Vibration Suppression Based on Input Shaping for Biped Walking

The non-rigid behavior of a humanoid robot system will cause vibrations during walking which can affect the walking stability. In this paper, a feed forward controller based on the input shaping method is proposed to reduce such vibrations, which are modeled with second-order processes. Then the corresponding input shapers are designed and applied to the reference ZMP trajectory. The motions generated from the modified referenced ZMP trajectory will yield significantly less vibrations. The effectiveness of our method was validated through experiments on a full-size humanoid robot.