Bipedal locomotion by swinging arm with flexible trunk

Many studies on bipedal robots have been reported. However, most of them focus on the structure and behavior of the lower body. In this study, we investigate the effect of arm swinging with a flexible trunk in a biped robot and realize natural walking. Our previous studies have shown mathematical analysis that the Center of Pressure(CoP) oscillates sideways by asymmetrically swinging arm and passively oscillating the viscoelastic joint embedded in the trunk. This paper shows that the passive oscillation of the flexible trunk by swinging the arm enables walking by driving the leg. It was confirmed that the physical robot achieved approximately 20 steps by adjusting the air supply and exhaust period of pneumatic artificial muscles that drive the joints.