跨河城市桥梁群体景观规划浅析——以郑东新区龙湖地区为例

桥梁群体的景观规划是当前跨河城市建设面临的重要课题,桥梁群体的景观设计与单体桥梁的景观设计相比设计过程更为复杂,内涵更加丰富,需要与城市规划、建筑设计、景观风貌结合得更加紧密。以郑东新区龙湖地区桥梁群为研究对象,通过对该地区35座桥梁群的景观规划分析,对桥梁群景观规划进行一些方法上的探讨。     

A curving ACC system with coordination control of longitudinal car-following and lateral stability

The paper presents a curving adaptive cruise control (ACC) system that is coordinated with a direct yaw-moment control (DYC) system and gives consideration to both longitudinal car-following capability and lateral stability on curved roads. A model including vehicle longitudinal and lateral dynamics is built first, which is as discrete as the predictive model of the system controller. Then, a cost function is determined to reflect the contradictions between vehicle longitudinal and lateral dynamics. Meanwhile, some I/O constraints are formulated with a driver permissible longitudinal car-following range and the road adhesion condition. After that, desired longitudinal acceleration and desired yaw moment are obtained by a linear matrix inequality based robust constrained state feedback method. Finally, driver-in-the-loop tests on a driving simulator are conducted and the results show that the developed control system provides significant benefits in weakening the impact of DYC on ACC longitudinal car-following capability while also improving lateral stability.     

信号协调控制下城市干道运行效率评价研究

以信号协调控制的城市干道为研究对象,从平均行程延误、排队长度、停车率、行程车速及饱和度方面建立干道运行效率评价指标,将信息论中熵值理论引入干道运行效率评价中,确定各评价指标的权重。基于未确知测度理论,建立城市干道运行效率等级评价和排序模型。以某具体干道作为实例分析,结果表明：基于熵权的未确知测度综合评价用于干道信号协调控制运行效率评价是切实可行的。     

Policy Simulation for New BRT and Area Pricing Alternatives Using an Opinion Survey in Jakarta

Abstract

An area pricing scheme for Jakarta, Indonesia, is currently under review as a transportation control measure along with the operation of new bus rapid transit (BRT) system. While this scheme may be effective for congestion reduction in the central business district (CBD), provision of alternative means of transportation for auto users that are ‘pushed-out’ is of great importance to obtain public acceptance. Hence, it is necessary to simulate simultaneously the area pricing scheme and the BRT development which may serve as an alternative for assumed ‘pushed-out’ auto users. Utilizing data from an opinion survey, this paper studies how BRT and auto ridership are likely to vary as a function of traveler and system attributes. Additionally, the study attempts to evaluate the way this new travel mode is distinguished from other existing conventional transportation alternatives in Jakarta. The survey data contains socioeconomic information of over 1000 respondents as well as details of to-work/school trips to the CBD including mode, travel cost, time, etc. Respondents were asked about their willingness to shift from their current mode to BRT to make the same travel for different BRT fare levels. Modeling efforts suggest that a mixed logit model performs better in explaining choice behavior. Therefore, this model was used for policy simulation. The simulation results brought about many implications as to the tested policies. While the developed models may be applied only to future BRT corridors in which the survey was conducted, they capture the key variables that are significant in explaining mode choice behavior and present great potential for practical use in policy simulation and analysis in a large metropolitan area of the developing world.     

基于双向最大绿波带宽的通用干道协调控制数解算法

针对现有数解算法假定绿波设计速度固定取值的局限,提出了一种基于双向最大绿波带宽的通用数解算法.首先确定了相邻理想间距的取值空间.其次推导了上行、下行偏移绿信比的计算公式.再次,给出了理想绿灯中心线其上下方绿信比的计算公式.最后,以双向绿波带宽之和最大为优化目标,以上行、下行绿波设计速度与信号周期为优化变量,建立了最大绿波带宽优化模型.以实例验证文中通用数解算法的有效性.分析结果表明:文中通用数解算法能够突破上行、下行绿波设计速度固定取值的局限,能够更易于获得理想的绿波协调控制效果,具有较好的通用性与实用性.     

车路协同环境下网联车出匝道控制和速度优化

文章旨在探索一种新的智能网联车技术,可以有效地解决传统车辆汇入匝道冲突区域时减速甚至停车所带来的延误问题,并且可以在车路协同环境下,通过 STM32 等硬件实现两阶段的优化模型,以达到更好的效果。通过智能网联车的自动驾驶功能和速度优化模型的配合,结合 GPOPS 软件寻找出车辆在匝道冲突区域行驶的最优轨迹,减少车辆在高速公路下匝道路段中不必要的加速、减速等情况、减少能耗、保证安全且提高车辆通行效率。     

基于固有可靠度和使用可靠度的干线协调效果评价

为缓解交通拥堵状况,许多城市实施了干线协调控制方法,但该方法缺乏合理有效的论证与评价,导致效果不佳。基于产品工作可靠性理论引入了固有可靠度与使用可靠度的基本概念,量化了行驶速度、交通流量、停车次数和绿波带宽表征参数,提出了固有可靠度和使用可靠度的评价隶属函数;基于此,分别建立了固有可靠度评价模型和使用可靠度评价模型,并构建干线协调可靠性综合评价体系;研究了干线协调控制实施前后的固有可靠性与使用可靠性;依托济南市烟台路实测数据,验证了该评价方法的实用性与科学性。     

智轨列车与常规公交共线组合发车间隔优化

智轨列车与常规公交的协同运营组织不仅有利于高质量满足乘客出行需求,而且有利于优化配置运输资源,合理设置发车间隔是协同运营组织方案编制的关键工作。针对智轨列车和常规公交共线运营时的组合发车间隔优化问题,以乘客出行成本最小和公交企业运营收益最大为目标,考虑2种不同交通工具的载客容量、行程时间、票价、首车始发时刻和乘客拥挤费用等影响因素,建立智轨列车与常规公交共线组合发车间隔优化模型,设计一种基于蒙特卡洛随机模拟条件下的枚举算法进行求解。通过算例对比分析智轨列车和常规公交最优组合发车间隔方案与单一模式智轨列车、单一模式常规公交的最优发车间隔方案以及二者的简单叠加组合方案,结果表明研究时段内最优组合发车间隔方案中由乘客出行成本和公交企业收益加权差构成的系统总费用最小,且合理安排2种交通工具的首车始发时刻有利于降低系统总费用。通过客流量灵敏度分析进一步探究了不同优化方法中客流量、乘客出行成本、企业运营收益和系统总费用之间的变化关系,结果表明线路客流量越大,组合发车间隔优化模型优化系统总费用的效果越明显,且主要通过增加公交企业收益降低系统总费用。研究方法和结论对智轨列车和常规公交共线运营系统优化决策具有参考价值。     

海南环新英湾地区综合交通发展与规划思路

海南环新英湾地区是海南省儋洋一体化发展战略的核心承载区,依托于国家港口型物流枢纽——洋浦港,并毗邻城镇,具有典型港产城一体化发展特点。基于区域特点,全面分析了环新英湾地区交通体系存在的问题及发展形势,分类、分层科学测算交通需求。以衔接、融合、协同、支撑为原则,以对外交通系统、内部道路系统和货运体系为主要内容,综合考虑城市、人口及产业需要,统筹制定了与区域协调发展相适应的综合交通发展规划,为区域社会经济发展提供坚实支撑。     

基于群体决策的多交叉口协同控制方法

基于竞争-合作的群体决策机制,将单点信号优化构建为各相位的交叉口通行权的竞争过程,将多点协同构建为上下游相位之间的协作过程,提出了一种兼顾多交叉口协同效益和单交叉口控制优化的路网信号配时设计方法;利用车路协同环境下路网内车辆路径信息的可感知性,动态精准地量化解析上下游交通耦合关系;在此基础上建立了分层动态决策框架,在单层决策中剥离了上下游交叉口控制决策对本地决策的影响,解耦协同控制模型中路网交通状态和信号控制决策之间的复合关系;设计了基于交叉口内各交通流向竞争力的分布式信号配时决策算法,并通过仿真试验平台比较了群体决策协同控制方法与传统协同控制方法的控制效果。研究结果表明: 相较于传统协同控制方法,群体决策协同控制方法可动态适应路网交通需求,在交通效率和稳定性上具有显著优势,在不同饱和度的交通需求水平下可降低车均延误15%以上;在路网交通饱和度较高的情况下, 群体决策协同控制方法延误降低幅度可达19.2%,控制优势更加明显;由于群体决策协同控制方法可在下游交叉口进口道车辆排队过长时减少上游车辆流出,可降低路网最大排队长度超40%,有效规避路网溢流风险;通过对群体决策协同控制模型的分布式求解,可实现单次决策过程计算时间小于0.01 s,具有应用于大规模复杂路网的实时信号配时决策的潜力。