A 7-Dof Wire-Driven Lightweight Arm with Wide Wrist Motion Range

摘要

Till date, various seven-degrees-of-freedom (7-DOF)robot arms have been developed globally. In general, the robot arms utilized in factories are required to possess speed, power, and accuracy. They are isolated from humans using a fence to ensure human safety. However, a home robot should work near humans at an appropriate speed without a fence. One approach to meeting this requirement involves the installation of various sensors on the robot to control and stop the robot safely even if a collision has occurred. However, a robot system is complicated and expensive. In order to give inherent safety to the robot, we should lighten the robot arm. In this study, a 7-DOF lightweight arm with a wide wrist-motion range is introduced. The weight of movable parts is approximately 2.87 kg. To achieve such properties, we propose the use of three mechanisms: a shoulder mechanism with hollow cylinders, a wrist mechanism with a wide workspace, and an integrated wrist and elbow mechanisms of high power. To verify its feasibility, a prototype of the robot is designed and developed. The experimental results demonstrate its powerful performance and wide workspace of the wrist.