arXiv Computer Vision By Lifan Zheng, Guotao Chen, Zhenyang Li, Shujie Cui, Qiang Huang, Fan Liu

Evaluation-Guided Demonstration Refinement for Vision-Language-Action Policies: The Winning Entry in the MetaFine Open Competition

Read the original on arXiv Computer Vision →

The paper describes a winning entry (MAI) in the MetaFine Open Competition, where a separate policy π_{0.5} was fine‑tuned for each of five tasks using a task‑specific training mixture and a set number of actions per prediction. Training began from official demonstrations and expert procedures, and local evaluation revealed frequent grasping, pushing, and insertion failures. These issues were mitigated by refining the demonstrated motions and adding expert continuations from states reached by the policy, while retaining the original demonstrations in training; checkpoints were evaluated on every instruction to ensure balanced performance, resulting in a first‑place score of 96.66.

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