Robotic Blower Defies Gravity

Robot-controlled levitation sytem uses air to mysteriously move objects laterally

Aaron Becker and Robert Sandheinrich, with help from professor Timothy Bretl, built a computer-controlled air jet system that can make spherical objects like ping-pong balls not only float in place but also move along complex trajectories - even performing some acrobatic maneuvers like passing through wire loops.

Their robotic air blower can also sort balls of different weights and precisely propel balls toward a target. And it can lift an apple and non-spherical objects like a water bottle.

The system consists of a gimbaled air jet with two degrees of freedom. The air jet is supplied up to 620 kPa through a DC motor-controlled valve. Stereo vision cameras track the objects, and a control algorithm uses the position data and a fluid dynamics model to adjust the air jet, varying its speed and direction to keep the object in equilibrium.

IEEE Spectrum