We have developed biped robots with a passive dynamic walking mechanism. This study proposes a compass model with a wobbling mass connected to the upper body and oscillating in the horizontal direction to clarify the influence of the horizontal dynamics of the upper body on bipedal walking. The limit cycles of the model were numerically searched, and their stability and energy efficiency was investigated. Several qualitatively different limit cycles were obtained depending mainly on the spring constant that supports the wobbling mass. Specific types of solutions decreased the stability while reducing the risk of accidental falling and improving the energy efficiency. The obtained results were attributed to the wobbling mass moving in the opposite direction to the upper body, thereby preventing large changes in acceleration and deceleration while walking. The relationship between the locomotion of the proposed model and the actual biped robot and human gaits was investigated.

翻译：我们开发了具有被动动态行走机制的双足机器人。本研究提出了一种指南针模型，该模型在上体连接了一个水平方向振荡的摆动质量，以阐明上体水平动力学对双足行走的影响。通过数值搜索了该模型的极限环，并研究了其稳定性和能量效率。根据支撑摆动质量的弹簧常数不同，获得了若干种定性不同的极限环。特定类型的解在降低稳定性、减少意外摔倒风险的同时提高了能量效率。所得结果归因于摆动质量与上体反向运动，从而防止了行走过程中加速度与减速度的大幅变化。进一步研究了所提模型的运动特性与实际双足机器人及人类步态之间的关系。