Investigation of changes in Driver's biosignals and thermal comfort according to the heating method in winter

In this study, thermal comfort was studied during actual driving of vehicles in winter with measurement of skin temperature, heart rate variability (HRV), and electroencephalogram (EEG), and the conducting of subjective questionnaires to examine the thermal comfort of the driver. HVAC heating, seat heating mode, and HVAC with seat heating mode were used to investigate changes in biosignals and subjective evaluations with time. As a result, after 30 min of pulse wave measurement, LF/HF showed an increase of 9.2% and 8.4% in heating seat and HVAC with heating seat, respectively, compared to HVAC heating, confirming that concentration was improved. Besides, the concentration of attention showed an increase of 119% and 2.19% in the heating seat and HVAC with heating seat, respectively. In the heating seat mode, because the HVAC system is not operated, the improvement of the car's interior temperature is delayed while driving, which greatly affects TSV. However, in the case of TCV or CLV, it was the highest after 30 min of driving, and concentration and comfort during driving were the highest. In addition, the driver's physiological changes in winter occurred sooner than the environmental changes, and the driver's psychological response was quicker than their physiological responses.