Interaction-Aware Whole-Body Control for Compliant Object Transport

TL;DR

This paper introduces an interaction-aware whole-body control system for humanoid robots that enhances stability and compliance during object transport in unstructured environments by combining bio-inspired control, trajectory optimization, and reinforcement learning.

Contribution

It presents a novel interaction-oriented control framework that separates interaction execution from support control, integrating RL and simulation-based training for robust real-world deployment.

Findings

Maintains stable, compliant object transport under disturbances.

Effective in scenarios where velocity tracking fails.

Robust to payload variations and external perturbations.

Abstract

Cooperative object transport in unstructured environments remains challenging for assistive humanoids because strong, time-varying interaction forces can make tracking-centric whole-body control unreliable, especially in close-contact support tasks. This paper proposes a bio-inspired, interaction-oriented whole-body control (IO-WBC) that functions as an artificial cerebellum - an adaptive motor agent that translates upstream (skill-level) commands into stable, physically consistent whole-body behavior under contact. This work structurally separates upper-body interaction execution from lower-body support control, enabling the robot to maintain balance while shaping force exchange in a tightly coupled robot-object system. A trajectory-optimized reference generator (RG) provides a kinematic prior, while a reinforcement learning (RL) policy governs body responses under heavy-load interactions and disturbances. The policy is trained in simulation with randomized payload mass/inertia and external perturbations, and deployed via asymmetric teacher-student distillation so that the student relies only on proprioceptive histories at runtime. Extensive experiments demonstrate that IO-WBC maintains stable whole-body behavior and physical interaction even when precise velocity tracking becomes infeasible, enabling compliant object transport across a wide range of scenarios.