Study On Signal Conditioning Of MEMS Seismic Accelerometer

With the rapid development of microelectronic technology and computer technology, over the past 10 years, in the seismic exploration, considerable, even fundamental significance progress has been made in the fields of digital seismic instruments, computers ,signal processing methods and technique means.However, there is no substantive changes in the speed sensor which is currently used in geophysical industry. Certain inherent shortcomings of this old-fashioned mechanical sensor are difficult to overcome. Because the sensors can't receive ideal original signal, the effects of post-processing is reduced badly. So the seismic detector has become one of the main bottlenecks which constrains oil geophysical technology to continue to develop and enhance.Micro Electronic Mechanical System ,MEMS for short, it is a emerging discipline of crossed Multidisciplinary which developed on the basis of microelectronics technology and silicon micromachining technology. New acceleration sensor based on MEMS technology break through the "Bottleneck" , it gradually becomes an important role in the development of geophysical exploration technology for its advantage on high sensitivity, resolution and vector fidelity as well as low-frequency response and wide-band. In development of the seismic exploration technology , it has gradually become an important tool for acquisition data of the field earthquake. Using the acceleration sensor with MEMS technology will advance oil exploration and seismic data receiving , which has important meaning for advance oil recovery ratio and seismic data receiving efficiency .Although there is emergence of a growing number of MEMS-based acceleration sensor research teams in the country and the gap is still prodigious abroad .What is more ,the practical application of the earthquake acceleration MEME in seismic exploration had not yet reached a high-quality performance level as other advanced countries . China's seismic exploration industry which simply rely on the introduction of foreign seismic acceleration of off-the-shelf products equipment , consider the purchase abroad which has a high level of acceleration by the high cost of funds as headaches round off problems .So to the good performance of foreign MEMS-based acceleration sensor, design the external auxiliary circuit , the data acquisition and signal conditioning work independently , independent research and development of a reliable earthquake MEMS accelerometer , that is better applied to the field of domestic seismic exploration. It's a very important practical significance to the sensor industry of China.The present work based on the using of a kind of MEMS accelerometer sensor chip Model 1221 produced by United States I/O, design external auxiliary circuit and stable low-voltage power supply independently, construct MEMS accelerometer earthquake for seismic exploration in the field of application, research conducted signal conditioning with the earthquake response of MEMS accelerometer system using in testing weak vibration signals arising in the course of some of the problems.This paper is composed of five chapters, discussing from the MEMS-based acceleration of the development of sensors, key technologies, signal conditioning, and several studies conducted , Finally, giving the test results of the experimentation in the field, and analysising the corresponding results. The first chapter expounds research background and significance on the subject. Then the development situation in and out of the country of MEMS seismic acceleration sensor is introduced.The second chapter introduces component and basic principle of the current seismic exploration system and analyses seismic acceleration sensor's characteristics and key role in the seismic exploration system. Then performance comparison of MEMS accelerometer application and the traditional detector are given. Seismic accelerometer system which is composed of MEMS acceleration sensor has some major problems in the process of signal acquisition, so this paper does a study on signal conditioning. The process of signal conditioning research is given in this chapter too.The third chapter gives the concept of signal conditioning and describes the necessity and significance of signal conditioning for MEMS seismic accelerometer. This chapter analyses the existence reasons of the system nonlinearity and the environment surrounding electromagnetic interference, and takes appropriate measures to improve the nonlinear degree of MEMS accelerometer system. In order to get board-level electromagnetic compatibility aspects, shielding methods are used in present work to restrain the radiation interference which is received by system. Then a stable 5 VDC power supply board with minimal noise is designed after taking full account of the details of EMC. This chapter does dynamic correction research on MEMS acceleration sensor, and achieves transmission band effect of dynamic correction broaden MEMS accelerometer sensor with three methods.The forth chapter is the test tache of the project. It shows the picture of the production, which is expounded in the third chapter about the nonlinear improve of the MEMS speedup senor. And the result of compare of the MEMS speedup senor with the performance of the conventional detector is also given in the chapter. The result of compare proved that the MEMS speedup senor will become the new production which will take place of the conventional detector, it will take the earthquake prospect technology to a new history period.The fifth chapter is the summation of the whole text .The next task about MEMS accelerometer is proposed in this chapter.