pi05_bi_two_tubes_all_step8000

pi05_bi — two_tubes_all, step 8000

openpi pi05_bi checkpoint fine-tuned on a bimanual two-tube pick-and-place task with paired RGB + tactile input. Step 8000 is the checkpoint with the best held-out validation loss for this run (see the curve below).

Task

Firstly, use the left hand to pick up the blue tube, and then use the right hand to pick up the green tube. Next, use the left hand to place the blue tube back firstly, and then use the right hand to place the green tube back.

Data

Derived from KaiyueChen/two_tubes_01 (LeRobot v2.1, 30 fps, robot_type: bimanual).

The split is per-source stratified with 10% held out (seed=42). val_unseen episodes are never trained on; val_seen is a same-sized sample drawn from the training episodes, so the two are directly comparable and their difference isolates memorisation from generalisation.

Normalisation statistics were computed on the training split only (quantile q01/q99, as PI05 expects) and ship with the checkpoint at checkpoint/assets/two_tubes_all/norm_stats.json. Computing them over the full dataset would leak held-out episodes into the input scaling.

Training

Validation

val_unseen bottoms out at step 8000 and does not improve afterwards: from step 4000 to 10000 it moves by only +0.9% while val_seen drops 14.4% and the gap more than doubles. Everything learned past ~step 4000 is memorisation rather than generalisation, which is why this checkpoint — not the final one — is the one to use.

Caveat on the numbers: each validation pass covers 20 batches × 128 frames ≈ 2,560 frames, which for ~800-frame episodes is only 3–4 episodes per split. The absolute val_unseen trend is meaningful; the exact value of gap is not.

Layout

checkpoint/
├── _CHECKPOINT_METADATA
├── assets/two_tubes_all/norm_stats.json
├── params/       # orbax OCDBT, inference weights
└── train_state/  # optimiser state, for resuming

Load with openpi by pointing the config's checkpoint directory at checkpoint/. Inference only needs params/ and assets/; train_state/ is for resuming.