In-Hand Manipulation Based on Ball-On-Cloth System

This paper presents a novel in-hand rolling manip- ulation method in which a ball on a cloth attached to fingertips is controlled using flexible and adaptive deformation of the cloth. First, an analytical model of the ball-on-cloth system is introduced. The shape of the cloth is simplified, and the rolling constraint of the ball on the cloth is defined focusing on the lowest point of the ball. Next, the relationship between the input to the cloth anchor point and the position of the lowest point of the ball is expressed by a linear approximation. Then, the input to generate the desired rolling orbit is designed. Next, as an example of utilizing the rolling orbits, a manipulation method to rotate the ball around a vertical axis is developed. Finally, a multi-fingered hand with a piece of cloth attached to the fingertips is developed, and the effectiveness of the proposed system is experimentally verified.