Researching On Design And Performance Of MEMS Digital Geophone

With the rapid development of the world economy, the road? railway?bridge and other road traffic load capacity is rapidly expanding.In recent years, the geological disasters such as the highway collapse and the settlement of the bridge are emerging in an endless stream.The people's lives and economic security have been threatened.The key equipment of geological exploration – detector that is an important basis for the assessment of geological safety.It is necessary to develop a kind of high precision and high resolution digital detector for tightening the geological structure detection and preventing the geological disaster effectively.MEMS acceleration sensor, circuit system, theoretical simulation and experimental testing are studied in the paper around the shallow geological exploration project. The project compromises the knowledge of geological exploration, circuit systems, signal and information processing, Shallow geological prospecting instrument is an important equipment of geological exploration, in which digital detector is the key equipment with great research significance and application value.The paper is based on the MEMS sensor, the peripheral circuit of the sensor, signal conditioning circuit, digital sampling and transmission system are designed.And the performance of the system is deeply studied.Modeling the specific geological structure combine with geological exploration principle. Emphasizes the relationship between the seismic wave velocity and the density of the geology?Spectral characteristics of different waves, etc.Multisim is used to simulate and optimize the parameters of the signal amplifier circuit combine with integrated circuit technology.Using the Quartus II to achieve logic design of digital sampling and transmission system that take the FPGA as the core of the A/D sampling, RS485 serial communication and so on.Finally, the author complete the circuit design contain the sensor conditioning circuit, A/D conversion circuit, RS485 communication circuit, FPGA and SDRAM.Circuit performance test and error analysis are carried out.The unit test and integration test are carried out for the design of MEMS digital detector system under laboratory conditions.Further research on system performance and optimization.In order to verify the practical application effect of the detector.Concrete geology, soft soil geology detection, single track geological detection.Experimental results show that the design of the MEMS digital geophone of this topic has a high resolution and precision as well as characteristics of low noise,Meeting the requirements of the digital detector for shallow geological exploration.