Agile underwater robot named “Sea Turtle” Photo: Science and Technology Daily
Chinese scientists have developed a new agile underwater robot named Sea Turtle, which has not only achieved a centimeter-level breakthrough in near-seafloor environmental observation, but, with its nimble movements, launched a new era of more precise, efficient, and eco-friendly underwater exploration.
The robot is expected to have wide applications in coral observation as well as underwater fishing, search, and rescue, Science and Technology Daily reported on Sunday.
Developed by a research team led by Wang Gang, a professor at the College of Shipbuilding Engineering, Harbin Engineering University, the 70-centimeter-wide underwater robot can dive to the seafloor and glide just a few centimeters above coral reefs, stirring only slight ripples of the sediment as it moves. It deftly twists through gaps and maneuvers past passing fish with the agility of an underwater flying disc.
According to Wang, existing deep-sea submersibles must wait a long time for sediment to settle before operating. Conventional benthic robots have poor terrain adaptability, and their propellers stir up sediment that damages the seafloor ecosystem, even as coral reefs worldwide are rapidly declining. Besides, traditional underwater robots provide unsatisfactory monitoring results, and divers have only two brief observation windows a year and cannot reach deep waters.
Wang’s team drew inspiration from sea turtles after studying dozens of marine animals, discovering that the turtles’ angled flipper strokes reduce water disturbance while maintaining efficient propulsion.
After numerous failures, the team derived a mathematical formula linking the robot’s low-disturbance navigation performance with its propulsion layout and shape parameters, greatly improving their research and development efficiency.
In comparative tests, the Sea Turtle robot, thanks to its precisely arranged propellers, produced almost no ripples while navigating, reducing sediment disturbance by 90 percent.
Unlike traditional underwater robots that maintain a certain height to handle unexpected situations, the Sea Turtle underwater robot must operate close to the seafloor – within 1 meter of coral – to capture precise color details. This requires extremely high sensitivity and the ability to instantly adjust its posture, ensuring it can navigate close to the bottom without accidents.
Through their efforts, the research team enhanced the robot’s environmental sensing, reducing sensor data noise by about 76.2 percent, shortening response time by 1.1 times, and improving stability by 7.16 times.
Meanwhile, the team integrated the robot’s posture information with algorithms, enabling the robot to adjust its orientation freely in 360 degrees like an octopus’ tentacles, which significantly enhanced the robot’s agility.
The Sea Turtle robot’s 360-degree maneuverability overcomes the technical bottleneck of full-range navigation in complex seafloor terrain, enabling it not only to be applied in coral observation, but also in underwater fishing, search, and rescue.
Global Times