Abstract
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 a load cell attached to the object when a human grasps two types of object different from one another in grasping length and weight. It's guessed that relative motion between a thumb and a forefinger is a bisical problem to human picking operation and also an imformative motion to understand it. In this report, a change of distances between a thumb and a forefinger is investigated in picking operation. An object beome larger than a size of space between the two fingers in a natural state, it takes a more time for a human to open the fingers and a maximum space between a finger and an object becomes more narrow. Then, operation becomes harder for an object larger than a size of space between the two fingers in a natural state. So, for a virtual object of a master robot, an object smaller than the natural space between the fingers may makes more efficiency and better feeling for operators.
