Control of the heel off to toe off motion of a dynamic biped gait

A mechanism for the control of the heel off to toe off motion of a dynamic biped gait is presented in this paper. It is argued that the reaction force between the ground and the biped foot is an important factor in a satisfactory implementation of dynamic gait. This force must be properly controlled while the foot is in the heel off to toe off phase. Since the foot rolls over the ground surface in this phase, and the global description of the surface is unknown, the foot has to execute a nonholonomic constraint motion. The formulations of nonholonomic constraints and system dynamics under the constraints are derived for the roll-over motion. A feedback control mechanism is designed based on the formulations.<>