Thin Flexible Sheet Handling Using Robotic Hand Equipped with Three-axis Tactile Sensors

Since a robotic hand equipped with three-axis tactile sensors can detect not only grasped force caused by pinching motion but also slippage generated by sliding fingers, it can be applied to various tasks such as cap twisting, exploring object shape and detecting hardness. Although thin sheet handling is considered one of the more difficult tasks in robotics because of object flexibility and thinness, the versatility of the hand seems to accomplish this task. In this paper, we evaluate the sensing ability of this sheet thickness to obtain basic data for handling and turning thin flexible sheets. In this experiment, we used 1,000-yen bills as specimens because they have precise and stable size and mechanical properties. Experimental results showed that the robotic hand could not distinguish sheet numbers through a pinching grip causing normal force but could distinguish them through sliding fingers causing tangential force.