Simulated regulator to synthesize ZMP manipulation and foot location for autonomous control of biped robots

Abstract

An autonomous biped controller synthesizing the ZMP manipulation and the foot location is proposed; each of them has a strongly nonlinear property, so that they had been hard to be synthesized without referential trajectories given as functions of time. The former is equivalent to the partial indirect manipulation of the reaction force through the contact points with the environment to control the center of mass (COM) under the current supporting state. The latter means discontinuous relocation of grounding feet in order to deform the supporting region to include the desired but unachievable ZMP in the future. They run on an identical control system without any confliction, since they originate from the same simulated regulator in the sense that the feasible region of ZMP is not bounded. It is also shown that a cyclic walk is automatically generated without giving a walking period explicitly by coupling the support-state transition and the goal-state transition in a simulation.