Re-posing Objects Considering Bipedal Stability Constraints: An Approach for Stability Preservation During Humanoid Manipulation

Abstract

This paper presents a balance-centered planner for object re-posing. It uses Center-of-Mass (CoM) constraints to preserve robot stability and provides stable, IK-feasible, and collision-free upper-body poses, allowing the robot to complete dexterous object manipulation tasks with different objects. The technical contributions of the planner are two-fold. First, it evaluates the robot stability margin for each robot pose during manipulation planning to find a stable manipulation motion. Second, it provides an RRT-inspired task-related stability estimation used to compare different bipedal stances. Simulations and real-world experiments are performed with the HRP-5P humanoid robot, the 5th generation of the HRP robot family, to validate the planner and compare different robot stances and approaches for object re-posing. The experiment results suggest that the proposed planner provides robust behavior for the humanoid robot while performing re-posing tasks.