| --- |
| dataset_info: |
| features: |
| - name: query |
| dtype: string |
| - name: image |
| dtype: image |
| - name: annot |
| dtype: string |
| - name: reasoning |
| dtype: 'null' |
| - name: cate |
| dtype: string |
| - name: task |
| dtype: string |
| - name: metadata |
| dtype: string |
| splits: |
| - name: train |
| num_bytes: 27980365.0 |
| num_examples: 409 |
| - name: test |
| num_bytes: 6820617.0 |
| num_examples: 100 |
| download_size: 34398301 |
| dataset_size: 34800982.0 |
| configs: |
| - config_name: default |
| data_files: |
| - split: train |
| path: data/train-* |
| - split: test |
| path: data/test-* |
| pretty_name: IMS/NASA-Bearing — Envelope Spectrum (signal→VLM, Category C) |
| tags: |
| - bearing-fault-diagnosis |
| - vibration |
| - signal-to-image |
| - ims |
| - nasa |
| - run-to-failure |
| - compute-then-check |
| license: cc-by-4.0 |
| task_categories: |
| - image-classification |
| --- |
| # IMS / NASA-Bearing — fault classification from the envelope spectrum (reasoning track) |
|
|
| Second signal dataset in the AI4Manufacturing FORGE corpus (Category **C**, task **T-C1**), from three **run-to-failure** experiments. Each record is the **envelope spectrum** of a 1 s vibration window with fault frequencies marked — the representation for faithful **compute-then-check** CoT. `reasoning` is empty; the **`IMS-annotated`** sibling fills it. |
|
|
| **Records:** 509 (splits {'train': 409, 'test': 100}); labels {'normal': 239, 'ball': 30, 'outer_race': 240}; evidence_tier {'confirmed': 509}. |
|
|
| ## Schema (7-field unified record) |
| | field | meaning | |
| |---|---| |
| | `query` | the classification instruction (representation-aware) | |
| | `image` | the rendered signal image (bytes embedded) | |
| | `annot` | gold fault class: normal / inner_race / outer_race / ball | |
| | `reasoning` | chain-of-thought (empty here; filled in the `-annotated` sibling) | |
| | `cate` / `task` | `C` / `T-C1` (signal fault classification) | |
| | `metadata` | JSON string: representation, set, timestamp, time_frac, channel, bearing, bearing_group, rpm, fs, fr_hz, features, fault_freqs, computed_verdict, computed_snr, evidence_tier, image_sha256, split | |
|
|
| ## Provenance & reproducibility |
| Generated **deterministically** by `forge_agent/examples/ims/convert.py` (`8f7c384bda`) → `forge_model/IMS/convert_ims.py` (`a88573f32f`); see `provenance.json`. |
|
|
| **Gold = the documented end-state defect** (readme / manufacturer teardown): Set 1 → bearing 3 inner-race + bearing 4 roller(ball); Set 2 → bearing 1 outer-race; Set 3 → bearing 3 outer-race. `normal` = the early files of each run; `fault` = the late files of the failed bearing (per-set window from the degradation onset). A computed `evidence_tier` (confirmed/weak/absent) flags detectability. |
|
|
| ## Caveats |
| - **Evidence-gated release — every image visibly supports its label.** IMS faults are WEAK run-to-failure signatures (the dataset's own reference paper, Qiu/Lee/Lin JSV 2006, studies *weak-signature detection*), so we curate by a computed `evidence_tier`: the **spectrum/reasoning** track keeps only `confirmed` records (the fault peak is actually present → faithful compute-then-check CoT); the **perception** tracks keep `confirmed`+`weak` and drop `absent`. |
| - **`inner_race` is EXCLUDED from this release.** IMS's Set-1 inner-race defect is a weak, multi-fault-mixed signature with too few detectable spectra to form a class (a handful of `confirmed` records). It is **retained in the raw form** (`evidence_tier` intact) for full transparency, but not published as a class. Published classes: **`normal` / `outer_race` / `ball`** — `outer_race` (Sets 2-3) is the clean, strong class; `ball` (Set-1 roller) is smaller and also weak. |
| - **Few distinct bearings** — each fault class comes from *one* run-to-failure bearing, so a strict bearing-wise split is impossible within a class; the split is file-stratified. Treat cross-bearing generalization claims with care. |
|
|
| ## Source & license |
| Source: **IMS / NASA-Bearing** — NSF I/UCR Center for Intelligent Maintenance Systems (imscenter.net) with Rexnord Corp.; three test-to-failure runs on Rexnord ZA-2115 bearings at 2000 rpm. Reference: H. Qiu, J. Lee, J. Lin, *J. Sound and Vibration* 289 (2006) 1066–1090. Distributed via the NASA Prognostics Data Repository. |
