Abstract
Recently, there has been extensive development in the field of bipedal robots. Some robots with the muscular arrangement of human leg by the mono-articular muscles and bi-articular muscles demonstrated stable walking motion. However, there were few examples that relations between the muscular arrangement and its motion control were examined in detail and applied the result to motion control of robot directly. This study focused on one of the effects of the bi-articular muscles on standing static stability by developing a bipedal robot with the muscular arrangement. The standing static stability was analyzed and experimented by using the relationship between stiffness characteristics and inverse pendulum model of the robot. The standing static stability was improved by one of the unique functions of the
bi-articular muscles without using complex computer control.