Design And Implementation Of Urban Intersection Traffic Signal Fuzzy Control System

With the rapid economic development and the speeding up urbanization process, the number of motor vehicles has been increasing sharply resent years, which leads the traffic problem to one of the urgent livelihood problems in China. Due to the time variation and randomness of the intersection vehicle flow in the modern urban transport system, the conventional control method of intersection traffic light has become difficult to meet the demands of traffic intersection such as the traffic capacity, traffic dispersion and so on.According to the problems, a real time intelligent traffic signal control system is projected based on fuzzy logic algorithm. The traffic flow of each intersection is acquired through the vehicle counting sensors in the system. And a single variable fuzzy logic controller with two dimensions inputs is designed aimed, the inputs of which are the number of waiting vehicles under the green light phase and the difference between and the number under the red light phase, while the output of which is the delay time of the green light. The fuzzy control rules table is translated into a query table off-time, and then the query table is stored in the memory for querying online. In practice, the green light time is adjust automatically based on the waiting cars in the cross road.The software and hardware of the intelligent traffic signal control system are proposed in the paper. The intelligent traffic signal control system based on fuzzy logic algorithm could control the traffic light, drive power and so on using C language. It adopts AT89S52 microcontroller as the core chip, and Intel8279 as input/output device.Two different ways of signal control are compared with the intersection traffic data. The results show that the vehicle actuated control is better than the multiple interval fixed-time control, and the advantage of the former is distinguished when there is not many vehicles in the cross road. Although the real data and status of the intersection traffic are update continuously, the real fuzzy logic control system can guarantee the optimal adaptability of the intersection, and reduce the vehicle's average waiting delay time.