Study on the psychological stress of occupants experienced by vehicle seat vibration in idle state via center of gravity sway measurement

This study aimed to quantitatively evaluate the factors that influence variations in psychological stress caused by seat vibrations. We employed the center of gravity sway measurements, a metric extensively studied in the realm of motion sickness. Our approach encompassed experiments and analyses to measure whole-body vibrations, scrutinize physiological responses, and assess the center of gravity sway. Our findings highlighted that the seat's vibration characteristics and their transmission to the occupant varied according to the occupant's center of gravity sway traits. We formulated a hypothesis to elucidate the correlation between the psychological stress induced by seat vibration and the nuances of the center of gravity sway. This theory was substantiated through correlation analysis. Involving 20 subjects, correlation analysis results showed a correlation between the peak strength of the PSD for the center of gravity sway's time variation around 2 Hz, the transmitted vibration, and the psychological stress deduced from electroencephalography (EEG) readings.