Sensing Characteristics of an Optical Three-Axis Tactile Sensor Under Combined Loading

Abstract

This paper describes an optical three-axis tactile sensor capable of detecting both vertical force and slippage force. The single sensor cell of the sensor was comprised of a columnar feeler and 2-by-2 conical feelers. We derived equations to precisely estimate the three-axis force and displacement from the area-sum and area-difference of contact areas of the conical feelers, based on a mechanical model of the columnar and conical feelers. A series of calibration experiments was performed to validate the equations. In the experiments, a probe capable of detecting three-axis force applied several combinations of horizontal and vertical forces to the tip of a columnar feeler of the tactile sensor. It was found that the equations were valid because the slope of horizontal force versus area-difference decreased with increasing vertical force. From experimental results, we determined the constants included in the equations. © 1999, The Japan Society of Mechanical Engineers. All rights reserved.