Eye-in-hand/eye-to-hand cooperation for visual servoing

Abstract

The use of a camera in a robot control loop can be performed with two types of architecture: for eye-in-hand camera when it rigidly mounted on the robot end-effector; and for eye-to-hand camera when it observes the robot within its work space. These two schemes have technical differences and they can play very complementary parts. Obviously, the eye-in-hand one has a partial but precise sight of the scene whereas the eye-to-hand camera has a less precise but global sight of it. The motivation of our work is to take advantage of both, free-standing and robot-mounted sensors, in a cooperation scheme. The system presented performs two separate tasks: a positioning task to perform in the global image, and a tracking task to perform in the local image. For robustness considerations, the control law stability is proved and several cooperative schemes are studied and compared in experimental results.