Research On Cloud Algorithm In Vehicle Network System And Software Realization Of Vehicle Terminal

In recent years,China’s rapid development brought great economic benefits,but the attendant is a huge traffic pressure.Car navigation system is a very effective system to improve traffic efficiency and ease traffic congestion.In car network system,navigation system is the most important subsystem,and shortest path algorithm is the most indispensable part of navigation system.As early as many years ago,the shortest path problem has been put forward,so far,many experts and scholars have studied and analyzed the different conditions,different network models of the shortest path problem,which is currently the most widely used,and others proposed four different The theoretical model in which the algorithm is the most classic and mature algorithm.In the design process,the traditional shortest path algorithm only takes into account the network topology characteristics,and can not take into account the network spatial distribution characteristics,resulting in the shortest path search process does not have the direction,so there will be multiple and eventually found the shortest path is not associated with the same node In the calculation,the efficiency of the algorithm is reduced,especially in the large sparse urban road network,the application of the various algorithms can not effectively meet the real needs of urban road network.Firstly,this thesis establishes the topology model of urban road,puts forward the calculation method of latitude and longitude of urban road and vehicle,and summarizes the topological characteristics of the actual road.The method includes the following steps: the method of preprocessing the latitude and longitude data is given.On the one hand,the length of the link between the two nodes is calculated accurately according to the latitude and longitude in the urban road.On the other hand,the latitude and longitude data of the node are transformed into Cartesian coordinates On the basis of summarizing the inherent characteristics of urban road length and node value.Then,the thesis will optimize the classical algorithm from two angles.In the storage mode,the implementation of the algorithm based on adjacency table is expounded.The result shows that the adjacency table greatly reduces the occupancy of space.In the search area limit,the search area size of the algorithm and the way of determining the boundary are proposed,and the reliability and validity of the algorithm are deduced and analyzed respectively.Finally,the effective performance of the algorithm before and after optimization is verified by data statistics and simulation.The results show that the improved algorithm has greatly improved both in running speed and in space.Finally,this thesis explores the requirements and design methods of the vehicle terminal and the cloud according to the basic structure of the car network system,and then gives the design method of the software in the vehicle terminal.