Dynamic Manipulation of a Sphere on a Disk by Inclination Control of the Disk

Human beings cannot control a position of sphere on the disk without seeing it. Because under such a condition, as we determine the position and estimate the motion of sphere by use of visual information, it is very difficult for human beings to control it using only tactile or force information of a hand. This is why the tactile and the force information are less quantitative for human beings than the visual information. On the other hand, a robot can deal with this qualitative information as quantitative values. Therefore, the robot seems to have the possibility that it carries out such difficult tasks for human beings using only force information. In this paper, we propose the estimation method of the position of sphere (made of crystal) on the disk from the force information measured with three-directional force sensors. Then, we tried to examine whether the robot fingers can control the motion of sphere on the disk using only these force information. Actually, the position and the velocity information estimated from force information enable the robot fingers to control the sphere by applying a simple PD control algorithm. Moreover, this paper adds Lyanpunov’s stability analysis of the proposed control algorithm. Finally, this results show new robot task which human beings cannot realize, whose demonstration is very interesting.