Anthropomorphic Robot Hand: Gifu Hand III

This paper presents an anthropomorphic robot hand called Gifu Hand III, which is a modified version of Gifu Hand II. The Gifu Hand is aimed to be used as a platform of robot hands for robotics research. The Gifu Hand III is improved on the points of backlash of transmission, opposability of the thumb, and mobility space of fingertips. The opposability of the thumb is evaluated by a cubature of opposable space. An explicit kinematical relation between the fourth joint and the third one is shown, where the fourth joint is engaged with the third joint by a planar four-bars linkage mechanism. The distributed tactile sensor, which has grid pattern electrodes and uses conductive ink, is mounted on the hand surface. The sensor presents 235 points expansion relatively to that of the Gifu Hand II. To reduce insensitive area, the electrodes width and pitch are expanded and narrowed, respectively. In consequence, the insensitive area is reduced to 49.1%. Experiments of grasping several objects are shown. With these improvements and experiments, the Gifu hand III has a higher potential to perform dexterous object manipulations like the human hand.