Study On Protection Method For Dilemma Zone Based On CVIS

In order to explore how the driving behavior,impact the dilemma zone distribution,the first-to-stop and the last-to-go vehicles,which most easily fall into the dilemma zone,had been taken as the research object.Through video observation experiment,the trajectory of the object vehicles,as well as the parameters of driving behavior(vehicle speed,distance to the stop line,acceleration,deceleration?reaction time),had been obtained.And descriptive statistical analysis and sample distribution fitting analysis were conducted,to get the distribution model of the driving behavior parameters.The dynamic dilemma zone which contains the driving behavior factors is attempted to model.First of all,a series of correlation hypotheses were made in which the vehicle speed,the distance to the intersection,and the time during which vehicle reached the stop line,were assumed to affect the driving behavior parameters.Then,the data of driver's behavior parameters were taken to verify the hypotheses,which indicated that the vehicle speed is the only factor that had a significant impact on driving behavior parameters in the proposed hypotheses.Based on the conclusion that speed had a significant impact on driving behavior parameters,the mathematical model of the relation between vehicle speed and reaction time,speed reduction,acceleration was established respectively,as followed the error verification and analysis of the model were carried out.Eventually,based on the formation mechanism of the dilemma zone as well as the driver's driving behavior parameter model,a dynamic dilemma zone model which contains driver behavior characteristics was built.In this dissertation,a protection and control algorithm for the individual vehicle trapped in the dilemma zone was proposed,in which including the algorithm of vehicle trajectory estimation,the guidance algorithm of dilemma zone avoidance,the dynamic extended green time protection algorithm for vehicles trapped in the dilemma area.Finally,according to the experimental data and the calibration to the driving behavior parameters,signal timing,vehicle input had been conducted in VISSIM.The traffic states during peak and middle peak periods in the real world were simulated through VISSIM.Simultaneously,the CVIS simulation which contains the dilemma zone protection and control algorithm is implemented by programming with PYTHON.By comparing the number of vehicles in the intersection while the red light was on in the middle peak period and peak period,conclusion that the proposed protect method based on the CVIS and dynamic dilemma zone model,can significantly reduce the probability of the vehicle fallen into the dilemma zone was made.And the effectiveness of the protect method in middle peak period is higher than the peak period.