The Dynamic Effect of Gearbox Parameters for Physical Human-robot Interaction Performance

The Physical Human-Robot Interaction (PHRI) can significantly improve working efficiency. How to make robots and humans interact safely and efficiently is an important research direction in advanced robotics. Cooperative robots are often one of the prominent carriers of PHRI due to their small size, lightweight, and exemplary safety. Modular joints are the critical components of collaborative robots. The high forward and backward drive capability of modular joints is the premise of PHRI. However, due to the high integration of modular joints, it is challenging to select components such as motors and gearboxes at the same time to meet the requirements of high forward and backward drive. This article aims to discuss the influence of gearbox parameters on PHRI. The dynamic model of modular joints is established. Based on this model, the influence of the transmission ratio on forward and backward driving performance is discussed. The influence of gearbox stiffness when the robot interacts with different environments is also discussed. All discussions have been verified by simulation.