Research And Realization Of Vehicle Navigation System

As a branch of Intelligent Transportation System, the Vehicle Navigation System is a high-tech system well intergrated with globle position technology,geographic information technology, multimedia, modem technology communication technology and embedded technology. It offers many kinds of important services, which include navigation & position and geography information, timely and efficiently for a driver while driving from one place to another. It is a typical representation of new type electronic productions on Vehicle. Its application greatly alleviated the trouble of city transportation system and improved the efficiency of road.Derived from the practical situation, the thesis makes a thorough study on the key technologies and the applied developments of the Intelligent Vehicle Navigation System.On the key correlative knowledges of the the Vehicle Navigation system, the GPS positioning modes in the vehicle navigation system are firstly introduced, and the main errors that influent the positioning accuracy are analyzed. Then the basic principle of Dead Reckoning system is introduced, and the errors of a few adoptable DR sensors are analyzed. At the same time, an Integrated Kalman Filter mechanization to realize the optimal synthesis of GPS/DR integrated navigation system is designed, the algorithm to which is presented. Practical applications have testified that the GPS/DR integrated algorithm which fuses the data collected from the sensors of GPS and DR makes the system have high accuracy positioning function.Based on the optimal route planning theory, the Dijkstra algrithm and heuristic searching algorithm are respectively presented. The algorithm to produce the instruction of the route guidance is designed, which can offer the driver with intelligent navigation information. Lastly the Bluetooth technology & Speech Recongtion technology, which are applied in Vehicular hand-free function, are gived.In the light of the features of embedded system and the functions of intelligent vehicle navigation embedded system, the whole solution of embedded intelligent vehicle navigation system based on ARM9 and WinCE technology is drown out according to the practical situation. Firsly the rock-bottom hardware platform of the embedded system including the circuit design of each module is described in detail.At the same time, the hierarchical structure is adopted to design the software of the embedded system. Customizing and transplanting Windows CE OS are stated at length. The hard problems met in software development, which include the program of the Bootlooader and the Drivers, are discussed in detail. The software of application layer is the principal part of the entire software design. According to modularization design idea from the software engineering, the total system framework of application layer is divided into several software modules, and how to design them is presented respectively.At present, a sample system based on the above research works and the configuration platform of system hardware & software has been developed successfully. The excellent performances of the sample system in real-world testing demonstrate that the key technologies used in this system are both available and practicable.