Physiological correlates of discomfort in automated driving

Comfort in automated driving is considered a key issue for broad acceptance of automated vehicles. The research project KomfoPilot at Chemnitz University of Technology aimed to investigate factors that influence comfort in automated driving as well as to identify physiological indicators of discomfort. In an empirical driving simulator study, 40 participants from 25 to 84 years old experienced three highly automated trips including six potentially uncomfortable situations in each trip. Participants reported perceived discomfort continuously by a handset control. The physiological parameters Heart Rate (HR) and Electrodermal Activity (EDA) were assessed using the smartband Microsoft Band 2; pupil diameter and eye blinks were measured by the SMI Eye Tracking Glasses 2. Results showed specific physiological reactions in situations that provoked moderate to high discomfort. Longer lasting and slowly evolving situations with lower reported discomfort did not show associated changes in physiological parameters. HR decreased consistently during uncomfortable situations, which could be related to the phenomenon preparation for action. Pupil diameter increased and eye blink rate decreased in uncomfortable situations that were visually monitored. EDA did not show specific effects, which, however could be attributed to measurement procedures of the smartband. The results serve as a basis for developing a real-time discomfort detection algorithm and will additionally be validated on-road. (C) 2019 Elsevier Ltd. All rights reserved.