Self-Excited Walking of a Biped Mechanism with Feet

In this paper we present a theoretical and experimental study of the self-excited walking of a biped mechanism with knees and feet on level ground. This biped mechanism possesses a single motor at the hip joint and active lock mechanisms at both knee joints. We first show that the self-excitation control enables the three-degrees-of-freedom planar biped model with feet to walk on level ground, and that a stable walking locomotion is possible over a wide range of feedback gain and a foot radius of up to 0.3 m. Subsequently, we describe the manufactured biped Robot 2 which is similar to the analytical model and we show that the biped robot can perform natural dynamic walking on a level floor. It is also shown that the simulated results agree well with the experimental results. We further describe the wireless-controlled biped Robot 3, which can walk on a level floor carrying batteries and electronic circuits inside the thighs. KEY WORDS—biped mechanism, natural walking, selfexcited walking, simulation, experiment