Some extensions of passive walking formula to active biped robots

This paper studies the dynamic principles of passive dynamic walking and proposes novel gait generation and control methods based on it. The authors have clarified a unified property of passive dynamic walking which shows that the walking system's mechanical energy increases proportionally with respect to the position of system's center of mass. Following this, the gait generation problem yields solutions of an indeterminate equation. By solving it for the control torque, active dynamic walking on a level can then be realized. In this paper, we first discuss the solutions and consider the unification of the previous gait generation methods from a variable virtual gravity point of view. Second, its applications to a kneed biped system considering ZMP condition and robust energy referenced control are discussed. The effectiveness of the proposed methods have been investigated through numerical simulations.