城市快速路入口匝道放行策略研究

针对如何把计算得到的匝道调节率值转化成实际的放行车辆问题,总结了国内外常用匝道放行策略,分析各自的优缺点。结合我国城市快速路的特性,提出适宜的匝道放行策略,并初步探讨了相应的匝道调节周期及信号灯配时,以此提高匝道控制的实施效果。     

低成本SCR系统计量装置的设计

针对国Ⅳ排放标准全面实施的要求及国外类似SCR系统的高价格,设计了一种低成本的SCR系统计量装置.该装置的系统执行器部分均采用国内产品;控制器部分采用Freescale 9S12单片机,并采用配套的编译工具Codewarrior进行底层驱动程序的开发.通过对电磁阀流量的标定,为上层控制策略的制订奠定了基础.     

Managing evacuation networks

This paper proposes a non-anticipative, adaptive, decentralized strategy for managing evacuation networks. The strategy is non-anticipative because it does not rely on demand forecasts, adaptive because it uses real-time traffic information, and decentralized because all the information is available locally. It can be used with a failed communication network.The strategy pertains to networks in which no links backtrack in the direction of increased risk. For these types of networks, no other strategy exists that can evacuate more people in any given time, or finish the evacuation in less time. The strategy is also shown to be socially fair, in the sense that the time needed to evacuate all the people exceeding any risk level is, both, the least possible, and the same as if less-at-risk individuals did not participate in the evacuation. The strategy can be proven optimal even when backflows happen due to driver gaming.     

An Adaptive Neuro-Fuzzy Inference System for estimating the number of vehicles for queue management at signalized intersections

Queue management is a valuable but underutilized technique which could be used to minimize the negative impacts of queues during oversaturated traffic conditions. One of the main obstacles of applying queue management techniques along signalized arterials is the unavailability of a robust and sufficiently accurate method for measuring the number of vehicles approaching a signalized intersection. The method based on counting vehicles as they enter and exit a specific detection zone with check-in and check-out detectors is unreliable because of the likely systematic under or over counting and the resulting cumulative errors. This paper describes the application of the Adaptive Neuro-Fuzzy Inference System (ANFIS) in the development of a new fuzzy logic-based approach for estimating the Number of Vehicles in a Detection Zone (NVDZ) by using detector time-occupancy data (instead of detector counts). Microscopic simulation results are used to evaluate the accuracy of the NVDZ estimates. Tests were carried out to determine the transferability of a tuned Fuzzy Inference System (FIS) and to check the sensitivity of the calibrated FIS to detection coverage, the location of the detection zone relative to the signalized (bottleneck) intersection, the length of the detection zone, and different signal timings at the bottleneck intersection. Results show that the NVDZ estimation based on fuzzy logic seems to be a feasible approach. Although the primary objective of developing the NVDZ estimation technique has been queue management, other applications such as ramp metering and incident detection could potentially use the same technique.     

基于人工神经网络的高速公路入口匝道控制算法

利用BP人工神经网络对高速公路单个入口匝道进行控制。根据具体问题对神经网络控制器的设计进行了讨论，利用BP改进算法对神经网络控制器进行训练。利用Matlab对控制器的控制效果进行了仿真，将仿真结果与车道、需求-容量控制的效果进行了比较，结果表明，该神经网络控制器可以获得优良的控制效果。     

高速公路入口匝道控制算法用户公平性分析

入口匝道控制是高速公路交通控制有效策略之一。为避免早期的入口匝道控制算法往往只注重效率而忽视用户的公平性,从而造成入口匝道的排队增加的缺陷,将经济学中的Gini系数引入高速公路入口匝道控制算法分析评价中来反映用户的公平性,以出行时间节省比为效率指标,并以长春市绕城高速公路的净月立交入口匝道为例,通过实际数据调查及计算机模拟对假定实施的入口匝道控制各方案的公平性进行了分析,为高速公路入口匝道控制策略的选取提供依据。     

快速路整体性匝道仪控仿真研究

以Payne车流模型和宏观交通流连续方程为基础,将多路段的动态交通流离散方程应用于控制系统的描述,以泰勒展开式及连锁律推导二阶非线性速率方程式,构建一非线性整体匝道仪控模型.算例中以快速路检测的实时资料为前提,matlab 6.5为仿真工具,进行模拟和数值计算,仿真结果表明:非线性控制模型可有效的疏解高峰期交通拥挤的状况.     

Behavior of the cell transmission model and effectiveness of ramp metering

The paper characterizes the behavior of the cell transmission model of a freeway, divided into N sections or cells, each with one on-ramp and one off-ramp. The state of the dynamical system is the N-dimensional vector n of vehicle densities in the N sections. A feasible stationary demand pattern induces a unique equilibrium flow in each section. However, there is an infinite set—in fact a continuum—of equilibrium states, including a unique uncongested equilibrium n^u in which free flow speed prevails in all sections, and a unique most congested equilibrium n^con. In every other equilibrium n^e one or more sections are congested, and n^u  n^e  n^con. Every equilibrium is stable and every trajectory converges to some equilibrium state.Two implications for ramp metering are explored. First, if the demand exceeds capacity and the ramps are not metered, every trajectory converges to the most congested equilibrium. Moreover, there is a ramp metering strategy that increases discharge flows and reduces total travel time compared with the no-metering strategy. Second, even when the demand is feasible but the freeway is initially congested, there is a ramp metering strategy that moves the system to the uncongested equilibrium and reduces total travel time. The two conclusions show that congestion invariably indicates wastefulness of freeway resources that ramp metering can eliminate.     

塔河油田集气总站计量输差分析及控制

天然气输差是控制输气成本的一个关键指标,可分为计量输差和漏失输差两大类。在实际生产中,由于产生输差的原因非常复杂多变,往往导致天然气计量交接不能满足精度要求。因此,找出影响其计量误差和提出改进措施有着重要的意义。以塔河油田集气总站为例,从旋进旋涡流量计和超声流量计的原理特点、现场应用情况、用户负荷、外部干扰等4个主要方面对引起计量输差的因素进行了探讨,并提出了6项控制措施。其中包括通过现场流程改造,有效解决了FT301超声流量计反向计量不准确的问题,使该站的站输差从5.26%降低到了0.68%,取得了较好的效果。