Curvature based shape estimation using tactile sensing

In this paper we propose an approach we call it a “Blind Man’s” approach to shape description in which tactile information is sensed from the fingertips of a dexterous hand. Using this contact information, we investigate two complementary methods for curvature estimation. The first method is based on rolling one finger to estimate curvature at a point on the surface. We use Montana’s equations for estimating curvature at a point using simulations and analyze the sensitivity of the approach to noise. The second method uses multiple fingers to slide along a surface while sensing contact points and surface normals. We present a method to extract the shape properties of a patch obtained by fitting a B-spline surface to this multi-fingered sweep across the surface of the object. The method enables us to extract higher level shape information based on the curvature properties of patch.