Study Of Three-component Digital Geophone Based On MEMS Accelerometers And Wireless Sensor Networks

Mine seismic exploration is an effective method in identifying underground geological structures. Seismic geophone is a core part of the seismic instruments, which direct influence the seismic exploration results. Therefore, it is very important to develop a three-component, high-dynamic and high-resolution digital geophone, which traditional geophone don't meet the need. Developing of three-component Digital geophone based on MEMS accelerometers and wireless sensor networks can increase the efficiency and detection accuracy and can detect the potential danger, which quickly provide necessary geological information in preventive measures and emergency rescue.In this dissertation, development and technology status of seismic exploration instruments at home and abroad, detector technology requirement of high resolution mine seismic exploration and physical characteristics of traditional detectors are analyzed. By fully considering combination requirements of mine seismic exploration technologies, by using components with high integration, low power consumption and small packaging, and by effectively integrating three-component MEMS accelerometer technology, high speed and high precision 24-bitΣ-Δanalog-digital converter technology and wireless sensor network technology, wireless digital detector is developed, which simplifies routine seismic data acquisition circuit greatly. For anti-interference design is used in hardware and software, the proposed method could effectively eliminate serious interference in analg signal transmission of traditional acquisition system, and improve some performance indexes such as signal-to-noise ratio, phase coincidence and signal distortion. The proposed method could assure high fidelity, high signal-to-noise ratio and high resolution in seismic signal pickoff. The whole system is miniature, portable, and low power consumption, which is suitable for mine underground operation.Integration and optimization are conducted to the laboratory prototype. Laboratory test and field test are conducted, which show that the designed prototype has wide frequency band, high accuracy, large dynamics, between centers crosstalk suppression ratio on three components. It can accurately pick up oscillation signal along different directions, providing foundation for multi-waves multi-component seismic exploration. The indexes meet the design requirement.The paper is supported by "Integrated underground exploration technology and equipment study of deep coal resource in old mines of "the eleventh five-year plan" national S&T support plan project and "Portable digital three-component detector development for mines" of innovation fund project of Coal Science Research Institute Headquarter. Study of wireless digital detector technology is of important operation significance for mine seismic exploration instruments to be popularized in safe production of coal industry.