Study On Multi-objectives Optimization Control Method Of Environment-friendly Traffic Signal

The effective traffic signal control makes the operation of the urban road traffic smoothly and orderly,therefore,it has been always a hot issue for the scholars.However previous studies focused more on the decrease of the traffic jam and ignored the effect of the traffic operation on the environment.With the enhancement of people environmental protection awareness,it is urgent for us to find a traffic signal control scheme that can consider the environment factors.Based on this purpose,this paper was formed.Firstly,we described the trajectory of the vehicle and divided it into uniform speed process,decelerating speed process,idle speed process and accelerating speed process.And we also described the trajectory of the vehicle with idle speed or without idle speed.Then we employed the regression analysis method to analyze and fit the relationship of delays and emissions,and gave the function relation obtained by the regression analysis.Considering that right turning vehicle at the intersection is not controlled by the intersection signal and it will slow down whether there is vehicle ahead or not,we adjusted the above-mentioned function relation and got a general formula for calculating the emission of a single vehicle.Through intersection traffic flow and the relationship among the parameters of signal control,we got a probability distribution function based on right light time.As the timing scheme was given,we can estimate the emission values of each traffic lane at the intersection and got emissions of the whole intersection finally.Then,on basis of contrasting with the current mainstream delay calculation methods,we selected the delay calculation method of HCM to calculate the total delay of the intersection.What's more,considering saturation constraints,we constructed the intersection comprehensive benefit index and established the multi-objective optimal control model of traffic signal.In this paper,we utilized the combination of Genetic Algorithm and Ant Algorithm to solve the model and employed Matlab programming tools to design the algorithm program.Finally,we chose the intersection of Renmin Street and Ziyou Road in Changchun as the case study.We investigated the intersection geometry information,vehicle flow rate,intersection timing information and set up two benefit measurements to evaluate overall operation efficiency of the intersection.We finished the model solution when the delays and emissions were under different proportions.And from different periods of time,we analyzed to optimize and deduce air quality benefits of motor vehicle emissions.Then,simulation was done by VISSIM software,in this way,we contrasted the delay and emission values before and after optimization.And it demonstrates that signal control method can improve operation and environment benefits effectively.