An optical tactile sensor using the CT reconstruction method

Abstract

Abstract The tactile sensors used for robotics and electrical artificial hands are designed to provide force information. They are required to have the capability of not only detecting pressure distribution with high sensitivity, but also to carry strength and provide flexibility in grasping objects. This paper proposes a two‐dimensional tactile sensor based on the pressure‐optical transmission conversion system and the principle of computer tomography. The sensor consists of a three‐layered silicon rubber sheet and an array of opto‐electrical elements embedded in the edge of the sheet. The pressure distribution is detected as an optical transmission pattern. The transmission pattern is reconstructed to a two‐dimensional distribution using the algorithm of the computer tomography (CT) pattern reconstruction. The merits of this method are: 1) the sensor is flexible and suitable for grasping objects; 2) the number of components and signal lines is small; 3) the sensor can withstand excessive force; and 4) the sensor can be attached to a curved surface. In this experiment, using thirty‐two pairs of circular sensor arrays, the pressure distribution of 200 sites with 2.5 mm resolution was obtained. This paper describes the design, the mechanism of transduction, and the performance of the tactile sensor.