Tactile feedback for multifingered dynamic grasping

Dynamic grasping force control for a multifingered hand is proposed and investigated. The grasping force of the finger is dynamically adjusted according to the tactile feedback so that each fingertip force always stays inside the friction cone detected by the tactile sensor and the fingertips maintain firm contact without any undesired slip nor detaching from the object while grasping it. The proposed method allows real-time control of the hand since it requires few numerical calculations. In order to enable the tactile feedback, a finger-shaped tactile sensor using an optical waveguide capable of detecting the contact location and the surface normal of the contacted object is developed. Finally, the validity of the proposed method is confirmed experimentally using a two-fingered hand with tactile sensors.