COM Shifter and Body Rotator for Step-by-Step Teleoperation of Bipedal Robots

This paper presents a controller for step-by-step teleoperation of bipedal robots, in which the user commands the robot's foot motions in a step-by-step manner through a pair of handheld 3-dimensional pointing devices. The proposed controller is intended to allow users to precisely manipulate the swing foot motions to traverse rough terrains by avoiding obstacles. It aims to realize quick response to user commands and stable automatic balancing even under erroneous user commands. The main components of the proposed controller are a COM (center-of-mass) shifter and a body rotator, which are simple sensory feedback controllers that do not involve first-in first-output (FIFO) buffers, time-series generation, or online optimization. The COM shifter is a controller to produce a COM motion according to a reference zero moment point (ZMP). The body rotator complements the COM shifter to produce an appropriate angular momentum rate to enhance the regulation of ZMP. The proposed controller is validated in our interactive/realtime simulation environment.