机器人开发者终于有了一个无需重新训练就能安全引导VLA模型的方法——通过语言反馈策略提升任务成功率，同时避免有害行为。做机器人控制或人机交互的团队可以直接在现有模型上尝试，值得关注。
该研究提出一种框架，通过交互式搜索语言序列来提升视觉-语言-动作（VLA）模型的闭环任务性能，并蒸馏为测试时的语言反馈策略（LFP）。同时学习一个改进头，预测何时语言引导能提升性能，并通过保形化处理防止有害干预。该方法适用于任意冻结的预训练VLA模型，无需访问原始训练数据或微调。在模拟和硬件实验中，该策略分别将基础VLA性能提升24.7%和65.0%，且在视觉和语义扰动下具有强无害性保证。
Learning What to Say to Your VLA: Mostly Harmless Vision Language Action Model Steering
Vision-Language-Action (VLA) models provide a natural language interface to robot control, but the mapping from language to behavior is often brittle and unintuitive: semantically similar instructions can induce drastically different behaviors, while some capabilities may not be elicitable through prompting alone. As a result, both human instructions and zero-shot language models can fail to reliably steer VLAs toward successful task execution. In this work, we propose a framework that interactively searches for language sequences that improve closed-loop VLA task performance, distills these sequences into a test-time language feedback policy (LFP), and learns an improvement head that predicts when language steering will improve performance. We conformalize this improvement head to prevent harmful steering interventions, where the LFP decreases task performance relative to the original instruction on out-of-distribution scenarios. Crucially, our approach operates on arbitrary frozen pre-trained VLAs, requiring neither access to the original training distribution nor fine-tuning of the underlying model. On seen environments, our conformalized LFP improves base VLA performance by 24.7% in simulation and 65.0% in hardware. On visual and semantic perturbations, our conformalized LFP has strong harmlessness guarantees, and produces recovery behaviors not observed with open-loop prompting.