Simulation And Research On Traffic Signal Intelligent Control Strategies For Intersection

With the continuous development of social economy and people’s living standard, the urban car ownership keeps increasing rapidly, which causes the urban road congestions, traffic delays, environmental pollution and other issues to get worse, lowers the capacity of urban road networks, and restricts the further development of urban social economy. As a joint of urban roads, the intersection plays an important role in the road network and traffic flow, and various traffic issues mainly appear at intersections. Hence, it is very imperative to delve into the problem of intersection signal control.In this thesis, the traffic flow and traffic signal control at single intersection are deeply discussed and researched. The major work is shown as follows:First, the current situation of traffic signal control is studied. The background and purpose of the research is comprehensively analyzed. The introduction of the traffic flow model, the signal control methods and the relevant knowledge of traffic signals is done in this thesis.Secondly, on the basis of the similarity between the chain reaction of nuclear fission and the process of the formation and dissipation of vehicle queue, this thesis, employing analogy method, describes the chain reaction phenomenon of the formation and dissipation of vehicle queue. By use of the vehicle blocking signal and dissipation signal, the chain reaction models of the formation and dissipation of vehicle queue are respectively constructed. And based on these two models mentioned above, the dynamic queuing model of vehicles at the signal intersection is constructed. The chain reaction model of vehicular queue provides novel ideas and methods to revealing the law of traffic queuing.Finally, on the basis of the vehicle dynamic model constructed above, this thesis, employing fuzzy control method, the inputs of which are respectively the current queue length of vehicles and the average density of traffic flow, designs two multi-phase fuzzy controllers. According to real-time road traffic flow, the proposed fuzzy controllers control the signal system and have been compared with timing control method. From the results of MATLAB simulation, the superiority of the proposed fuzzy controllers is proved. Then, on the base of the fuzzy controllers, this thesis respectively proposes single-lane and multi-lane multistage fuzzy control strategies based on queue length, which are simulated and compared by employing MATLAB.