这篇论文用缓存中间动作的思路让VLA模型推理快11到34倍，而且不用重新训练，机器人实时控制场景很实用。
论文提出ActionCache，一种即插即用的外部缓存，用于加速基于流匹配的视觉-语言-动作（VLA）模型推理。ActionCache通过存储紧凑多模态键的中期动作，从相似过往上下文（跨不同回合甚至任务）中检索来预热生成，减少迭代去噪步骤。在仿真和真实环境实验中，ActionCache在低延迟下保持高任务成功率，对π₀.₅和GR00T-N1.6分别实现高达11.75倍和34.43倍的推理加速。
Training-Free Acceleration for Vision-Language-Action Models with Action Caching and Refinement
Vision-Language-Action (VLA) models have emerged as a promising approach for generalizable robotic manipulations. In particular, flow matching-based VLA models have shown remarkable success due to their capability to generate precise and smooth action sequences and capture multimodal distributions. However, the iterative denoising process in the action head acts as a major computational bottleneck, posing a critical challenge for real-time deployment. To address this challenge, we propose ActionCache, a plug-and-play external cache that opportunistically reuses past intermediate actions to warm-start generations from the vicinity of target actions, thereby drastically reducing the inference latency. Specifically, ActionCache stores the intermediate actions with compact multimodal keys, which enables retrieval from similar past contexts across different episodes or even different tasks. Experimental results in simulation and real-world environments demonstrate that ActionCache maintains high task success rates in a low-latency regime, achieving inference acceleration of up to $11.75\times$ and $34.43\times$ for representative flow-based VLA models, $π_{0.5}$ and GR00T-N1.6, respectively.