Analysis of human gait using an Inverted Pendulum Model

IPM(Inverted Pendulum Model) has been widely used for modeling of human motion gaits. There is a common condition in most of these models, the reaction force between the floor and the humanoid must go through the CoG (Center of Gravity) of the a humanoid or human being. However, the recent bio-mechanical studies show that there are angular moments around the CoG of a human being during human motion. In other words, the reaction force does not necessarily pass through the CoG. In this paper, the motion of IPM is analyzed by taking into consideration two kinds of rotational moments, namely around the pivot and around the CoG. The human motion has been decomposed into the sagittal plane and front plane in the double support phase and single support phase. The motions of the IPM in these four different phases are derived by solving four differential equations with boundary conditions. Simulation results show that a stable human gait is synthesized by using our proposed IPM.