A Weight Shift by Control of Center of Pressure of Ground Reaction Forces in Biped Double Support Phase

In this paper, we consider the weight shift in biped double support phase under variable environment. In conven-tional method, motion pattern of body parts that leads the center of mass or center of pressure of ground reaction forces to the desired position is planned first, and then execute position al feedback against it. This indirect method causes problems such that the planned motion pattern is not suitable, or how this pattern should be modified, for the varied environment. Here, we show that, by selecting the center of pressure as the controlled variable, not only the motion planning of body part becomes unnecessary, but also the motion pattern automatically changes with the environmental conditions. The stability of the control method is discussed and its validness is examined by simulations and robot experiments.