The Design and Development of an Anthropomorphic Worm-Gear Driven Robotic Hand: BIT-JOCKO

Abstract

A lightweight dexterous robotic hand named BITJOCKO with twenty degrees of freedom is presented in this paper. Each knuckle of the hand is equipped with an individually controlled servomotor to enable both-direction bending movements in the range of 0°-100°. The specially designed worm-gear of the drive system not only enlarge the torque of the motor shaft but also equip it with special ability when holding items. Each servomotor is connected with a worm gear. Compare to other forms of a driving system like direct-drive joint, bevel gear joint and harmonic joint. Such characteristics of the worm gears enable the dexterous hand to keep its pose even when the motor forces are turned off after seizing objects. That means this hand is capable of holding weight with considerable self-locking torque. The total weight of BITJOCKO is only 1.1 kilograms. The mechanical design and the philosophy behind is illustrated in detail.