Inverse kinematics with floating base and constraints for full body humanoid robot control

Abstract

This paper explores inverse kinematics for full body, floating base, task space control on a real humanoid robot. We discuss how constraints can be used to address the issue of under-actuation due to floating base, and list the sufficient conditions for maintaining task space control of arbitrary robot tasks. We suggest a controller based on a task priority framework and demonstrate the feasibility of the approach on the SARCOS/ATR CBi humanoid robot. We implement examples of position control via constrained floating base inverse kinematics as first approach to full body model-based inverse dynamics control. The examples demonstrate center of gravity position tracking as well as hand figure-8 tracking while simultaneously balancing.