Research On Phase Design And Signal Control Method For Isolated Intersection

Transportation signal control, which plays an important role in the development of urban road transportation, can effectively improve the order and efficiency of the road traffic. Nowadays, the isolated intersection of traffic signal control still occupies a large proportion among the urban traffic systems. Therefore, it's significant to optimize signal timing and improve the efficiency of intersection traffic. Isolated intersection is as the research object of the urban traffic signal control system, and this thesis makes researches on phase design of traffic signal control and the method of signal timing, aiming at improving the effect of signal control at isolated intersection and relieving of urban traffic jam.The main tasks and research results of this paper are as follows:1. At the aspect of phase optimization design, firstly, applying graph theory to draw traffic flow compatible chart, namely, each traffic flow is regarded as a node, link between nodes which have no conflict is regarded as a side; furthermore, to make sure the phase set of given intersections in terms of relationship of connectivity. Secondly, the construct pruning method is adopted to optimize calculation of the traffic flow compatible chart and picking out minimum phase digits, the corresponding phase combination as well. Finally, a case study is applied to present the process in detail. The results show that this method can properly optimize the minimum phase digits and the corresponding phase combination.2. At the aspect of the single intersection traffic signal control , similarity is researched and analyzed between dividing time slices in the operating system and assigning green time on the basic unit and state, the essence, dispatching mode, resources composited way in basic unit, performance evaluation, etc; Moreover, according to merits of flexibility and real-time characteristic in process scheduling, dynamic and static parameters which are used to make sure the grade of phase are chosen, and the calculation method of assigning green time is proposed in each signal period. Meanwhile, the process of the adaptive traffic signal control, which is based on optimization scheduling, is presented. 3. For designing simulation platform which based on SUMO software, this thesis make isolated intersection as the research object and use the traffic signal phase optimization design model which is based on the pruning algorithm. Furthermore, fixed timing control, indective-loop control as well as signal control method of process optimization scheduling are applied to isolated intersection. As comparison of simulation results show, in the situation of middle reachable rates, signal control method in process optimization scheduling has reduced average delay time and improved traffic efficiency.