Analysis Of Vehicle Braking Warning At Unsignalized Intersection Based On V2I

Since the 21st century,my country’s automobile industry has developed rapidly,especially the rapid development of intelligence and networking.While the number of cars is increasing year by year,the incidence of traffic accidents remains high,especially at unsignalized intersections,which is as high as 35%.Frequent traffic accidents have caused huge losses to people’s lives and properties.Therefore,reducing the incidence of traffic accidents at unsignalized intersections and reducing the severity of traffic accidents is of great significance to the improvement of the entire traffic safety environment.At present,more and more vehicles are equipped with advanced driving assistance systems.Through the vehicle’s own perception module and V2I technology,information sharing between vehicles and roads can be realized,and the decision-making and control modules can be used to optimally control the vehicle and improve the vehicle.safety and comfort.First of all,according to the characteristics of two types of unsignalized intersections in urban and rural highways in my country,this paper extracts the traffic characteristics of the two types,and uses Pre Scan software to construct three types of unsignalized intersections:cross-type,Y-type,and X-type.The results of this study are more in line with the actual situation of unsignalized intersections in my country.At the same time,a typical traffic accident at a non-signaled intersection is taken as an example to analyze the cause of the accident,and the PC-Crash software is used to reproduce and simulate the collision process of the accident to obtain the cause of the accident and the collision parameters.Secondly,this paper compares and analyzes four AEB models,and intends to select the TTC algorithm model for braking early warning.Because the traditional TTC model has certain defects,especially when the vehicle is at a high speed,the collision avoidance effect is not ideal,so this paper Under the analysis of the influencing factors of the braking distance,the reaction time that meets 90%of drivers is selected,and the relative acceleration is introduced as the risk judgment condition in the traditional TTC model,so that the calculation results of the TTC are more in line with the actual needs.Thirdly,this paper divides the vehicle driving safety state into four levels for early warning and graded braking according to the three time thresholds ofTTC_w、TTC_p、TTC_a under medium and low vehicle speed conditions.Through 5 sets of simulation experiments,the speed critical point for the vehicle to effectively avoid collision under the medium and low speed time threshold is determined,and then 5 sets of control experiments of the limit vehicle speed are designed to obtain the most suitable TTC high speed time threshold.Then,an optimized TTC model that can automatically switch the time threshold according to the speed of the vehicle is constructed using Simulink software.Finally,according to the distribution of three types of unsignalized intersections,this paper sets up TIS sensors,and uses UDP communication in Simulink software as the communication connection between roadside sensors and vehicles.Then,the co-simulation of Pre Scan software and Simulink software is used to obtain the change curves of the speed and braking pressure of the main vehicle.The results show that the optimized TTC model can effectively avoid the occurrence of collision accidents under various unsignalized intersection conditions.