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为了提高协调系统运行的稳定性及控制效果,针对车流随机特性,采用理论分析和仿真计算相结合的方式,探讨车流速度波动和车流到达率波动2个因素对协调系统控制效果的影响机理。理论分析中,将变动的车流速度转化为区间数形式,根据单向协调相位差求取公式,得到理想相位差的变动区间;根据相位清空可靠度计算公式,得到车流到达率波动与最佳周期、协调相位绿灯时间、车均延误时间、最大排队长度等的解析关系,并进一步借助双向协调系统中求取相位差的数解法,得到关于车流到达率波动方差的相位绿时差。仿真分析中,利用MATLAB与VISSIM搭建仿真平台,选取2个几何线形规则的信号交叉口,制定模拟协调控制方案,选取仅改变车流速度、仅改变车流到达率、同时改变车流速度和到达率这3种情况进行仿真,以车均停车时间、平均排队长度、车均停车次数、车均延误时间为指标,评价其对协调系统控制效果的影响。研究结果表明:车流速度波动方差、车流到达率波动方差与控制效果均呈正相关关系,车流速度波动的影响大于车流到达率波动的影响,两者同时波动时不是简单的叠加关系,而是相互抵消影响,其控制效果介于2种情况之间;仅车流到达率波动的情况下,协调相位双侧车流到达率波动时,控制效果优于单侧车流到达率波动;车流处于自由流与拥挤流之间切换状态时,控制效果优于拥挤流状态,劣于自由流状态。
In order to improve the stability and control effect of coordinated system operation, aiming at the stochastic characteristics of traffic flow, theoretical analysis and simulation are combined to explore the influence mechanism of traffic flow fluctuation and traffic flow arrival rate on the control performance of coordinated system. In the theoretical analysis, the changing traffic flow speed is transformed into the form of interval numbers, and the formula is obtained according to the one-way coordinated phase difference, and the variation interval of the ideal phase difference is obtained. Based on the phase clearance calculation formula, the traffic arrival rate fluctuation and the optimal period , Coordinating the green light time, the vehicle delay time, the maximum queue length and other analytical relationships, and further by means of a two-way coordination system to obtain the phase difference of the number of solutions to obtain traffic arrival rate variability of phase green time lag. In the simulation analysis, using MATLAB and VISSIM to build a simulation platform, we select two signalized intersections with geometric rules and establish a simulation coordination control scheme. Only changing the traffic flow rate, only changing the traffic arrival rate, and changing the traffic speed and arrival rate The simulation was carried out to evaluate the effect of parking control time, the average queue length, the number of vehicle parking and the vehicle delay time as indicators. The results show that: the variance of traffic flow velocity and the variation of traffic arrival volatility have a positive correlation with the control effect. The influence of traffic flow velocity fluctuation is greater than that of traffic arrival rate fluctuation. The two fluctuations are not simple superposition, but offset each other , And the control effect is between two kinds of situations. When only the arrivals fluctuate, the control effect is better than that of unilateral arrivals when the arrival arrivals of coordinated two-sided traffic flows are fluctuating. The traffic flows are in free flow and crowded flows When the state is switched over, the control effect is better than the state of the crowded flow and worse than the state of the free flow.