基于动态交通需求估计的高速公路优化控制模型研究

依据动态交通需求估计信息,基于分层递阶的思想,建立了一个高速公路优化控制模型. 模型分为4个主要模块:交通需求预测模块对长时期内总的交通需求进行预测,提前确定将来排队长度的上界;全局最优控制模块预测未来的交通状态,为路网中的各个匝道建立协调约束;交通需求估计模块对真实交通流进行估计;局部反馈控制模块根据对真实交通条件的估计信息及全局最优控制层的寻优结果决定匝道调节率. 仿真结果表明,控制系统具有良好的动态性能,协调了各个匝道之间的利益,实现了高速路网整体性能的优化.

Study on Freeway Optimal Control Based on Evaluation of Dynamic Travel Demand

According to the information of the dynamic travel demand evaluation, freeway optimal control model is proposed based on the hierarchy theory. Four control modules are introduced including the travel demand forecasting module which predicts the total travel demands for a long time and determines the upper bound of the queue length; the global optimal control module which predicts the traffic state and identifies the constraints for the link (ramp) of network; the travel demand evaluation module which estimates the real-time traffic conditions; and the local feedback control module which calculates the ramp control rate according to the evaluating information of the real-time traffic conditions and the optimal results from the previous module. The simulation results show that the control system is of good dynamic performance. It coordinates the benefits and optimizes the whole performance of the freeway network.