Pages 319-320
The purpose of this study is to clarify the specification required for the force feedback master manipulator that a human operates without a feeling of wrongness. We measure the motion of human hands and the grasping force with two CCD cameras and load cells attached to the objects respectively when the human grasps two types of objects different from one another in grasping length and weight. Bending and stretching of the three joints of the forefinger is dominant to the motion of the forefinger, and the tip of the forefinger moves within a plane. The tip of the thumb moves within a plane too, however the slope angles of the plane differ according to the subject. At the beginning of a grasp the overshoot of the grasping force tends to arise because of the inertia force of the object when the object is lifted up suddenly. When the overshoot of the grasping force doesn't arise, the stabilization time of the grasping force is about one second.
