Compliant humanoid robots combine general motion tracking with safe responses
Compliant GMT: Making General Motion Tracking Compliant via Residual Reference Adaptation
Robotics
Summary
Humanoid robots often move stiffly when imitating human motions, which can cause unsafe reactions when they bump into things or people. The authors present Compliant GMT, a system that helps robots both follow a wide range of motions and gently respond to physical interactions. They do this by adapting a robot’s motions based on its recent movements, allowing it to be flexible and safe. Tests show this method balances accurate motion imitation with better safety and robustness during real-world use.
What this means in practice
- •For robotics engineers: Enable humanoid robots to safely imitate diverse human motions while adapting to physical contact in real environments.
- •For robotics hardware developers: Design robots that maintain natural motion tracking with built-in compliance to reduce damage from unexpected disturbances or collisions.
Authors
Venki Parsuram, Michelle Wang, Jin-Hyuk Hong, Pulkit Agrawal
Abstract
We propose Compliant GMT (C-GMT), a modular framework for full-body compliant responses in general motion tracking. As humanoid robots move into real world deployment, they not only need to perform any motion but also respond safely and robustly to interaction forces. Existing general motion tracking policies can imitate diverse motions but are trained to be stiff, leading to unexpected and unsafe behaviors under disturbance. Prior work in compliant humanoid control trades off compliance and generality. There exist examples of full-body compliant responses, but these are heavily curated to single-reference policies. On the other hand, general motion trackers (GMT) are trained to rigidly imitate massive motion capture datasets. Our key insight is to leverage the generality of pretrained GMTs for motion tracking while introducing compliance from a residual adapter that conditions on a history of proprioception. This enables our approach, C-GMT, to achieve both general motion tracking and whole-body compliant responses. Compared to state-of-the-art general motion trackers and single-motion compliant policies, C-GMT demonstrates competitive performance in both motion tracking accuracy and compliance adherence. We further demonstrate improved safety, robustness, and error tolerance in simulation and real-world G1 experiments.