抄録
A passive walker with knees can walk down shallow slope in a natural gait and can exhibit a stable limit cycle only by interaction between the nonlinear dynamic system and the environment. Though the passive walker is simple, it is a sort of hybrid system which combines the continuous dynamics of leg-swing motion and the discrete event of leg-exchange. This study aims to construct the general design framework of realizing the natural and efficient walking on level ground and uphill. In this paper, we focus on the stability mechanism of fixed point in passive walking. At first, a generation method of fixed point based on its physical structure, which is formed by an energy balance, a leg-exchange phenomenon, and a leg-swing motion, is proposed. Secondly, for the purpose of highest local stability of the fixed point, a dynamics-based control method utilizing the fixed point's stability mechanism is proposed. The validity of the proposed methods is confirmed by the simulation of finite time settling in the level-walking.
