A robot developed by researchers at the at the Learning Algorithms and Systems Laboratory (LASA) at EPFL (Ecole Polytechnique Fédérale de Lausanne, Switzerland) can react on the spot, grasping flying objects thrown at it with complex shapes and trajectories in less than five hundredths of a second.
The arm measures about 1.5 meters long, and has three joints and a sophisticated hand with four fingers. It was programmed at LASA and designed to test robotic solutions for capturing moving objects, which requires the integration of several parameters and reacting to unforeseen events in record time.
To obtain the desired speed and adaptability, LASA researchers were inspired by the way humans themselves learn: by imitation and trial and error. This technique, called “Programming by Demonstration”, does not give specific directions to the robot. Instead, it shows examples of possible trajectories to it. It consists in manually guiding the arm to the projected target and repeating this exercise several times.
The research was conducted with a ball, an empty bottle, a half full bottle, a hammer, and a tennis racket. These five common objects were selected because they offer a varied range of situations in which the part of the object that the robot has to catch does not correspond to its center of gravity. The case of the bottle even offers an additional challenge since its center of gravity moves several times during its trajectory. When projected into the air, all these items will make even more complex movements, often involving several axes. As a result, when the moving objects are submitted to the robot’s abilities, the outcomes turn out quite interesting.