基于可能度的交叉口信号控制区间优化模型

Interval Optimization Model of Signal Control at Intersection Based on Possibility Degree

为了满足城市道路不确定性交通需求,提高不确定环境下交通信号控制方案的可靠性,针对交通信号控制配时参数优化问题,结合区间优化理论提出了交叉口信号配时参数区间优化模型。首先,采用5 min采集标段确定高峰期交通量区间,并以此交通量区间作为控制系统输入参数;其次,以交叉口机动车平均控制延误区间为目标函数,构建区间值信号配时参数非线性优化模型;再者,以交叉口服务水平为性能目标,利用区间可能度模型对区间值优化模型进行转换,并采用遗传算法求解;最后,运用VISSIM仿真软件分别对北京市典型的三相位与两相位交叉口晚高峰时段进行模拟仿真。结果表明,该配时参数区间优化模型可行、有效。对于交通量波动较大的三相位交叉口,该区间优化方法明显优于Webster方案、鲁棒优化方法、实测数据,平均延误和交叉口通行能力较实测结果的优化程度分别为26.57%与7.07%;对于交通量相对平稳的两相位交叉口,区间优化方法可行,且能达到预期控制效果,但均弱于其他方案。进一步,选取北京市东三环8个交叉口进行信号配时参数区间优化,以高峰时段内5 min采集标段的饱和度和车均延误的波动趋势来分析控制方案的稳定性。分析表明,区间优化方法对各个路口高峰时段间而言都能达到预期控制效果,且更适合于交通量波动相对较大的交叉口,其方案的控制效果更稳定。

In order to meet the traffic demand and improve the effective of the traffic signal control under uncertain condition,this paper initially proposed a new signal timing interval optimization model of traffic signal control based on the interval optimization theory.Firstly,the traffic flow interval in rush hour was determined by 5 min acquisition section and used as the input parameters of traffic control system.Secondly,the interval-valued nonlinear optimization model of signal timing was constructed by taking the average vehicle control delay interval as the objective function.Thirdly,taking the intersection service level as the performance objective,this model was transformed by using the interval possibility degree model and solved by using genetic algorithm.Finally,the three-phase and twophase intersections in rush hour in Beijing were simulated by using VISSIM simulation software.The results show that the method is feasible and effective,and is obviously superior to Webster scheme,robust optimization method and measured data at three-phase intersection with large fluctuation of traffic flow.The vehicle average delay decreases by 26.57%and capacity increases 7.07%compared with the measured data.At the two-phase intersections with relatively stable traffic volume,the interval optimization method is feasible and can achieve the expected control effect,but it is weaker than other schemes.Furthermore,the signal timing interval optimization model was used by the eight intersections in rush hour in Beijing with VISSIM simulation software and analyzed by the fluctuation trend of the saturation and the average delay of the 5 min acquisition section.The analysis show that the interval optimization model can achieve the expected control effect for each intersection during peak hours,and is more suitable for intersections with large traffic flow fluctuations,and the performance of the control scheme is more stable.