Design And Implementation Of Lightweight And Small Piezoelectric Ceramic Seismic Source

Microseismic monitoring technology is an effective method to monitor the occurrence of micro-fracture in rock mass during the process of rockburst.The important goal of micro-seismic monitoring technology is to achieve effective and reliable positioning of micro-seismic events,However,due to the uncertainty of the micro-seismic sources,It makes the accurate and effective verification of the positioning effect of the current micro-seismic monitoring technology a difficult problem.With the continuous development of science and technology,foreign related research institutions have proposed an active source microseismic monitoring method.It is hoped that this method can verify the positioning effect of current microseismic monitoring technology in real time by using known active seismic sources,and improve the real-time positioning accuracy of microseismic monitoring technology.As one of the main equipments used in active seismic microseismic monitoring technology,vibroseis plays a vital role in this technology,however there are a series of problems in the viable sources commonly used in the market,such as The sniper-type source is high price,low output signal accuracy,and low usage in China.The spark source is extremely complicated operation and poor signal repeatability.The hydraulic source is large working noise and environmental damages.The precision mechanical vibrator is heavy mass,large volume,and poor maneuverability,These problems make it impossible to apply them to active source microseismic monitoring technologyIn view of the current market vibroseis can not be used for micro-seismic monitoring.This paper presents a design method for a small portable piezoelectric ceramic source,aiming to develop a vibrator for microseismic monitoring.This paper will carry out related research and design from the perspectives of material selection,working principle and structural design of portable small piezoelectric ceramics.The compact and small piezoelectric ceramics adopts a modular and separate design,which divides the source into three modules and completes the design one by one.Firstly,a piezoelectric ceramic material is selected through a related process to form a piezoelectric ceramic stack,and then the piezoelectric ceramic stack is packaged by an external mechanical structure to form a piezoelectric ceramic excitation body capable of generating an exciting force.Secondly,the signal generator designed by FPGA combined with DDS technology scheme can realize the frequency modulation,phase modulation and amplitude modulation functions of the signal generator.Finally,using a high-voltage integrated op amp combined with multiple sets of MOSFETs and designing a power amplifier with reference to a Class B power amplifier circuit,the voltage and current of the signal generator output signal can be amplified.Finally,the overall test by the source shows that the developed compact and small piezoelectric ceramic source has obvious advantages compared with other types of vibrators,not only in light weight,small size,strong maneuverability,but also adopts modular separation design concept.It makes it easier to operate and can be quickly installed and disassembled,which greatly improves work efficiency.At the same time,it also has good reliability,can work continuously for a long time,besides the output signal is stable and repeatable,which can generate stable exciting force.