Development of an Anthropomorphic Robot Hand with Size and Motion Range Identical to a Human Hand

摘要

The anthropomorphic robot hand with the linear actuators consisting of a motor and a lead screw has the stronger grasping power than the hand actuated by motors and insufficient gear reduction. This paper presents the UPS/RPS-RR parallel mechanism to use the linear actuators effectively for the robot hand It enables us to get the forward/inverse kinematic solutions, while the previous mechanism for the linear actuator failed. Since the grasping motion of the developed hand is composed of the active motion of the proximal phalange and the passive motions of the middle and the distal phalanges, the linkage mechanism is designed to make the motion range of the phalanges the same as that of a human hand. Then, all the phalanges of each finger are bent gradually in the whole motion range from a completely opened hand to a closed hand as a human hand does. This robot hand has four fingers including a thumb. Each finger has 2-DOF and each proximal phalange is actuated by two linear actuators. The palm itself has 2-DOF to make the motion of the thumb and the small metacarpi similar to the natural palm arch of a human hand. Finally, instead of using specially manufactured actuators, the usage of commercial store-bought actuators enables our hand to be a cheaper candidate for the educational robot hand.