Adaptive Control Of Traffic Signal Based On Dynamic Priority

Urban transport plays a very important role in the economic development and it is the lifeblood of socio-economic. With the rapid economic development, traffic congestion has become a major problem faced by all the countries. Traffic congestion leads to huge economic cost and a series of problems such as security issues, energy issues, land issues and environmental issues. Therefore, we must take effective segments to solve the problem of traffic congestion. Urban traffic signal control is an important part of the traffic signal control system, and it is a hotspot in the field of control and traffic engineering. The transport system has characteristics of randomness, nonlinear and time-varying, traditional signal control method based on precise mathematical model cannot solve the problem effectively. In this paper we propose an adaptive control of traffic signal based on dynamic priority.We carry out the research on urban traffic signal control. As for the deficiencies of the existing traffic signal control system, an adaptive control of traffic signal based on dynamic priority method is proposed to solve the problem of urban traffic congestion. This method contains the optimum phase control strategies and stability supervisory mechanism. In order to respond to traffic flow conditions in real time, we get rid of the cycle, split and offset parameters in traditional traffic signal control systems. Optimal phase control strategy is to model the road network with a directed weighted graph. Then the priority is calculated based on PageRank method, and the green time is allocated according to the priority of the sections. Stability supervisory mechanism is a supplement of the optimal phase control strategy, and its responsibility is to supervise the number of vehicles on sections. If a road does not get the green time, and causes system instability, then it will be given the green time of the road immediately. Due to the removal of the cycle, split and offset parameters, the method in this paper is more flexible and can be able to respond to changes in traffic flow in real time. The system has stability problems due to the removal of the cycle parameter, so in this paper we propose a stability supervisory mechanism to ensure the stability of the system.Simulation experiments on19junctions of Dalian in VISSIM platform show that this method is superior to the traditional traffic fix signal control method, and it remains a better performance in the case of traffic congestion.