Utilization of Movement Prioritization for Whole-Body Humanoid Robot Trajectory Generation

This paper addresses the problem of whole-body trajectory generation in humanoid robot performing a manipulation task. The approach utilizes coordination of prioritized movements of the Center of Mass (CM), foot and hand. A Center of Mass trajectory is computed from the desired Zero Moment Point (ZMP) trajectory while stepping. The ability to maneuver horizontal CM is related to the ability to maintain balance. Generally, the vertical CM movement is left unspecified. In this paper, the horizontal CM manipulability is associated with the CM height through the shape of the CM manipulability ellipsoid. A posture with a larger horizontal CM manipulability ellipsoid is more stable in the sense that its CM can be easily maneuvered as required by the desired ZMP with less joint effort. Computer simulation was conducted to verify the performance and consistency of the proposed approach for generating balance stepping motion with a manipulation task.