Developed by the Korean Institute of Ocean Science and Technology (KIOST), the Crabster offers a solution to a longstanding problem. While propeller-driven craft do not work well in fierce tides, and divers are limited to calm, relatively shallow seas, the new machine mimics the design of crabs and lobsters that live in stormy waters but are still able to control their movements.
The Crabster is 2.4m long, 2.4m wide and 1.3m tall -- rising to 1.8m when it stands up. Including payload it weighs around 650 kg, and its six legs contain 30 motors, giving the remote pilot control and dexterity. As the Crabster creeps along the ocean floor, it can adapt its posture to different current or pressure conditions to a depth of around 200 meters. Using sonar, it scans the landscape for objects of interest, and can relay images through onboard cameras.
Crabster is undergoing final tests in "aggressive waters" ahead of its first mission. In May, it is scheduled to be hunting for ancient artifacts in the Yellow Sea, where existing crafts have failed.
Lead researcher Bong Huan Jun told CNN the machine had performed "very well" in tests but was undergoing constant modification. "We are performing tests nearly every day," Huan Jun told CNN. "We upgrade Crabster software for more stable and fast walking and manipulation."
The researcher says the robot's speed of just 10 cm/second is one of the main challenges his team face, along with enhancing the vehicle's stability in strong currents and on rough terrain. The underwater vision system is another priority. But should Crabster succeed in its maiden voyage, Huan Jun predicts a widespread impact.
"We suppose CR200 can conduct seabed mapping, survey and inspection of wrecks, pipelines, ecosystems and pollution down to a 200-meter depth. CR200 will help divers or work instead of them in harsh environments. It also could assist in locating underwater resources, carrying out underwater mining, and responding to oil spill incidents."