Research On Signal Processing Method Of Robust And Fast Array Of Vector-side Array

The vector hydrophone can collect the acoustic pressure data and the vibration velocity data at the same time,which has obvious performance advantage compared with the traditional acoustic pressure hydrophone.Since its appearance,vector hydrophone has been widely concerned by the scholars in the field of underwater sound,and has been applied to sonar equipment such as buoy sonar and towed line array.At present,the application of hydrophones is mostly based on the assumption of free field.When vector hydrophones are loaded in the underwater parts of large instruments such as ships,the acoustic field near the hydrophones will be distorted due to the existence of the anti-sound baffle,which no longer satisfies the assumption of free field.Due to the large array elements such as the side array,computational complexity becomes an important consideration for the practicability of the algorithm.In the actual Marine environment,due to the existence of multiple disturbances,the guidance vector mismatch in array received data will have an important impact on the algorithm.In view of the above situation,the vector-side array beamforming method under plane baffle is studied from two aspects of robustness and speed respectively.This paper firstly introduces the application status of vector hydrophone under baffled conditions and the development history of robust beamforming and dimensionality reduction beamforming at home and abroad.Then,the equivalent reflection coefficient of the steel-air-steel rectangular plane cavity baffle is analyzed.Based on this,the vector uniform linear array model with the plane baffle condition as the background is established.Then,the vector array algorithms of conventional beamforming,MVDR and MUSIC in plane baffle and free field are analyzed and compared respectively.The vector array with the same number of array elements has higher gain than the sound pressure array and can solve the problem of left and right string ambiguity in direction finding of the sound pressure array.In order to solve the problem that the output SNR of MVDR beamforming algorithm decreases seriously in the case of steering vector mismatch,the classical robust Capon beamforming(RCB)algorithm and the feature subspace based RCB algorithm are studied and applied to the vector array in the condition of baffle.The two algorithms have better robustness and higher output SNR than MVDR algorithm in the case of steering vector mismatch.In order to solve the problem of large amount of computation caused by high complexity,this paper studies the fast dimensionality reduction beamforming based on MVB framework and the fast dimensionality reduction MUSIC algorithm based on multi-level Wiener filter.Both of these algorithms significantly reduce the computational complexity and can effectively reduce the computational time when dealing with large arrays.