Rolling based manipulation for multiple objects

Discusses the manipulation of multiple objects under rolling contacts. For manipulating multiple objects, there are two key issues which do not arise in the manipulation, of a single object, (1) each object's motion is restricted by the other objects, and (2) the contact force among objects is not controlled directly. As for (1), we first formulate the motion constraint for the whole grasp system, and then provide a necessary condition for manipulating multiple objects uniquely. As for (2), we provide a condition for determining the contact forces among objects uniquely. We further show a sufficient condition for manipulating multiple objects within the object motion constraint. Under this sufficient condition, we propose a control scheme for object motion by taking the motion constraint into account. An experimental result is provided to confirm our idea.