towards nature for answers to technical challenges.

A team from the Department of Electrical and Computer Engineering led by Associate Professor S K Panda has designed five underwater robotic prototypes. One resembles a turtle, three look like fishes of different forms, while the fifth, a spherical model, mimics a puffer fish in structure but uses a jet propulsion technique similar to jellyfishes and squids. These biomimetic creatures are scalable, modular and possess features that help them blend into their environment.

"We expect to invent robots capable of performing collaborative intervention missions three to five years down the road. What we plan to do in the near future is to develop fish with muscles, which can undulate the way real fish do," said Associate Prof Panda.

The turtle robot is unique in that it does not need a ballast system used in similar robots for submerging. The smaller and lighter NUS model enables the installation of more components such as a lab-on-a-chip or camera. It can also be fitted with solar panels and turbines to harvest energy from the sun and sea currents, respectively, thereby increasing its energy efficiency. The turtle robot can also dive at an angle and sink vertically, allowing it to enter vertical tunnels or pipes in the seabed with very small diameters.

PhD candidate Abhra Roy Chowdhury developed the first lifelike fish robot three years ago after spending considerable time studying the manoeuvrability and energy-efficient movements of real fish. He based his research on the yellow-fin tuna and the freshwater largemouth bass which have the most common fish body types and swimming patterns. From his findings, he designed a bio-inspired dynamics and behaviour-based control architecture for these biomimetic platforms.

Recent technological advances have enabled these robots to provide more computational power at lower prices, said Research Engineer Bhuneshwar Prasad. The robots could take photos with a camera and process selected images before sending them to a remote computer, hence shortening the process and minimising energy consumption, he explained.

The team plans to develop central pattern generators - biological neural networks that when activated produce rhythmic motor patterns and motion in the absence of inputs that carry specific timing information. This will allow the robotic fish to respond to its surroundings and make crucial decisions in order to complete a mission.

The researchers do not see their robotic creatures as replacements for the more sophisticated Remotely Operated Vehicles - tethered robot submarines that are controlled by pilots on a mother ship. Rather, they view them as complementary intelligent vehicles with specific functionalities performing at par with other vehicles on a mission.