Performance analysis and planning in graspless manipulation

Graspless manipulation is a process in which objects are manipulated by making use of the environment surrounding it. Graspless manipulation enables a robot to handle objects that cannot be rigidly grasped due to the environment presenting obstacles in the way of its fingers. However, in the manipulation, the handled objects can easily slip out of the robot's fingers. Therefore it is necessary to make a plan for robust manipulation, suitable for various environments. We propose a planning method for graspless manipulation. First, considering the stability of the manipulation itself, a stability index is proposed. Then, the topological relationships are expressed among the object and its environment. Using the stability index, feasible motions are obtained as a safe route from one state of relationships to another. By means of these regions being connected, a plan of a manipulation can be obtained. The proposed method is simulated and experimented.