Research On Shock Wave Overpressure Test System And Data Processing Method For Optical Fiber Transmission

Shock wave overpressure test is an important test item of detonation physical test,and it is very important to better obtain the shock wave overpressure signal and perform subsequent processing of the measured signal in the harsh test environment of the explosion site,which is very important to restore a more realistic explosion site and ammunition damage assessment.The explosion site is often accompanied by physical phenomena such as high temperature,high pressure,high-speed products,and strong electromagnetic pulses.Traditional shock wave overpressure testing adopts a stored test method,which does not allow real-time condition monitoring and data transmission.Optical fiber transmission technology has the characteristics of not being affected by electromagnetic interference and supporting longdistance transmission.In this paper,a shockwave overpressure test system based on optical fiber transmission is designed,and the data processing method of shockwave overpressure is studied.Firstly,the design method and key technologies of the traditional shock wave storage test system are analyzed,and the data storage implementation method based on the shock wave storage test technology is highly complex and poorly expandable,and the real-time transmission and status detection of test data cannot be realized,and a shock wave test system based on optical fiber transmission is designed.The system uses FPGA as the main control chip,and adopts high-speed serial transceiver technology to realize the optical fiber transmission function,which solves the limitations of strong electromagnetic pulse interference and insufficient transmission distance in the explosion test for the application of real-time data transmission technology.The use of DDR3 dynamic random memory chip simplifies the implementation of shock wave data storage logic and improves the system storage bandwidth.Using Ethernet transmission technology,the near-end optical fiber signal of the host computer is converted into Ethernet frame format and sent to the host computer;Changed the Flash storage policy and simplified the implementation method of data backup.This paper introduces the overall design,hardware design and logic implementation of the shockwave test system based on optical fiber transmission in detail,and verifies the key system modules and overall functions to prove the correctness of the design.Aiming at the characteristics of a large amount of environmental noise in the measured shock wave data,a joint signal noise reduction method based on empirical wavelet transform and singular value decomposition is proposed.According to the theoretical formula,the pressure-time noise model of shock wave is established,and by comparing it with Bessel lowpass filtering,EEMD decomposition noise reduction and wavelet decomposition noise reduction methods in the noise model,the results show that the combined noise reduction method SNR and RMSE evaluation index are the best,and the original shock wave signal is well restored.The effectiveness of the joint noise reduction method is verified by the measured data.The noise reduction processing of a certain test data was carried out,and the accurate explosion shock wave parameters of the measured data were extracted for damage assessment,and the damage assessment results of the shock wave of this test on buildings and personnel at different blast center distances were obtained.