Dynamic balance concept and the maintenance of the dynamic balance in humanoid robotics

One of basic characteristics of regular bipedal walk of humanoid robots is the maintenance of their dynamic balance during the walk, whereby a decisive role is played by the unpowered degrees of freedom arising at the foot-ground contact. Hence, the role of Zero-Moment Point (ZMP) as an indicator of dynamic balance is indispensable. The paper gives a very detailed discussion of some basic theoretical assumptions related to the notion of dynamic balance (term stability, is often used as a synonym, which we consider erroneous). Some special cases of gait in which dynamic balance need not be realized are also discussed.