Hand/eye coordination: role of the active observer

This paper presents a study of the role of the observer in the hand/eye coordination problem. We show, or rather confirm analytically the intuitive concept that all poses of the observer are not equally good in terms of the visual servoing to perform, and that a good pose can be chosen that facilitates both the local control problem and the learning of the visuo-motor coupling. We represent the relation between the visual input and the movements of the actuators by a surface, whose shape depends on the geometry of the manipulator and on the position of the observer (camera) relative to it. If the observer is active, it can therefore, simply by changing its viewpoint, modify the shape of the surface, and sometimes even its topology. In the context of this representation, a good activity of the observer is one that achieves "desirable" effects on the shape of the surface, thereby improving the performance of control algorithms and the facilitating the learning of the visuo-motor coupling itself.