The Research Of Vehicle Navigation Real-time Spatial Data Model Based On Embedded System

Geographic Information System (GIS) is devoted to gather, storage, manage, analyze and express spatial data, and embedded GIS is defined as a GIS running on embedded devices. With rapid development of the Embedded Computer System and quick promotion of the social needs, Embedded GIS is widely used in City Intelligent Traffic Information System (ITS), Automotive Electronic System (AES), Location-based Services System (LBS) and Digital of Weapons and Equipment System (DWES), which achieves some functions like easy to moving, large-scale map browsing, path analyzing and information retrieval, etc. All of them have brought significant economic and social benefits.Spatial Data Model is the most important part of GIS, particular in Embedded GIS. The focus attention of Spatial Data Model is spatial data, whose own form of organization and scheduling model effect the data flow directly, determine the overall performance of the system, especially in some applications having high requirement of real-time.As an important component of the Automotive Electronic System, Vehicle Navigation System integrates main functions of GPS and GIS and is able to provide drivers with orientation and guidance services. Electronic map is the core of the Navigation System. We use Embedded GIS to manage the electronic map data. Because the scarcity of resources of embedded devices, we must consider how to use the system resources rationally and minimize the consumption, such as CPU computation, usage of memory and etc., to improve efficiency. To meet this requirement, we must design and establish an embedded data model, which can efficiently manage the spatial data and provide services for the upper.This paper mainly discussed the embedded real-time spatial data model, firstly, it introduced the general conception, feature and application of the Embedded System, GIS and Vehicle Navigation System; Secondly, it presented the concept of the embedded real-time spatial data model, analyzed some of its elements, such as conceptual model, data structure and logic model, etc.; Thirdly, it studied the navigation map data formats and standards, embedded spatial data indexing, multi-level cache design and so on. We also specifically analyzed the navigation system's overall data needs. Then, by using the OO and UML tools, we provided a design solution of embedded real-time spatial data model. Finally, we implemented the model to a car navigation system, and gave a detailed system design and operation of the program results.