H∞ controller for a visual servoing system

In this paper, the model for a one-dimensional visual servoing system implemented in our laboratory is initially presented. The system setup is composed by a PUMA robot manipulator, a CCD camera rigidly mounted on the end-effector of the robot, and some image processing hardware. The aim of the system is to keep a desired relative position between the object and the camera, handling the autonomous object motion as a disturbance input to the model. An H_∞ controller is then proposed in order to minimize the effects of this arbitrary object displacements. The principles used in the design of this controller and its performance are finally presented.