Walking Control of a Biped Robot by Impedance Control

In this paper, a robust impedance control scheme is used to control a biped locomotion in saggital plane. In particular, the torque observer is introduced and external-force feedback is achieved without force sensor. By the reaction force feedback, the stability of the biped robot increase at the contact of the swing leg and the arbitral impedance control is realized without force sensor. The walking trajectory reference is created from the virtual inverse pendulum model. Simulation and experimental results also show that the effect of the collision between biped leg and the ground is eased and by the proposed control method, the biped robot recover more quickly than the traditional robust position control.