Traffic Flow Simulation Base On Granular Computing And Three-tier Structure

Traffic system is a large and complex system with nonlinear, random, larger variable and uncertainty, a lot of subject experts pay attention to that, and present a variety of traffic models. For it has simple rules and can simulate complex and rich phenomena, cellular automata have become a research focus on the traffic flow study. By dividing the complex issues into a number of simpler problems, the granular computing can improve problem solving and analytical ability and is an important tool to solve the vague, imprecise, incomplete problem and process massive information.This traffic flow system is based on three-tier structure model of granular computing simulation of traffic flow. Granular computing is introduced into the cellular automata model, and form three-tier structure model consisting of cell, granular computing and traffic network. In this model, firstly, in the framework of grains, all vehicles belonging to a grain update in accordance with rules of their own, and complete the grain update; secondly, in the framework of the transport network, all grains belonging to the network update in accordance with rules in the granular computing layer, and complete the network update. The lane-changing rules and car-following rules are introduced into cellular automata, the main study results and reads as follows:This paper is based on three-tier structure model consisting of cell, granular computing and traffic network, firstly, improving the three-tier structure model, and introduce the lane-changing rules and car-following rules into the cellular automata. Secondly, the new three-tier structure mode is applied to traffic system which contains two lane, two way and crossroads. Using visual window display the operational status of the entire transport system, and spatiotemporal pattern show the tracks of all vehicles. Finally, this paper adopts object-oriented thinking and C# language of coding in Visual Studio 2005 platform to simulate the three-tier structure traffic flow model, and analyze the impact of split, the intersection location, the size of the signal cycles on the three-tier structure traffic flow model. After comparing with the original NS simulation traffic system, we find that it is feasible and valuable to use three-tier structure model in the study the traffic flow system.