Seamless Control of Multi-Fingered Robot Hands Based on Relative Motion of Grasp Polyhedrons (Soft Contact Case)

This paper considers a new feedback control design methodology for multi-fingered robot hands applicable to multiple contact situations. In our previous work, in the hard contact case, we proposed a control design method applicable to variable contact situations based on the relative motion of the grasp polyhedrons, whose vertexes are defined by the contact points on the fingers and the object. In this paper, we extend our previous results to the soft contact case, where deformation of the fingers and/or the object is included in the consideration. The proposed controller can directly handle the tasks with multiple contact situations such as the catching/releasing task by choosing appropriate desired trajectories without switching control architecture. A numerical example of the catching/releasing task for a moving object is conducted to show effectiveness of the proposed method.