考虑安全间距的合流区可变限速协调控制方法

Coordinated control method of variable speed limit in on-ramp area considering safety distance

针对匝道合流冲突的问题,分析了合流区车辆换道特性及运动轨迹,提出了满足车辆合流需求的车辆安全间距计算模型。首先,将其纳入可变限速的控制框架中,运用模型预测控制方法,建立了网联环境下合流区可变限速协调控制方法和模型。然后,利用元胞自动机搭建仿真环境,实现了网联车在上游控制区的速度协调控制。最后,将匝道与主道车辆到达率按照低、中、高进行27个场景的设置,选取交通量、速度、密度、行程时间作为评价指标,通过仿真分析了控制策略下的合流区交通状况。仿真结果表明:匝道车辆到达率会影响控制策略的实施效果,低密度时,效果不显著;中密度时,控制策略优势得以体现;高密度时,策略失效。

To improve the problem of traffic congestion in merging area,the paper describes the lane changing characteristics and trajectories of vehicles in on-ramp area,the calculation model of minimum safe spacing for vehicles meeting the demand of vehicle merging is proposed.First,the calculation model is incorporated into the control framework of variable speed limit.The coordinated control method and model of variable speed limit in on-ramp area under the intelligent network environment are constructed by applying model predictive control method.Then,the simulation environment is built by using cellular automata to realize the speed control of connected vehicle in upstream control area.Finally,the ramp and main road vehicle arrival rate is set in 27 scenarios according to low,medium and high,and traffic volume,speed,density and travel time are selected as evaluation indexes.The traffic conditions of on-ramp area under control are analyzed through simulation.The simulation results show that the on-ramp vehicle arrival rate affects the implementation effect of the control strategy.When the density is low,the effect is not significant;when the density is medium,the advantage of the control strategy is reflected;when the density is high,the strategy is invalid.