update docs

This commit is contained in:
Michel Aractingi
2026-01-14 16:38:09 +01:00
parent fd7cb9a5c5
commit faa276b8cf

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@@ -465,15 +465,16 @@ This script:
### Step 5b: Train Policy with RA-BC
Once you have the progress file, train your policy with RA-BC weighting. The progress file is auto-detected from the dataset path (`sarm_progress.parquet`). Currently PI0, PI0.5 and SmolVLA are supported with RA-BC:
Once you have the progress file, train your policy with RA-BC weighting. Currently PI0, PI0.5 and SmolVLA are supported with RA-BC:
```bash
python src/lerobot/scripts/lerobot_train.py \
--dataset.repo_id=your-username/your-dataset \
--policy.type=pi0 \
--use_rabc=true \
--rabc_head_mode=sparse \
--rabc_kappa=0.01 \
--sample_weighting.type=rabc \
--sample_weighting.progress_path=path/to/sarm_progress.parquet \
--sample_weighting.head_mode=sparse \
--sample_weighting.kappa=0.01 \
--output_dir=outputs/train/policy_rabc \
--batch_size=32 \
--steps=40000
@@ -488,12 +489,13 @@ The training script automatically:
**RA-BC Arguments:**
| Argument | Description | Default |
| ---------------------- | ---------------------------------------------------------- | ---------------------------------- |
| `--use_rabc` | Enable RA-BC sample weighting | `false` |
| `--rabc_progress_path` | Path to progress parquet file (auto-detected from dataset) | `sarm_progress.parquet` in dataset |
| `--rabc_head_mode` | Which SARM head's progress to use: `sparse` or `dense` | `sparse` |
| `--rabc_kappa` | Threshold κ for high-quality samples | `0.01` |
| Argument | Description | Default |
| ----------------------------------- | ------------------------------------------------------ | --------- |
| `--sample_weighting.type` | Weighting strategy type (`rabc` or `uniform`) | `rabc` |
| `--sample_weighting.progress_path` | Path to progress parquet file (required for RABC) | (required)|
| `--sample_weighting.head_mode` | Which SARM head's progress to use: `sparse` or `dense` | `sparse` |
| `--sample_weighting.kappa` | Threshold κ for high-quality samples | `0.01` |
| `--sample_weighting.epsilon` | Small constant for numerical stability | `1e-6` |
### Tuning RA-BC Kappa
@@ -511,30 +513,30 @@ The `kappa` parameter is the threshold that determines which samples get full we
Monitor these WandB metrics during training:
| Metric | Healthy Range | Problem Indicator |
| ------------------ | ------------- | ------------------------- |
| `rabc_mean_weight` | 0.3 - 0.8 | ≈ 1.0 means kappa too low |
| `rabc_delta_mean` | > 0 | Should be positive |
| `rabc_delta_std` | > 0 | Variance in data quality |
| Metric | Healthy Range | Problem Indicator |
| ------------------------------- | ------------- | ------------------------- |
| `sample_weight_mean_weight` | 0.3 - 0.8 | ≈ 1.0 means kappa too low |
| `sample_weighting/delta_mean` | > 0 | Should be positive |
| `sample_weighting/delta_std` | > 0 | Variance in data quality |
**If `rabc_mean_weight ≈ 1.0`:** Your kappa is too low. Most samples have `delta > kappa` and bypass the soft-weighting entirely. RA-BC becomes equivalent to vanilla BC.
**If `sample_weight_mean_weight ≈ 1.0`:** Your kappa is too low. Most samples have `delta > kappa` and bypass the soft-weighting entirely. RA-BC becomes equivalent to vanilla BC.
**Setting kappa based on your data:**
The default `kappa=0.01` was tuned for the paper's T-shirt folding task (~90s episodes at 30fps). For your dataset, check the logged `rabc_delta_mean` and `rabc_delta_std`:
The default `kappa=0.01` was tuned for the paper's T-shirt folding task (~90s episodes at 30fps). For your dataset, check the logged `sample_weighting/delta_mean` and `sample_weighting/delta_std`:
```
# If delta_mean ≈ 0.03 and delta_std ≈ 0.02:
# Most deltas fall in range [0.01, 0.05]
# Option 1: Set kappa = delta_mean (medium selectivity)
--rabc_kappa=0.03
--sample_weighting.kappa=0.03
# Option 2: Set kappa = delta_mean + delta_std (high selectivity)
--rabc_kappa=0.05
--sample_weighting.kappa=0.05
# Option 3: Set kappa = delta_mean + 2*delta_std (very selective)
--rabc_kappa=0.07
--sample_weighting.kappa=0.07
```
**When RA-BC may not help:**
@@ -550,8 +552,9 @@ accelerate launch \
src/lerobot/scripts/lerobot_train.py \
--dataset.repo_id=your-username/your-dataset \
--policy.type=pi0 \
--use_rabc=true \
--rabc_kappa=0.01 \
--sample_weighting.type=rabc \
--sample_weighting.progress_path=path/to/sarm_progress.parquet \
--sample_weighting.kappa=0.01 \
--output_dir=outputs/train/policy_rabc \
--batch_size=32 \
--steps=40000
@@ -576,7 +579,7 @@ accelerate launch \
### RA-BC
1. **Train SARM first**: RA-BC quality depends entirely on SARM quality
2. **Monitor `rabc_mean_weight`**: If it's ≈ 1.0, increase kappa (see [Tuning RA-BC Kappa](#tuning-ra-bc-kappa))
2. **Monitor `sample_weight_mean_weight`**: If it's ≈ 1.0, increase kappa (see [Tuning RA-BC Kappa](#tuning-ra-bc-kappa))
---