WAM-Diff: A Masked Diffusion VLA Framework with MoE and Online Reinforcement Learning for Autonomous Driving

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Xu, Mingwang, Cui, Jiahao, Cai, Feipeng, Shang, Hanlin, Zhu, Zhihao, Luan, Shan, Xu, Yifang, Zhang, Neng, Li, Yaoyi, Cai, Jia, Zhu, Siyu
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912766892179456
author Xu, Mingwang
Cui, Jiahao
Cai, Feipeng
Shang, Hanlin
Zhu, Zhihao
Luan, Shan
Xu, Yifang
Zhang, Neng
Li, Yaoyi
Cai, Jia
Zhu, Siyu
author_facet Xu, Mingwang
Cui, Jiahao
Cai, Feipeng
Shang, Hanlin
Zhu, Zhihao
Luan, Shan
Xu, Yifang
Zhang, Neng
Li, Yaoyi
Cai, Jia
Zhu, Siyu
contents End-to-end autonomous driving systems based on vision-language-action (VLA) models integrate multimodal sensor inputs and language instructions to generate planning and control signals. While autoregressive large language models and continuous diffusion policies are prevalent, the potential of discrete masked diffusion for trajectory generation remains largely unexplored. This paper presents WAM-Diff, a VLA framework that employs masked diffusion to iteratively refine a discrete sequence representing future ego-trajectories. Our approach features three key innovations: a systematic adaptation of masked diffusion for autonomous driving that supports flexible, non-causal decoding orders; scalable model capacity via a sparse MoE architecture trained jointly on motion prediction and driving-oriented visual question answering (VQA); and online reinforcement learning using Group Sequence Policy Optimization (GSPO) to optimize sequence-level driving rewards. Remarkably, our model achieves 91.0 PDMS on NAVSIM-v1 and 89.7 EPDMS on NAVSIM-v2, demonstrating the effectiveness of masked diffusion for autonomous driving. The approach provides a promising alternative to autoregressive and diffusion-based policies, supporting scenario-aware decoding strategies for trajectory generation. The code for this paper will be released publicly at: https://github.com/fudan-generative-vision/WAM-Diff
format Preprint
id arxiv_https___arxiv_org_abs_2512_11872
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle WAM-Diff: A Masked Diffusion VLA Framework with MoE and Online Reinforcement Learning for Autonomous Driving
Xu, Mingwang
Cui, Jiahao
Cai, Feipeng
Shang, Hanlin
Zhu, Zhihao
Luan, Shan
Xu, Yifang
Zhang, Neng
Li, Yaoyi
Cai, Jia
Zhu, Siyu
Robotics
Artificial Intelligence
Computer Vision and Pattern Recognition
End-to-end autonomous driving systems based on vision-language-action (VLA) models integrate multimodal sensor inputs and language instructions to generate planning and control signals. While autoregressive large language models and continuous diffusion policies are prevalent, the potential of discrete masked diffusion for trajectory generation remains largely unexplored. This paper presents WAM-Diff, a VLA framework that employs masked diffusion to iteratively refine a discrete sequence representing future ego-trajectories. Our approach features three key innovations: a systematic adaptation of masked diffusion for autonomous driving that supports flexible, non-causal decoding orders; scalable model capacity via a sparse MoE architecture trained jointly on motion prediction and driving-oriented visual question answering (VQA); and online reinforcement learning using Group Sequence Policy Optimization (GSPO) to optimize sequence-level driving rewards. Remarkably, our model achieves 91.0 PDMS on NAVSIM-v1 and 89.7 EPDMS on NAVSIM-v2, demonstrating the effectiveness of masked diffusion for autonomous driving. The approach provides a promising alternative to autoregressive and diffusion-based policies, supporting scenario-aware decoding strategies for trajectory generation. The code for this paper will be released publicly at: https://github.com/fudan-generative-vision/WAM-Diff
title WAM-Diff: A Masked Diffusion VLA Framework with MoE and Online Reinforcement Learning for Autonomous Driving
topic Robotics
Artificial Intelligence
Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2512.11872