Vissim在城市交叉口信号配时方案优化中的应用——以“粤海门村”交叉口为例

城市交叉口车辆之间干扰频繁,加上信号配时不合理,使得车辆的延误时间过长,交叉口的通行量不高.以粤海门村交叉口为例,在交通流量数据调查的基础上,通过“等效交通量”方法优化信号配时方案,运用Vissim建立微观仿真模型,并对优化前后的配时方案进行仿真评价.仿真结果表明：优化方案使得交叉口人均延误时间下降了16.6％,停车时间下降了19.3％,平均排队下降了10.6％,通行量增加了2.4％.     

基于GPS轨迹数据的公交车辆行程时间预测

文章通过对停靠站公交车辆停靠情况(停靠站公交车到达车头时距)以及信号控制节点处(包括信号控制交叉口和信号控制路段)通行时间的特征进行研究,进而探寻公交车辆行驶特性,提出公交车辆行驶特征的统计规律和公交车到达时间的预测方法,为公交信号优先协调控制提供技术支撑。     

基于多源数据融合的信号交叉口延误估计研究

为了获得更准确的信号交叉口延误,为评价信号交叉口的运行效率和服务水平提供精确的评价指标,论述了利用线圈检测器和浮动车数据来估计信号交叉口延误的方法。在对BP神经网络作简要介绍的基础上提出基于改进BP算法的信号交叉口延误估计模型。把通过线圈检测器和浮动车数据估计的信号交叉口平均延误进行融合,得到更为精确的信号交叉口平均延误。最后通过实例对该模型进行了验证,分析结果表明:采用数据融合方法得到的信号交叉口延误的相对误差明显低于基于线圈检测器和浮动车数据估计的信号交叉口延误的相对误差,因此采用数据融合方法估计信号交叉口的延误可以提高延误估计的精度,论证了该模型的实用性和有效性。     

基于粒子群算法下的交叉口信号配时优化

为了合理地优化交叉口信号配时,通过分析交叉口的评价指标,建立了以车辆的平均延误、停车次数最小、交叉口整体通行能力最大、各相位有效绿灯时间和交叉口周期时长作为约束条件的数学模型。并通过改进前人研究基础上的动态加权系数,将多目标的非线性优化问题转化为单一目标的非线性规划问题,为了得出更科学稳定的解,提出了改善粒子群算法系统稳定性的2种方法,并将其与粒子群算法结合起来。然后以Matlab为求解工具,结合临邑市某一交叉口实例进行求解分析。最后的结果表明,在使用改进后的粒子群算法进行优化后交叉口通行能力较之现状提升了9%,延误下降了28%,停车次数下降了9%,且各项优化结果均优于Webster,改进后的算法在程序中运行300代,到216代才开始收敛,而未改进的算法稳定性较差,优化结果和收敛曲线则随着实验次数的变化而变化,最后的结论证明了该算法和模型的可靠性。     

关于实现交叉口公交优先研究的文献综述

公交优先是解决城市交叉口拥堵的一项有效的策略,为了实现这个目的,对设置公交专用道策略、信号控制策略和设置预信号相关的文献进行综述,希望能为相关学者的进一步研究有所帮助.     

基于VISSIM仿真的交叉口信号配时优化设计

交叉口作为城市道路的交通咽喉,其通行效率直接影响到城市整体道路的运行效率。为了提高城市道路交叉口的通行能力等,文章以金华市八一南街—宾虹路为实例,利用VISSIM微观仿真软件分析交叉口的延误时间、停车次数、排队长度以及尾气排放等输出参数,对比信号配时优化前后的方案。结果表明,优化后的交叉口信号配时方案下平均停车延误降低了17.33%,总体停车次数降低了21.13%,平均排队长度降低了36.51%,尾气排放的污染物以及总油耗也有所减少,交叉口的交通状况得到明显改善。     

“公交优先”,思路再开阔些

大禹治水,与其堵,不如疏。治马路塞车亦如此。乘机动车不如骑车快,于是人们便会选择骑车。可自行车一多,与机动车混行,便会更塞车。"公交优先",则把人们吸引到公交车上,从而减少了其他车辆上路。问题是,我们的公交车有没有这大容量,大到让人们感到比任何车都快捷舒适?"公交优先"的思路不能只限于公共汽车上,还应扩大思路,同时,"公交优先"必须真正"优先",治不住乱占公交车道的其他车,公交优先还是空的。     

基于VISSIM的轨道交通站点施工期间导行方案设计

城市私家车的增加,使车辆需求与道路供给的矛盾愈加严重。为解决这个问题,发展公共交通是必要的。地铁具有运量大、效率高、安全性高等特点,更能满足城市发展的需求。但其施工期间对地面交通产生影响巨大,容易造成道路堵塞。因此,制定合理的交通导行方案尤为重要。文章以青岛市太行山路站施工期内为具体实例,对施工路段的道路、交通流等交通特性进行分析,确定影响范围,然后提出施工区交通组织优化方案,最后运用VISSIM进行仿真评价。结果表明,仿真周期内,通过施工交叉口的车辆数从373辆减少到263辆;同时,车流的平均排队长减小5,平均延误时间减少6秒。     

缓解交通压力的几点建议

无可非议，公交车是人均占用交通资源“面积一时数”最低的交通工具之一。但它缺乏一定的个性化、随机性、便捷性、舒适性和准点率，所以目前人们对它的选择也有一定的局限性。通过对公交服务和设施的改进，来吸引更多层次的人群改用公交车出行，是缓解交通压力的有效方法。为此提出如下8点改进建议：     

常规公交专用道交叉口出口设置策略研究

本文主要研究常规公交专用道交叉口出口设置策略,从而保证公交车辆和社会车辆的顺畅通行。论文首先介绍了国内外公交专用道的设置条件;而后介绍了国内主要城市公交专用道发展概况;再后介绍了四种公交专用道出口设置策略;最后通过对比分析,得出四种设置策略的适用条件及其优缺点。     

基于Synchro的信号交叉口优化仿真研究

通过对西安市某信号控制交叉口进行大量实际观测,分析了该交叉口存在的问题并提出解决方案,运用Synchro仿真系统中信号配时优化模型、用于延误计算的百分比延误模型和服务水平模型,对解决方案进行了优化仿真分析,交叉口各项评价指标均得到明显改善,验证了改善方案的可行性。     

An integrated arterial coordinated control model considering green wave on branch roads and pedestrian crossing time at intersections

Urban fine management needs scientific traffic management methods and efficient signal control programs. Green wave control is usually used to facilitate the unban traffic. However, maximum bandwidth optimization on arterial traffic signal timing is usually yielded from the sacrifice of the branch road. The green wave on branch roads and pedestrian crossing time at intersections are often neglected. In this paper, an extended integrated green wave control method is presented to solve the coordinated control issue, which considers green time constraints to ensure necessary time for vehicles on branch roads and pedestrian crossing time at intersections. Non-coordinated phase saturation is first introduced to describe the green time on branch roads. Next, the arterial roads are partitioned to enlarge the green wave bandwidth and an extended green wave optimization model with green time constraints is proposed. Combined with the green wave searching method, an improved genetic algorithm is applied. Finally, a real-world case study in Shenzhen, China, is employed to assess the model. Results show the proposed model can (1) reach the same public green time as in the traditional method and (2) increase the average sub-green wave bandwidth to improve the signal control.     

基于VISSIM仿真的交叉口延误分析

本文结合VISSIM仿真软件，对一新建信号交叉口进行延误分析，通过与HCM2000法计算结果的比较，验证VISSIM软件在实际交叉口交通运行状况仿真模拟中的有效性、精确性及实用性。     

浅谈公交优先对城市综合发展的作用

随着城市规模的扩大和城市人口的增加,城市交通的压力也正在不断加剧,公交优先的方向应当始终坚持。实行公交优惠票价政策,体现了社会资源共享的公平性和经济合理性,有助于缓解交通拥堵,减轻大气污染保护环境,也有助于建立和谐社会,促进城市繁荣和城市综合发展。     

基于模糊控制的城市交叉路口智能交通系统研究

文中根据模糊控制理论对交叉路口的交通控制进行优化。路权相位的切换按各路口的等待车流量大小顺序排列,车流量较大的相位优先通行。绿灯时间根据各路口车流量差异合理分配,以实现平均延误时间最小化,同时兼顾公平。     

单点信号交叉口通行能力和服务水平分析

本文分析了单点信号控制交叉口通行能力和服务水平的影响因素 ,揭示了交叉口通行能力与延误随信号周期长度变化的规律 ,从而得出交叉口延误最小、通行能力最大的信号周期的取值范围 ,提出了交叉口饱和度接近饱和或过饱和时的交通管理措施     

浅谈工程机械静液传动嵌入式控制器的设计

电子控制系统是现代工程机械的重要组成部分,其性能的优劣直接影响着现代工程机械的动力性、经济性、可靠性、工作效率等。因此,电子控制系统的设计占有非常重要的地位,本文分析了基于MC9S08DZ32的嵌入式控制器的设计方法,包括各种信号处理、功率驱动及总线接口等。     

Irregular workloads with MRP systems: Some causes and consequences

Material Requirements Planning (MRP) systems have been widely applied in industry to better manage multiproduct, multistage production environments. Although many applications have been quite successful, much is still left to the planner's intuition as to how to assure that master schedules, component lot sizes, and priorities realistically conform to the capacity limits at individual work centers. Capacity issues may indeed be the soft spot in MRP logic.This paper explores some possible causes of irregular workload patterns when using an MRP system. Better insight on which factors cause temporary bottlenecks could help managers better assess the vulnerability of their plants to this problem. It might also suggest ways of dampening peaks and valleys. The problem setting is a multistage environment; several products are made from various subassemblies and parts. Each shop order is routed through one or more capacitated work centers. An order is delayed either by temporary capacity shortages or the unavailability of components. Of course, the second delay can be caused by capacity problems previously encountered by the shop orders of its components.Seven experimental factors are tested with a large-scale simulator, and five performance measures are analyzed. The factors are the number of levels in the bill of material, the average load on the shop, the average lot size, the choice of priority rule, demand variability, the use of a gateway department, and the degree of equipment specialization. We have one measure of customer service, two for inventory, and two for workload. The workload measures are unconventional, since our interest is when workload variability occurs and how it affects inventory and customer service.The simulator has been developed over the course of eight years, and since this study has been further enhanced to handle many more factors. The simulator was validated recently with real data at two manufacturing plants. It is quite general, in that the bills of material, shop configuration, routings, worker efficiencies, and operating rules can be changed as desired.An initial screening experiment was performed, whereupon the average load and priority rules were not statistically significant at even the .05 level. A full factorial analysis with two replications was then conducted on the five remaining factors. Multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA) statistical tests have been performed.The results confirm that workload variability can have a detrimental impact on customer service and inventory. The following structural changes to the manufacturing system can be beneficial, but tend to be more difficult to achieve. More BOM levels improve customer service, but increase inventory and capacity bottlenecks. Resource flexibility is a powerful tool to reduce workload variability. Capacity slack averaging much over 10% is wasteful, having no benefits for inventory and customer service. In general, revising the routing patterns only, such as creating more dominant paths, will not give big payoffs. The following procedural changes are easier to implement. Master schedules which smooth aggregate resources are an excellent device to reduce workload variability. Even with a smooth MPS, debilitating workload variability can still occur due to the design of the BOM, lot size, and leadtime offset parameters. Selecting a priority rule does not seem to be of overriding importance compared to master scheduling and component lot sizing. These findings must be considered within the context of the range of plant environments encompassed by this study.