Analysis and control of grasping motion by two cooperative robots

The grasping motion done by two robot manipulators is analyzed. The analysis makes it clear that the reaction force sensed at each end-effector can be decomposed into two force components, that is, motion-inducing force and object-squeezing force. Based on the force decomposition, two types of robust motion controller for cooperating manipulators are proposed. The proposed controllers track desired contact force and internal force with strong robustness to object/manipulator dynamics. Finally, some experimental results show the feasibility of robust grasping motion by the proposed controllers.