2P2-F03 Development of a Power-Assist Machine for the Upper Limb Using Differential Gears and Application to a Power-Assist Unit Construction System

Abstract

We developed a power assist machine attached to the upper limb, using differential gears for nurses who care an old person being bed ridden, or workers who often lift loads up and down. Two motors behind the shoulder of the equipped person provide motive power to drive shoulder and elbow joints, and the differential gear makes it possible to divide the power between them effectively. This differential gear system can reduce the backlash of gears. The five degrees of freedom of shoulder blade motion were taken into account with the shoulder-joint link mechanism. Furthermore, to grasp the behavior of the arms of the equipped person, pressure sensors were attached under the upper and lower arms. As a result of the experiment wearing the machine, the arms of equipped person could fluctuate at will.