🤖 AI Summary
This work addresses the challenges of high inference latency, insufficient action precision, and poor decision interpretability in end-to-end autonomous driving by introducing MVLAD-AD, a novel framework that incorporates a masked vision–language–action diffusion model into driving policy learning. To enhance both accuracy and efficiency while preserving physically plausible trajectories, the approach leverages discrete action tokenization, geometry-aware embedding learning, and an action-prioritized decoding mechanism. Experimental results demonstrate that MVLAD-AD significantly outperforms existing autoregressive and diffusion-based methods on standard benchmarks such as nuScenes, achieving state-of-the-art performance in planning accuracy, inference speed, and semantic interpretability.
📝 Abstract
Large Language Models (LLMs) and Vision-Language Models (VLMs) have emerged as promising candidates for end-to-end autonomous driving. However, these models typically face challenges in inference latency, action precision, and explainability. Existing autoregressive approaches struggle with slow token-by-token generation, while prior diffusion-based planners often rely on verbose, general-purpose language tokens that lack explicit geometric structure. In this work, we propose Masked Vision-Language-Action Diffusion for Autonomous Driving (MVLAD-AD), a novel framework designed to bridge the gap between efficient planning and semantic explainability via a masked vision-language-action diffusion model. Unlike methods that force actions into the language space, we introduce a discrete action tokenization strategy that constructs a compact codebook of kinematically feasible waypoints from real-world driving distributions. Moreover, we propose geometry-aware embedding learning to ensure that embeddings in the latent space approximate physical geometric metrics. Finally, an action-priority decoding strategy is introduced to prioritize trajectory generation. Extensive experiments on nuScenes and derived benchmarks demonstrate that MVLAD-AD achieves superior efficiency and outperforms state-of-the-art autoregressive and diffusion baselines in planning precision, while providing high-fidelity and explainable reasoning.