Goal-Directed Learning of Hand-Eye Coordination in a Humanoid Robot

Visuo-motor coordination is known to be highly important for the development of a broader range of cognitive and motor skills in human infants and can thus be considered one of the key skills for robots to master. In this paper, we investigate how a recent concept in developmental robotics, referred to as goal babbling, relates to a visuo-motor coordination task in the humanoid robot Aldebaran Nao that requires coordinated control of two subsystems of motors, namely head and arm motors. The idea of goal babbling builds on findings in developmental psychology showing that human infants attempt goal-directed movements early on in their development enabling them to rapidly and efficiently bootstrap their motor system. Goal babbling has been shown to be superior to the classical idea of random motor babbling for the learning of body kinematics in robotic systems, in particular for systems with many degrees of freedom. Our results not only support the utility of goal babbling for the acquisition of visuo-motor coordination skills but also suggest that goal babbling is particularly effective in the case where two separate motor sub-systems, head and arm, need to be coordinated.