A system structure with trajectory planning and control for robotic dynamic manipulation

We present a control framework for robot systems to perform dynamic manipulation tasks, with robotic batting as an example. A properly preplanned trajectory for manipulators is recognized to be important to increase the probability of success. A nominal path for a manipulator to travel in a swing motion is computed while optimizing the stochastic dynamic manipulability measure to cope with the unpredictable deviation of the ball. A nominal trajectory along the path is then planned in a minimum-time fashion for the benefit of catching the ball as accurately as possible, the behavior of which is observed visually and estimated on-line. A control structure consisting interpolatively of a path velocity controller to follow the nominal trajectory and a resolved-acceleration-natured ball-deviation compensating controller, together with a ball motion prediction, is proposed. The effectiveness of the proposed approach is examined using computer simulations. The strategy provided in this paper will be useful to make manipulators perform further task requirements better for a wide range of dynamic manipulations.