| --- |
| license: cc-by-4.0 |
| task_categories: |
| - image-classification |
| pretty_name: Mendeley Rotor Faults — Perception Representations (signal→VLM) |
| tags: |
| - rotor-fault-diagnosis |
| - vibration |
| - signal-to-image |
| - unbalance |
| - misalignment |
| - looseness |
| configs: |
| - config_name: spectrogram |
| data_files: |
| - split: train |
| path: spectrogram/train-* |
| - split: test |
| path: spectrogram/test-* |
| - config_name: scalogram |
| data_files: |
| - split: train |
| path: scalogram/train-* |
| - split: test |
| path: scalogram/test-* |
| - config_name: waveform |
| data_files: |
| - split: train |
| path: waveform/train-* |
| - split: test |
| path: waveform/test-* |
| - config_name: reshaped |
| data_files: |
| - split: train |
| path: reshaped/train-* |
| - split: test |
| path: reshaped/test-* |
| --- |
| # Mendeley rotor faults — perception representations (visual grounding) |
|
|
| Part of the AI4Manufacturing FORGE corpus (Category **C**, task **T-C1**) and its **first rotor-family** dataset: the fault is in the *shaft line* — unbalance, misalignment, mechanical looseness — not in a bearing or a gear. One-second vibration windows from a belt-driven rotor bench, rendered as **perception** images, one HF **config** per representation. |
|
|
| **Records:** 2000 across 4 configs (500 windows each); labels {'normal': 125, 'misalignment': 125, 'unbalance': 125, 'looseness': 125}. |
|
|
| ## Configs |
| ```python |
| load_dataset("AI4Manufacturing/MENDELEY-rotor-perception", "spectrogram") |
| ``` |
|
|
| | config | records | splits | |
| |---|---|---| |
| | `spectrogram` | 500 | {'train': 400, 'test': 100} | |
| | `scalogram` | 500 | {'train': 400, 'test': 100} | |
| | `waveform` | 500 | {'train': 400, 'test': 100} | |
| | `reshaped` | 500 | {'train': 400, 'test': 100} | |
|
|
| ## Schema (7-field unified record) |
| | field | meaning | |
| |---|---| |
| | `query` | the classification instruction (one of 30 deterministic paraphrases per representation) | |
| | `image` | the rendered signal image (bytes embedded) | |
| | `annot` | gold rotor condition: normal / misalignment / unbalance / looseness | |
| | `reasoning` | empty — this release has no reasoning track (see *Why perception-only*) | |
| | `cate` / `task` | `C` / `T-C1` (signal fault classification) | |
| | `metadata` | JSON string: representation, features (time-domain stats), computed_verdict, computed_indication, harmonic_profile, harmonic_elevation, evidence_tier, `evidence_is_gate: false`, channel, fr_hz + fr_source, test_id, window_idx, fs, image_sha256, split | |
|
|
| ## Splits |
| `train` / `test`, **test-wise** (leakage-safe): each of the 20 recorded tests is a distinct physical assembly and lives wholly on one side; the last test of each condition is held out. Windows never cross tests. |
|
|
| ## Why perception-only (measured, not assumed) |
| There is deliberately **no reasoning/CoT sibling**. A label-free shaft-order detector (`forge_tools.shaft_harmonics`) was run against a same-rig healthy baseline; its per-class firing rate and median 1× elevation, measured at build time, are: |
|
|
| | gold class | detector fires `rotor_anomaly` | median 1× elevation | 1× elevation range | |
| |---|---|---|---| |
| | normal | 0.088 | 1.6 | 0.3 – 3.9 | |
| | misalignment | 0.008 | 1.4 | 0.5 – 2.5 | |
| | unbalance | 1.000 | 28.2 | 18.2 – 38.9 | |
| | looseness | 0.944 | 13.4 | 1.6 – 28.1 | |
|
|
| Read that table honestly: **unbalance** and **looseness** are strongly detectable, but **misalignment is indistinguishable from healthy** — its entire 1× elevation range sits *inside* the healthy range, so no threshold can separate them. That is the physics, not a bug — a misalignment signature is primarily **axial**, and this bench has four *radial* accelerometers and no axial one. Unbalance and looseness are also not separable *from each other* here (both simply lift 1×). And an *absolute* harmonic gate is useless on this rig: its belt/pulley drivetrain means the **healthy** state already carries a strong 2×/3× ladder (its healthy 2× sits ~9× above its own 1×), so 'harmonic structure present ⇒ fault' fires on **97.6% of healthy windows** (122/125 in this build). |
|
|
| Because a compute-then-check chain-of-thought could not honestly reach 2 of the 4 classes, the labels ship as **implanted gold** (the rig operator's documented condition) and `reasoning` stays empty. The shaft-order evidence still travels on every record as **informational metadata** (`evidence_is_gate: false`) — nothing was dropped, relabelled or filtered by it, so you can audit the claim above yourself from the published rows. |
|
|
| ## Provenance & reproducibility |
| Generated **deterministically** by `forge_agent/examples/mendeley_rotor/convert.py` (`e6069b7005`) → `forge_model/MENDELEY_ROTOR/convert_mendeley_rotor.py` (`7708e1353d`); see `provenance.json`. |
|
|
| 25 evenly-strided 1 s windows per test (consecutive seconds are highly correlated; striding avoids near-duplicate rows), channel 0 (`V_coupling`), shaft rate estimated per test with a bounded+gated search that falls back to the documented nominal and records `fr_source`. Images carry no titles and no condition text in their filenames (answer-leak hygiene). |
|
|
| ## Caveats |
| - **Not a reasoning dataset.** Use it for representation diversity / visual grounding. |
| - **Misalignment is unlearnable-from-physics here** and may be hard for a model too; the evidence table above is the honest prior. |
| - **One bench, one speed regime** (~21.8 Hz rotor, belt-driven). Cross-rig generalization is untested. |
| - Radial channels only — no axial instrumentation. |
|
|
| ## Source & license |
| Source: **Mechanical faults in rotating machinery dataset** (normal, unbalance, misalignment, looseness) — L. Brito, G. A. Susto, J. N. Brito, M. Duarte, Mendeley Data, [doi:10.17632/zx8pfhdtnb.1](https://doi.org/10.17632/zx8pfhdtnb.1). **License: CC BY 4.0**; this derived dataset is redistributed under the same terms with attribution to the original authors. |
|
|
