Tendon Arrangement and Muscle Force Requirements for Humanlike Force Capabilities in a Robotic Finger

Human motion can provide a rich source of examples for use in robot grasping and manipulation. Adapting human examples to a robot manipulator is a difficult problem, however, in part due to differences between human and robot hands. Even hands that are anthropomorphic in external design may differ dramatically from the human hand in ability to grasp and manipulate objects due to internal design differences. For example, force transmission mechanisms in robot fingers are generally symmetric about flexion / extension axes, but in human fingers they are focused toward flexion. This paper describes how a tendon driven robot finger can be optimized for force transmission capability equivalent to the human index finger. We show that two distinct tendon arrangements that are similar to those that have been used in robot hands can achieve the same range of forces as the human finger with minimal additional cost in total muscle force requirements.