A hybrid LLM and machine learning framework for early fire detection in subway tunnels
摘要
Fire detection is vital in subway tunnels where confined geometries and ventilation complicate safety monitoring. Existing approaches, including classical machine learning methods, typically detect fire from multivariate correlations but often lack the contextual reasoning required for disambiguation. This limitation becomes critical when HVAC-driven airflow disrupts thermal stratification and dilutes gas concentrations, creating ambiguous patterns that mimic fire signatures. Recent studies suggest that Large Language Models (LLMs) may help address this challenge by translating structured sensor summaries into concise semantic descriptions. To examine this role in fire detection, we propose HyFiD, a hybrid framework that employs an LLM as a semantic feature extractor to augment classical classifiers. By converting momentary multi-sensor readings (temperature, smoke, O