5-DOF Robot Arm using Passive Joint Assisting Spatial Motion of Human Upper Limb

Abstract

This study proposes that a robot, which has a characteristic of high precision positioning, is applied for the assistance of positioning in milling with a human hand. By assisting a tool position by the robot, the human can focus an adjusting of a milling speed or force depending on a cutting resistance. To move the robot cooperating with the human motion like this, we propose a 5-DOF(degree-of-freedom) robot arm using passive joints. When the human moves an output point of the proposed arm, the arm can measure the human motion by rotating the passive joints. Then, the arm conducts a position control to go back on a target path using actuated joints. Using a prototype of the arm, we confirmed that the arm can assist in the positioning cooperating with the human motion according to experiments assisting milling with a human hand.