Skin vibration and contact force in active perception for roughness ratings

Abstract

When we touch an object, we can obtain tactile information through our skin. Thus it is important to reveal the relationship between the subjective sensation and objective quantities like the skin vibration elicited on our skin. In this paper, we focus on roughness perception, one of the main tactile sensations of materials. We measured skin vibration and contact force in natural active roughness perception for a large set of different materials, of which the physical roughness could be expressed in various industrial roughness measures like Ra. The results showed that there was no relationship between contact force and subjective roughness, so apparently humans do not control contact forces intentionally in a roughness estimation task. Power functions were fitted to each relationship between the other objective parameters and estimated roughness. The goodness-of-fit value of skin vibration was significantly better than any of the other parameters. Thus, the main conclusion is that these results suggest that skin vibration plays a determining role in roughness perception.