Visually servoing a gough-stewart parallel robot allows for reduced and linear kinematic calibration

This paper focuses on the benefits of using computer vision to control a Gough-Stewart parallel robot. Namely, it is recalled that observing the legs of such a mechanism with a calibrated camera, thus following the redundant metrology paradigm, simplifies the control law. Then, we prove in this paper that such a control law depends on a reduced set of kinematic parameters (only those attached to the geometry of the robot base) and that these parameters can be obtained by solving a linear system. Moreover, we show that the camera can be calibrated without much experimental effort, simply using images of the robot itself. All this means that setting up the control system consists only in placing the camera in front of the robot.