DYNAMIC WALKING CONTROL OF A BIPED ROBOT ALONG A POTENTIAL-ENERGY CONSERVING ORBIT

To reduce the complex walking dynamics of a biped, we noted a particular class of trajectories of an ideal biped model where the center of gravity of the body moves horizontally and the horizontal motion of the center of gravity can be expressed by a simple linear differential equation. We used the term "potential energy conserving orbit" to describe this class of trajectories. Based on these properties, control laws were formulated for walk initiation, walk continuation, and walk termination. The walking motion is controlled by support leg exchange. In addition, robust realization of the walking control is considered. An experimental walking machine was designed as a nearly ideal biped model. To make the legs lighter, four dc motors were mounted in the body, and the legs are parallel link structures. The results of the experiment describe five steps of dynamic walking including walk initiation.