Impedance control and modulation for stable footing in locomotion of biped robots

Proposes an impedance control method with impedance modulation strategy for biped robot locomotion. The constrained leg as well as the free leg is controlled by the impedance control. To reduce the magnitude of an impact with the ground and guarantee a stable footing when a foot contacts with the ground, the paper proposes to increase the damping of the leg drastically and to modify the reference trajectory of the leg. Computer simulations with a 3-DOF environment model with a combination of a nonlinear and linear compliant contact model show that the proposed controller is superior to computed-torque controllers in the impact regulation and stability robustness in locomotion