| There are various uncertainties in actual traffic system. How to start from the characteristics of urban transportation system, to fully consider the influence of uncertainties on the traffic signal control, has become the internal requirement to solve the problem of urban traffic signal control. The existing isolated intersection signal theories and artery signal coordination theories less consider the influence of uncertainties on signal control. Aiming at this deficiency, this paper researched the influence of uncertainties on signal control actual efforts in term of isolated intersection delay model, optimization of cycle length of isolated intersection under the fluctuation of arriving traffic flow rate, evaluation method of arterial green wave coordinated control scheme based on Set Pair Analysis by using uncertainty analysis theory-Set Pair Analysis. The main scientific researches and research results are as follows.(1) In order to overcome the limitation that the existing isolated intersection delay models or optimization methods of cycle length based on minimum delay are deduced from the hypothesis that vehicle arrives all follow certain distribution. A delay model based on random arrival and fixed-time departure was established by collecting headway samples at upstream approach section and using vehicle arrival-departure curve. And then, a method of searching optimized cycle length within a certain cycle range was proposed. This method doesn’t depend on specific arrival distribution of vehicles and has good applicability and robustness.(2) Aiming at the fluctuation of actual arrival rate at intersection approach, the relationship between signal cycle and delay in different arrival cases. A method of calculating average delay was proposed by adopting vehicle arrival & departure curve and using headway samples collected at upstream section, which realized the optimization of cycle length at isolated intersection under the fluctuation of arrival rate. Taking four-phase intersection for example, a method of calculating delay was analyzed based on headway samples from upstream section. And the cycle length obtained by this method has a good applicability for the case of fluctuation of actual arrival rate by comparison. This effectively promotes the applicability and robustness of signal control scheme of isolated intersection.(3) Considering the feature of vehicle actual running speed varied in velocity band, we analyzed the control effect of different traffic signal coordinated control schemes by using set pair analysis. We pursued the maximum bidirectional green wave bandwidths under the uncertainty of actual speed. By collecting vehicle running speed samples on arterial road, we could generate multiple alternative schemes of arterial green wave coordinated control. After computing the connection degree between running speed and green wave bandwidth, we could select the alternative scheme which has the maximum connection degree as the optimal green wave coordinated control scheme. So the green wave coordinated control schemes could be evaluated and optimized in consideration of the uncertainty of actual speed. The simulation analysis and practical application of the actual example show that, this method can make use of collected samples of running speed directly and select an optimal green wave coordinated control scheme from multiple alternative scheme set. The green wave control demand of the platoon can be satisfied mostly in the velocity band. It also makes as many vehicles in a platoon get into the green wave band as possible.(4) For the proposed optimization model and method, the concrete procedure in the application of the method is given through mathematic examples or real ones. The accuracy of the model and method was proved through the comparison of relative index obtained by traffic simulated software. |
