Whole-body humanoid control from upper-body task specifications

This paper introduces a very efficient, modified resolved acceleration control algorithm for dynamic filtering and control of whole-body humanoid motion in response to upper-body task specifications. The dynamic filter is applicable for general upper-body motions when standing in place. It is characterized by modification of the commanded torso acceleration based on a geometric solution to produce a ZMP which is inside the support. The resulting feasible modified motion is synchronized to the reference motion when the computed ZMP for the reference motion again falls within the support. Contact forces at each foot are controlled through a dedicated force distribution module which optimizes the ankle roll and pitch torques. The proposed approach uses time-local information and is therefore targeted for online control. The effectiveness of the algorithm is demonstrated by means of simulated experiments on a model of the Honda humanoid robot ASIMO using a highly dynamic upper-body reference motion.