排序方式: 共有26条查询结果,搜索用时 31 毫秒
21.
Hyun Woong Cho Bhargava R. Chilukuri Jorge A. Laval Angshuman Guin Wonho Suh 《运输规划与技术》2020,43(5):475-487
ABSTRACT This paper presents a case study of the optimal ALINEA ramp metering system model of a corridor of the metro Atlanta freeway. Based on real-world traffic data, this study estimates the origin-destination matrix for the corridor. Using a stochastic simulation-based optimization framework that combines a micro-simulation model and a genetic algorithm-based optimization module, we determine the optimal parameter values of a combined ALINEA ramp metering system with a queue flush system that minimizes total vehicle travel time. We found that the performance of ramp metering with optimized parameters, which is very sensitive possibly because bottlenecks are correlated, outperforms the no control model with its optimized parameters in terms of reducing total travel time. 相似文献
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地质雷达信号采样定时控制 总被引:3,自引:1,他引:2
针对地质雷达信号数据采集过程中,采样时刻的定时精度与定时范围难于兼顾的实际,基于斜波发生器原理,用高分辨率数模转换器生成基准比较电压,实现高精度可编程定时电路。可编程计数范围为16bit,实际最小定时单位达8ps,折合采样频率高达50GHz。使用该定时器的地质雷达,采样时刻抖动小于1ps;室内条件下用2GHz天线在3m范围内探测移动金属板,测量误差为1%;野外环境下用100MHz天线对湖底6 2m内的不同目标进行勘探,测量误差在5%~8%范围内,实现地质雷达对地下目标体的高精度定位。 相似文献
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以大连开发区小窑湾立交桥为例,从设计概述、主要技术指标及线形设计方面对该立交桥进行论述,并对立交桥线形设计进行总结。 相似文献
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Ramp metering (RM) is the most direct and efficient tool for the motorway traffic flow management. However, because of the usually short length of the on-ramps, RM is typically deactivated to avoid interference of the created ramp queue with adjacent street traffic. By the integration of local RM with mainstream traffic flow control (MTFC) enabled via variable speed limits (VSL), control operation upstream of active bottlenecks could be continued even if the on-ramp is full or if the RM lower bound has been reached. Such integration is proposed via the extension of an existing local cascade feedback controller for MTFC-VSL by use of a split-range-like scheme that allows different control periods for RM and MTFC-VSL. The new integrated controller remains simple yet efficient and suitable for field implementation. The controller is evaluated in simulation for a real motorway infrastructure (a ring-road) fed with real (measured) demands and compared to stand-alone RM or MTFC-VSL, both with feedback and optimal control results. The controller’s performance is shown to meet the specifications and to approach the optimal control results for the investigated scenario. 相似文献
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结合广深高速公路太平立交至五点梅立交段的改造,提出了4个设计方案,经综合比较,方案一充分利用现有加宽工程,将左出虎门方向的交通量全部改为右出,使其与广深高速公路其他立交的出口方式相协调,减少了该路段的交织问题,也降低了该出口的事故发生率。 相似文献
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