Experimental Research On Reasonable Time Difference Of Electronic Detonators Based On MATLAB

With the development of digital detonator technology,the manufacturing industry technology of digital detonator is maturing day by day,which effectively solves the problems of low delay time precision and large dispersion of common detonators.At the same time,there is relatively little research on the choice of reasonable time difference for digital detonators.When choosing the extension time in the project,it also depends on the project experience and empirical formula,which lacks reasonable scientific basis.Based on a large number of experimental vibration monitoring data and through numerical simulation,this paper analyzes in detail the influence of blasting time difference on the peak velocity,main vibration frequency and instantaneous energy of blasting vibration waveform,and comprehensively determines the optimal time difference.Firstly,the blasting vibration speed is predicted.Although Sadovsky's empirical formula is simple and convenient to calculate the blasting vibration speed,the prediction error of Sadovsky's empirical formula is about 30%,which cannot meet the requirements of modern blasting for prediction accuracy.However,the BP neural network prediction model is used to predict the blasting vibration speed and the main vibration frequency,and the error between the predicted value and the measured value is less than 2%,greatly improving the prediction accuracy.Then,according to the superposition principle of linear elastic signals,the explosion vibration waveform under different time difference is simulated by using a single-segment waveform,and the variation rule of the vibration peak speed with the time difference is analyzed.It is found that when the delay is 8?12ms,the peak vibration speed falls to the lowest value.Through wavelet analysis and Hilbert-Huang analysis,the time-frequency analysis of the signal shows that the main vibration frequency of the superimposed signal shows a periodic step-wise decreasing change with the increase of time difference.when the delay is 12?16ms,the main vibration frequency is the largest from the natural natural natural vibration frequency of the building.During the energy analysis,it is found that the energy of blasting vibration is widely distributed in frequency,and the distribution form shows the nature of symmetry about the main vibration frequency.50?80%of the instantaneous energy is distributed within the main vibration frequency band of blasting vibration of 30?60Hz.considering the principle that the greater the instantaneous energy is,the greater the damage to surrounding buildings is,the best time difference is 9?11 ms.Finally,on the basis of blasting vibration test and numerical simulation,using wavelet analysis and Hilbert-Huang change signal processing method,the variation law of the time difference of electronic detonator on the peak velocity,main vibration frequency and instantaneous energy of blasting vibration waveform is studied,thus determining the optimal time difference under the test condition to be 11?12ms,providing a selection method for selecting the optimal blasting time difference in later engineering.