hz1919810/lingbot-va-arx-teacher-step3000
LingBot-VA ARX SFT Teacher — v2 split, step 3000
Video–action world-model (LingBot-VA) fine-tuned on the ARX LIFT R5 dual-arm WAM-OPD task set. This is the transformer of the SFT teacher at optimizer step 3000.
*⚠️ This is the v2 diagnostic run, not the contract deliverable. v2 was trained from base on a 160-episode train split (of 199; per-task 40/10, seed 42) specifically to measure overfitting on held-out data. The contract's full-data teacher is the separate v1 (all-199)* run. Do not conflate the two: use v2 for the overfitting analysis below; use v1 for any all-data delivery.
Provenance
Held-out validation (39 episodes, teacher-forced denoising loss, 4 draws)
Overfitting: validation loss bottoms at step 1500 and rises monotonically through 5000 (+~20%). Step 3000 is past the validation minimum (overfit side).
Important caveat on this metric
The validation loss above is teacher-forced, one-step denoising error — the training objective on unseen data. It is an overfitting tripwire, not a task-success ranking. For a world model, low denoising loss does not imply good multi-step rollouts or real-robot success (compounding error is invisible here). Final checkpoint selection requires closed-loop rollout / real-robot evaluation, which for this real-robot dataset is the data owner's call.
Files
transformer/ — diffusers-format WanTransformer3DModel (config.json + bf16 safetensors). Load with the LingBot-VA stack; switch attn_mode to torch/flashattn for inference (training used flex).
