Application Of Fuzzy Control And Optimization In Traffic Light Timing

With the rapid development of the economy,the number of cars in China has increased dramatically,and the demand for traffic conditions has been expanding.However,the traffic light timing scheme has been lagging behind the urban traffic demand standards,making traffic congestion more serious.At present,traffic congestion has gradually become a factor restricting the sustainable development of most cities in China.Intersection is the key point in urban road network.Traffic congestion often occurs at intersections.Proper adjustment of the traffic lights at the intersection can not only improve the capacity of the whole urban traffic system to a certain extent,but also make the trip safer and quicker.In this paper,the traffic parameters of intersections may fluctuate in a relatively short time.A genetic algorithm is used to optimize the setting of the traffic lights in the fuzzy control system,and the traffic light timing scheme at the crossroads is dynamically adjusted in real time.First of all,this paper selects trident and three phase control as the research object.According to the queue length and lane number of each phase,the priority of each phase's traffic is determined,and the phase transformation order of the intersection is designed.Then the maximum queue length of the current green traffic phase and the traffic volume of the next traffic phase are taken as the input variables of the fuzzy controller.At present,the green light extension time of the passing phase is taken as the output variable of the fuzzy controller.After the fuzzy reasoning and the clear processing,the corresponding timing scheme is obtained,so that the adjustment time of the green light duration of each phase of the intersection is adjusted.Secondly,the delay time of vehicles at intersections is chosen as the evaluation index,and then the mathematical model is established and the objective function is constructed according to the model.Genetic algorithm is used to encode the central point and width of the Gauss type membership function in fuzzy controller,initialize population,select fitness function,evaluate the fitness of individuals,select crossover and mutation,and obtain the optimal membership function,and then verify its feasibility through simulation.Finally,taking a trident intersection in Changsha as an example,the traffic basic data of the intersection are collected,and the optimized traffic light timing scheme is applied to the intersection simulation experiment of VISSIM traffic software simulation.The effectiveness of the proposed method is verified by comparing the data before and after optimization.