Online construction of the manipulation model of an unknown object by a robot hand using the regrasping primitives

This paper presents a planner which explores an unknown polyhedral object w ith a multifingered hand in a systematic way by constructing the manipulati on-model of the object. The manipulation-model of an object we proposed pre viously is a database which consists of landmark orientations of the object , the applicability of manipulation primitives to them and intertransformat ions among them. In this paper, two regrasping primitives, rotation and piv oting, are employed. A multifingered hand probes a given unknown object for pivot/rotation axes. If a new axis is found, the planner recursively perfo rms pivoting or rotation-test (which is similar to rotation but does not ac tually rotate the object) about the found axis and searches the object for more axes. The manipulation-model of the object is constructed based on the found axes. An experiment for constructing a manipulation-model of a non-c onvex polyhedral object is conducted using a four-fingered hand. Force/torq ue sensors mounted on the fingertips collect the data of the object. A geom etrical model of the object is also constructed.