Robust walking by resolved viscoelasticity control explicitly considering structure-variability of a humanoid

This paper discusses the resolved viscoelasticity control (RVC) method that explicitly considers the structure-variability for a humanoid. In a previous report, the author proposed resolving the virtual viscoelasticity at the center of gravity into the joint viscoelasticity considering redundant degrees of freedom, and named this method as RVC. However, the author considered only the single support phase; therefore, the humanoid could be regarded as an open kinematic chain and the RVC was implemented easily. In this paper, the author extends the previous work on the RVC by considering structure-variability - the method now considers an open kinematic chain in the single support phase and a closed kinematic chain in the double support phase. This extension helps realize stable and robust walking motion on uneven terrains. The proposed method is validated using forward dynamics simulations.