基于缺失阵的混合波叠加近场声全息技术对机械噪声源的识别定位

发布时间：2018-03-01 20:42

本文关键词： 近场声全息波叠加法统计最优传声器阵列　出处：《南华大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文的研究内容作为国家自然科学基金项目的一部分，主要研究基于传声器阵列的近场声全息技术获取机械设备关键声源附近的中低频信息。近场声全息技术可以十分有效的识别定位噪声源并实现声场的可视化，它的应用为机电产品的噪声控制、低噪声设计和声质量设计提供了极大的便利。根据大型设备声学故障检测和诊断的需要，从实际的工程应用出发，对基于小型传声器阵列测量的近场声全息技术进行了研究。本文主要的工作内容包括： 1）文章首先阐明了本文的课题来源，，回顾了近场声全息技术和阵列测量技术的研究现状，针对现有技术应用于实际的局限性及其发展趋势，确定了本文的研究内容。 2）针对本文的研究对象，分析了机械性噪声产生的原理。对基于傅立叶变换的近场声全息技术，研究了关键参数的选择对重建精度的影响。研究了基于波叠加的数据外推方法，降低了全息孔径对传统近场声全息技术的限制。 3）仿真验证了结合吉洪诺夫正则化方法的统计最优近场声全息比基于傅立叶变换的近场声全息具有更高的重建的精度。引入了基于混合波叠加法的声场重建技术，实现了小测量孔径下，声场信息的精确重建。同时针对机械设备工作现场的复杂性，在全息测量面两侧都存在声源的情况下，引入了基于混合波叠加法的声场分离技术，结合了波叠加和统计最优方法的优点，此方法降低了测量成本、提高了实验效率。 4）近场声全息技术中，还有一个重要的方面就是数据的采集，依靠传声器阵列进行数据采集，本文研究了在不同缺失阵列下，声场的重建效果，并通过在缺失阵中增加传声器测量点的方法，在一定程度上提高了声场的重建精度；针对里面阵与外围阵的缺点，通过在其中增加传声器测量点来提高声场重建精度；仿真验证了在缺失阵测量下，声场分离的可行性。 5）最后进行了实验，实验基于十字阵列进行数据采集，然后利用混合波叠加近场声全息技术对模拟机械噪声源进行声场重建，从而实现对噪声信息的重建，实验得到了良好的效果。
[Abstract]:The research content of this paper is a part of the National Natural Science Foundation of China. This paper mainly studies the near field acoustic holography technology based on microphone array to obtain the middle and low frequency information near the key sound source of mechanical equipment. The near field acoustic holography technology can identify and locate the noise source effectively and realize the visualization of sound field. Its application provides great convenience for noise control, low noise design and sound quality design of mechanical and electrical products. The near field acoustic holography based on small microphone array measurement is studied. The main work of this paper is as follows:. 1) at first, the source of this thesis is clarified, the research status of near-field acoustic holography and array measurement is reviewed, and the research content is determined in view of the limitation and development trend of the existing technology applied in practice. 2) aiming at the research object of this paper, the principle of mechanical noise generation is analyzed. For the near field acoustic holography technology based on Fourier transform, the influence of the selection of key parameters on reconstruction accuracy is studied, and the data extrapolation method based on wave superposition is studied. The limitation of holographic aperture on traditional near-field acoustic holography is reduced. 3) the simulation results show that the statistical optimal near-field acoustic holography combined with Tikhonov regularization method has higher reconstruction accuracy than that based on Fourier transform, and the acoustic field reconstruction technique based on mixed wave superposition method is introduced. The accurate reconstruction of sound field information under small aperture measurement is realized. In view of the complexity of the working field of mechanical equipment and the presence of sound sources on both sides of the holographic measurement plane, the technique of acoustic field separation based on mixing wave superposition method is introduced. Combining the advantages of wave superposition and statistical optimal method, this method reduces the measurement cost and improves the experimental efficiency. 4) in the near field acoustic holography technology, there is also an important aspect of data acquisition, which depends on microphone array for data acquisition. In this paper, the effect of sound field reconstruction under different missing arrays is studied. The reconstruction accuracy of sound field is improved to a certain extent by adding the measuring points of microphone in the missing array, and the accuracy of sound field reconstruction is improved by adding the measuring points of microphone to the inner array and the peripheral array. Simulation results show that the separation of sound field is feasible under the measurement of missing array. 5) finally, the experiment is carried out, which is based on cross array data acquisition, and then uses mixed wave superposition near-field acoustic holography to reconstruct the sound field of analog mechanical noise source, so as to realize the reconstruction of noise information. The experiment has achieved good results.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP212.9;TB53

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