VISUAL SERVOING IN THE TASK-FUNCTION FRAMEWORK - A CONTOUR FOLLOWING TASK

We describe an approach to contour following unknown objects using a hand-eye robotic system. Relevant and sufficient feature points providing optical flow data are extracted from the edges of the target object. The desired motion of the end-effector is computed with the objective of keeping the visual features always at the same target location in the image plane. A cartesian PD controller is used to perform the desired motion by the robot's end-effector. To address the control issues, we take advantage of the unifying robot control theory stated in the literature as the task-function approach [21]. To validate our approach, we restricted our experiments to motionless objects positioned in a plane parallel to the image plane: three degrees of freedom (two of translation, one of rotation) are thus controlled.