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2018_EJRNL_PP_V_DE_LEON-GOMEZ_1.pdf
Terbatas Rita Nurainni, S.I.Pus
» ITB

The modeling of humanoid robots with many degrees-of-freedom (DoF) can be done via the completedynamic model. However, the complexity of the model can hide the essential factor of the walking, i.e.theequilibriumoftherobot.Onealternativeistosimplifythemodelbyneglectingsomedynamicaleffectslikeinthe3DLinearInvertedPendulum(LIP)model.Nonetheless,theassumptionthattheZMPwillbeat the base of the pendulum is not ensured and the resulting walking gaits can make the Zero MomentPoint (ZMP) evolve outside of the convex hull of support when they are replicated on the completemodel of any humanoid robot. The objective of this paper is to propose a new model for walking thathasthesamedimensionasthe3DLIPmodelbutconsidersthecompletedynamicsofthehumanoid.Theproposed model is calledessential modeland it can be written based on the internal states of the robotandpossibleexternalinformation,therebygeneratingmodelsfordifferentpurposes.ThemainadvantageoftheessentialmodelisthatitallowstogeneratewalkinggaitsthatensurethattheZeroMomentPoint(ZMP)iskeptinadesiredpositionoritfollowsadesiredpathwhilethegaitisperformed.Furthermore,impactsoftheswingfootwiththegroundcanbeconsideredtocomputeperiodicwalkinggaits.Inordertoshowtheadvantagesoftheproposedmodel,numericalstudiesareperformedtodesignperiodicwalkinggaitsforthehumanoidrobotROMEO.