Passivity-based multi-contact balancing of humanoid robots based on power-conserved transformations

We present a method to control multi-contact balance for humanoid robots. Our method is based on physical transformations, which conserve the power generated by fully actuated control inputs. We calculate several controlled wrenches to determine contact sets obtained from the quasi-static balance of a humanoid model and superimpose the wrenches after transforming them around the corresponding contact sets. The superimposed input dynamically stabilizes the whole-body motions. We experimentally validated the effectiveness of this control method with the humanoid robot E2-DR.