Modeling and Control of Stable Limit Cycle Walking on Floating Island

This paper discusses modeling of a legged robot for stable limit cycle walking on a floating island and motion control method focusing on its center of mass (COM). First, we develop a mathematical model that integrates a 6-DOF robot and a floating island, and design the control input for achieving output following. Second, we conduct a test simulation by using simple desired trajectories of the COM, and discuss the problem with undesirable behavior of the generated ground reaction forces. Furthermore, we introduce fifth-order functions of time to smoothly control the COM motion and generate the preferred resultant behavior of the ground reaction forces.