| From the late 21st century, embeded technology has become the trends of communication and consumable produces. Embedded Geography Information System (Embedded GIS) is an integration of embedded products and GIS, and a hybrid system of software and hardware. It is an ideally solution of navigation, location, geography information query and spatial data management for mobile user.Due to the low computational ability of embedded system, the way designing hardware and software for embedded GIS differ a lots from the ordinary computer system. The software must be pruned and optimized according to the specialty of embedded GIS system. And the hardware resources also need to be explored.The research area covered by the thesis includes embedded system design, hardware infrastructure of embedded GIS system, architecture of NAND flash, error detect code/error check code and there algorithm, journal file system, GIS file index, wear leveling for NAND flash, file system page cache and write delay, dynamic compression in file system etc.First, the thesis first analysis the embedded GIS status in quo, technology background, difficulty it facing. Then introduce the embedded GIS hardware infrastructure, and using two level of flash storage system to store different kinds of files. The theory of journal file system is introduced and a journal file system for NAND flash chip is designed under for Linux kernel. Because the reliability of NAND flash chip is relatively low, the error detection and correction algorithm is discussed, and an algorithm fit for embedded system is introduced. Also in the file system, an wear leveling function is provided.In order to satisfy the character of embedded GIS which has large amount of data, and strict requirement of real time response, real time compression is offered in the file system. Also a build in index for GIS data which can enhance the performance is also fulfilled in the file system.
|
PDF Full Text Request