A robot that can catch.

Robots are still, on the whole, kind of slow responders. The big breakthrough a couple of years ago with Big Dog was that it could run without tipping over – it could respond to changes in terrain and orientation at about the rate of a trotting mastiff. Now, LiveScience reports, some European researchers have design a robot arm that can see a thrown object and respond quick enough to catch it in mid-air:

“Increasingly present in our daily lives and used to perform various tasks, robots will be able to either catch or dodge complex objects in full motion,” Aude Billard, head of the team at the École polytechnique fédérale de Lausanne (EPFL) that developed the arm, said in a statement.

To achieve such rapid responses, researchers took inspiration from human learning methods of imitation, and trial and error. They used a technique called “programming by demonstration,” in which the robot is not given specific instructions. Instead, researchers manually guided the arm to a catching position several times, until the robot learned to move into position itself.

The team tested the arm by throwing several different objects at it: a ball, an empty bottle, a half-full bottle, a hammer and a tennis racket. These objects have different centers of gravity, presenting unique challenges for the robot.

During the first learning phase, the researchers threw objects at the robot several times. The robot used a series of cameras positioned around it to measure the trajectory, speed and rotation of the object in order to model its movement. It then performed a speedy calculation to move itself in the right direction, correcting its trajectory in real time and synchronizing its finger movements to catch the object.

The robotic arm is already being used as part of EPFL’s Clean-mE project to develop technologies for recovering and disposing of space junk orbiting the Earth, researchers said.

Video at the link.