  Gaze stabilization is an important requisite for humanoid robots. Previous
work on this topic has focused on the integration of inertial and visual
information. Little attention has been given to a third component, which is the
knowledge that the robot has about its own movement. In this work we propose a
comprehensive framework for gaze stabilization in a humanoid robot. We focus on
the problem of compensating for disturbances induced in the cameras due to
self-generated movements of the robot. In this work we employ two separate
signals for stabilization: (1) an anticipatory term obtained from the velocity
commands sent to the joints while the robot moves autonomously; (2) a feedback
term from the on board gyroscope, which compensates unpredicted external
disturbances. We first provide the mathematical formulation to derive the
forward and the differential kinematics of the fixation point of the stereo
system. We finally test our method on the iCub robot. We show that the
stabilization consistently reduces the residual optical flow during the
movement of the robot and in presence of external disturbances. We also
demonstrate that proper integration of the neck DoF is crucial to achieve
correct stabilization.
