TAM: Torque Adaptation Module for Robust Motion Transfer in Manipulation
Summary
The Torque Adaptation Module (TAM) is a novel learned module designed to achieve robust motion transfer in robot manipulation, addressing discrepancies arising from the sim-to-real gap, unknown payloads, or variations between robot instances. Operating between the low-level controller and the robot's torque interface, TAM comprises a history encoder that embeds proprioceptive history into a latent state and a torque adaptor that computes residual torque corrections. A key advantage is its ability to reuse the same TAM weights across policies with different action spaces (joint targets, end-effector targets, direct torques) without requiring policy retraining or domain randomization. TAM is trained entirely in randomized simulation, using multi-robot pretraining followed by robot-specific fine-tuning, requiring no real-robot data. Evaluated zero-shot on a real Franka Panda robot, TAM significantly improved performance in dynamic manipulation tasks, including a vision-based box pushing policy (RL), a flip policy (BC), and an MPC ball-on-plate balancing controller, outperforming online system identification and RMA baselines.
Key takeaway
For Robotics Engineers and ML Engineers deploying robot policies, if you are struggling with sim-to-real gaps, unknown payloads, or robot instance variations, consider integrating TAM. This module allows you to achieve robust real-world performance with existing policies without costly retraining or extensive real-robot data collection. You can enhance dynamic, contact-rich manipulation tasks by adding TAM as a modular, torque-level adaptation layer.
Key insights
TAM adapts torque commands at the robot interface, enabling robust motion transfer and decoupling policy training from robot dynamics.
Principles
- Adaptation at the torque interface enhances policy reusability.
- Proprioceptive history can infer robot dynamics mismatch.
- Sim-only training can yield effective zero-shot real-world transfer.
Method
TAM employs a history encoder to summarize proprioceptive history into a latent state and a torque adaptor to predict residual torque corrections at 1 kHz, applied between the low-level controller and the robot plant.
In practice
- Integrate TAM with existing RL, BC, or MPC policies.
- Fine-tune TAM in simulation for specific robot models.
- Apply to contact-rich dynamic manipulation tasks.
Topics
- Sim-to-Real Transfer
- Robot Manipulation
- Torque Control
- Adaptive Control
- Reinforcement Learning
- Behavior Cloning
- Model Predictive Control
Code references
Best for: Research Scientist, AI Scientist, Robotics Engineer, Machine Learning Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.AI updates on arXiv.org.