Boundary Analysis Of Intersection Dilemma Zone And Active Safety Assistant Decisionmaking System Based On Vehicleroad Cooperation

In order to solve the problem of traffic safety at intersections from the perspective of active safety,this paper analyzes the driving characteristics of vehicles at intersections and the dynamic boundary of the dilemma zone,constructs the active safety model of dilemma zone,and designs an active safety assistant decision-making system based on vehicle-road cooperation.This paper provides a theoretical and methodological basis for solving the safety problems in the dilemma area of intersection and reducing the accident risk of intersection.Firstly,the video acquisition scheme of vehicle information in the dilemma zone is designed to obtain the relevant parameter information,and then combined with the signal log to form the vehicle space-time trajectory.Through the analysis of vehicle space-time trajectory,the vehicles which are easy to fall into the dilemma during the signal transition period are divided into LP vehicles and FS vehicles.The distance,speed and acceleration between these two types of vehicles when the yellow light is on are described and statistically analyzed,and the best fitting distribution of each parameter is given.The relationship between acceleration,deceleration,reaction time and related factors was constructed by curve regression analysis,and the corresponding model was constructed.The GHM model is improved according to the acceleration,deceleration and reaction time models,and the dynamic boundary of the intersection dilemma zone is analyzed.Secondly,based on the dynamic distribution characteristics of the dilemma zone boundary,the active security model of the dilemma zone is established.The boundary of the dilemma zone corresponding to different yellow light time is studied,and the dynamic control model of yellow light time is proposed based on fuzzy control theory.According to the dynamic characteristics of the dilemma zone boundary,the fixed-point boundary model of the intersection is established.The traffic state of the vehicle is determined by analyzing the distance between the rear edge of the dilemma zone fixed-point boundary and the front edge of the dilemma zone fixed-point boundary.Then,based on the study of the dilemma zone active safety model,the design idea,system objectives and basic functions of the system are clarified,and the intersection active safety assistant decision-making system is designed.The system is divided into three modules: information collection,decision control and function execution,and each module is designed in detail.Combining the dynamic control model of yellow light time based on fuzzy control and the fixed-point boundary model of the intersection dilemma zone,four strategies are proposed: pass,decelerate-stop,decelerate-intensify braking and decelerate-dynamic yellow light time.Meanwhile,the algorithm flow of system control decision is designed.Finally,after the field data collection of Qingdao experimental road section,the driving simulation scene is built by using Unity 3D.Using C # language to develop Unity3 D,the traditional road simulation environment and the active safety assistant decisionmaking system simulation environment are established.After the simulation driving experiments in two driving environments,the experimental data are analyzed to verify the effectiveness of the system.