| Explosion height is an important performance indicator to measure the effectiveness of modern weapons such as terminal-sensitive bombs,grenades and air-explosive bombs.The main methods to realize explosion height measurement are CCD intersection measurement method,sound source localization method,and Wide field television theodolite.The sound source location technology based on microphone array has the advantages of simple principle,simple array and anti-electromagnetic interference,and is widely used in blast height measurement.In bomb height measurement,the noise and reverberation in the environment are the main factors that affect the accuracy of sound source height measurement.Therefore,it is the main research direction of related fields to achieve high-precision explosion height measurement by reducing the interference of noise.This topic takes the microphone array positioning in the outdoor environment as the research,and selects several typical microphone array structures for analysis.On the basis of the five-element cross array structure,a three-dimensional six-element acousto-optic array is designed to measure the height of the explosion.Combined with the practicability of the system,the complexity of the algorithm and the positioning accuracy and other factors,the explosion height of the three-element array fusion is constructed measuring system.Through the simulation experiment of blasting height measurement of three-dimensional six-element acoustoptic array,combined with the established positioning mathematical model,it can be found that the main factors affecting the accuracy of blasting height measurement of the array are delay estimation error,the change of sound velocity in the test environment and the measurement error of array spacing.In order to solve the problem of large error of time delay estimation,the generalized quadratic cross-correlation algorithm is improved,and wavelet filtering is introduced to denoise.Simulation results show that the accuracy of time delay estimation can be improved effectively by combining the wavelet filtering algorithm with the improved generalized quadratic cross-correlation algorithm.Aiming at the problem that the measurement accuracy of blast height is reduced due to the change of sound velocity,the characteristics of sound propagation in air and the factors affecting the change of sound velocity in air are analyzed,and the real-time sound velocity in air is calculated according to the relationship between sound velocity and temperature,air pressure and humidity to replace the common values.Finally,firecrackers were used to simulate the shells,and the built test system was used to measure the firecrackers at different heights and azimuths.The experimental results show that:for the firecrackers with low positions,the measurement error of the pitch angle of a single array is less than 1.5°,and the measurement of the azimuth angle is less than 1.5°.The error is within 1°,and the relative error of the blasting height is within 4.68%;for firecrackers with a higher position,the relative error of the blasting height obtained by using a single base array is larger,and the relative error range is within 5.25%.At this time,it is necessary to use three matrix arrays to measure the orientation information of the blasting point at the same time,and use the Fermat point estimation method of different planes to calculate the final blasting point height.The obtained blasting height measurement error is less than 3%.The six-element acousto-optic array can achieve high-precision frying height measurement.It is verified that the three-dimensional six-element acoustooptic array can realize high precision measurement of blast height. |
