Measurement of static constraints imposed by a human hand on a grasped object

This paper proposes a method of directly measuring static constraints imposed by a human hand on a grasped object. Based on the analysis of the demonstration data of the human grasp, the static constraints are expressed as a combination of frictional force and normal force generated by the human hand. The static constraints are an important property to be mapped to robotic hands in the programming-by-demonstration. Measured static constraints are to be generated to robotic hands to establish the stable grasp. In the experiments, we have successfully measured the static constraints appeared in various different grasps used in the daily human life.