Research On The Intelligent Control Technology Of Traffic Signal In Urban Grade Intersection

With the rapid development of the urbanization, the problem of city transportation has be becoming the same issue to each big city in China. More and more phenomenon indicates that the city traffic jam is usually manifested in the urban intersections, which are the converge points and play important role in road net and traffic flow. Now our internal cities mostly introduce overseas traffic control systems which were designed in terms of the traffic circumstance of the developed country, have some localizations and couldn't adapt to the current traffic demand. Therefore, According to the fact, we exploitured the traffic signal control system of the grade intersection which is based on intelligent control technology to satisfy the current traffic demand.The dissertation adopted the intelligent control technology which combined fuzzy control with genetic algorithm to control traffic signal of the grade intersection, and designed multiphase self-adaptive fuzzy control system so as to reduce the average delay time and to improve the traffic power of the traffic vehicle in grade intersection and used MATLAB to simulate the multiphase self-adaptive fuzzy control system. The main contents in this dissertation includes:Firstly, the main control parameter and performance index and now the control method of traffic signal used in common were introduced in detail, and the importance of the research on the traffic signal of urban grade intersection was expatiated in this dissertation;Secondly, aiming on the characteristics of high complexity and randomicity of the traffic flow, the multiphase classification fuzzy control system was designed, which is easy to acquire fuzzy control rules and could greatly decrease the number of fuzzy rules, is very suitable to complex urban intersection control;Thirdly, writing the emluator using MATLAB7.0 to simulate themultiphase classification fuzzy control system under different traffic environment, and comparing with the time control which worked under the same traffic environment. The emulational results explained that the multiphase classification fuzzy control method synthetically considering the queue length of each roadway to decide the distribution of green time, and it is more similar to hominine decision-making process and could control the grade intersection in effect.Fourthly, aiming on the fuzzy controller with the disadvantage that the membership functions are decided by expers experience so as to influence the control performance, so this dissertation adopts genetic algorithm to optimize the membership functions of the fuzzy controller.Fifthly, writing the emluator using MATLAB7.0 to simulate the optimized fuzzy controller under the different traffic environments, and comparing with the unoptimized fuzzy controller which worked under the same traffic environment. The emulational results indicats that the intelligent control technology which combined fuzzy control with genetic algorithm could lower the average delay time in the flat surface for the vehicle which was going through the single intersection than the time controlling and it is easier to adapt to the complicated and versatile transportation environment.In the end, summarizing the whole work, and pointing out some content which would be researched in the future.