Self-Excited Vibratory Actuator. 3rd Report, Biped Walking Mechanism by Self-Excitation.

Abstract

As a practical example of a self-excited actuator theoretically presented in the 1st report, we developed a biped walking mechanism driven by a self-excited actuator. Referring to a biped walking toy which walks on a slope with a self-excited mechanism using potential energy, we proposed a mechanism which walks on flat ground with two single-link legs. Biped walking motion is realized by the swing roll motion of the upper body driven by a two-degree-of-freedom self-excited vibration system with asymmetric stiffness matrices. The fundamental characteristics of the self-excited actuating system are analyzed theoretically, and its efficiency and robustness are discussed by comparing the equivalent forced excitation system. The theoretical results are verified from the experimental study of the prototype. It is also found that the self-excited system has a better robustness to disturbance and variation of system parameters caused by walking motion, and can realize stabler walking motion, compared to the forced excitation system.