Research On Projectile Impact Location Based On Vibration Signal

During the range test,whether it is the performance parameter test of the newly developed ammunition or the measurement of the power and firing accuracy of the artillery system,it is necessary to recover and detect the test projectile.Therefore,it is very important to determine the impact point of the projectile in the range test.Based on the seismic effect of the projectile landing,the impact location of the projectile is studied based on the vibration signal of the projectile landing,which lays the foundation for the design of the projectile impact location system.The acquisition and preprocessing of vibration wave are studied.This paper introduces the propagation,composition and attenuation law of the vibration wave,analyzes the spectrum characteristics of the vibration signal collected by the geophone at different distances from the vibration target,and determines that the R wave should be used as the effective signal in the process of projectile impact location.The influence of different geological characteristics on the propagation and attenuation of seismic signal is summarized.The measurement method to determine the propagation velocity of vibration wave signal under the geological condition of range is given.Aiming at the problem of low sensitivity of geophone,the optimal geophone string parallel operation scheme is obtained through analysis and calculation,and second-order voltage controlled voltage source Butterworth low-pass filter circuit are designed to preprocess the geophone output signal.The joint time delay estimation method of vibration signal is studied.That is to say,by using wavelet de-noising and various time-delay estimation methods to estimate the time-delay difference of the vibration signal,the bior2.4 wavelet is selected as the wavelet basis function to decompose and reconstruct the signal,and three layers are selected as the optimal decomposition layers of the vibration signal.The maximum and minimum estimation criterion is determined,and the soft threshold function has good denoising effect.Through simulation analysis,the effects of basic cross-correlation,several weighted cross-correlation,high-order spectral time delay estimation and other time delay estimation methods are compared.The time delay estimation method combined with wavelet threshold denoising and high-order cumulant is determined to meet the time delay estimation requirements of projectile impact location process.The location model of projectile impact point which can provide three-dimensional coordinates is studied.The positioning model of seven element interchange array is proposed,and the factors affecting the positioning error are analyzed.On the basis of this array model,the improved model,the stereo intersection dual array positioning model,is put forward.Through derivation,the calculation formula of the projectile impact point coordinates of the dual array is given.Through simulation analysis,it is verified that the positioning accuracy of the dual array is greatly improved compared with the seven element stereo intersection array.The error of the impact point distance coordinate parameter is very stable with the change of the array element spacing D,and the spherical coordinate has three coordinates The error of component is generally small,which can meet the accuracy requirements of projectile impact location.The software of projectile impact location is developed.The software can calculate the spherical coordinates of the impact point of the projectile,and display the relative position of the impact point on the software.