Automatic determination of finger control modes for graspless manipulation

To achieve various manipulation tasks by robot fingers, we have to use both position control and force control appropriately. In this paper, we propose a method to determine such control modes of robot fingers in graspless manipulation. Using the method, we can assign a position- or force-control mode to each robot finger so that the maximum manipulation stability will be achieved without excessive internal force. Desired finger forces are also determined for robot fingers to be force-controlled. We show some numerical examples of automatic determination of control modes in graspless manipulation of polyhedra on a plane by two robot fingers.