Three-dimensional object manipulation by two robot fingers with soft tips and minimum D.O.F

Abstract

This paper shows through faithfully deriving Paffian forms of 3-D rolling contact constraints that 3-D pinching can be stabilized by using a pair of robot fingers with a hemispherical soft tip and minimum degrees of freedom under the gravity effect. The proposed control input is based on fingers-thumb opposition without using object information or external sensing. Stability analysis of the closed-loop dynamics is presented by using a Lyapunov method. Finally, for the sake of confirmation of effectiveness of the proposed control signals, numerical simulations are carried out.