Journal of Bionic Engineering (2025) 22:642–653 https://doi.org/10.1007/s42235-024-00640-1

Design and Experimental Study of Special Elastic Leg Joint for  Quadruped Robots 

Zisen Hua1  · Chi Chen1  · Xuewen Rong2  · Yibin Li2

1 School of Artificial Intelligence, Anhui University of Science  & Technology, Taifeng Road, Huainan 232001, Anhui  Province, China 

2 School of Control Science and Engineering, Shandong  University, Jingshi Road, Jinan 17951, Shandong Province,  China

Abstract 

In this paper, a novel passive flexible leg joint method is proposed with the aim of enhancing the impact buffering capability as well as reducing energy consumption. The innovative structure cleverly incorporates micro-plate springs, offering  significant stiffness adjustment capabilities. To meet the stiffness requirements, the relationships between foot-ground  contact force and the deformation force of the elastic component, as well as the influence of elastic component deformation and foot cushioning amplitude are comprehensively analyzed. With the aid of finite element optimization analysis, a  single-leg experimental platform is designed, and the effectiveness and applicability of the novel structure are validated  through experiments including unloaded free swinging, freely falling body motion and ground squats experiments. Comparative experiments results show the evident superiorities of the passive compliance joint. 

Keywords Quadruped robot · Passive compliance · Leg joint · Motion energy efficiency