Development of Joint on Torque Compensation Mechanism Using Torsion Springs for Quadruped robot

Abstract

Quadruped robot is effective for stable movement on uneven terrain such as disaster sites and construction sites. The leg mechanism of such a robot requires asymmetrical output characteristics, as it needs to exert a large downward force on the foot when supporting the body weight with a supporting leg, while only exerting a small upward force during swing leg motion. In this study, we developed a mechanism to assist the joint torque during supporting leg motion using a spring, which can be attached to the pitch axis drive motor shaft at the leg root where the weight of the main body is significant for movement on uneven terrain. We confirmed the effects during swing and support phases, as well as the spring effect. Additionally, using a quadruped walking model, we verified that the use of torsion springs improves coordinate accuracy during walking.