First Physics Audit of Open-X Embodiment — 216 Episodes, 78.1% Pass Rate
First Physics Audit of Open-X Embodiment — 216 Episodes, 78.1% Pass Rate
I built a tool that applies biomechanical physics laws to sensor data before training.
No ML. No learned classifier. Just equations — F=ma coupling, rigid-body kinematics,
jerk bounds, Hurst persistence.
I ran it on RoboTurk from Open-X Embodiment. Here is what came out.
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The Audit
Dataset: RoboTurk (Open-X Embodiment, Stanford)
Episodes: 216 human-teleoperated demonstrations
Windows certified: 1,143
| Tier | Count | % |
|------|-------|—|
| GOLD | 284 | 24.8% |
| SILVER | 609 | 53.3% |
| BRONZE | 242 | 21.2% |
| REJECTED | 8 | 0.7% |
Pass rate (GOLD+SILVER): 78.1%
Top failing law: imu_internal_consistency — 32.4% of windows
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What the Finding Means
imu_internal_consistency checks that translational acceleration and rotational
acceleration are physically coupled — as they are in real human motion.
In RoboTurk, world_vector (translation) and rotation_delta (rotation) are
commanded through separate channels in the smartphone teleoperation interface.
They have different latencies. S2S detects this mismatch.
This is not a bug in the data. It is a measurable property of the teleoperation
interface — and S2S quantifies it. 32.4% of windows have translational and
rotational commands that are physically inconsistent with each other.
For robot training: a model trained on these windows learns motion where the
hand translation and wrist rotation are decoupled. That is not how humans move.
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Comparison to Real Human IMU
| Dataset | Pass Rate | Top Law |
|---------|-----------|---------|
| NinaPro DB5 (real human, 2000Hz) | 100% SILVER | none |
| RoboTurk (teleoperation, 15Hz) | 78.1% | imu_consistency 32.4% |
Real human IMU passes everything. Teleoperation data has a measurable quality gap.
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Reproduce It
pip install s2s-certify
git clone GitHub - timbo4u1/S2S: Physics certification for robot training data. Checks 11 biomechanical laws before your model trains. · GitHub
cd S2S && python3 certify_roboturk.py
Full audit data: Scan2s/s2s-certified-motion · Datasets at Hugging Face
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This is the first physics audit of Open-X Embodiment I am aware of.
If anyone has run similar analysis on other Open-X subsets I would like to know.
The tool works on any IMU/EMG dataset. Zero dependencies. Pure Python.
Discussion in the ATmosphere