Dynamic grasping for an arbitrary polyhedral object by a multi-fingered hand-arm system

This paper proposes a novel control method for stable grasping using a multi-fingered hand-arm system with soft hemispherical finger tips. The proposed method is simple but easily achieves stable grasping of an arbitrary polyhedral object using an arbitrary number of fingers. Firstly, we formulate nonholonomic constraints between a multi-fingered hand-arm system and an object constrained by rolling contact with finger tips, and derive a condition for stable grasping by stability analysis. A new index for evaluating the possibility of stable grasping is proposed and efficient initial relative positions between finger tips and the object for realizing stable grasping are analyzed. The stability of the proposed system and the validity of the index are verified through numerical simulations.