Investigations Of Intelligent And Control Of Urban Traffic Signal

The aggravation of urban traffic jam becomes a social issue for the development of cities over the world, as it causes frequent traffic accidents, increased vehicle delay, and worsening environment. ITS (Intelligent Transportation System) is one importation solution to traffic jam. Intelligent control of urban traffic signal is not only a hot issue of both automatic control and traffic engineering, but an important element of ITS.As a complex system of heavy nonlinearity, randomness, Time-variability and uncertainty, urban traffic system is beyond the capability of traditional control method which is based on precise mathematical model, so increased importance is attached to artificial intelligence (AI) method.In this dissertation, in order to relieve traffic jam, in-depth study on intelligent control of urban traffic signal is carried out based on the fusion of fuzzy logic and genetic algorithm. At first, the paper regards a single intersection as research object, we design a multi-Phase fuzzy traffic control arithmetic, writing the emulator using MATLAB7.0 to simulate the multiphase fuzzy control system under different traffic environment, and comparing with the time control which worked under the same traffic environment. The emulation results explained that the multiphase fuzzy control method synthetically considering the queue length of each roadway to decide the distribution of greentime,and it is more similar to hominine decision-making Process and could control the single intersection in effect.Though Fuzzy Logic Control does not need to set up precise mathematical model, it still presents a difficulty for deciding all the membership functions correctly only by human experience.Therefor, in order to solve this problem, the Genetic Algorithm is used to real-timely optimize membership functions because the Genetic Algorithm has got the strong searching ability without knowing the mechanism of the object and only driven by the fitness function. The emulation results indicates that the intelligent control technology which combined fuzzy control with genetic algorithm could lower the average delay time of the vehicle.Finally, A hierarchical coordination control algorithm for artery is put forward.