The Research On Urban Traffic Signal Control System Based On Intelligence Control Method

With the rapid development of the urbanization, the problem of city transportation has been becoming the same issue to each big city in China. As the converge points of urban traffic, the urban intersections are play important role in the road net and traffic flow. How to improve the capacity and reduce the delay of intersections maximum by road resource with existence and scientific traffic control method is an important topic of the traffic engineering. Traffic signal control is one of the most efficient methods. And the new ways for the real-time traffic control system are provided by the improvement of intelligence control methods.First, the aim and classify of urban traffic signal control system are introduced by this thesis, and the optimization methods for signal control system are introduced emphatically. And then the main parameters, evaluating indicators, vehicle arrival distribution and correlative intelligence control methods of urban traffic signal control system are expatiated. Based on the analyses of conventional single intersection signal control methods, the limitations of conventional methods such as incomplete advisement and great operand are found. Aimed at the limitations, the conception of'large phase'is introduced and then a new traffic signal control method based on fuzzy logic and GA for the urban single intersection is presented. In this control system, the phases in the same direction are merged into a'large phase'. The estimate green time of the large phase are calculated first according to the queue length of green light direction. And then the estimate green time are adjusted by the adjustment time which are calculated by the fuzzy logic controller which is optimized by GA according to the vehicle arrival imbalance of two relatively direction in recent green light phase and total queue length of red light direction. After that, the green light times of each'small phase'in the big phase are optimized by GA. In this signal control system, clear the queue of recent large phase is guaranteed, and the otherness of each turning in each direction of the intersection is considered. The complexity of the system could be reduced by the conception of'large phase'and'classification control'The validity and progress of this control system is validated by the simulating and comparing with the timing control system. The result of simulation indicates that the control effect and calculation efficiency are enhanced, especially when the traffic flow of intersection has great discrepancy and diversification.