Modeling And Simulation Research On Urban Traffic Flow Based On Cellular Automata

Make sure to provide more accurate decision basis and reference data for urban traffic management and system optimization,many experts at home and abroad have studied the microscopic characteristics of urban road traffic flow and established various traffic flow models.Cellular automaton is widely used in traffic flow research because of its advantages of flexible rules,simple algorithm,and effective simulation.In view of this,the paper uses the theory of cellular automata to establish an urban traffic flow model based on velocity effect and security,and uses it to simulate various complex environments in urban roads.The main work of the thesis is as follows:(1)Based on the characteristics of urban road vehicles under the influence of multiple factors,a two-lane cellular automaton traffic flow model considering the vehicle speed and velocity change and introducing a safety factor was established.The lane changing rules and location updating rules are given again,and the model was simulated using C# and MATLAB to obtain the relationship between flow and density and space-time diagram.The influence of different safety parameters on flow and density and the relationship between density and flow in different initial conditions of the same safety parameters are analyzed.(2)Based on the two-lane traffic flow model considering the vehicle speed and velocity change and introducing a safety factor,a new safety distance two-lane traffic flow model considering the speed of the preceding vehicle is proposed.Using C# and MATLAB for numerical simulation,the basic map and space-time diagram are firstly analyzed.The improved model can better represent the characteristics of traffic flow.After analyzing the effects of different maximum decelerations on traffic flow,we can see that: The greater maximum deceleration,the greater the flow of traffic on the road.(3)Establish a comprehensive evaluation model,namely the improved TOPSIS method,using this method to carry out a comprehensive evaluation of the classic NS model and the proposed two-lane traffic flow model for two cities.The evaluation results show that the improved safety distance two-lane cellular automaton traffic flow model has higher accuracy and is closer to the measured data.The relative proximity of the improved safety distance two-lane traffic flow model considering the speed of the preceding vehicle is relatively close,so the model is better and is closer to the measured data.