冰雪天气下高速公路可变限速控制研究

Variable Speed Limit Control of Expressway Under Snow and Ice Weather

摘要:

为保障冰雪天气条件下高速公路的行车安全与通行效率,在建立安全限速模型与交通流预测模型的基础上,提出一种基于粒子群优化算法的可变限速控制策略。首先,通过分析冰雪天气下车辆制动性能和交通流演化规律,提出适用于冰雪天气条件的高速公路安全限速模型以及交通流预测模型；其次,设计了兼顾通行效率与行车安全的优化目标函数,并考虑实际行车需求给出相关约束条件；最后,基于交通流预测模型并结合粒子群优化算法对可变限速值进行求解,并通过搭建的元胞自动机交通流模型将所提出的可变限速策略的控制效果与固定限速方案和分段安全限速方案进行对比仿真实验。仿真结果表明,相比于固定限速方案,可变限速控制减少了总行程时间、总行程延误时间和车辆冲突时间；相比于分段安全限速方案,可变限速控制有效减小了管控路段内的车辆行驶速度标准差,总行程延误时间和车辆冲突暴露时间也有所降低,验证了所提出可变限速控制策略的有效性。

Abstract:

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.