A Light-Weight Quasi-Direct Drive Collaborative Robot Arm.

Robot arms are widely used in industrial production and many other applications. However, its widespread application in our daily life, which involves contact-rich human-robot-environment interactions, is limited by its actuation paradigm, backdrivability, and compliance. These boarder potential applications requires the arm to have good compliance and force control performance, as well as reactive and dynamic manipulation capabilities. In this paper, we propose a novel quasi-direct drive(QDD) robot arm with extraordinary compliance, backdrivability, and force-transparency. Compared to active force control, e.g. impedance control, our robot arm's compliance is the natural result of proprioceptive actuation. Our robot arm is also simpler and lighter. This provides possibility of installing the arm on mobile platforms to increase its overall workspace. This paper discusses the robot mechatronics design, modeling and control, system integration and experiments. The result proves our proposed design is promising for human-robot-environment interactions.