scholarly journals Experimental Analysis of Driver Visual Characteristics in Urban Tunnels

2021 ◽  
Vol 11 (9) ◽  
pp. 4274
Author(s):  
Song Fang ◽  
Jianxiao Ma
Keyword(s):  
Traffic Safety ◽  
Clustering Algorithm ◽  
Pupil Diameter ◽  
Data Fitting ◽  
Eye Tracker ◽  
Tunnel Length ◽  
Point Distribution ◽  
Change Rate ◽  
Visual Characteristics ◽  
Diameter Change

Through an urban tunnel-driving experiment, this paper studies the changing trend of drivers’ visual characteristics in tunnels. A Tobii Pro Glasses 2 wearable eye tracker was used to measure pupil diameter, scanning time, and fixation point distribution of the driver during driving. A two-step clustering algorithm and the data-fitting method were used to analyze the experimental data. The results show that the univariate clustering analysis of the pupil diameter change rate of drivers has poor discrimination because the pupil diameter change rate of drivers in the process of “dark adaptation” is larger, while the pupil diameter change rate of drivers in the process of “bright adaptation” is relatively smooth. The univariate and bivariate clustering results of drivers’ pupil diameters were all placed into three categories, with reasonable distribution and suitable differentiation. The clustering results accurately corresponded to different locations of the tunnel. The clustering method proposed in this paper can identify similar behaviors of drivers at different locations in the transition section at the tunnel entrance, the inner section, and the outer area of the tunnel. Through data-fitting of drivers’ visual characteristic parameters in different tunnels, it was found that a short tunnel, with a length of less than 1 km, has little influence on visual characteristics when the maximum pupil diameter is small, and the percentage of saccades is relatively low. An urban tunnel with a length between 1 and 2 km has a significant influence on visual characteristics. In this range, with the increase in tunnel length, the maximum pupil diameter increases significantly, and the percentage of saccades increases rapidly. When the tunnel length exceeds 2 km, the maximum pupil diameter does not continue to increase. The longer the urban tunnel, the more discrete the distribution of drivers’ gaze points. The research results should provide a scientific basis for the design of urban tunnel traffic safety facilities and traffic organization.

scholarly journals Workload assessment for mental arithmetic tasks using the task-evoked pupillary response

2015 ◽  
Author(s):  
Gerhard Marquart ◽  
Joost de Winter
Keyword(s):  
Mental Arithmetic ◽  
Pupil Diameter ◽  
Mental Workload ◽  
Self Report ◽  
Blink Rate ◽  
Eye Tracker ◽  
Practical Applications ◽  
The Mean ◽  
Nasa Tlx ◽  
Diameter Change

Pupillometry is a promising method for assessing mental workload and could be helpful in the optimization of systems that involve human-computer interaction. The present study focuses on replicating the studies by Ahern (1978) and Klingner (2010), which found that for three levels of difficulty of mental multiplications, the more difficult multiplications yielded larger dilations of the pupil. Using a remote eye tracker, our research expands upon these two previous studies by statistically testing for each 1.5 s interval of the calculation period (1) the mean absolute pupil diameter (MPD), (2) the mean pupil diameter change (MPDC) with respect to the pupil diameter during the pre-stimulus accommodation period, and (3) the mean pupil diameter change rate (MPDCR). An additional novelty of our research is that we compared the pupil diameter measure with a self-report measure of workload, the NASA Task Load Index (NASA-TLX), and with the mean blink rate (MBR). The results showed that the findings of Ahern and Klingner were replicated, and that the MPD and MPDC discriminated just as well between the lowest and highest difficulty levels as did the NASA-TLX. The MBR, on the other hand, did not interpretably differentiate between the difficulty levels. Moderate to strong correlations were found between the MPDC and the proportion of incorrect responses, indicating that the MPDC was higher for participants with a poorer performance. For practical applications, validity could be improved by combining pupillometry with other physiological techniques.

scholarly journals Workload assessment for mental arithmetic tasks using the task-evoked pupillary response

2015 ◽  
Author(s):  
Gerhard Marquart ◽  
Joost de Winter
Keyword(s):  
Mental Arithmetic ◽  
Pupil Diameter ◽  
Mental Workload ◽  
Self Report ◽  
Blink Rate ◽  
Eye Tracker ◽  
Practical Applications ◽  
The Mean ◽  
Nasa Tlx ◽  
Diameter Change

Pupillometry is a promising method for assessing mental workload and could be helpful in the optimization of systems that involve human-computer interaction. The present study focuses on replicating the studies by Ahern (1978) and Klingner (2010), which found that for three levels of difficulty of mental multiplications, the more difficult multiplications yielded larger dilations of the pupil. Using a remote eye tracker, our research expands upon these two previous studies by statistically testing for each 1.5 s interval of the calculation period (1) the mean absolute pupil diameter (MPD), (2) the mean pupil diameter change (MPDC) with respect to the pupil diameter during the pre-stimulus accommodation period, and (3) the mean pupil diameter change rate (MPDCR). An additional novelty of our research is that we compared the pupil diameter measure with a self-report measure of workload, the NASA Task Load Index (NASA-TLX), and with the mean blink rate (MBR). The results showed that the findings of Ahern and Klingner were replicated, and that the MPD and MPDC discriminated just as well between the lowest and highest difficulty levels as did the NASA-TLX. The MBR, on the other hand, did not interpretably differentiate between the difficulty levels. Moderate to strong correlations were found between the MPDC and the proportion of incorrect responses, indicating that the MPDC was higher for participants with a poorer performance. For practical applications, validity could be improved by combining pupillometry with other physiological techniques.

scholarly journals Workload assessment for mental arithmetic tasks using the task-evoked pupillary response

2015 ◽  
Author(s):  
Gerhard Marquart ◽  
Joost de Winter
Keyword(s):  
Mental Arithmetic ◽  
Pupil Diameter ◽  
Mental Workload ◽  
Pupillary Response ◽  
Self Report ◽  
Blink Rate ◽  
Eye Tracker ◽  
Strong Correlations ◽  
Practical Applications ◽  
Diameter Change

Pupillometry is a promising method for assessing mental workload and could be helpful in the optimization of systems that involve human-computer interaction. The present study focuses on replicating the pupil diameter study by Ahern (1978) for mental multiplications of varying difficulty, using an automatic remote eye tracker. Our results showed that the findings of Ahern were replicated and that the mean pupil diameter and mean pupil diameter change (MPDC) discriminated just as well between the three difficulty levels as did a self-report questionnaire of mental workload (NASA-TLX). A higher mean blink rate was observed during the multiplication period for the highest level of difficulty in comparison with the other two levels. Moderate to strong correlations were found between the MPDC and the proportion of incorrect responses, indicating that the MPDC was higher for participants with a lower performance. For practical applications, validity could be improved by combining pupillometry with other physiological techniques.

Detecting Deception: Effect of Auditory and Visual Stimuli on Pupil Dilation

2019 ◽  
Vol 47 (3) ◽  
pp. 1-10
Author(s):  
Kiho Kim ◽  
Yeonsil Lee ◽  
Hui-Teak Kim ◽  
Jang-Han Lee
Keyword(s):  
Pupil Diameter ◽  
Physiological Responses ◽  
Visual Stimuli ◽  
Lie Detection ◽  
Emotional Arousal ◽  
Pupil Dilation ◽  
Question Type ◽  
Sensory Stimulus ◽  
Eye Tracker ◽  
Control Question

We investigated the effects of auditory and visual stimuli on pupil dilation induced by emotional arousal during deception. The 33 participants were free to select to be in either a guilty or a not-guilty group. The guilty group performed a theft crime mission, and the not-guilty group performed a legal mission. To detect deception, we measured their pupil diameter with an eye tracker, and they completed the Control Question Test that is typically employed in polygraph tests, and which is based on a comparison of physiological responses to crime-relevant questions and comparison questions. This test was presented via one of three stimuli: auditory, visual, or dual sensory (auditory and visual simultaneously). The findings revealed that the diameter of the pupils of the guilty group increased differently according to the question type when both auditory and visual stimuli were presented simultaneously. Results suggest that pupil dilation could be the deception discriminant, and the use of more than one sensory stimulus may support lie detection in forensic investigations.

scholarly journals Impact of Urban Undersea Tunnel Longitudinal Slope on the Visual Characteristics of Drivers

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shoushuo Wang ◽  
Zhigang Du ◽  
Fangtong Jiao ◽  
Libo Yang ◽  
Yudan Ni
Keyword(s):  
Repeated Measures ◽  
Three Dimensional ◽  
Fixation Time ◽  
Eye Tracker ◽  
Three Dimensional Model ◽  
Longitudinal Slope ◽  
Visual Characteristics ◽  
The Difference ◽  
Vehicle Test ◽  
The Impact

This study aims to investigate the impact of the urban undersea tunnel longitudinal slope on the visual characteristics of drivers. 20 drivers were enrolled to conduct the real vehicle test of the urban undersea tunnel. First, the data of average fixation time and visual lobe were collected by an eye tracker. The differential significance was tested using the one-way repeated measures analysis of variance (ANOVA). Then, the difference between the up-and-down slope (direction) factor and the longitudinal slope (percent) factor on the two indexes were analyzed using the two-way repeated measures ANOVA. Second, by constructing a Lorentz model, the impact of the longitudinal slope on the average fixation time and the visual lobe were analyzed. Besides, a three-dimensional model of the longitudinal slope, average fixation time, and visual lobe was quantified. The results showed that the average fixation time and visual lobe under different longitudinal slopes markedly differed when driving on the uphill and downhill sections. The average fixation time and visual lobe under two factors were markedly different. Moreover, with an increase in the longitudinal slope, the average fixation time exhibited a trend of increasing first then decreasing; the visual lobe exhibited a trend of decreasing first and then increasing. The average fixation time reached the minimum and maximum value when the slope was 2.15% and 4.0%, whereas the visual lobe reached the maximum and minimum value when the slope was 2.88% and 4.0%. Overall, the longitudinal slope exerted a great impact on the visual load of the driver.

scholarly journals A framework to estimate cognitive load using physiological data

2020 ◽  
Author(s):  
Muneeb Imtiaz Ahmad ◽  
Ingo Keller ◽  
David A. Robb ◽  
Katrin S. Lohan
Keyword(s):  
Cognitive Load ◽  
Human Error ◽  
Human Performance ◽  
Predictive Accuracy ◽  
Pupil Diameter ◽  
High Accuracy ◽  
Physiological Data ◽  
Workload Management ◽  
Different Levels ◽  
Diameter Change

Abstract Cognitive load has been widely studied to help understand human performance. It is desirable to monitor user cognitive load in applications such as automation, robotics, and aerospace to achieve operational safety and to improve user experience. This can allow efficient workload management and can help to avoid or to reduce human error. However, tracking cognitive load in real time with high accuracy remains a challenge. Hence, we propose a framework to detect cognitive load by non-intrusively measuring physiological data from the eyes and heart. We exemplify and evaluate the framework where participants engage in a task that induces different levels of cognitive load. The framework uses a set of classifiers to accurately predict low, medium and high levels of cognitive load. The classifiers achieve high predictive accuracy. In particular, Random Forest and Naive Bayes performed best with accuracies of 91.66% and 85.83% respectively. Furthermore, we found that, while mean pupil diameter change for both right and left eye were the most prominent features, blinking rate also made a moderately important contribution to this highly accurate prediction of low, medium and high cognitive load. The existing results on accuracy considerably outperform prior approaches and demonstrate the applicability of our framework to detect cognitive load.

scholarly journals Physiological indices and driving performance of drivers at tunnel entrances and exits: A simulated driving study

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243931
Author(s):  
Jinliang Xu ◽  
Xiaodong Zhang ◽  
Huan Liu ◽  
Kaige Yang ◽  
Fangchen Ma ◽  
...  
Keyword(s):  
Heart Rate ◽  
Growth Rate ◽  
Pupil Diameter ◽  
Driving Performance ◽  
Simulation Software ◽  
Motion Platform ◽  
Tunnel Length ◽  
Simulated Driving ◽  
Physiological Indices ◽  
Tunnel Entrance

The entrance and exit sections of a tunnel are the accident black-spots in an expressway. For a safe operation of road tunnels, it is necessary to understand a driver’s physiological indices and driving performance when driving through tunnels. In this study, the UC-Win/Road simulation software was used to build 12 tunnel models of different lengths. A simulated driving experiment was carried out in a 6-DoF motion platform. The lateral position of vehicles characterizing the driving performance was measured using the motion platform. Electrocardiogram and eye movement data of 25 recruited drivers were collected simultaneously through the experiment. The spatial changes in a driver’s heart rate (HR) growth rate, RMSSD, pupil diameter growth rate and vehicle lateral deviation within 300 m before and after the tunnel entrance and exit were analyzed to determine the variation rules in the different tunnels. The study identified the length range in the tunnel entrance and exit sections that influences the drivers. A quantitative analysis was further carried out to analyze the relationship between the physiological indices and the driving performance indicator. The results showed that a driver’s heart rate fluctuates significantly 250 m before the tunnel entrance and 50 m before the exit. In this region, the pupil diameter increases gradually, and drivers tend to shift the vehicle to the left. At the tunnel exit, the HR and RMSSD are affected significantly by the tunnel length, and the variation is higher in longer tunnels. In comparison, the tunnel length has no significant effect on the physiological indicators and driving performance of the drivers at the entrance and exit.

Driver’s Psychophysical Performance at Urban Tunnel

2014 ◽  
Vol 641-642 ◽  
pp. 871-880
Author(s):  
Qian Xu ◽  
Fei Shao ◽  
Tang Yi Guo ◽  
Lu Lu Luo
Keyword(s):  
Heart Rate ◽  
Eye Movement ◽  
Pupil Diameter ◽  
Eye Tracker ◽  
Recording Instrument ◽  
Visual Scanning ◽  
Middle Aged ◽  
Age And Gender ◽  
And Gender ◽  
Pupillary Change

The objective of this work is to investigate how driving performance is varied in psychophysical phenomenon in urban tunnel. Twelve drivers participated in the real road experiments study, and they were classified into three groups according to age and gender. In experiments, by using the physiology recording instrument and Tobii Studio eye tracker system, the heart rate (HR) and eye movement, the pupillary change of the drivers at the entrance and exit of urban tunnel were separately investigated. Experimental results indicate that drivers’ performance while driving through an entrance and an exit are highly variable at speed, at HR increasing rate, and pupil diameter increasing rate. Middle-aged females and older-aged males are more sensitive to tunnel environment than middle-aged males. There is non-significant effect of tunnel zone on the visual scanning for all the drivers in this study.

Research of Highway Alignment Design Safety Evaluation Using Curvature Change Rate

2012 ◽  
Vol 238 ◽  
pp. 493-496
Author(s):  
Sheng Neng Hu
Keyword(s):  
Traffic Safety ◽  
Road Traffic ◽  
Design Method ◽  
Selection Index ◽  
Safety Evaluation ◽  
Highway Design ◽  
Change Rate ◽  
Evaluation Standard ◽  
Road Traffic Safety ◽  
Highway Alignment

Aiming at the disadvantages of traditional design method of highway alignment and existent problems including subjectivity, reliability index, comprehensive, applicability etcetera in highway alignment evaluation with running speed. On the basis of the “safety first” idea for highway design, the concept of change rate of curvature has been proposed. Curvature change rate is the clear factor impacting on road traffic safety. Road quality evaluation standard is established based on the curvature change rate and its application method in highway alignment design method. The method not only effectively evaluates highway alignment quality, but also may be used as the basis for the selection index of highway geometric design.

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