SensorCaps
LLM-generated IMU captions (35,960 pairs) from HHAR/MotionSense/Shoaib/UCI-HAR/PAMAP2 (+ in-the-wild phones); TimeNet bash-lab/sensorcaps
Released with LLaSA (Large Language and Sensor Assistant; Imran et al., UbiComp Companion 2025 / arXiv 2406.14498). Pipeline: take windows from public HAR sets → downsample IMU to 10 Hz, round to 6 decimals → prompt GPT-4o-mini with activity summary + raw IMU + handcrafted features (FFT, min/max/median/variance, …) → emit (1) ≤25-word motion caption and (2) longer temporal narration. Soft labels: captions are LLM-generated, not human narrations.
- Type
- Dataset
- DOI
- Not reported
- Licence
- Not reported
- Access
- Not reported
- Subjects
- Not reported
- Signals
- IMU
- PPG sites
- None
- Setting
- In the wild, Lab
- Wrist
- Yes
- Raw waveforms
- No
- Tasks
- Not reported
- Updated
- Nov 10, 2026
Original description
SensorCaps is an LLM-assisted softly-labelled IMU sensor data captioning dataset with feature summarizations and narrations of human activities.
Wearable systems can recognize activities from IMU data but often fail to explain their underlying causes or contextual significance. To address this limitation, we introduce two large-scale resources: SensorCap, comprising 35,960 IMU–caption pairs, and OpenSQA, with 199,701 question–answer pairs designed for causal and explanatory reasoning. OpenSQA includes a curated tuning split (Tune-OpenSQA) optimized for scientific accuracy, narrative clarity, and diagnostic insight. Leveraging these datasets, we develop LLaSA (Large Language and Sensor Assistant), a family of compact sensor-aware language models (7B and 13B) that generate interpretable, context-rich responses to open-ended questions grounded in raw IMU data. LLaSA outperforms commercial LLMs, including GPT-3.5 and GPT-4o-mini, on benchmark and real-world tasks, demonstrating the effectiveness of domain supervision and model alignment for sensor reasoning.
Verbatim fromHugging Face· Description from the Hugging Face card; licence as stated on the card

Key numbers
How it works
No model in the hub reports results on this dataset yet.
- Sampling
- SensorCaps release: IMU resampled/serialized at 10 Hz (≤100 timesteps, 6 decimal places); source rates vary (HHAR device-max; MotionSense/UCI-HAR/Shoaib ~50 Hz; PAMAP2 IMU 100 Hz)
- Reference labels
- activity
Papers using this dataset· 1
#111 of 158 most-used datasets by published papers and models · #50 of 70 IMU
Cite
No citation metadata yet.
Cite the ChatPPG record
Cite the dated snapshot 2026-10 for a fixed, reproducible version. Please also cite the original publications listed above.
APA
ChatPPG. (2026). SensorCaps: dataset record (Version 2026-10) [Data set]. ChatPPG Research Hub. https://chatppg.com/research/datasets/sensorcaps
BibTeX
@misc{chatppg_dataset_sensorcaps,
author = {{ChatPPG}},
title = {{SensorCaps: dataset record}},
year = {2026},
month = nov,
version = {2026-10},
howpublished = {\url{https://chatppg.com/research/datasets/sensorcaps}},
note = {ChatPPG Research Hub, Snapshot 2026-10, https://chatppg.com/research/snapshots/2026-10}
}CITATION.cff
cff-version: 1.2.0 message: "If you use this resource, please cite it as below." type: dataset title: "SensorCaps: dataset record" authors: - name: "ChatPPG" url: "https://chatppg.com/research/datasets/sensorcaps" repository-artifact: "https://chatppg.com/research/snapshots/2026-10" version: "2026-10" date-released: "2026-11-10"
History
Record updated
Papers
- LLaSA: A Sensor-Aware LLM for Natural Language Reasoning of Human Activity from IMU DataUses SensorCapsCompanion of the 2025 ACM International Jo · 2025
- Accelerometry-Based Machine Learning Estimation of Energy Expenditure and Physical Activity Intensity Classification in Daily TasksSame task: Activity recognitionSensors 26 · 2026
ActiNet: an open-source tool for activity intensity classification of wrist-worn accelerometry using self-supervised deep learningSame task: Activity recognitionScientific Reports · 2026
