Fingertip force control based on max torque adjustment for dexterous manipulation of an anthropomorphic hand

Despite recent progress, the performance of force control algorithms still appears to be poor when applying to systems with significant backlash, low precision of position sensors, low communication bandwidth and computation power. Anthropomorphic robot hands with tendon driven joints are typical examples of such systems. To overcome this difficulty, this paper proposes an approach that uses the torque saturation (max-torque) of the joint position control loops to control the end-effector (fingertip) force. This control scheme has been implemented and tested on the Shadow motor robot hand. An application of this control scheme has also been implemented for two fingers holding and rotating an object around the vertical axis. This experiment shows the strong potential of this force control algorithm for grasping and dexterous manipulation activities.