REDUCTION OF THE END-EFFECTOR SENSITIVITY TO THE STRUCTURAL DEFLECTIONS OF A SINGLE FLEXIBLE LINK - THEORETICAL AND EXPERIMENTAL RESULTS

The fine positioning problem of the gripper of flexible robotic manipu lators is addressed in this study. A two-axis cartesian micro-manipula tor is implemented to reduce the sensitivity of the gripper to the str uctural deformations of a single flexible link. A laser head with a du al axis photodetector are used to provide direct measurements of the t ransverse deflections at the free-end of the beam and to detect mechan ical inaccuracies caused by manufacturing imperfections and assembly m isalignment. The advantages of the integrated system of the micro-mani pulator with a single compliant beam are demonstrated and compared to the one without the micro-manipulator for two different control scheme s, ''rigid body controller (RBC)'' and ''rigid and flexible motion con troller (RFMC).'' Both theoretical and experimental results have prove n the capability of the micro-manipulator in significantly improving t he gripper positional accuracy. Furthermore, it was demonstrated that the micro-manipulator tends to complement rather than overlap the effo rts exerted by the host beam controller.