Measuring Drivers’ Physiological Response to Different Vehicle Controllers in Highly Automated Driving (HAD): Opportunities for Establishing Real-Time Values of Driver Discomfort

Vishnu Radhakrishnan,Foroogh Hajiseyedjavadi,Richard Romano,Tyron Louw,Erwin R Boer,Chongfeng Wei,Michael G Lenné,Evangelos Paschalidis,Natasha Merat

doi:10.3390/info11080390

Vishnu Radhakrishnan, Foroogh Hajiseyedjavadi + Show 7 more

Open Access

https://doi.org/10.3390/info11080390

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Journal: Information	Publication Date: Aug 8, 2020
Citations: 11	License type: CC BY 4.0

Affiliation: University of Leeds, PureTemp (United States)

Abstract

This study investigated how driver discomfort was influenced by different types of automated vehicle (AV) controllers, compared to manual driving, and whether this response changed in different road environments, using heart-rate variability (HRV) and electrodermal activity (EDA). A total of 24 drivers were subjected to manual driving and four AV controllers: two modelled to depict “human-like” driving behaviour, one conventional lane-keeping assist controller, and a replay of their own manual drive. Each drive lasted for ~15 min and consisted of rural and urban environments, which differed in terms of average speed, road geometry and road-based furniture. Drivers showed higher skin conductance response (SCR) and lower HRV during manual driving, compared to the automated drives. There were no significant differences in discomfort between the AV controllers. SCRs and subjective discomfort ratings showed significantly higher discomfort in the faster rural environments, when compared to the urban environments. Our results suggest that SCR values are more sensitive than HRV-based measures to continuously evolving situations that induce discomfort. Further research may be warranted in investigating the value of this metric in assessing real-time driver discomfort levels, which may help improve acceptance of AV controllers.

Highlights

In the recent past, there has been an increasing interest in implementing vehicles with a range of advanced driver assistant systems (ADAS), fuelled by manufacturers’ desire to introduce higher levels of vehicle automation capability [1]
As discussed in the Introduction, previous research has shown that Root mean square of successive differences (RMSSD) values tend to decrease with an increase in discomfort, whereas mean heart rate (HR) and nSCR/min values tend to increase with an increase in discomfort [7,32]
Discomfort ratings were similar across all the drives establish whether drivers’ physiological state changes in line with the behaviour of different in the rural environment

Summary

Introduction

There has been an increasing interest in implementing vehicles with a range of advanced driver assistant systems (ADAS), fuelled by manufacturers’ desire to introduce higher levels of vehicle automation capability [1]. The comfort of the driver is considered to be a determining factor for the broader acceptance of the automated system [4]. This could have the additional benefit of reducing unnecessary driver initiated takeovers, which can otherwise jeopardise the safety of the vehicle and its occupants [5]. This study, conducted as part of the HumanDrive project, considered the effect of a number of road and vehicle-based factors on driver comfort, investigating whether physiological metrics can be used to provide an objective measure of comfort, to help inform the design process when investigating the acceptance of future automated vehicles

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