Experimentally supported control design for a direct drive robot

We promote the idea of an experimentally supported control design as a successful way to achieve accurate tracking; of reference robot motions, under disturbance conditions and given the uncertainties arising from modeling errors. The H/sub /spl infin// robust control theory is used for design of motion controllers. Potential of the theory is additionally enhanced by incorporating a disturbance-based control design cycle. Within each iterative cycle we experimentally evaluate effects of designed H/sub /spl infin// controllers on a direct-drive robotic set-up. The controllers resulting from such iterative design are indeed specialized for this robot, but they significantly improve both performance and robustness against disturbances and modeling errors, as compared with conventional industrial motion controllers. Superior performance is experimentally demonstrated in both configuration (joint) and task (Cartesian) spaces of the robot.