The Study Of Optimizing Timging Signal Based On The Multi-objectve Model In The Small And Medium-sized Cities

With the increasing of number of urban vehicles,which causes to issues of delays and poor air quality becomes increasingly serious.Urban arterial road is the main undertaker for the urban transportation,the intersection is the key point of the main road traffic network,improving the traffic capacity of the main road of the city by reasonably regulating intersections.At present,the signal lights of the intersection generally use timing control,manual control or single target optimization control,which has been unable to meet the development of the changing requirements of effectiveness,high efficiency,integrity of.In this paper,taking the main road of Changan Avenue as an example,the existing signal timing scheme of the existing problems and shortcomings is optimized.Firstly the paper dose to evaluate and analyze the current status of the signal timing.Secondly the paper can get timing parameters of every intersection,aiming at a single point of intersection by using optimization timing method of fuzzy dynamic based on multi-objective model.In the multi-objective optimization model,three indexes of delay,capacity and parking times are selected as the objective function,saturation constraints are added to the constraints.The weight coefficient of the multi-objective optimization model is solved by analytic hierarchy process(AHP),the optimal signal period is obtained.Taking queue length as fuzzy control variable.In this paper,the fuzzy dynamic control is applied to the multi phase,and the green time of the phase is adjusted to adjust the effective green time of the corresponding phase According to the actual flow,the paper use synthetically the method of dynamic timing and integrated timing and applies to phases by control of fuzzy dynamic,the optimized parameters of each intersection are obtained.Secondly the paper introduces some key parameters and coordination models,and use dynamic control scheme of the line control,then it puts forward the scheme of the line control for urban arterial road.The final results are obtained.To reduce traffic delays and congestion,and improve the operation of urban traffic network,The public cycle time is adjusted according to the traffic flow cycle of the key intersection on the trunk.The possibility of a line control system is proposed,all the streets become to fit the line control system.The green brand is 32 s,speed is 42km/h.Finally,VISSIM was used for testifying the effectiveness of the optimization model.At last the design project is appraised by the three aspects of the signal intersection quality index.The simulation results show that the optimized scheme reduces the intersection delay by 0.4s~3.5s,the number of stops by 3m~18m,and travel time by 0.4s~3.4s,which greatly improves the operation condition of the small and medium-sized urban network.