3D Multifingered Caging

—Derivation of Sufficient Conditions for Four Kinds of Simple-shaped Objects by a Symmetric Robot Hand—

Abstract

Caging is a geometrical method to constrain an object: a position-controlled robot surrounds the object to make it be inescapable from the cage composed by the robot bodies. In this paper, we propose three-dimensional caging by a multifingered hand (3D multifingered caging). In multifingered caging, force control is not necessary to constrain an object. This is an advantage over conventional grasping from the viewpoint of easy execution by actual robots. Furthermore, considering a margin of caging constraint allows the error of position control and deformation of objects to some extent. We classify 3D multifingered caging according to states of constraint, and derive sufficient conditions for caging of some simple-shaped objects. We show some configurations of a robot hand for caging planned with the sufficient conditions.