考虑环境效益的城市快速路匝道协调控制

针对城市机动车尾气污染严重的问题,提出一种考虑环境效益的城市快速路入口匝道协调控制策略.以城市快速路宏观交通流模型为基础,将宏观交通变量转化为微观变量,然后采用微观排放模型计算尾气排放量.在模型预测控制的框架下,综合交通效率和环境效益指标,建立非线性动态优化控制命题,并基于极小值原理进行求解.在多匝道快速路网的仿真结果表明,该策略在兼顾交通通行效率的同时能有效减少机动车尾气CO,HC排放,燃油消耗也显著减少,只有NOx因平均车速的提高略有增加.

Coordinated Ramp Metering of Urban Expressway Considering Environment Benefits

The problem of designing coordinated ramp metering strategies considering environment benefits is presented in this paper.The urban expressway network is modeled by a macroscopic traffic flow model.Then,the macroscopic traffic variables are transformed into microscopic variables,which make the emission amount calculated by a well developed microscopic emission model.The coordinated ramp metering problem is formulated as a model predictive control structure,in which the objective is a combination of traffic efficiency and environment benefit.Finally,a gradient-based numerical solving algorithm is introduced for a hypothetic expressway network.Simulation results show that,using the derived optimal ramp metering strategy,the traffic efficiency as well as the environment benefit can be improved and the emission of CO,HC and fuel consumption is greatly reduced.