Adaptive robust controls of biped robots

This paper presents a structure of robust adaptive control for biped robots, which includes balancing and posture control for regulating the centre-of-mass (COM) position and trunk orientation of bipedal robots in a compliant way. First, the biped robot is decoupled into the dynamics of COM and the trunks. Then, the adaptive robust controls are constructed in the presence of parametric and functional dynamics uncertainties. The control computes a desired ground reaction force required to stabilise the posture with unknown dynamics of COM and then transforms these forces into full-body joint torques even if the external disturbances exist. Based on Lyapunov synthesis, the proposed adaptive controls guarantee that the tracking errors of system converge to zero. The proposed controls are robust not only to system uncertainties such as mass variation but also to external disturbances. The verification of the proposed control is conducted using the extensive simulations.