Design and Modeling of a Novel Cable-Driven Elbow Joint Module for Humanoid Arms

Humanoid arms are important components of humanoid service robots. Due to the complexity and diversity of the service scenarios in the operation of humanoid service robots, humanoid arms needs to simultaneously meet the design requirements of lightweight, flexibility, and expandability. In this paper, a cable-driven elbow joint module for humanoid service robots is designed using a modular approach. The cable-driven elbow module uses an anti-parallel mechanism as a rolling joint to achieve a degree-of-freedom flexion/extension motion. The moment arm length of the anti-parallel mechanism is optimized and kinematic analysis is performed. Simulations are conducted to verify the accuracy of the kinematics model. A physical prototype of the cable-driven elbow module is fabricated by 3D printing, and a control system is developed for the flexion/extension motion experiments.