Research On The Traffic Light Dynamic Timing Algorithm Based On Improved PSO

Nowadays,the scale of the city is getting bigger and bigger,and the traffic jam is getting worse day by day.The traffic signal controller at the intersection has the functions of time division and variable period control.The reasonable timing scheme of the traffic signal controller can effectively alleviate the traffic congestion.Since the traffic signal controller is the carrier to realize the traffic signal light control,this paper mainly studies the built-in signal timing algorithm of the traffic signal controller.In this paper,by studying relevant references at home and abroad,the parameters of vehicle delay,number of stops,capacity,pedestrian delay,exhaust emissions and phase difference of trunk line coordination control at a single intersection are taken as the optimization object.The simulation results show that the signal timing scheme can effectively improve the efficiency of the road.In view of the current situation of urban road traffic congestion,the main research contents of this paper are as follows:(1)At first,through the study of many intelligent algorithms,Particle Swarm Optimization(PSO)is selected as the Optimization algorithm in this paper.Then the shortcomings of the basic PSO are improved and analyzed by simulation.The simulation results show that the improved PSO can improve the optimal value,variance and mean value of the solution and running time of the algorithm obviously compared with the basic Particle Swarm Optimization.(2)On the research of traffic signal light control method at a single intersection,Based on the improved Webster delay model,this paper takes cycle length and effective green light duration as the restriction conditions,and considers five indicators in the performance evaluation index of a single intersection as the optimization index of the signal light timing at a single intersection,then establishes a multi-objective function model with constraints.It can be converted into a single objective function by the penalty function,and then solved by the improved Particle Swarm Optimization.The simulation results show that the proposed signal timing scheme is better than the previous one,and four of the five indicators have achieved the desired effect.(3)The coordinated control of traffic signal lights is an important part of urban road network.Based on the signal timing of a single intersection,the paper studies the coordinated control of the main road.Because the coordinated control of trunk lines is complex,this paper only optimizes the delay time of vehicles on trunk lines,and establishes a mathematical model of the minimum delay time of two-way coordinated control on trunk lines related to phase difference.Finally,the phase difference of the minimum delay time of trunk line vehicles is obtained by simulation analysis with an example.By adjusting the phase difference between the adjacent intersections on the trunk road,the traffic jam on the trunk road can be reduced.