---
license: apache-2.0
task_categories:
  - robotics
tags:
  - LeRobot
  - manipulation
  - pick-and-place
  - cafe-serving
  - omx
size_categories:
  - 100K<n<1M
---

# serving_ab — Café Pick-and-Place (Long Episode + Atomic Demos)

LeRobot **v3.0** dataset for OpenManipulator-X (OMX) café serving task.
This is the **merged dataset combining Category A (Long Episode) and Category B (Atomic Demos)** used for the full GR00T N1.7 fine-tuning schedule.

---

## Dataset summary

| Item               | Value                                          |
| ------------------ | ---------------------------------------------- |
| Robot              | OpenManipulator-X 4-DOF (`omx_follower`)       |
| Codebase version   | `v3.0`                                         |
| Total episodes     | 425 (A: 265, B: 160)                           |
| Total frames       | 219,877                                        |
| Total duration     | ~2h 2m @ 30 fps                                |
| FPS                | 30                                             |
| Cameras            | `observation.images.top`, `observation.images.wrist` (640×480, 30 fps) |
| State / Action dim | 6 each (single_arm × 5, gripper × 1)           |
| Action horizon     | 16 (configured via `examples/OMX/omx_config.py`) |
| Tasks              | 3 (see below)                                  |

## Tasks (`task_index`)

| index | instruction                                |
| :---: | ------------------------------------------ |
| 0     | `pick up plate and place at target zone`   |
| 1     | `pick up cup and place at target zone`     |
| 2     | `return to home`                           |

### task distribution

| task_index | frames | pct  |
| ---------- | -----: | ---: |
| 0 (plate)  | 74,679 | 34.0% |
| 1 (cup)    | 96,803 | 44.0% |
| 2 (home)   | 48,395 | 22.0% |

---

## Composition

### Category A — Long Episode (265 episodes, eps 0~264)

Multi-step pick-and-place scenarios starting and ending at home pose.

| sub-id | scenario             | env state            | total |
| :----: | -------------------- | -------------------- | ----: |
| A-1    | one cup              | cup=1                |  35   |
| A-2    | one plate            | plate=1              |  35   |
| A-3    | two plates           | plate=2              |  40   |
| A-4    | two cups             | cup=2                |  40   |
| A-5    | one cup + one plate  | plate=1, cup=1       |  50   |
| A-6    | two cups + one plate | plate=1, cup=2       |  45   |
| A-7    | empty (stop)         | empty / leftovers    |  20   |

### Category B — Atomic Demos (160 episodes, eps 265~424)

Skill-focused demonstrations to strengthen foundational grip reliability and multi-object handling.

| sub-id | skill                            | total |
| :----: | -------------------------------- | ----: |
| B-1    | plate single pick-and-place      |  50   |
| B-2    | cup single pick-and-place        |  50   |
| B-3    | sequential two plates            |  20   |
| B-4    | sequential 2~3 cups              |  20   |
| B-5    | retry recovery                   |  20   |

Pick locations follow a **3×4 grid (12 positions, 7.5 cm spacing)** spanning the OMX reachable workspace; each cell is visited 4~5 times in B-1/B-2 and 3 times in A-1/A-2 for position diversity.

---

## Label boundary scheme

Multi-task episodes are segmented into per-action task ranges. Boundaries were auto-detected from gripper state events (`fully_close` → next `start_open`); missing boundaries in incomplete episodes were estimated from the median position percentile of complete episodes in the same scenario.

| sub-id | segment pattern                                                |
| :----: | -------------------------------------------------------------- |
| A-1    | `cup(1) → home(2)`                                             |
| A-2    | `plate(0) → home(2)`                                           |
| A-3    | `plate(0) → plate(0) → home(2)` (per-plate segment restart)    |
| A-4    | `cup(1) → cup(1) → home(2)` (per-cup segment restart)          |
| A-5    | `cup(1) → plate(0) → home(2)`                                  |
| A-6    | `cup(1) → cup(1) → plate(0) → home(2)`                         |
| A-7    | `home(2)` only                                                 |
| B-1    | `plate(0) → home(2)`                                           |
| B-2    | `cup(1) → home(2)`                                             |
| B-3    | `plate(0) → plate(0) → home(2)`                                |
| B-4    | `cup(1) → cup(1) → home(2)` (or 3 cups)                        |
| B-5    | `<obj> → <obj> → home(2)` (retry segments same task_index)     |

---

## Repository layout

```
serving_ab/
├── data/chunk-000/file-000.parquet           # all 219,877 frames concatenated
├── meta/
│   ├── info.json                              # codebase_version=v3.0, totals
│   ├── tasks.parquet                          # task_index → instruction
│   ├── tasks.jsonl                            # mirror of tasks.parquet
│   ├── modality.json                          # GR00T modality mapping (state/action/video/annotation)
│   ├── stats.json                             # aggregate stats (mean/std/min/max/q01/q99)
│   └── episodes/chunk-000/file-000.parquet    # per-episode metadata + stats (107 cols)
└── videos/
    ├── observation.images.top/chunk-000/file-000.mp4    # ~924 MB
    └── observation.images.wrist/chunk-000/file-000.mp4  # ~1.59 GB
```

---

## Companion datasets

| Repo                                                                | Format | Episodes | Notes                       |
| ------------------------------------------------------------------- | ------ | -------: | --------------------------- |
| [`jae0311/serving_a`](https://huggingface.co/datasets/jae0311/serving_a) | v3.0   |    265   | Category A only (long episodes) |
| [`jae0311/serving_b`](https://huggingface.co/datasets/jae0311/serving_b) | v2.1   |    160   | Category B only (atomic demos)  |

---

## Recommended training schedule (GR00T N1.7)

| Stage | Data           | max-steps | LR     | Goal                                              |
| :---: | -------------- | :-------: | :----: | ------------------------------------------------- |
| 1     | `serving_b`    | 5,000     | 1e-4   | atomic pick-and-place reliability (90%+)          |
| 2     | `serving_ab`   | 25,000    | 5e-5   | long-episode performance from Stage 1 checkpoint  |

- effective batch size: 32 (per_device_batch=8 × grad_accum=4)
- action horizon: 16
- color jitter: brightness 0.2, contrast 0.2, saturation 0.4, hue 0.08

---

## Acknowledgments

- Model: [GR00T N1.7](https://huggingface.co/nvidia/GR00T-N1.7-3B) (NVIDIA)
- Dataset format: [LeRobot](https://github.com/huggingface/lerobot)
- Robot: ROBOTIS OpenManipulator-X