Dynamically consistent motion design of a humanoid robot even at the limit of kinematics

A motion design for humanoid robots to satisfy dynamical constraints on the external forces even at the kinematic exceptions such as singular configurations and joint angle limits is proposed. It enables robots to mimic natural, comfortable and lively human motions, which leverage the limit of kinematics, based on a robust numerical solver of the prioritized inverse kinematics. The idea of prioritization is to strictly constrain the least number of contact points to form the supporting region which contains the desired ZMP and to unconstrain the other points rather than to keep foot-flat. It increases available degrees-of-freedom instead of degenerate components. Motion continuity in spite of the discontinuous change of a set of constraints is also taken into account. Knee-stretched walks are demonstrated as an application with the inverse dynamics analyses.