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.Comment: 6 pages, 8 figures, accepted to IEEE International Conference on
Robotics and Automation (ICRA 2023