Journal of Bionic Engineering (2025) 22:133–143https://doi.org/10.1007/s42235-024-00622-3

A Walk Primitive with Double Support for Biped Robots

Guoshuai Liu1  · Zhiguo Lu1  · Zhongqing Li1  · Jin Xuan2  · Aizun Liu2

1 School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China 

2 Aerospace Times FeiHong Technology Company Limited, Organization, Beijing 100094, China

Abstract 

Walking is the basic locomotion pattern for bipedal robots. The walking pattern is widely generated using the linear inverted pendulum model. The linear inverted pendulum motion of each support period can be designed as a walk primitive to be connected to form a walking trajectory. A novel method of integrating double support phase into the walk primitive was proposed in this article. The method describes the generation of walking patterns using walk primitives with double support, specifically for lateral plane including walking in place, walking for lateral, and walking initiation, and for sagittal plane including fixed step length walking, variable step length walking, and walking initiation. Compared to walk primitives without double support phase, those with double support phase reduce the maximum speed required by the robot and eliminate the need to adjust foothold for achieving continuous speed. The performance of the proposed method is validated by simulations and experiments on Neubot, a position-controlled biped robot. 

Keywords Biped robot · Linear inverted pendulum · Walk primitive · Double support