摘要
为改善高速公路施工区路段车辆运行状态,建立了一种集合优化换道比例和可变跟车时距的换道控制策略。通过引入交通运行效率和冲突风险目标函数并进行在线求解,从而对施工区车辆行驶轨迹进行优化,提高了车辆的平顺性。在网联自动车环境下,以施工区上游路段车辆平均速度为目标函数,借助遗传算法遍历交通流状态集合,求解换道比例,以此调整施工区上游车辆分布。以施工区汇入路段车辆交通效率和冲突风险为可变跟车时距模型的目标函数,调用CPLEX/Matlab求解器得到汇入路段可变跟车时距。为了在线计算和可视化建立了Matlab/Vissim_COM的仿真平台,通过Matlab编程技术以单步仿真的方式提取Vissim车辆信息,将CPLEX求解器和Vissim的封装环境以函数调用的方式与遗传算法结合,对车辆信息进行优化计算和参数反馈。在总仿真次数达到400次时,模型控制得到最优。结果表明,与未实施控制相比,在最优控制中,当仿真时长达到800 s时,每条车道交通量输入达到700 veh/h,优化效果较为明显,即全局车辆在汇入路段"曝光"次数减少,车辆行驶轨迹变的"平滑",全局运行速度提高了48%,速度标准差的变化幅度降低,全局车辆的速度离散性得到改善,以后侵入时间表征冲突风险,冲突次数降低了39%,高速公路施工区车辆运行状态得到了改善。
To optimize driving status of vehicles at freeway work zone,a lane-changing control strategy that integrates optimized lane-changing ratio and variable headway is established.The objective functions of traffic operation efficiency and conflict risk are introduced and solved online,so as to optimize the trajectory of vehicles at work zone,and then the ride comfort of vehicle is improved.Under the environment of connected and autonomous vehicle,the average speed at upstream of the work zone is selected as the objective function,and the genetic algorithm is used to solve lane change ratio by traversing the traffic flow state to adjusts the distribution of vehicles at the upstream of the work zone.The vehicle traffic efficiency and conflict risk of the merging area are regarded as the objective function of the variable headway model.Besides,the CPLEX/Matlab solver is called to solve the variable headway at merging area.To calculate and visualize,the simulation platform of Matlab/Vissim_COM is established.The Matlab programming technology is used to extract vehicle information of Vissim in a single-step simulation.The CPLEX solver and Vissim packaging environment are combined with the genetic algorithm in the form of function calls to optimize the vehicle information and feedback.When the total number of simulations reaches400,the effects of model control is optimal.The results of the optimal control show that when the simulation time reaches800 s,the traffic input of each lane reaches700 veh/h,at this time the optimization effect is obvious.Compared with the cases where lane change control is not implemented,the number of"exposures"of the global vehicles at the merging area is reduced which contributes to the"smoothness"of vehicles’driving trajectory,and the global vehicle speed is increased by48%.The variation range of the speed standard deviation is reduced,and the speed dispersion of the global vehicle is improved.The number of conflicts reduces by39%using post encroachment time as the index.With this method,the
作者
李晓虎
麦乐
任杰
刘浩学
朱彤
LI Xiaohu;MAI Le;REN Jie;LIU Haoxue;ZHU Tong(School of Automobile,Chang'an University,Xi'an 710064,China)
出处
《交通信息与安全》
CSCD
北大核心
2020年第3期40-47,共8页
Journal of Transport Information and Safety
基金
国家重点研发计划项目(2018YFC0807500)
国家自然科学基金项目(51878066)资助。
关键词
交通工程
施工区
网联自动车辆
换道控制策略
轨迹优化
traffic engineering
work zone
connected and autonomous vehicle
lane change control algorithm
trajectory optimization
