Experimental verification of a new passivity condition including the human arm impedance

It is well known that friction in haptic devices plays a key role in dissipating surplus energy and maintaining passivity of the haptic system. It is also shown in the previous study [14] that the surplus energy can be also dissipated by careful exploitation of human operator's damping. This paper defines a Passivity Margin and extends the original passivity condition [14] that includes the human arm impedance. It is also experimentally verified that this new passivity analysis method predicts actual phenomena well. Experiment results show that the maximum achievable stiffness of the haptic system varies widely depending on the human arm impedance, and is predictable more accurately using the new passivity condition compared to the previous results in the literature.