High Speed and High Sensitivity Slip Sensor for Dexterous Grasping

Slip-detecting tactile sensors are essential if robot hands are ever to achieve the gripping motions of human hands. In our previous research, we developed a flexible, thin, and lightweight slip sensor that exploits resistance changes in pressure conductive rubber. However, using this sensor, it was difficult to distinguish between object slip and changes in normal force. Therefore, in this research, we investigate a method of identifying object slip by analyzing the frequency components of the output signal from the sensor. As a result, we find that high-frequency components of several kilohertz or more are included in the complex voltage signal immediately before object slip. Therefore, using this high-frequency component, we develop a simple structure sensor that distinguishes between both contact and a state of immediately before slip with high sensitivity. Moreover, we design a slip sensor for a robot hand and examine the effects of noise by manipulation. Finally, we describe an experiment involving the adjustment of the gripping force of a robot hand.