Grammar of the Wave: Towards Explainable Multivariate Time Series Event Detection via Neuro-Symbolic VLM Agents

Sky Chenwei Wan, Yifei Wang, Tianjun Hou, Xiqing Chang, Aymeric Jan


Abstract
Time Series Event Detection (TSED) aims to localize semantically meaningful events in time series data, with critical applications in high-stakes domains. Unlike statistical anomalies, events are often defined by natural-language descriptions with internal temporal-logic structures across multiple physical channels. However, in real-world settings, dense event annotations are expensive to obtain, making purely supervised learning difficult. We introduce Language-guided TSED, a setting where a model is given textual event descriptions and must ground them to intervals in multivariate signals with little or no labeled data. To address this problem, we propose Event Logic Tree (ELT), a knowledge representation framework that converts linguistic descriptions into structured temporal logic over signal primitives. Building on ELT, we present SELA, a neuro-symbolic VLM agent framework that iteratively grounds primitives from signal visualizations and composes them under ELT constraints, producing both event intervals and faithful tree-structured explanations. We further release a real-world benchmark across energy and climate domains with expert knowledge and annotations. Experiments show that SELA improves over supervised fine-tuning and existing zero/few-shot time series reasoning baselines.
Anthology ID:
2026.emnlp-main.290
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
6638–6656
Language:
URL:
https://aclanthology.org/2026.emnlp-main.290/
DOI:
Bibkey:
Cite (ACL):
Sky Chenwei Wan, Yifei Wang, Tianjun Hou, Xiqing Chang, and Aymeric Jan. 2026. Grammar of the Wave: Towards Explainable Multivariate Time Series Event Detection via Neuro-Symbolic VLM Agents. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 6638–6656, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Grammar of the Wave: Towards Explainable Multivariate Time Series Event Detection via Neuro-Symbolic VLM Agents (Wan et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.290.pdf