WMPO: World Model-based Policy Optimization for Vision-Language-Action Models

Fuente: arXiv
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Autori principali: Zhu, Fangqi, Yan, Zhengyang, Hong, Zicong, Shou, Quanxin, Ma, Xiao, Guo, Song
Natura: Preprint
Pubblicazione: 2025
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author Zhu, Fangqi
Yan, Zhengyang
Hong, Zicong
Shou, Quanxin
Ma, Xiao
Guo, Song
author_facet Zhu, Fangqi
Yan, Zhengyang
Hong, Zicong
Shou, Quanxin
Ma, Xiao
Guo, Song
contents Vision-Language-Action (VLA) models have shown strong potential for general-purpose robotic manipulation, but their reliance on expert demonstrations limits their ability to learn from failures and perform self-corrections. Reinforcement learning (RL) addresses these through self-improving interactions with the physical environment, but suffers from high sample complexity on real robots. We introduce World-Model-based Policy Optimization (WMPO), a principled framework for on-policy VLA RL without interacting with the real environment. In contrast to widely used latent world models, WMPO focuses on pixel-based predictions that align the "imagined" trajectories with the VLA features pretrained with web-scale images. Crucially, WMPO enables the policy to perform on-policy GRPO that provides stronger performance than the often-used off-policy methods. Extensive experiments in both simulation and real-robot settings demonstrate that WMPO (i) substantially improves sample efficiency, (ii) achieves stronger overall performance, (iii) exhibits emergent behaviors such as self-correction, and (iv) demonstrates robust generalization and lifelong learning capabilities.
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id arxiv_https___arxiv_org_abs_2511_09515
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle WMPO: World Model-based Policy Optimization for Vision-Language-Action Models
Zhu, Fangqi
Yan, Zhengyang
Hong, Zicong
Shou, Quanxin
Ma, Xiao
Guo, Song
Robotics
Artificial Intelligence
Vision-Language-Action (VLA) models have shown strong potential for general-purpose robotic manipulation, but their reliance on expert demonstrations limits their ability to learn from failures and perform self-corrections. Reinforcement learning (RL) addresses these through self-improving interactions with the physical environment, but suffers from high sample complexity on real robots. We introduce World-Model-based Policy Optimization (WMPO), a principled framework for on-policy VLA RL without interacting with the real environment. In contrast to widely used latent world models, WMPO focuses on pixel-based predictions that align the "imagined" trajectories with the VLA features pretrained with web-scale images. Crucially, WMPO enables the policy to perform on-policy GRPO that provides stronger performance than the often-used off-policy methods. Extensive experiments in both simulation and real-robot settings demonstrate that WMPO (i) substantially improves sample efficiency, (ii) achieves stronger overall performance, (iii) exhibits emergent behaviors such as self-correction, and (iv) demonstrates robust generalization and lifelong learning capabilities.
title WMPO: World Model-based Policy Optimization for Vision-Language-Action Models
topic Robotics
Artificial Intelligence
url https://arxiv.org/abs/2511.09515