Swumanoid, developed by the Nakashima Group at Tokyo Institute of Technology, is a humanoid robot that replicates the motion of a swimmer. In the future, this robot is expected to help researchers analyze how people can swim faster, and develop speed enhancing swimming apparel.
“In research on swimming, one problem is, it’s hard to know how much propulsive force the hands create during a stroke. There have been attempts to measure such things using actual swimmers, but it’s hard to attach sensors to the hands of an actual swimmer. Also, a person can’t repeat exactly the same movement many times.”
For Swumanoid, a 3D body scanner was used to measure the body of a competitive swimmer, and reproduce it at half-scale. The complex swimming motions of a person are reproduced using 20 computer-controlled waterproof motors.
“When a swimmer moves, the motion of the shoulders is quite large. Ordinary humanoid robots aren’t designed for such large motions, so to replicate the big movements in a crawl stroke, we’ve installed special joints in the shoulders of Swumanoid.”
The robot overall has a special-purpose drive using four struts, and the force the robot receives from the water can be measured. Because the robot is currently at the prototype stage, its swimming speed, corrected for size, is 0.64 m/s or approximately three times slower than the current world record for the 100m freestyle. From now on, the researchers are planning improvements to make it faster.
“Swumanoid can already do the butterfly and backstroke. The breaststroke involves a different leg motion, so it can’t be done with the robot’s current legs. But we are developing legs to enable Swumanoid to do the breaststroke.”
“Currently, the robot doesn’t always swim as it’s instructed. So we’d like to enable it to swim freely. Humanoid robots can already walk and run, but if we have a robot that truly swims, it could be used not just for sports research, but also for rescuing people in the water.”