共查询到19条相似文献,搜索用时 218 毫秒
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为充分利用交叉口有限的进出口车道资源,提升交叉口时空资源利用率及通行能力,采用基于预信号的交叉口几何设计方法,构建了以最大化通行能力为目标的交叉口车道划分模型及配时方案求解模型。在此基础上考虑车辆随机到达性,提出了基于实时交通需求的预信号动态控制方法。最后,基于实例,通过对比不同信号控制方案下的运行情况,利用VISSIM仿真平台进行验证,仿真结果表明:相较于传统的交叉口控制方法,所提出的车道划分模型及信号动态控制算法可有效提升交叉口通行能力并减小延误。 相似文献
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为提高城市快速路的运行效率,避免快速路入口匝道处发生拥堵并影响地面交通,结合快速路交通状态的实时判别、匝道调节率及交叉口信号配时方案,提出了针对快速路典型交通状态下的精准协同控制模型。协调控制模型的四个子模型为,流量精准推送模型、交叉口关键相位迟闭、早断配时优化模型、匝道排队调节控制模型。案例仿真表明:协调控制信号迟闭策略下匝道通过流量、车均延误,交叉口平均排队长度、车均延误分别优化了2.3%、40.4%、21.8%、22.4%;协调控制信号早断策略下匝道车均延误、平均排队长度,交叉口平均排队长度、车均延误分别优化了22.6%、31.7%、9.7%、4.5%;协调控制较大程度上提升了研究区域运行效率。 相似文献
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建立了在饱和度约束下以延误、停车次数、通行能力为性能指标的单交叉口多目标控制模型;模型可以根据交通状态的不同对交通控制的目标有所侧重:交通状态趋向拥挤时要确保发挥路口的最大通行能力,非拥挤状态时应尽可能减少路口信号控制的延误和停车次数;最后利用遗传算法对模型进行优化。实验结果表明,该模型能较好地适应实际的交通状态的变化,可有效改善交叉口的交通状况。 相似文献
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机动车流量、行人流量均较大的信号控制交叉口,行人路权往往过低,过街闯红灯现象普遍,且难以控制与避免,严重降低了交叉口运行效率。为了有效解决这一问题,采用机动车效益、行人效益、交叉口通行能力为评价指标,以交叉口饱和度为约束条件,在机动车效益指标中考虑了行人闯红灯对机动车造成的延误影响,建立了交叉口多目标信号配时优化模型;设计了求解模型的遗传算法。算例结果表明,所提出的模型能较好改善交叉口综合效益。 相似文献
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为提高交通控制系统的适应性和鲁棒性,采用强化学习方法实现交通控制模型的学习能力.对固定周期和变周期两种模式下的单交叉口信号配时优化进行研究,构造了等饱和度优化目标的奖赏函数,建立了等饱和度和延误最小两个优化目标的离线Q学习模型.采用对流量进行离散的方法解决了状态维数爆炸问题.通过算例对建立的4种离线Q学习模型解的结构、最优解的分布进行分析,结果表明相对于在线Q学习模型,离线Q学习模型更适合交叉口信号配时优化.采用“离线学习,在线应用”的方法,将建立的定周期延误最小离线Q学习模型与Webster定周期模型的性能进行对比,总体上前者的车均延误和累积延误低于后者. 相似文献
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城市道路交叉口信号控制是交管工作持续关注的课题,关于协调好有限的道路资源与日益增长的交通需求之间的矛盾,有着至关重要的作用。由于道路自身条件约束,交通流的组成特点复杂,路网交通路呈现非线性动态特征,无法进行精准的数学建模控制。本文提出的迭代学习控制方法,根据交通流的组成和变化特点调整信号控制周期及有效绿灯时长,实现交通信号动态优化控制,保证车辆在路网中能够高效、平稳地通行,是针对非线性动态交通流的一种动态寻优控制算法,能够有效减少路口车辆等待时间、提高通行效率。考虑对不同相位设计方案的适应性,在传统配时优化模型的基础上,构建综合相位设计元素的交通信号迭代学习控制模型,并通过Vissim仿真软件和Python编程语言搭建仿真测试环境,验证了提出模型的有效性。 相似文献
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《Expert systems with applications》2014,41(1):168-175
This paper aims to design an optimal logistics network including suppliers and retailers by taking into account the order quantity of products under uncertain consumer demand pattern. This research proposes a mixed-integer bi-level programming model and employs the iterative-optimization method. In the bi-level programming, the upper model is the logistics network design (LND) problem, which is designed for suppliers and consists of the hub locations, wholesale price of the products as well as the transportation flow of the commodity. The lower model is the order quantity determination (OQD) problem for retailers. It processes a special case of inventory problem in which the customer demand is stochastic and follows a series of assumed probability distributions. By applying the proposed methodology in a computational experiment, this research shows that if there were a large number of suppliers in the logistics system, retailers could order the product with relatively low price and the largest profit belongs to the retailer who could sell the commodity at the highest price. 相似文献
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为了解决交通高峰时段城市区域路网过大的交通需求引起的路网通行效率下降以及区域内部交通流分布的异质性产生的道路资源浪费等问题.本文提出了基于区域路网固有属性宏观基本图(Macroscopic fundamental diagram,MFD)的过饱和区域控制优化模型,建立了边界控制信号和内部控制信号目标函数的双层规划优化,进一步设计了基于BP(Back propagation)神经网络的自适应动态规划(Adaptive dynamic programming,ADP)模型,对建立的双层规划区域交通信号进行求解,实例仿真结果验证了本文方法的有效性.通过本文的研究分析,对城市区域交通的需求管控、拥堵政策制定等城市区域交通管理具有一定的指导意义. 相似文献
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基于Stackelberg博弈的动态用户最优配流和信号控制 总被引:3,自引:0,他引:3
研究了动态用户最优配流与信号控制的组合问题.首先基于交通分配将交通流分配到合适的路网上由信号控制来适应这些交通流的思想,并由此建立了交通分配和信号控制的Stackelberg博弈模型,模型的上层是动态用户最优,下层是信号控制优化.然后,通过对模型离散化应用模拟退火算法进行求解.最后,对一个简单的交通网络进行仿真,仿真结果表明所提方法的有效性. 相似文献
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夏新海 《计算机工程与应用》2020,56(23):245-252
针对传统分布式自适应交通信号控制协调效率受限,并且存在维数灾难问题,建立了城市区域交通信号控制系统模型,将其优化问题建模为局部交叉口交通信号博弈协调控制,提出基于交叉口交通信号控制agent局部信息博弈交互的学习算法。在学习过程中交叉口交通信号控制agent进行局部信息博弈交互,自主调整交通信号控制策略使其逐步学习到最优策略。通过设计不同的交通需求情景,对路网平均延误和平均停车次数进行加权构建性能评价指标,相对于遗传算法和感应控制方法,博弈学习取得更好的交通信号控制效果,其能收敛到最优性能评价指标,其具有更好的交通需求管控能力。 相似文献
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Nima Safaei Mohammad Saidi-Mehrabad Masoud Babakhani 《Journal of Intelligent Manufacturing》2007,18(3):383-399
The paper proposes a fuzzy programming based approach to design a cellular manufacturing system under dynamic and uncertain
conditions. The dynamic condition indicates a multi-period planning horizon, in which the product mix and demand in each period
can be different. As a result, the best cells designed for one period may not be efficient cells for subsequent periods and
some of reconfigurations are required. Uncertain condition implicates to the imprecise nature of the part demand and also
the availability of the manufacturing facilities in each period planning. An extended mixed-integer programming model of dynamic
cellular manufacturing system, in which some of the coefficients in objective function and constraints are fuzzy quantities,
is solved by a developed fuzzy programming based approach. The objective is to determine the optimal cell configuration in
each period with maximum satisfaction degree of the fuzzy objective and constraint. To illustrate the behavior of the proposed
model and verify the performance of the developed approach, a number of numerical examples are solved and the associated computational
results are reported. 相似文献
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动态交通分配与信号控制的组合模型及算法研究 总被引:7,自引:0,他引:7
This paper presents a generalized bi-level programming model of combined dynamic traffic assignment and traffic signal control, and especially analyzes a procedure for determining the equilibrium queuing delays on saturated links for dynamic network signal control satisfying the FIFO (first-in-first-out) rule. The chaotic optimal algorithm proposed in this paper can not only present the optimal signal settings, but also calculate, at each interval, the link inflow rates and outflow rates for the dynamic user optimal problem, and provide real-time information for the travelers. Finally, a numerical example is given to illustrate the application of the proposed model and solution algorithm, and comparison shows that this model has better system performance. 相似文献
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LIAN Ai-Ping GAO Zi-You 《自动化学报》2005,(5)
This paper presents a generalized bi-level programming model of combined dynamic traffic assignment and traffic signal control,and especially analyzes a procedure for determining the equilibrium queuing delays on saturated links for dynamic network signal control satisfying the FIFO (first-in-first-out)rule.The chaotic optimal algorithm proposed in this paper can not only present the optimal signal settings,but also calculate,at each interval,the link inflow rates and outflow rates for the dynamic user optimal problem,and provide real-time information for the travelers.Finally,a numerical example is given to illustrate the application of the proposed model and solution algorithm, and comparison shows that this model has better system performance. 相似文献