Reference ZMP Generation for Teleoperated Bipedal Robots Walking on Non-Flat Terrains

Abstract

This paper proposes a method for generating the reference Zero Moment Point (ZMP) for teleoperated bipedal robots walking on non-flat terrains. It consists the preview control and auxiliary ZMP method to realize ZMP-based walking. An auxiliary ZMP is used to generate the COG trajectory in realtime by reducing the time delay caused by the preview control. The problem with such ZMP-based walking is that a ZMP cannot be defined when the both feet are not on a same plane. Hence, in the proposed method, the virtual ZMP method is applied to calculate the ZMP. In order to calculate the virtual ZMP, the proposed method determines a virtual plane from the positional relation between the feet. This method does not use environmental information to determine the virtual plane. Therefore, this method is suitable to generate the reference ZMP of the teleoperated bipedal robot. The proposed method is validated through a realtime simulation environment involving haptic devices.