EEG-TransMTL : A transformer-based multi-task learning network for thermal comfort evaluation of railway passenger from EEG

The evaluation of thermal comfort for railway passengers holds considerable importance, not only in reducing energy consumption but also in enhancing the passengers' experience. This paper presents a Transformer-based multi-task learning network (TransMTL) designed for railway passenger thermal comfort evaluation using EEG. We utilized manual features to extract temporal and frequency information, while a Transformer encoder distilled spatial information. The multi-task learning structure enhances model robustness by leveraging thermal comfort task correlations. We conducted experiments during winter and summer with high-speed railway passengers, establishing a comprehensive EEG dataset. The results demonstrated that our proposed EEG-TransMTL model outperformed classical machine learning and deep learning models in all four thermal comfort evaluation tasks, achieving accuracy rates of 65.00%, 66.70%, 80.38%, and 71.01%, respectively. We enhanced model interpretability by visualizing attention weights from the Transformer encoder, identifying key EEG channels. A simplified model utilizing only eight crucial channels also delivered notable performance. This research provides a practical and neuro-mechanism interpretable solution for thermal comfort evaluation.