A Tactile Sensor Based on Discrete CT Algorithm

Abstract

In order to cause a tactile sensor to be thin shape, a new optical tactile sensor is developed by applying computed tomography (CT). The present tactile sensor is comprised of infrared emitting diode array, the receiving phototransistor array and transparent silicon rubber plate. Infrared rays emitted from the diode array are directed into an end of the plate and their intensity distribution is measured by the phototransistor array mounted on the other end. If CT algorithm is directly applied to the tactile sensor, there are two defects such as shape of sensing area limited to a circle and long calculation time. Thus, a new CT algorithm oriented to tactile sensing is proposed to overcome these defects. In the present algorithm, a square sensing area is divided to an n-by-n array and algebraic equations are derived from relationship input and output light intensities on assumed light projections. To validate the present algorithm, a sires of simulation was performed and it was found that tactile image was completely reconstructed in the case under 6-by-6 array.