Effects of saccadic and scent stimulations on driver attentiveness in automated driving systems

Abstract

Level 3 automated driving requires a driver to operate a vehicle in response to a takeover request according to the Society of Automotive Engineers; therefore, the driver should maintain a state of wakefulness. The study aimed to evaluate and verify whether the presented stimuli, i.e., saccade-inducing stimuli (SaS) as visual stimuli, scent stimuli (ScS) as olfactory stimuli, and a combination of saccade-inducing and scent stimuli (CoS), can maintain the wakeful state of a driver. A driving simulator (DS) that can reproduce the actual movement of a motor vehicle using a turn table and six-axis motion device is used to simulate driving under four different conditions: no stimulation, SaS, ScS, and CoS. The percentage of eye closure (PERCLOS) and the electroencephalogram (EEG) analysis were used for the quantitative evaluation, while the participants were subjected to subjective evaluation. The results showed that the average increase in arousal time for each condition was 30.2, 53.7, and 82.3% for the SaS, ScS, and CoS cases, respectively. The average reduction rate in the EEG readings was 39.9, 41.0, and 71.4% for the SaS, ScS, and CoS cases, respectively. All participants indicated that the CoS had the highest effect of arousal as a driver stimulation tool.