Passive dynamic autonomous control of bipedal walking

This paper proposes the novel control method named Passive Dynamic Autonomous Control. PDAC is based on the following concept which Grizzle et al. used previously: 1) point-contact 2) interlocking. Point-contact means that the contact state between a robot and the ground is made point. This makes it possible to control based on the robot inherent dynamics although the control becomes difficult. Interlocking means that all robot joints axe connected and interlocked. We present the new approach using this concept to describe the robot dynamics as a 1-DOF autonomous system. Due to autonomy, this approach has two following notable point: 1) period from foot-contact to next foot-contact can be obtained 2) there is a conservative quantity. In this paper, the coupling method of the sagittal and lateral motion that takes advantage of point 1 is proposed. In addition, the stabilizing method based on the conservative quantity is designed. By means of PDAC and these methods, stable 3-dimensional walking based on the robot inherent dynamics is realized.