网联环境下的交叉口信号配时与车辆轨迹联合优化方法

Coordinated Signal Timing Optimization with Vehicle Trajectory Under Connected Environment

文中提出一种综合考虑交叉口信号配时和车辆轨迹的联合优化法.以车辆的原始轨迹为基础,以交叉口车辆通行时间最小化为信号控制优化目标,建立信号配时优化模型来计算最优的信号周期序列和相位时间,并根据相位时间划分车辆运动轨迹为到达交叉口停车线前的加速、匀速阶段,以及驶过交叉口停车线的加速、匀速阶段,在每个阶段获取最佳的车头时距和期望速度,优化车辆的原始轨迹.基于新的轨迹再次进行信号配时优化.以交通需求量、左转比率和信号周期时长作为考虑因素,进行SUMO仿真实验将所提出的联合优化法与实时信号控制方法进行比较.结果表明:联合优化法在不同的平衡交通需求量下能够提高交叉口通行能力30.5%;在随机交通需求量下能提高交叉口通行效率17.3%;而在不同的左转比率和信号周期时长情况下能提高通行效率66.6%和21.7%,验证了提出的联合优化方法提高线交叉口通行效率的有效性.

A joint optimization method considering intersection signal timing and vehicle trajectory was proposed.Based on the original trajectory of vehicles,taking the minimization of vehicle transit time at intersections as the goal of control optimization,a signal timing optimization model was established to calculate the optimal signal cycle sequence and phase time.According to the phase time,the vehicle trajectory was divided into acceleration and constant speed stages before reaching the intersection stop line and acceleration and constant speed stages when passing through the intersection stop line,and the optimal headway and expected speed were obtained at each stage to optimize the original trajectory of the vehicle.The signal timing optimization was carried out again based on the new trajectory.Taking traffic demand,left turn ratio and signal cycle time as consideration factors,the SUMO simulation experiment was carried out,and the proposed joint optimization method was compared with the real-time signal control method.The results show that the joint optimization method can improve the intersection capacity by 30.5%under different balanced traffic demands.Under the random traffic demand,it can improve the intersection traffic efficiency by 17.3%.However,the traffic efficiency can be improved by 66.6%and 21.7%under different left turn ratios and signal cycle duration,which verifies the effectiveness of the proposed joint optimization method to improve the traffic efficiency of intersections.