README.md

---
pretty_name: UF850 Quest VR Press Buttons Raw
language:
  - en
tags:
  - robotics
  - teleoperation
  - xarm
  - quest-vr
  - realsense
  - raw-data
size_categories:
  - 10K<n<100K
---

# UF850 Quest VR Press Buttons — Raw Data

Raw, untrimmed UF850 teleoperation trajectories collected with a Quest VR
controller and two Intel RealSense cameras. No retained trajectory was trimmed,
resampled, or action-normalized. Camera frames were captured as YUYV and stored
as JPEG at collection time.

## Task and prompt

Every episode uses the same English task instruction:

> First press the blue button, then press the red one, and finally press the orange one

The canonical prompt is stored in `episode_meta.json` as `task`. It is
intentionally not duplicated in every step-level `data.json`.

## Task layout

![External-camera view of the initial task layout](layout_external.jpg)

In this external-camera view, the buttons are arranged orange, red, and blue
from left to right. The commanded sequence is blue, then red, then orange
(right to left in this view).

## Dataset summary

| Item | Value |
| --- | ---: |
| Episodes | 50 (`episode_000`–`episode_049`) |
| Transition steps | 20,659 |
| JPEG images | 41,318 (20,659 per camera) |
| Nominal transition rate | 10 Hz |
| Nominal transition time | 34.43 minutes |
| Image size | 1920×1080 |

## Cameras

| File | Role | RealSense serial | Capture mode |
| --- | --- | --- | --- |
| `cam_0.jpg` | wrist | `845112070404` | 1920×1080 YUYV @ 30 FPS |
| `cam_1.jpg` | external | `215222078407` | 1920×1080 YUYV @ 30 FPS |

## File layout

To keep the Hub repository reliable and easy to download, each episode is
distributed as one uncompressed tar archive. The archive is only a container:
the JPEG and JSON file bytes inside are unchanged from the validated raw
capture.

```text
README.md
layout_external.jpg
SHA256SUMS
episodes/
  episode_000.tar
  episode_001.tar
  ...
```

Extract an episode with, for example:

```bash
tar -xf episodes/episode_000.tar
```

Each archive expands to the original capture layout:

```text
episode_NNN/
  episode_meta.json
  step_00000/
    cam_0.jpg
    cam_1.jpg
    data.json
  step_00001/
    ...
```

Each step contains the synchronized observation and camera pair at time `t`,
plus the raw robot-state difference to the following sample:

```text
action[t] = state[t + 1] - state[t]
```

Actions are not divided by `dt`.

### `data.json`

- `observations.ee_pos`: `[x, y, z, roll, pitch, yaw]`
- `observations.joint_pos`: six joint angles
- `observations.gripper_pos`: raw xArm gripper position
- `action.delta_ee_pos`: next-minus-current TCP delta
- `action.delta_joint_pos`: next-minus-current joint delta
- `action.delta_gripper`: next-minus-current gripper delta
- `meta`: schema version, step number, sampling time, real `dt`, camera
  timestamps/frame numbers/skew, frame age, state-read duration, and wrapped
  Euler-angle delta

Units are millimetres for TCP XYZ, degrees for TCP Euler angles and joint
angles, and the raw xArm scale (nominally 0–850) for the gripper. Delta fields
use the corresponding source units.

### `episode_meta.json`

Episode metadata records the task prompt, start/end times, termination reason,
camera identities, collection configuration snapshot, step count, and error
statistics.

## Validation and raw-data notes

- All 50 published episodes were checked for contiguous numbering, required
  files, full 1920×1080 JPEG decoding, finite JSON values, next-current action
  alignment, camera synchronization, frame ordering, and episode metadata
  consistency.
- One original capture was excluded before publication because it began at the
  preceding orange-button endpoint and included a return/gripper-reset segment
  before the intended task. The remaining original episodes were renumbered
  contiguously; their images, step JSON, observations, and actions were not
  modified.
- Published `episode_005` and `episode_013` have episode metadata reconstructed
  from preserved step records from an earlier cleanup. Published `episode_034`
  and `episode_040` were reconstructed during this publication cleanup using
  preserved step timestamps, finalized-file times, the shared task, and the
  common collection configuration.
- Static prefixes and tails are retained because this is a raw dataset. In
  particular, `episode_013` contains an approximately 17.8-second static
  segment after the useful motion.
- Raw Euler deltas retain the legacy direct-subtraction behavior, including
  wrap-boundary values near ±360°. A wrapped rotation delta is also available
  in each step's metadata.