The Study Of Navigation Path Planning Based On The Embedded Electronic Map

The traffic is an important pillar of national economy development. For a long time, the traffic problem has already become an important problem which troubled urban development. Especially when driving into an unfamiliar city, guiding motorists on the right path and reaching their destinations becomes very important. Along with the rapid development of science and technology, computer technology, internet technology and communication technology have infiltrated into traffic field gradually. ITS(Intelligent transportation system) is proposed precisely in this context. Traffic geographic information system play a pivotal role in ITS, and has become an important research direction of GIS(Geographic Information System). Vehicle navigation system is a typical example of Traffic geographic information system, has great market prospect and development potentiality. The path planning module, as a core module among whole navigation system, compared with operating on Personal Computer, running in embedded devices requires shorter time and datas storage space small enough, that result in new demands for path planning algorithm's design in time and space.The paper mainly involved embedded development (mainly software development), geographic information system of topography, datas organization method, digital map visualization, best path planning technology etc.On the basis of analyzing the data forming and model of electronic map, the paper extracted necessary datas from MIF files of MapInfo format electronic map, analyzed the road network based on graph theory. After comparing several kinds of classic storage structure of graph, combined STL(Standard Template Library) effectively, puted forward a datas organization method of road network. And used distance as road resistance weight, on the basis of analyzing and comparing several classical shortest path algorithm, combined specific characteristic of traffic network, improved heuristic A~* algorithm in data storage, search strategies etc. Adopted C++ language in program implementation aspect, data initialization and algorithm was implemented in two different class respectively: CwayPoint class and CAStar class, reduced coupling of them, reflected the modular idea of large software programming really. Came ture the basic functions of embedded navigation electronic map: zoom out, zoom in, roaming, inquiry of interested points, route planning etc. Finally, gave the expected experiment results under the embedded development environment that we set up.The research of this paper used linux and Qt/Embedded as developing platform, taked advantage of free resources fully. Comparing with most existing navigation system which use WINCE operating system and EVC(Embedded Visual C++) as platform, saved cost of development greatly.