Whole-body cooperative balancing of humanoid robot using COG Jacobian

Abstract

Since humanoid robots have a number of degrees-of-freedom in general, a pattern-based approach of the motion control reduces its difficulty. It is necessary, however, to absorb and compensate disturbances in order to maintain the stability of robots in the real world. We developed a balancing method for humanoid robots with a little modification of predesigned motion trajectories. The method proposed has an advantage that it is allowed to choose any combination of joints as modified properties, so that it has enough flexibility, being applicable for various types of robots and motions. It consists of two phases; in the first phase, the referential COG displacement is decided in accordance with both the short-term and the long-term absorption of disturbances. And in the second phase, the COG is manipulated with the whole-body cooperation, using the COG Jacobian. We verified the validity of the method with some simulations.