Design And Implementation Of MEMS Digital Geophone Based On FPGA

With the rapid development of the economy,people are increasingly demanding energy.In the process of underground energy harvesting,various topographic structures are encountered,so the stratigraphic structure must be explored before collection.As the core equipment of exploration,the performance of geophone is directly related to the final result.In this thesis,based on the characteristics of traditional geophones with large interference and low frequency band,an FPGA-based MEMS digital geophone is designed.The morphological filter is added to the geophone to filter out the noise in the signal.The acquisition of geophysical seismic wave signals has achieved certain engineering significance.The main research contents of this thesis are as follows:(1)The model is built by forward modeling software to analyze the amplitude characteristics and spectral characteristics of seismic wave signals.The digital geophone design scheme is proposed according to the exploration requirements.The hardware circuit design of the geophone is carried out,and the circuit structure and wiring are optimized to complete the hardware circuit layout.(2)For the noise interference in the collected signal,based on the basic principle of the morphological filter,a suitable filter is designed by comparing and analyzing the structural elements of the morphological filter.(3)Based on the hardware circuit and the morphological filter design,the logic design of the digital geophone system controlled by FPGA is carried out.It implements hardware circuit control,signal filtering,and data storage and transmission functions.(4)In order to verify the effect of the geophone,the modules and systems of the geophone are tested separately in the room,and the test results are good.On the basis of the actual field test,an obvious useful seismic wave signal can be collected.The test results show that the developed digital geophone can achieve seismic wave signal acquisition,and the performance meets the requirements of the index,which has certain practical value.