I have to admit that I'm a sucker for simple solutions to difficult problems. At ICRA this week, one of the cleverest new designs (and winner of the award for best video) was for a small tube climbing robot. The Biorobotics lab and Manipulation lab at Carnegie Mellon University have been working for several years on dynamic climbing bots that can climb between walls without any special attachment mechanism. But they wanted to come up with a smaller design that could make it up three-dimensional tubes.
The result is this little device. It's simple motor turns an unbalanced mass at a uniform velocity. As the mass swings around, it causes the robot to bounce back and forth between the tube walls. Two rubber o-rings let the researches specify the exact contact points and increase friction with the walls.
This isn't the first tube-climbing, vibrating robot, but it has some distinct advantages. Earlier designs relied on fibers or bristles to create anisotropic friction with the walls and vibration caused motion in the direction of lowest friction. The problem with these designs comes when you need to remove the robot--now you're forced to work against the maximum friction.
What's most impressive about Carnegie Mellon's new bot is its speed, versatility, and payload capability. In the video, you can see that it travels up to 20 body-lengths per second and has a payload capacity of roughly 5x it's weight. The robot can even climb different sized tubes, although at different rates.
The researchers say they weren't application driven, but it's not hard to imagine such a simple device coming in handy for navigating tubing quickly.
(Video courtesy of Amir Degani, Siyuan Feng, Howie Choset, and Matthew T. Mason)
Joshua J. Romero is a software developer and journalist. A former IEEE Spectrum senior editor, he holds a bachelor’s degree in astronomy and physics from the University of Arizona and a master’s in journalism from New York University.
