A Base-Located Gravity Compensation Mechanism With Double Multi-Winding for Enhanced Intrinsic Safety and Energy-Efficiency

Recent advancements in manipulator technology have addressed the integration of manipulators in human-centric environments, emphasizing the need for intrinsic safety and energy efficiency. However, conventional manipulators face challenges with safe interaction and increased energy consumption, hindered by heavy motors and gearboxes. This article introduces a novel gravity compensation mechanism (GCM) that not only significantly enhances energy efficiency but also intrinsic safety via low-inertia mechanical structure and low-powered motors. It is achieved through the strategic placement of heavy components of the GCM at the base and integrating low-powered motors at the joints. By integrating a double multiwinding mechanism and a new joint decoupling mechanism, we effectively addressed the inevitable issues of increased joint load due to the routing of multiple cables and joint coupling caused by positioning springs at the base. We demonstrate the application of our GCM in a lightweight 3-DOFs serial manipulator with parallel pitch joints, showing substantial improvements in gravity torque compensation and energy efficiency. Experimental analysis and supplementary video confirm the effectiveness of our design in reducing joint torque and energy consumption, offering a viable solution for sustainable and safe robotic applications in service environments.