New 'ultra-fast' bionic arm can catch objects on the fly

Researchers have developed a bionic arm that is capable of reacting on the spot and grasping objects with complex shapes and trajectories in less than five-hundredths of a second.

With its palm open, the robot is completely motionless. A split second later, it suddenly unwinds and catches all sorts of flying objects thrown in its direction -a tennis racket, a ball, a bottle.

This arm measures about 1.5 meters long and keeps an upright position. It has three joints and a sophisticated hand with four fingers. It was programmed at the Learning Algorithms and Systems Laboratory at EPFL (LASA) and designed to test robotic solutions for capturing moving objects.

It is unique, as it has the ability to catch projectiles of various irregular shapes in less than five hundredths of a second.

This robotic arm already has a very real potential application in space. It has been associated to the Clean- mE project carried out by the Swiss Space Center at EPFL, which aims to develop technologies for the recovery and disposal of space debris orbiting around Earth.

Fitted on a satellite, the arm would have the task of catching flying debris, whose dynamics are only partially known. Hence, the robot will not be able to work out such dynamics with precision until in space, by observing the movement of the approaching objects.

The ability to catch flying things requires the integration of several parameters and reacting to unforeseen events in record time. "Today's machines are often pre-programmed and cannot quickly assimilate data changes, added Aude Billard. Consequently, their only choice is to recalculate the trajectories, which requires too much time from them in situations in which every fraction of a second can be decisive."

This research has been published by IEEE transactions on robotics, the first journal in the field.