国产欧美精品一区二区,中文字幕专区在线亚洲,国产精品美女网站在线观看,艾秋果冻传媒2021精品,在线免费一区二区,久久久久久青草大香综合精品,日韩美aaa特级毛片,欧美成人精品午夜免费影视

In order to availably guarantee the driving safety and efficiency of expressway under snow and ice weather, a variable speed limit control strategy based on particle swarm optimization algorithm was proposed on the basis of the safety speed limit model and traffic flow prediction model. Firstly, by analyzing the vehicle braking performance and traffic flow evolution law under snow and ice weather, the highway safety speed limit model and traffic flow prediction model suitable for snow and ice weather were proposed. Secondly, the optimization objective function of traffic efficiency and traffic safety is designed, and the constraint conditions are given considering the actual traffic demand. Finally, based on the traffic flow prediction model and particle swarm optimization algorithm, the variable speed limit value is solved, and the cellular automata traffic flow model is used to compare the control effect of the proposed variable speed limit strategy with the fixed speed limit strategy and the segmented safety speed limit strategy. The simulation results show that compared with the fixed speed limiting strategy, the variable speed limiting control method can reduce the total time spend, total time delay and exposed time to collision. Compared with the segmented safety speed limiting strategy, the variable speed limiting control method can effectively reduce the standard deviation of vehicle speed in the controlled section, and the total time delay and exposed time to collision are also reduced, which validates the effectiveness of the proposed variable speed limiting control strategy.