基于MEMS地震仪的天然地震信号采集系统的开发硕士学位论文 精品

中国石油大学硕士研究生学位论文(申请工学硕士学位)

基于MEMS地震仪的

天然地震信号采集系统的开发

学科专业：信号与信息处理

培养方向：信号的检测与处理

The Development of Seismic Signals Acquisition System Based on MEMS Seismometer

Thesis Submitted to

China University of Petroleum

in partial fulfillment of the requirement

for the degree of Master of Science Engineering

by

MA Qiu-fang

(Signal and Information Processing)

Tutor:Professor MA Xi-geng

Professor ZHOU Yao-qi

April,2007

基于MEMS地震仪的天然地震信号采集系统的开发

摘要

检测和分析地震信号可以帮助人类认识地球构造，预测地震自然灾害。由于地震信号的频率很低且能量非常微弱，所以难以准确检测，因此有必要设计一款高性能的地震信号采集系统。

本文针对传统地震仪体积大、频带窄的缺点，提出了基于MEMS技术的三分量地震仪的设计方案。使用低频响应好、灵敏度高的MEMS 加速度传感芯片1221x-002感测地震信号，并设计放大、滤波、去直流分量等信号调理电路对传感信号进行处理，提高信噪比。再将整个检测电路进行合理装配和调试，研制出三分量地震仪。为了构成高精度数据采集系统，还选择24位高分辨率数据采集器DT9820采集地震信号，并设计配套的数据采集处理软件。数据采集软件使用Visual C++编程，软件的主要功能包括数据采集、曲线绘制、PSN文件存储和FFT频谱分析等。

在设计中，着重分析了系统设计关键，提出了降低功耗、提高抗干扰能力等硬件优化措施和合理分配缓冲区、运用WINDOWS消息响应机制、合理组织软件各功能模块、采用GPS授时器授时等软件措施。通过这些措施提高了系统实时性和可靠性。

实验结果表明，系统能够进行高精度实时数据采集和信号分析，输出的数据和专业分析软件WinQuake兼容，且应用软件界面友好、稳定可靠，达到了设计要求。

关键词：MEMS地震仪，数据采集，DT9820，PSN数据格式

The Development of Seismic Signals Acquisition System

Based on MEMS Seismometer

MA Qiu-fang(Signal and Information Processing) Directed by Professor MA Xi-geng,Professor ZHOU Yao-qi

Abstract

Detection and analysis of seismic signals can help people understand earth’s structure and predict earthquake disasters.It is difficult to detect seismic signals accurately because its frequency is too low and energy is too weak.So it is necessary to design a high-performance seismic signals acquisition system.

This theses introduces the design of a tri-axis seismometer based on MEMS technology,aims to overcome the disadvantages of traditional seismometers,such as large volume and narrow band.In the design,1221x-002 is chosen to detect earthquake,and subsequent signal conditioning circuits are designed to improve signal to noise ratio,including amplifying,filtering and DC removing.By reasonable assembly and testing,a seismometer with three sensing directions is finally developed.Then DT9820,a data acquisition board with 24 bit resolution,is chosen to convert the seismic data.Based on the board,an acquisition and processing software is programmed with Visual C++6.0.The main functions of the developed software include data acquisition,curve portray,storing of PSN files and FFT spectrum analysis.

Many methods are used to improve the system’s real-time property

and reliability.Power saving and anti-interference are introduced to optimize hardware performance.Reasonable allocation of buffers,utilization of WINDOWS message mechanism and GPS module are also applied in the acquisition and processing software.

The results of experiments prove that the developed system can meet the need of real-time data acquisition and signal analysis.The saved data can be read by the WinQuake,a professional seismic signals processing software.Furthermore,the designed software is full of friendly user interface and stable performance.

Key words：MEMS Seismometer,Data Acquisition,DT9820,PSN Data Format