Design And Analysis Of Sound Field Localization System Based On Second-order Interference

Passive localization technology of sound source is a new technology which integrates acoustics,signal detection,digital signal processing and electronics.It involves a wide range of complex theoretical knowledge,and requires a variety of advanced technologies to achieve good research results,and it's widely used in military and civilian applications which has extremely important significance.In this paper,a spatial positioning method based on Hanbury Brown-Twiss(HBT)interference in the sound field is presented.The second-order interference principle,which has been fully verified in optical theory,is applied in acoustics positioning,and accurate positioning of target sound source is achieved.At the same time,the passive source positioning system of the sound source is designed and the parameters that affect the positioning performance of the system are analyzed specifically.The main research contents of this article are as follows:Firstly,based on the second order interference principle of the acoustic field,the second order interference positioning method is proposed,and the positioning model is established to provide theoretical support for subsequent simulations and experiments.Secondly,the processing method of the received acoustic signal is studied: a series of preprocessing is carried out to the received acoustic signal,including pre-filtering,preamplification,windowing and framing,and effective endpoint detection.Then according to the second-order interference localization model,verify the second-order interference principle of the sound field through simulation,and analyze the influence of array structure parameters(Array spacing,Spatial distribution of array elements,Array spacing)and sound source parameters(Frequency,SNR,Number of sound sources)on the positioning effect.The simulation results show that:(1)The two-dimensional planar array realizes the comprehensive positioning of the sound source in the range of [0,360°].(2)The array element spacing should be selected within the range of 20-100cm;Within a certain range,the greater distance between the arrays,the farther the sound source can be located;With more the number of elements has the better of the positioning effect and the array structure with the best overall performance is an irregular double five-element array.(3)The positioning of the sound source can be achieved when the sound source signal is single frequency or mixed.The wider the frequency spectrum,the better the positioning effect,and the second order interference positioning method can also locate the dual sound source.When the SNR is 0dB,the location of sound source can still be realizedFinally,according to the positioning theory and simulation results,the overall experimental design is carried out,and the passive positioning experiment of the sound source under different parameters is carried out.The experimental results are consistent with the simulation results(1)Both double three-element array and double five-element array can locate the sound source within [0,360 °];The asymmetric double five-element array can locate the sound source at a distance of 71 m under the condition that the array spacing is 7.5m and the array element spacing is within 100cm;(2)The asymmetric double five-element array can also locate the sound source point 71 m away when the sound signal is mixed and single frequency,with the relative positioning errors are 1.4% and 2.2% respectively;When the SNR is reduced by half,the position of the sound source at a distance of 52 m can be realized,with a relative error of 1.1%.In this paper,a passive sound source positioning system is designed based on the second order interferometric positioning principle,and the influence of array structure and sound source parameters on the system is analyzed.It lays a foundation for the research of passive positioning technology of sound source.