Analysis And Modeling Of Traffic Flow Operation Chearacteristics Of Undersea Tunnel Based On Bayonet Video Data And Real Vehicle Experiment

The undersea tunnel has promoted the social and economic development between the two sides of the sea.The undersea tunnel passes through the seabed,and the longitudinal section is a special ‘V’ type structure.The internal space is relatively closed,and the driving environment is poor,which is quite different from the characteristics of urban road traffic flow.With the increase of traffic flow in undersea tunnels,once a traffic accident occurs,it is difficult to rescue,which is easy to cause traffic congestion or even paralysis.It is of great research value and significance to improve the traffic management level and driving safety of undersea tunnels and prevent the frequent traffic congestion of undersea tunnels by analyzing the traffic flow operation characteristics of undersea tunnels and discovering their operation rules.This paper summarizes the research status of traffic safety and traffic flow in undersea tunnels,analyzes the factors affecting the operation of traffic flow in undersea tunnels from two aspects of environmental characteristics and traffic characteristics of undersea tunnels,and explores the influence of various factors on traffic flow in undersea tunnels.Firstly,the video data method is used to obtain the traffic flow data of the undersea tunnel.The Simi Motion software was used to extract the video data of the Jiaozhou Bay undersea tunnel,and the peak hour section flow under different horizontal and vertical alignments was obtained,and the flow characteristics of the undersea tunnel were analyzed.The speed and headway under different slopes are counted,and the influence of slope on speed and headway is analyzed.By extracting the velocity and flow value of the entrance and exit of the undersea tunnel,the boundary line regression equation of the velocity-flow relationship of the undersea tunnel is established.The traffic flow characteristics of undersea tunnel are analyzed from the macro level.The results show that the peak hour section flow is affected by the radius and slope of the horizontal curve.The larger the radius of the horizontal curve,the greater the peak hour section flow.In the downhill section,the greater the slope,the greater the peak hour section flow;the speed of the undersea tunnel is skewed normal distribution,which is obviously affected by the slope.The average speed of the downhill section is significantly higher than that of the uphill section.There is a significant negative linear correlation between high speed and flow in the traffic flow of undersea tunnel,while the linear correlation between low speed and flow is not obvious.The average headway of the vehicle in the downhill section of the undersea tunnel is larger than that in the uphill section.In the downhill section,the average headway increases with the increase of the slope,while in the uphill section,the average headway decreases with the increase of the slope.Secondly,the real vehicle experiment method which can better reflect the continuous traffic flow is used to obtain the traffic flow data of the undersea tunnel.A real vehicle experiment scheme was designed.The traffic environment parameters such as illumination and slope of undersea tunnel and the traffic flow characteristic parameters such as vehicle speed,headway and acceleration under car-following condition were collected through real vehicle experiments.The experimental data were preprocessed and the outliers were tested.The correlation between illumination,slope,horizontal curve radius and traffic flow characteristic parameters of undersea tunnel was tested by partial correlation analysis.According to the correlation analysis,the fitting model of vehicle speed,headway,longitudinal acceleration and lateral acceleration under the influence of illumination and horizontal and vertical alignment was established.The relationship between illumination,slope,horizontal curve radius and speed,headway and acceleration of undersea tunnel is quantitatively analyzed,and the variation law of traffic flow characteristic parameters of undersea tunnel is explored from the micro level.The results show that there is a significant negative correlation between speed,headway and illumination in the entrance and exit section of the undersea tunnel,while the longitudinal acceleration is significantly affected by the illumination and slope of the entrance and exit section.In the tunnel,the speed and headway are negatively correlated with the slope,and positively correlated with the radius of the horizontal curve.The speed and headway increase with the increase of the slope in the downhill section,and decrease with the increase of the slope in the uphill section.The lateral acceleration is negatively correlated with the radius of the horizontal curve,and the lateral acceleration decreases with the increase of the radius of the horizontal curve.Finally,the traffic flow model of undersea tunnel is established by using the method of cellular automata model modeling.The section of undersea tunnel is divided,and the optimal speed limit fuzzy control system of undersea tunnel considering illumination and horizontal and vertical alignment is established by using fuzzy control algorithm.The driving evolution rules of the cellular automata model of different sections of the undersea tunnel are established,the three-lane lane change rules in the model are established,and a cellular automata model of traffic flow suitable for the undersea tunnel is established.Taking Jiaozhou Bay undersea tunnel as an example,the simulation results show that the model can simulate the temporal and spatial evolution characteristics of traffic flow in undersea tunnel,which provides a reference for the management of traffic flow in undersea tunnel.