With robotics emerging as a major area of focus for military applications, especially the bio-inspired ones, countries across the globe are investing heavily in this domain. But, not many have tasted success so far.
However, Santhosh Ravichandran, an MS student specialising in machine design at IIT Madras, has developed a first-of-its kind turtle shaped Robotic Underwater Vehicle (ROV) with bio-inspired propeller similar to a dolphin fin in just three months.
Called ‘Duli’, a Sanskrit name for a turtle, it had immediately caught the attention of Defence Research Development Organisation (DRDO). The robot has unique hydrodynamics with exceptional energy efficiency and camouflage abilities suited for carrying out of underwater SEAL operations. It can do visual inspection withstanding the undercurrent of the ocean, it is claimed.
Santhosh said the currently available underwater robots are predominantly operated with mechanical thrusters, which gives only 30 per cent energy efficiency (read output to input), while Duli with bio-inspired flap movement will give 70 per cent efficiency similar to biological organisms like dolphins.
The novelty of Duli the is bio-inspired tail that could be used for rapid long motion which is eco-friendly. It will do sensitive jobs like surveying coral reefs without causing any disturbance to marine life. The mechanical pectoral thrusters are used only for manoeuvring. Usually bio-inspired designs suffer from complexities in control systems such as under-actuation, lower manoeuvrability.