Simultaneous Control of Grasp/Manipulation and Contact Points of an Object with Rolling Contact by Two-fingered Robot Hand with Constraint of Degrees of Freedom

Abstract

This paper considers simultaneous control of grasp/manipulation and contact points of an object with the pure rolling contact by two-fingered robot hand. We consider the case where the number of the degrees of freedom (DOF) of each finger is constrained. First, we derive a relationship between the rolling velocity and the motion of the fingers and the object, which determines the number of the DOF of the system. Second, we provide explicit expressions of the contact force and the motion of the fingers and the object, which can be directly used for the simultaneous control. Utilizing the results, we provide a general formulation of a linearizing compensator for the simultaneous control. Controlling the contact points can be realized by making the rolling velocity follow the appropriate trajectory with the nonholonomy of rolling. A numerical example shows the effectiveness of the method.