Prismatic Quasi-Direct-Drives for dynamic quadruped locomotion with high payload capacity

Abstract

Recent advancement in quadrupedal robustness and agility has shown the exciting progress towards the early adoption, yet there remains a challenge to enhance the payload capacity for the dynamic locomotion with electrically actuated legged robots. This study presents Kirin, a quadruped robot with prismatic leg driven by quasi-direct drives (QDDs) for the high-payload capacity during the dynamic locomotion. Instead of the typical leg mechanisms using articulated joints, QDDs are integrated with the belt-driven linear mechanism to achieve the prismatic leg movement. The resultant design achieves an exceptional payload against the robot’s weight. The normalized work capacity (NWC) is compared to the existing quadruped robots with well-known designs. The trotting locomotion and the payload adaptive control are further investigated to enable the dynamic locomotion while carrying high payload. Experiment results show that our prismatic QDD legs can effectively balance the high payload carrying and the dynamic locomotion.