Position and Orientation Control of Polygonal Objects by Sensorless In-hand Caging Manipulation

In this work, we propose an approach to manipulate objects by position-controlled robot hands: in-hand caging manipulation. In this method, an object is manipulated based on caging without force sensing or force control. An object is caged by a robot hand throughout manipulation, and we can locate the object around a goal by deformation of the cage without sensing the object configuration. In this paper, we considered 2-D polygonal objects as the targets of in- hand caging manipulation. We also considered some position- controlled hands as the devices to manipulate the objects. A motion planning algorithm for the hands was proposed and applied to planar in-hand caging manipulation. By moving the hands according to the result of the motion planning, it was possible to manipulate the objects without sensing. Our proposed method can be applied to a device such as a part feeder that aligns variously shaped parts in the same pose.