A High-Performance Anthropomorphic Robotic Arm for Household Applications

Anthropomorphic robotic arms, mimicking the structure and function of human arms, show great potential for helping people in various tedious and repetitive household tasks. However, such arms mostly consist of multiple serial links controlled independently by actuators at joints with high reduction ratios, posing challenges in household services in terms of load capacity, responsiveness, and safety. In this paper, we propose a high-performance anthropomorphic arm called TRX-Arm based on differential cable transmission, characterized by features of high dynamics, high load capacity, and inherent compliance. TRX-Arm is composed of three deferential cable-driven coupling joints and one independent roll joint. Thanks to the cable differential transmission, the joints are capable of achieving doubled torque and stiffness without replacing motors. To enhance safety in human-robot interaction, the actuators including motors, reducer, belt, and pulley are mounted at the shoulder near the base and drive the joints remotely using cables, thereby minimizing the inertia of the whole arm. The workspace of TRX-Arm has a volume of 1.56 m³, much larger than that of the human arm. Real experiments show its capabilities including high repeatability and load capacity as well as high dynamic behavior of a dual-arm robot platform built with TRX-Arms.