bohlt/openarm2-shirt-fold-pi05-hf-phase-aligned-5k-v2

Pi0.5 OpenArm2 T-shirt Folding — HF-Initialized 5K Fine-Tune

This is a training candidate, initialized from Hugging Face's final Pi0.5 folding policy and fine-tuned for 5,000 steps on phase-aligned Anvil OpenArm 2 T-shirt-folding demonstrations. It has not yet been performance-validated on hardware and is not deployment-approved.

Provenance

Item	Value
Base checkpoint	lerobot-data-collection/folding_final
Base revision	695abe40dbf3aac04efda59c1501d748681fa0fb
Dataset	bohlt/openarm2-shirt-fold-phase-aligned-v1
Dataset revision	8411e3e85eaf3e482b4ccb1cac9d4fc02891305e
Training scope	Pi0.5 action expert only
Steps / batch size	5,000 / 16
Seed	1000
Action representation	Chunk-relative arm joints; grippers excluded from relative conversion
Checkpoint interval	500 steps
Folding code revision	d7e2d09
Anvil training revision	8cb3b44
W&B run	v48pp7bv

Aggregate results

Metric	Value
Final logged train loss	0.087000
Final W&B train loss	0.063375
Final validation loss	0.105837
Final test loss	0.084726
Actuator-audit validation aggregate	0.107207
Actuator-audit test aggregate	0.088134

Per-actuator held-out loss

The grippers are the dominant residual-error channels. Their mean loss is 0.1757 validation / 0.1594 test, compared with 0.0974 / 0.0779 across the 14 arm joints. The highest individual channel on both splits is right_gripper.pos. This is a normalized flow-matching loss, not an angle error or a measured joint-limit violation.

Actuator	Validation loss	Test loss
right_joint_1.pos	0.103824	0.065850
right_joint_2.pos	0.104756	0.091587
right_joint_3.pos	0.093135	0.063144
right_joint_4.pos	0.098640	0.084986
right_joint_5.pos	0.068296	0.069760
right_joint_6.pos	0.069995	0.056355
right_joint_7.pos	0.109297	0.094386
right_gripper.pos	0.193641	0.183934
left_joint_1.pos	0.092994	0.075194
left_joint_2.pos	0.089928	0.063051
left_joint_3.pos	0.096795	0.070497
left_joint_4.pos	0.099758	0.089794
left_joint_5.pos	0.113030	0.094465
left_joint_6.pos	0.129621	0.084174
left_joint_7.pos	0.093949	0.088008
left_gripper.pos	0.157661	0.134964

Raw values and provenance are in metrics.

Checkpoints

Numeric checkpoints are published every 500 steps from 000500 through 005000. The latest tag resolves to the complete step-5,000 checkpoint. Each checkpoint contains the policy, processors, embodiment contract, split information, and training state.

Limitations and required validation

• Offline loss does not establish physical folding success.
• Prediction joint-limit violations must be audited against the repaired Anvil OpenArm 2 embodiment contract before hardware execution.
• Gripper channels have materially higher held-out loss and deserve focused rollout inspection.
• Trainer and actuator-audit losses use stochastic flow-matching samples and are not expected to be bit-identical.
• No hardware, deployment, or shadow-policy evaluation is claimed here.