| The coal mining not only makes the original geologic structure form fault, but also leads to the strata cracks from shallow to deep. All the gathering of gas, movement of underground water, breakdown of the coal rocks and the mining stress field do have matter with the cracks. The major and extraordinary accidents, especially the gas accidents and underground sudden water damage accidents always happen within the old mining areas or the fracture development zones. Visual detection of cracks in coal strata can provide foundation for original fracture field and space-time evolution fracture field. Embedded crack endoscope can provide the wall image of the drill hole directly by pictures or videos, which can be used for qualitative identification of the case in the boreholes and qualitative analysis the geological phenomena in the boreholes, such as width, inclination and produce shape of the crack. The superior characteristic can make up the shortcomings of the conventional exploration techniques, so it can provide credible information for the research on flow characteristics of gas and water under mining fracture field conditions.Based on the consideration of the efficient energy recycling, special technology mining, kilometers deep well drilling and multi-layer cross mining technology have been widely used. In order to solve the major accidents accompanied with the geological complexity changes, the research for embedded cheap and high quality borehole fracture imaging equipment is of great significance in that it can predict the dynamic changes of strata promptly so that we can reduce various accidents effectively.In this issue we use the 32-bit ARM chip PXA300 as the core, and Linux operating system, QT Graphical interface and XviD open source MPEG-4 video codec to carry out the research and design of the coal strata fracture endoscope. Firstly, the development of crack endoscope both at home and abroad is introduced and the objective and main content of the research is established. Secondly, the overall structure design of the system is introduced through comparative study of the CPU chip, the embedded operating system, the Graphical interface and the MPEG-4 video codec. And finally the embedded system platform is established. Thirdly, according to the study objectives, we design the hardware platform and set up the development environment. Fourthly, we introduce in detail the establishment of the hole software operation platform, including Bootloader, the transplant of Linux kernel, the production of Linux root filesystem, the custom and transplant of the graphical interface of QT development environment, the transplant of camera driver, XviD library and touch screen etc. Fifthly, on the basis of the built system, we programme the embedded system. Sixthly, we simulating test on each module, with the results showing that they all meet the design requirements, realizing the function of real-time display photograph video and storage of images.System implementation:CCD sensor image resolution 752×582(CCD Effective Pixels); TFT LCD display screen 5.6 inches; Display colors 16 bit true color(16 million colors); Display resolution 800×480; Recording resolution 720×576; Video format MP4 format(HD); 25frames per second to complete the compression, Maximum recording time(4G memory) 180 minutes. |
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