Stride and walking-cycle online changing for biped robot in frontal plane

When a walking trajectory of a 3-dimensional (3D) biped robot is changed, it is necessary to consider not only a sagittal trajectory but also a frontal trajectory. In this paper, an online stride changing method and a walking cycle changing method of biped robots using linear pendulum mode are proposed. With these methods, the trajectory planning is easier than that with some conventional methods because switching from a trajectory of single support phase to a trajectory of double support phase is unnecessary. Moreover, the moving range of center of gravity (COG) is decided arbitrarily. The validity of the proposed methods is confirmed by simulations and experiments.