Single Spring Gravity Compensator for a Multi-DOF Manipulator

Abstract

Robotic manipulators are typically engineered with high-power systems to handle payloads and counteract gravity, owing to their robust and weighty structures. However, there is now a growing need for eco-friendly and safe human-robot collaboration solutions that require power-efficient innovations. Currently, gravity compensation techniques employ various counterbalancing mechanisms that are specific and challenging to expand for systems with higher degrees of freedom (DOF). In response, this research introduces a novel gravity compensator system capable of effectively counterbalancing manipulators with multiple degrees of freedom (DOF) using only one spring. The proposed system uses parallelogram mechanisms, cam follower systems, and a square-root mechanism to solve potential equations mechanically. The proposed system can generalize the design of a gravity compensator for a multi-DOF manipulator using only one linear spring. This paper outlines the design and development of prototypes, focusing on one- and three-degree-of-freedom manipulators, which serve as experimental testbeds. The experiment shows that our gravity compensator system significantly reduces the required torques, power, and overall energy consumption of the robotic system. This innovative approach addresses existing challenges and paves the way for sustainable and power-efficient robotic manipulator design.

Keywords

• Gravity compensator
• low power
• manipulator
• robotic arm
• multi DOF