Analysis Of Pedestrian Eye Movement Characteristics In Urban Underground Space Based On Visual Tracking Technology

The development and utilization of urban underground space is an important means to increase urban capacity,alleviate urban traffic,and improve urban environment.It is also an inevitable trend for future urban transportation development.Pedestrians are the main objects of travel in underground spaces,and the visual system is an important channel for pedestrians to obtain external information during their travels.In the relatively closed traffic environment of underground spaces,studying the eye movement characteristics of pedestrians traveling in underground spaces is extremely necessary for urban underground space traffic management.Firstly,based on two scenarios of urban underground pedestrian crossings and underground parking lots,investigate and analyze the characteristics of pedestrian crossing traffic and pedestrian traffic characteristics in underground spaces;Observe and analyze the environmental characteristics of these two scenarios,focusing on factors that may affect pedestrian travel,such as light,noise,etc.,in preparation for eye movement characteristics experiments.Secondly,aiming at the problem of eye movement characteristics experiment,we selected the underground parking lot of Nanjing Forestry University and the underground crossing of Longpan Road as the experimental sites to carry out field eye movement characteristics experiments respectively,and designed the experimental scheme in advance.With pedestrians as the experimental objects,under the premise that the subjects are completely natural,we use eye trackers to collect eye movement data of pedestrians in different urban underground spaces to ensure the accuracy of the data.Thirdly,for the analysis of pedestrian eye movement characteristics,according to the data content output by the eye tracker,select appropriate index parameters to evaluate the eye movement characteristics of pedestrians in the gaze area,Eye strain degree and other aspects,and summarize the visual behavior characteristics of pedestrians in these two scenarios.Fourthly,analyze the differences in eye movement characteristics between underground parking lots and underground street crossings from two aspects: gaze transfer characteristics and visual load level,and explore the differences in eye movement characteristics of pedestrians in different underground spaces in cities.Fifthly,based on eye movement indicator data,conduct a reasonable evaluation of pedestrian visual attention.Finally,based on the current problems and eye movement characteristics in different underground spaces in cities,improvement measures and suggestions are proposed.The results show that:(1)in terms of gaze area: in the two underground spaces,pedestrians tend to pay more attention to the upper and middle areas in the horizontal direction;Pedestrians tend to pay the most attention to the middle area in the vertical direction,while paying less attention to the traffic situation on both sides,indicating that pedestrians tend to focus more on the environment directly ahead and in the distance.(2)In terms of targeting: in underground parking lots,pedestrians pay particular attention to vehicle information,followed by signs and markings;In underground street crossings,pedestrians are more concerned about roads,signs,and other pedestrians.(3)In terms of visual load and degree of compression: Under two types of underground spaces,the visual load and level of compression of pedestrians from the entrance area to the exit area show a trend of first increasing and then decreasing,and reach a peak in the corridor area.However,compared to underground parking lots,the corridor area has a greater degree of apparent load and is more susceptible to compression,while the entrance area is relatively small.(4)In terms of Eye strain degree: in the two underground spaces,the pedestrian in the corridor area has the greatest degree of Eye strain,and the walking process of pedestrians in the corridor area is more tense than that in the entrance and exit areas.(5)In terms of lighting conditions,both types of underground spaces have the most obvious pupil contraction in the exit area.The difference in pupil diameter between the entrance and exit areas is significantly greater than that in the aisle area,with relatively large data fluctuations.(6)The principal component analysis method was used to obtain a visual attention evaluation formula.The evaluation results obtained by combining this formula with one-way ANOVA showed that pedestrian flow is a significant factor affecting pedestrian visual attention.The research results are not only conducive to a deeper understanding of the eye movement patterns and travel behavior needs of pedestrians in two types of underground spaces,but also helpful for traffic management departments to provide targeted guidance on the humanized development of urban underground spaces.