A MICRO OPTICAL THREE-AXIS TACTILE SENSOR CAPABLE OF RECOGNIZING A MICRO OBJECT

微型光学三轴触觉传感器不仅能感知垂直力，还能感知水平力。从光波导型触觉传感器橡胶片表面形成的锥形触角的接触面积测量垂直力。从锥形触头的水平位移中检测到水平力。为了验证上述原理，一个装有扭矩传感器的机器人在一个大尺寸的触觉传感器表面施加了几个合力。试验结果表明，在组合力条件下，垂直力的确定是唯一的，水平力的确定是在垂直力的基础上修正水平力与水平位移的关系。随后，利用精密电火花铣床研制了微型光学触觉传感器。在传感器中，垂直力由灰度值积分比由锥形触头的接触面积更精确地确定。最后，其他人尝试将传感器应用到主从系统中，使用能够生成虚拟表面纹理的触觉呈现设备。三名受试者辨别出了十种纹理图案。

A micro optical three-axis tactile sensor was capable of sensing not only vertical force but also horizontal force. The vertical force was detected from the contact area of conical feelers formed on the rubber sheet surface of an optical waveguide type tactile sensor. The horizontal force was detected from the horizontal displacement of the conical feelers. To validate the above-mentioned principle, a robot equipped with a torque-moment sensor applied several combined forces to a large sized tactile sensor surface. As indicated by the experimental results, the vertical force was specified uniquely under combined force conditions and the horizontal force was specified by modifying the relationship between the horizontal force and the horizontal displacement on the basis of vertical force. Subsequently, the micro optical tactile sensor was developed using a precise electric discharge milling machine. In the sensor, the vertical force was more precisely determined by integration of gray scale vale than by the contact areas of conical feelers. Finally, the others attempted to apply the sensor to a master-slave system using a tactile presentation device capable of generating virtual surface texture. Three human subjects discriminated ten pattern of the texture.