Urban Traffic Control Signal Timing Research

With the high growth of economic, the urbanization function is enhancing and the economy and culture level is improving, the urban activity of citizen becoming usually. These make the high increasing of urban traffic demand. At the same time, with the high increasing of urban traffic demand, it makes many problems such as urban traffic congestion, traffic delay, traffic accident and traffic pollution and so on. Obviously, building more roads and bridges are the direct solution to resolve these urban traffic problems, but due to the funds and the urban room, this method is not feasible. The purpose of this paper is to study the urban traffic signal control, find the right urban traffic signal control algorithm and alleviate the congestion of urban traffic to a certain extent. The detailed research work done in this thesis is listed below:1. Aiming at the signal dynamic optimization problem of the artery of the urban traffic, a artery traffic optimization and control model is put forward, whose objective is to minimize the total delay queue vehicles over the control period. And the dynamic optimization model which adopt signal cycle, split and offset as the decision variables is set up.2. To the signal optimization problem of the artery traffic, a hybrid optimization algorithm of "genetic-ant" is presented. In the algorithm, a genetic algorithm is firstly adopted to search for the optimal solution to the optimization problem, and then a ant algorithem is adopted to intensify the search for the optimal solution. The simulation results indicate the validities of the proposed hybrid optimization algorithm in artery hybrid optimization.3. Through studying the area traffic control problems, a area traffic optimization model is established that is to minimize the total delay time as the goal, and to adopt signal cycle, green time, phase and offset as decision variables. And then the optimization problem is tranformed into a multi-stage decision problem to solve.4. To the signal optimization problem of the area traffic, a hybrid optimization algorithm of "chaotic-ant" is presented. In the algorithm, a ant algorithm is used to search for the global optimal solution to the optimization problem, and then a chaotic variable is used to search for the local optimizaion. The simulation results indicate the validities of the proposed hybrid optimization algorithm in area hybrid optimization.Finally, the work of this dissertation is summarized and the prospective of further research in traffic control systems is also discussed.