城市快速路速度引导预测控制模型

Speed guidance predictive control model on urban expressway

在城市快速路控制系统中,将速度引导作为控制变量,建立了宏观动态交通流模型。以车辆总行程时间与速度引导为目标函数,计算了城市快速路入口区域流量和匝道入口区域流量,建立了快速路速度引导预测控制模型,对速度引导进行优化设计,利用MATLAB软件对下游交通流突变进行仿真分析。分析结果表明:通过速度引导控制,交通流平均速度由72.704 6km.h-1上升到74.167 6km.h-1,交通流平均密度由23.011 2veh.km-1下降到21.156 7veh.km-1,波动均小于8%;速度方差下降,且最大值仅为420(km.h-1)2;速度引导控制前后的速度方差与密度方差之比分别为3.57、1.91;在交通流突变时段内,速度引导控制前后的速度方差与密度方差之比分别为4.56、2.34。可见,速度引导控制模型有效。

In the control system of urban expressway, speed guidance was taken as control variable, and the macro dynamic traffic flow of urban experssway model was established. Total vehicle traveling time and speed guidance were taken as objective functions, and the entrance flows of urban expressway and ramp were calculated. The speed guidance predictive control model of urban expressway was established to optimize speed guidance, and the mutation of downstream traffic flow was simulated by using MATLAB. Simulation result shows that because of speed guidance control, the average speed of traffic flow increases from 72. 704 6 km~ h-1 to 74. 167 6 km ~ h-1, the average density of traffic flow decreases from 23. 011 2 veh ~ km-1 to 21. 156 7 veh ~ km-1 , and their fluctuations are less than 8%. The speed variance of traffic flow decreases, and the maximum value is only 420 （kin ~ h-1）2. The speed and density deviation ratios between before and after speed guidance control are 3.57 and 1.91 respectively. During traffic flow＇s mutation period, the speed and density deviation ratios between before and after speed guidance control are 4. 56 and 2. 34 respectively. So the control model is effective. 2 tabs, 12 figs, 17 refs.