AdaVLA: Adaptive Step Flow Matching for Training-free Acceleration of Vision-Language-Action Models

2026-08-29

AI Summary

为解决VLA模型在设备上部署的计算开销问题，提出AdaVLA框架，通过自适应调整推理步骤和MLP剪枝比例，在不需训练数据的情况下加速模型推理。

Abstract

Vision-Language-Action (VLA) models, built upon Vision-Language Models (VLMs), have significantly enhanced robotic capabilities by leveraging internet-scale knowledge and multimodal reasoning. However, the intensive computational overhead of VLAs constrains on-device deployment, hindering real-time responses to environmental changes. While various acceleration techniques have been proposed, they often rely on fine-tuning or access to training datasets, which are frequently unavailable due to privacy and proprietary concerns. Moreover, although flow-matching-based VLAs have emerged as efficient alternatives to standard diffusion models, current acceleration efforts largely target VLM inference costs, failing to address the iterative ODE solving process inherent in flow matching inference. To address these limitations, we propose AdaVLA, an online, training-free adaptive framework for fast yet accurate flow-matching-based Vision-Language-Action models. We introduce a novel metric derived from the flow matching trajectory curvature to quantify action generation confidence during inference. This metric enables the dynamic reduction of inference steps and the adaptive adjustment of MLP pruning ratios through an efficiently computed importance evaluation, requiring no access to training data. Experimental results on the LIBERO benchmark using a Jetson AGX Orin device demonstrate that our method achieves $1.87\times$ and $2.24\times$ speedups for $π_{0.5}$ and X-VLA, respectively, with negligible degradation in success rates. Furthermore, we validate the robustness of our approach on real-world robotic tasks using SmolVLA.

Problem

• Vision-Language-Action
• computational overhead
• on-device deployment
• flow matching
• inference cost

Innovation

• Adaptive Step Flow Matching
• Training-free Acceleration
• Flow Matching Trajectory Curvature
• Dynamic Inference Steps Reduction
• MLP Pruning Ratios Adjustment