Attractive regions formed by constraints in configuration space-attractive regions in motion region of a polygonal or a polyhedral part with a flat environment

It is found that the attractive regions exist in the motion region of a polygonal part in 2D during a pushing process by a fence or grasping process by a parallel jaw gripper. Taking a triangular part as an example, the paper provides the strategies to move the polygonal part, from any pose on the plane to a unique pose (by grasping) or a pair of symmetric poses (by grasping) of a parallel jaw gripper. The key point is to enable more than one stable state in the last stage to stay in one local attractive region in the current stage. Furthermore the relationship between the shape of the polygonal part and the action steps can be easily deduced due to the number of attractive regions are given clearly. It is also found that there are also many attractive regions in motion regions of a polyhedral part in 3D during a pushing process by a fence or grasping process by a parallel jaw gripper. These attractive regions in the motion region of the polygonal or polyhedral part can also be used to help the identification of the objects on the same conveyer with incomplete information.