Causally Debiased Latent Action Model for Embodied Action Conditioned World Models

2026-07-10Computer Vision and Pattern Recognition

Computer Vision and Pattern RecognitionRobotics
AI summary

The authors studied models that predict future robot views based on actions, which usually need lots of labeled data. They found that current models mix up important action details with irrelevant background info, making control harder. To fix this, they created CD-LAM, which uses three new training methods to focus the model on important action info and ignore distractions. Their approach improved how well models follow actions and adapt, using much less fine-tuning data than before.

action-conditioned world modelslatent action modelsrobot planningcontrastive learninglatent space calibrationembodiment-centric reconstructioncausal debiasingrobot-action followingfine-tuning efficiencyvisual fidelity
Authors
Yufan Wei, Kun Zhou, Lingjun Mao, Zijun Zhang, Ziming Xu, Ziqiao Xi, Shuang Liang, Ruobing Han, Yuchen Yan, Xinyue Wang, Fan Feng, Biwei Huang
Abstract
Action-conditioned world models (ACWMs) aim to simulate future observations conditioned on embodied actions, offering a promising foundation for robot planning, policy evaluation, and data augmentation. However, learning controllable ACWMs requires large-scale action-labeled data, which remains costly to collect in the real world. Latent action models (LAMs) mitigate this bottleneck by inferring latent actions from unlabeled videos, but existing LAMs are typically trained with reconstruction-only objectives and therefore entangle action-relevant dynamics with action-irrelevant visual factors such as backgrounds and untouched objects. In this work, we identify this action-irrelevant bias as a key obstacle to controllable ACWMs and introduce evaluation metrics to measure latent-action bias, action following, and robustness. We propose CD-LAM, a causally debiased framework for LAM-based ACWMs. CD-LAM introduces three efficient fine-tuning objectives: embodiment-centric reconstruction, action-centric contrastive learning, and latent space calibration, which together encourage embodiment-focused, action-aware, and calibrated non-collapsed latent action representations. Experiments on 2B and 14B ACWM backbones show that CD-LAM substantially improves latent-action controllability, downstream robot-action following, visual fidelity, and adaptation efficiency, requiring only 6k fine-tuning steps and more than 12$\times$ fewer robot-action adaptation updates than the baseline.