Real-time visual servoing using controlled illumination

A real-time visual servoing approach is applied to robotic tasks consisting of the positioning of the end effector with respect to a priori known polyhedral objects. The vision apparatus is constituted by a compact CCD camera rigidly coupled with two laser stripes mounted on the wrist of a robot manipulator. The objective is to servo the robot end effector at a constant position and orientation with respect to a known object in three-dimensional space in the field of view of the sensory system. The approach is expressed in terms of sensor-based control (Samson et al. 1991) applied to visual servoing (Chaumette 1990; Urban 1990). In the case of camera-light stripe coupling, the elementary visual signals used for visual servoing are the points of discontinuity in the light stripes. The feasibility of the approach is demonstrated in a factory automation task consisting of the positioning of the end-effector tool over a vehicle battery. Both simulation and experimentation results are presented, proving the robustness and stability of the algorithm. 19 refs.