On estimating local shape using contact sensing

Ž . In this paper we investigate an exploratory procedure EP for determining the local shape or curvature of objects with curved surfaces, using contact sensing by a Ž . dexterous robotic agent. The EP is based on rolling a probe a finger on the surface of Ž . an unknown object. Using the known geometry of the probe tip fingertip and the sensed displacement of contact point, we use kinematic equations for two rigid bodies in contact to estimate the curvature of the unknown object at a point. We demonstrate this approach with simulations and analyze its sensitivity to noise caused by sensing and measurement errors. This local information can then be used in the global object shape reconstruction algorithms. 2000 John Wiley & Sons, Inc.