Exploration and Reconstruction of Unknown Objects using a Novel Normal and Contact Sensor

Abstract

Tactile sensing of surface normals is essential for exploration of unknown objects. Many tactile sensors have been developed for contact measurement. However, few of these sensors provide surface orientation, and only up to a limited degree. This paper presents a novel contact and surface orientation sensor concept and its application for surface reconstruction of unknown objects. The sensor is comprised of an Inertial Measurement Unit (IMU) and a pressure sensor to accurately estimate the surface orientation in a wide range, while at the same time measuring contact force. We describe the developed sensor prototype and evaluate its performance regarding contact detection capability and normal estimation accuracy. We use this to reconstruct the surface of unknown objects using the humanoid robot ARMAR-III resulting in a mean reconstruction accuracy of 3.6 mm.