Research On Intelligent Control System Of Traffic Signals Based On Logical Rules

Traffic signal is one of the most significant element to control traffic network in big cities. The increasing number of traffic flux in recent years actually poses a great challenge. Thus, it is meaningful to improve the traffic efficiency in the crossroads in order that traffic jam can be lessened. Since the traditional method with fixed signal for time distribution can not meet the requirement of the frequently changing situation, an effective, flexible as well as intelligent system for time distribution is needed to guarantee the favorable passage of vehicles in a single crossroad, which has already been one part of researches on Intelligent Transport System (ITS).With a detailed analysis of traffic characteristics of crossroads in big cities, a logical control model of traffic signals is established based on logical rules. Taking traffic flux in all directions into consideration, the flux in each branch is employed as a variant of input, from which results in turn a corresponding output of logical control of traffic signals. Approximately similar to the actual traffic situation of crossroads, this model can reflect its feature of being disperse and random. After the introduction to Pan Boolean Algebra, a new method of logical control, characterized with concise presentation and available programming, is proposed, which lays a theoretical foundation for the control of traffic signals according to the actual situation.In order to validate the logical control model, a simulation has been conducted with Matlab and has been proved to be effective in improving the traffic capacity of crossroads, reducing the traffic delays and cutting down the waiting time. It is characterized by optimizing the control of traffic signals and is evidently preferable to the traditional one. A in-lab presentation system with actual traffic situation has also been designed to simulate the intelligent traffic control. The result proves to be feasible and confirms the advantages of the logical control proposed in this dissertation.The result of the system, with its practical value, is supposed to slove the problem of traffic signals in crossroads of big cities.