The Study And Application On The Traffic Lights Based On Logical Control

With the development of social economy, the countries all over the world are striding towards the urbanized diretion. The automobile's popular rate is getting higher and higher. Regardless of being a developed country or a developing country, the traffic congestion intensifies, the accidents happen frequently,the transportation environment deteriorates. The problem becomes serious day by day. Meanwhile, the overall resources waste that the traffic jam initiates and the contamination resulted from the automobile emission are even more difficultly calculated. Under this situation, the thought of considering synthesizing the vehicles and paths from the system's viewpoint and focusing on improving operating efficiency by making full use of existing traffic facility to save the massive construction fund and time arises at the historic moment. The intelligence of transportation system is just the product of this thought. At present, our country has started a widespread and deep research in this domain.The logical control is one of the intelligent control. It is easier to accept the thought by bringing in causal relation as well as induction and inference. This paper takes the traffic lights control in'T'-junction of the city as an example and elaborates the application of logical controlling thought specifically. Firstly, take the general glistening order of traffic lights as a premise, take enhancing the efficiency of every intersection as the principle, the paper formulates the corresponding rules in view of the quantity of vehicles in different time. After studying A,B and C intersections separately under the conditon of small flow; general flow; large flow, 27 different kinds of rules are formulates altogether. Small flow of C intersection is selected to introduce this rules.Now, there are 9 kinds of situations. But only 4 kinds are inducted after analysis at last. Then, the Pan-Boolean algebra is used to simplify the complex multi-state and many-variable system to calculated symbols. It makes the controlled process easy to understand.There are many methods to realize the traffic lights control. EDA technology is the best choice to be taken after analysis and compaing. Based on it, this paper designed the hardware circuit of entire transportation control system. It includes the power circuit, communication circuit, the clock circuit, the keyboard entry circuit, JTAG debugging and downloading line disposition circuit, the demonstration circuit as well as alarm circuit. Then, the VHDL was used to design parameters and programming in each module. Combining the hardware circuit with software programming makes the realization functions of each module concrete. Finally, this paper described some questions appeared in each debugging process and provides the solution methods. Subsequently, a module's waveshape simulation chart was also given.The paper has studied the application of logical control in the traffic control system. The method is EDA technology. Unify them dffectively, utilize them in the intelligence traffic control. Thus, it established omni-directional real-time, accurate and highly effective transportation control system.