RL Token (RLT) encoder-decoder trained on the 6-dataset build-block-tower mixture, on top of the published pi05-build-block-tower-6mix VLA baseline.
What is this?
This model is a lightweight transformer encoder-decoder which takes inputs from a frozen Pi-05 VLA backbone. The encoder compresses the VLA's final-layer prefix embeddings into a single RL token via a learned query. The decoder autoregressively reconstructs the original embeddings from only this token, forcing it to act as an information bottleneck. See Xu et al. (2026), Precise Manipulation with Efficient Online RL for the method.
