Traffic Oscillation Absorption Strategy of Urban Expressway Based on WT-WOA
-
摘要: 城市道路交通瓶颈点的交通震荡是诱发交通事故、通行延误和增加能源消耗的主要原因,缓解交通震荡可以显著提升交通运行效率和安全。为精确获取交通震荡的周期,研究了基于小波变换(wavelet transform,WT)的交通波时频分析方法,并开发了基于鲸鱼优化算法(whale optimization algorithm,WOA)的小波参数自适应标定方法。通过构建以交通震荡起止时间的识别误差绝对值为适应度函数,采用全局搜索机制克服局部最优问题,动态优化小波变换的尺度系数与平移系数,克服了小波变换易陷入局部最优的缺点,并解决了传统交通震荡识别方法中由于判别参数在阈值上下波动,导致识别不准确或误判的问题。在此基础上,提出融合能源消耗和驾驶安全的多目标协同交通波吸收控制框架,通过建立以燃油消耗率和交通安全指标的多目标优化函数,设计基于速度引导的车辆准入控制机制,在瓶颈区域上游实施动态速度调控,通过优化部分车辆行驶速度,减少进入交通瓶颈区的车辆数量,从而加快交通震荡的消散,抑制频繁加减速导致的能源损耗和安全风险。研究结果表明:在道路瓶颈区实施交通波吸收方法后,碰撞持续时间和综合碰撞时间分别降低了73.86%和61.07%,燃油消耗降低16.15%;分析网联自动驾驶车辆渗透率变化对控制方法影响发现,能耗和安全风险随渗透率增加而减小,渗透率≥0.3时,控制方法效果显著,能耗与安全风险都显著降低。Abstract: Traffic oscillations are primary causes of traffic accidents, delays, and increased energy consumption at bottlenecks of urban road networks. Mitigating oscillations can significantly improve traffic efficiency and safety. A wavelet transform-based time-frequency analysis method is used to accurately capture the cycle of traffic oscillations. Additionally, an adaptive wavelet parameter calibration method is developed based on the whale optimization algorithm (WOA). A fitness function is set up based on the absolute error in identifying the start and end times of traffic shockwaves. In further, a global search mechanism is introduced to overcome the issue of local optima, dynamically optimizing the scale and translation coefficients of the wavelet transform. This approach addresses the common problem of wavelet transforms getting trapped in local optima, and the inaccuracies or misjudgments caused by fluctuations in the discriminative parameters around threshold values in traditional traffic oscillations identification methods. Based on this, a multi-objective collaborative traffic wave absorption control framework integrating energy consumption and driving safety is proposed. A multi-objective optimization function is then investigated incorporating fuel consumption rate and traffic safety indicators. A speed-guided vehicle access control mechanism is designed with dynamic speed regulation implemented upstream of the bottleneck area. By optimizing the speed of specific vehicles, the number of vehicles entering the bottleneck is reduced, accelerating the dissipation of traffic oscillations and suppressing energy loss and safety risks caused by frequent acceleration and deceleration. The results indicate that collision duration and overall collision time decreased by 73.86% and 61.07% respectively, while fuel consumption was reduced by 16.15%, after implementing the traffic wave absorption method in the bottleneck area. The energy consumption and safety risks decrease as the penetration rate increases by analysis of the impact of changes in the penetration rate of connected and autonomous vehicles on the control method. When the penetration rate reaches 0.3 or higher, the control method becomes significantly more effective, with notable reductions in both energy consumption and safety risks.
-
Key words:
- traffic engineering /
- traffic oscillations /
- wavelet transform /
- traffic wave absorption /
- traffic simulation /
-
-
表 1 选取不同吸收车辆及速度的控制策略对安全指标的影响
Table 1. The impact of different absorption vehicle control strategies on safety indicators
吸收车辆 TET TIT 吸收速度 J排序 吸收车辆 TET TIT 吸收速度 J排序 1 2.08 0.09 15.96 10 6 55.87 50.42 36.44 4 2 33.90 46.18 24.41 8 7 47.73 41.50 38.32 5 3 73.86 61.07 25.79 1 8 44.32 38.57 38.91 6 4 70.45 59.73 30.71 2 9 40.34 36.03 41.11 7 5 61.17 50.41 33.08 3 10 36.36 31.53 42.34 9 注:吸收速度的单位为km/h;J排序为不同控制策略下的适用度函数值排序 表 2 不同控制策略下的评估结果
Table 2. Evaluation results under different control strategies
控制类型 本策略 WT-JAD 完全JAD 无控制 行程时间/s 2 616.5 2 618.3 2 626.2 2 648.9 总延误/s 665.3 665.9 665.9 665.9 平均PMX/mg 0.362 0.370 0.447 0.490 平均NOX/mg 0.305 0.313 0.332 0.354 平均油耗/ml 661.019 692.595 730.189 788.319 平均CO/mg 18.615 20.133 21.768 24.870 注:基于小波变换的JAD策略、完全消除交通震荡的JAD策略在图表中命名分别简化为WT-JAD策略、完全JAD策略 表 3 最优交通震荡吸收策略下各车辆在震荡区的行程时间
Table 3. Travel time in the oscillation zone under the traffic oscillation mitigation strategy
车辆 无控制/s 本策略/s 车辆 无控制/s 本策略/s 头车 36.7 36.7 后车5 34.3 34.1 后车1 36 36 后车6 33.9 33.4 后车2 34.4 34.4 后车7 34 33.3 后车3 34.8 35 后车8 34.3 33.6 后车4 34.2 34.2 后车9 34 33.1 -
[1] KHONDAKER B, KATTAN L. Variable speed limit: a microscopic analysis in a connected vehicle environment[J]. Transportation Research Part C: Emerging Technologies, 2015, 58: 146-159. doi: 10.1016/j.trc.2015.07.014 [2] LU W, YI Z W, GU Y L, et al. TD3LVSL: a lane-level variable speed limit approach based on twin delayed deep deterministic policy gradient in a connected automated vehicle environment[J]. Transportation Research Part C: Emerging Tech-nologies, 2023, 153: 104221. doi: 10.1016/j.trc.2023.104221 [3] IORDANIDOU G R, Papamichail I, RONCOLI C, et al. Feed-back-based integrated motorway traffic flow control with delay balancing[J]. IEEE Transactions on Intelligent Transportation Systems, 2017, 18(9): 2319-2329. doi: 10.1109/TITS.2016.2636302 [4] HAN Y, HEGYI A, YUAN Y F, et al. Resolving freeway jam waves by discrete first-order model-based predictive control of variable speed limits[J]. Transportation Research Part C: Emerging Technologies, 2017, 77: 405-420. doi: 10.1016/j.trc.2017.02.009 [5] MURALIDHARAN A, HOROWITZ R. Computationally efficient model predictive control of freeway networks[J]. Transportation Research Part C: Emerging Technologies, 2015, 58: 532-553. doi: 10.1016/j.trc.2015.03.029 [6] 邵敬波, 黄轲, 张兆磊, 等. 高速公路连续瓶颈混合交通流可变限速与换道协同控制方法[J]. 交通信息与安全, 2023, 41 (3): 59-68, 79. doi: 10.3963/j.jssn.1674-4861.2023.03.007SHAO J B, HUANG K, ZHANG Z L, et al. A cooperative control method of variable speed limit and lane changefor mixed traffic flow on continuous bottlenecks of freeway[J]. Journal of Transport Information and Safety, 2023, 41(3): 59-68, 79. (in Chinese) doi: 10.3963/j.jssn.1674-4861.2023.03.007 [7] 白如玉, 焦朋朋, 陈越, 等. 基于强化学习的车道级可变限速控制策略[J]. 交通信息与安全, 2024, 42(1): 105-114. doi: 10.3963/j.jssn.1674-4861.2024.01.012BAI R Y, JIAO P P, CHEN Y, et al. Differential Variable Speed Limit Control Strategy Based on Reinforcement Learning[J]. Journal of Transport Information and Safety, 2024, 42(1): 105-114. (in Chinese) doi: 10.3963/j.jssn.1674-4861.2024.01.012 [8] ZHANG H Y, DU L L. Platoon-centered control for eco-driving at signalized intersection built upon hybrid MPC system, online learning and distributed optimization part Ⅱ: Theoretical analysis[J]. Transportation Research Part B: Methodological, 2023: 172199-216. [9] HE H W, HAN M, LIU W, et al. MPC-based longitudinal control strategy considering energy consumption for a dual-motor electric vehicle[J]. Energy, 2022, 253: 124004. doi: 10.1016/j.energy.2022.124004 [10] AL-GABALAWY M, HOSNY N S, ABORISHA A S. Model predictive control for a basic adaptive cruise control[J]. International Journal of Dynamics and Control, 2021, 9(3): 1132-1143. doi: 10.1007/s40435-020-00732-w [11] 吴文静, 战勇斌, 杨丽丽, 等. 考虑安全间距的合流区可变限速协调控制方法[J]. 吉林大学学报(工学版), 2022, 52 (6): 1315-1323.WU W J, ZHAN Y B, YANG L L, et al. Coordinated control method of variable speed limit in on-ramp area considering safety distance[J]. Journal of Jilin University(Engineering and Technology Edition), 2022, 52(6): 1315-1323. (in Chinese) [12] 韩雨, 郭延永, 张乐, 等. 消除高速公路运动波的可变限速控制方法[J]. 中国公路学报, 2022, 35(1): 151-158.HAN Y, GUO Y Y, ZHANG L, et al. An optimal variable speed limit control approach against freeway jam waves[J]. China Journal of Highway and Transport, 2022, 35(1): 151-158. (in Chinese) [13] ZHENG Z D. Recent developments and research needs in modeling lane changing[J]. Transportation Research Part B: Methodological, 2014, 60: 16-32. doi: 10.1016/j.trb.2013.11.009 [14] LI Y, LI Z B, WANG H, et al. Evaluating the safety impact of adaptive cruise control in traffic oscillations on freeways[J]. Accident Analysis & Prevention, 2017, 104: 137-145. [15] YUAN R, YU H, ZHANG G H, et al. Optimal control strategy for traffic platoon longitudinal coordination around equilibrium state enabled by partially automated vehicles[J]. Transportation Research Part C: Emerging Technologies, 2024, 159: 104463. [16] WU Y K, TAN H C, QIN L Q, et al. Differential variable speed limits control for freeway recurrent bottlenecks via deep actor-critic algorithm[J]. Transportation Research Part C: Emerging Technologies, 2020, 117: 102649. [17] DU Y, MAKRIDIS M A, TAMPÈRE C M J, et al. Adaptive control with moving actuators at motorway bottlenecks with connected and automated vehicles[J]. Transportation Research Part C: Emerging Technologies, 2023, 156: 104319. [18] NISHI R. Theoretical conditions for restricting secondary jams in jam-absorption driving scenarios[J]. Physica A: Statistical Mechanics and its Applications, 2020, 542: 123393. [19] HE Z B, ZHENG L, SONG L Y, et al. A jam-absorption driving strategy for mitigating traffic oscillations[J]. IEEE Transactions on Intelligent Transportation Systems, 2017, 18(4): 802-813. [20] ZHENG Y, ZHANG G Q, LI Y, et al. Optimal jam-absorption driving strategy for mitigating rear-end collision risks with oscillations on freeway straight segments[J]. Accident Analysis & Prevention, 2020, 135: 105367. [21] 李凯, 孙佳, 陈非, 等. 基于智能网联车的高速公路移动瓶颈实时检测方法[J]. 交通信息与安全, 2024, 42(5): 24-32. doi: 10.3963/j.jssn.1674-4861.2024.05.003LI K, SUN J, CHEN F, et al. A method for real-time detecting freeway moving bottlenecks using intelligent connected vehicles[J]. Journal of Transport Information and Safety, 2024, 42(5): 24-32. (in Chinese) doi: 10.3963/j.jssn.1674-4861.2024.05.003 [22] 陈鼎, 周水庭, 陈云, 等. 拥堵指数自适应调节的交通运行状态识别方法及应用研究[J]. 交通运输系统工程与信息, 2022, 22(2): 137-144.CHEN D, ZHOU S T, CHEN Y, et al. Traffic performance identification method based on adaptive congestion index[J]. Journal of Transportation Systems Engineering and Information Technology, 2022, 22(2): 137-144. (in Chinese) [23] 付子圣, 李秋萍, 柳林, 等. 利用GPS轨迹二次聚类方法进行道路拥堵精细化识别[J]. 武汉大学学报(信息科学版), 2017, 42(9): 1264-1270.FU Z S, Ll Q P, LLU L, et al. Identification of urban network congested segments using GPS trajectories double-clustering method[J]. Geomatics and Information Science of Wuhan University, 2017, 42(9): 1264-1270. (in Chinese) [24] 韦伟, 毛保华, 陈绍宽, 等. 基于当期事件识别的拥堵传播特征研究[J]. 交通运输系统工程与信息, 2016, 16(4): 165-170.WEI W, MAO B H, CHEN S K, et al. Spatial propagating study of urban traffic congestion based on current event recognition[J]. Journal of Transportation Systems Engineering and Information Technology, 2016, 16(4): 165-170. (in Chinese) [25] LI X P, PENG F, OUYANG Y F. Measurement and estimation of traffic oscillation properties[J]. Transportation Research Part B: Methodological, 2009, 44(1): 1-14. [26] ZHENG Z D, AHN S, CHEN D J, et al. Freeway traffic oscillations: microscopic analysis of formations and propagations using wavelet transform[J]. Transportation Research Part B: Methodological, 2011, 45(9): 1378-1388. [27] LI S Y, YANAGISAWA D, NISHINARI K. A jam-absorption driving system for reducing multiple moving jams by estimating moving jam propagation[J]. Transportation Research Part C: Emerging Technologies, 2024, 158: 104394. [28] DU W D, ZHANG Q Y, CHEN Y P, et al. An urban short-term traffic flow prediction model based on wavelet neural network with improved whale optimization algorithm[J]. Sustainable Cities and Society, 2021, 69 [29] 李熙莹, 梁靖茹, 郝腾龙. 考虑连锁冲突的城市公交车行车风险量化分析方法[J]. 交通信息与安全, 2022, 40(3): 19-29. doi: 10.3963/j.jssn.1674-4861.2022.03.003LI X Y, LANG J R, HAO T L. A method for quantitatively analyzing risks associated with the operation of urban buses considering chained conflicts[J]. Journal of Transport Information and Safety, 2022, 40(3): 19-29. (in Chinese) doi: 10.3963/j.jssn.1674-4861.2022.03.003 [30] 王顺超, 李志斌, 吴瑶, 等. 面向瓶颈多簇运动波消除的拥堵吸收智能驾驶模型[J]. 中国公路学报, 2022, 35(1): 137-150.WANG S C, Ll Z B, WU Y, et al. An intelligent jam-absorbing driving strategy for eliminating multiple traffic oscillations at bottlenecks[J]. China Journal of Highway and Transport, 2022, 35(1): 137-150. (in Chinese) -