Development of simultaneous measurement system of incipient slip and grip/load force

This paper presents a simultaneous measurement system of incipient slip, which is considered to have explicit relation with force control, and grip/load force while grasping objects. The system composed of a translucent acrylic plate sustained by a 6-axis force-torque sensor, and a monocular camera inside the acrylic plate to observe the contact region. We realize the measurement of incipient slip by tracking dot patterns drawn on finger tip of the subjects. Measured data while subjects are lifting the device with their thumb and index finger, against proportionally increasing force are also presented. The experimental results suggest that the mean slip has analogous profile even though the frictional condition differs. The results of this research are useful not only when clarifying mechanism of force control, but designing control criteria for dexterous manipulation using robot hand covered with elastic tactile sensors.