Biologically-inspired postural and reaching control of a multi-segment humanoid robot

This article presents a biologically-inspired framework for postural and reaching control of a multi-segment humanoid robot. In addition to the inherent instability of humanoids, multi-segment motion introduces destabilising dynamic coupling effects that requires heterogeneous control in the form of full state feedback. Thus, a robust multi-input-multi-output tracking control architecture with feedback, feedforward, and integral control parts is implemented. This article addresses as well a variety of external disturbances that might act on the humanoid such as supporting surface translational and rotational motion as well as external pull/push forces acting on the body of the humanoid. Two methods are developed to estimate these disturbances for the purpose of compensating them: a vestibular stand-alone Kalman filter and a central extended disturbance observer. Simulation experiments demonstrate good performance for both and highlight the merits of the central extended observer which is based on a full k...