Speed Distribution Law And Control Method Of Hybrid Vehicle On Freeway

Speed is an important index to measure the running status of the vehicle, and on the highway the distribution of the vehicle speed affects the safety level, so it is very important to study the distribution characteristics of vehicle speed for the highway traffic safety. Based on the Project supported by the National Natural Science Foundation of China "Accident risk assessment and safety design parameter optimization of highway traffic flow under the influence of visibility (No.51308177)", the data acquisition of the car speed on the highway was carried out in order to analyze the characteristics of vehicle speed distribution. First of all, the factors which influence the vehicle speed distribution were studied by making a reasonable speed survey to measure the speed on the general sections, sub confluence of the highway. Environmental factors are essential in the study of the factors influencing the speed of the vehicle, therefore the data collection on the different weather, road surface and other external conditions is indispensable. Then the speed was measured by different vehicle type, after that paper studied the relationship between the speed difference and traffic safety of large cars and small cars; the improvement of the method was given to reduce the accident rate on the highway. The paper studied the reasons of influencing the distribution characteristics of the operating speed and the vehicle speed, analyzed the causes of the inter vehicle speed difference, and discussed how to improve the safety situation of the highway by means of traffic management control.Afterwards, the paper used Logistic regression analysis to explore the relationship between vehicle speed distribution characteristics and the influencing factors, then the speed of the vehicle is divided into low speed, constant speed, high speed three continuous range, by which a Logistic regression model was established between the variables and the influencing factors. The model analyzed the tendency of the vehicle speed range from the angle of occurrence probability. The results showed that the main determinants of the vehicle speed tend to be higher or lower were the lane location and weather factors. Then the paper used the MATLAB software and the collected data to establish equation of the speed difference, saturation, the proportion of the cart and the accident rate, moreover a three-dimensional map was supplemented. By setting the ratio of saturation and cart, the two-dimensional diagram of the accident rate and the velocity difference was obtained.Finally, according to the model, the paper proposed limiting-velocity and safety control measures of an example Beltway.