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基于平面螺旋传声器阵列的声成像定位技术研究
Research of Acoustic Imaging System Based on the Spiral Array
【作者】 张洪铭;
【作者基本信息】 山东科技大学 , 通信与信息系统, 2011, 硕士
【摘要】 近年来,噪声治理问题越来越受到重视,噪声检测广泛应用在家电、汽车、船舶、飞机、机械制造等行业,通过噪声源定位和噪声源分离可以用来降低机器噪声,检测设备故障,国内外许多专家学者在噪声源检测方面做了不少理论研究和应用开发工作,提出来很多方法,如声压级近场测量法、选择隔声法、表面振速测量法、声全息法,这些方法各有局限性。随着阵列处理技术的发展,采用传声器阵列进行噪声源识别的技术日趋发展起来,其中阵型的选择和算法研究是传声器阵列进行声源定位的关键技术。本文在这两方面进行了理论研究和仿真对比,并在这基础上设计了基于平面螺旋的声成像定位系统。本文的主要研究工作主要有以下几个方面:1.研究了阵列基础理论,分析了阵列接收信号的数学模型,建立任意结构的阵列窄带信号模型,并推导了典型阵列的阵列流形。2.深入分析了阵列结构对阵列波束指向性的影响,并仿真比较了各种规则阵列和不规则阵列,通过比较发现优化的螺旋形阵列的波束指向性最好,旁瓣级更低,从而有更好的空间分辨率高。3.深入研究了常规波束形成算法,分析了束控和加权对波束指向性的影响,介绍了MVDR算法和MUSIC子空间算法,并与常规波束形成算法进行了仿真对比。4.分别从硬件系统和软件实现介绍本课题组所研发的基于平面螺旋的声成像定位系统,并对各个性能指标进行测试。测试结果表明,声成像定位系统具有较高的空间分辨率和较强的抑制虚源能力,因此在噪声源的定位与提取、机器噪声故障诊断、噪声降噪等方面有较好的应用前景。
【Abstract】 Noise control problems receives more and more attention in recent years, noise detection is widely used in household appliance, automobiles, ships, aircraft, machinery manufacturing and other industries. It can reduce machine noise and detect equipment failure through noise source location and noise source separation. Many domestic and foreign experts have done a lot of theoretical research and application development work in the noise source detection and proposed a number of ways, such as near-field pressure level measurement, sound insulation selection, surface velocity measurements, acoustic holography. These methods all have their limitations. With the development of array processing technology, the use of microphone array for noise source identification becomes more developed. Array design and Algorithm Research are two key technologies of microphone array sound source localization. This article has carried on the theory research and simulation contrast, and design acoustic imaging system based on the spiral array.The research results in this thesis listed as follows:1. Basic Array signal theory had been studied, mathematical models of the signal arriving at array are analyzed. the narrowband of the output data of array with arbitrary geometry are given.2. The array structure influence on beam pattern the array is analyzed, and comparative simulation all kinds of regular array rule and Irregular arrays rules. By comparing, the beam direction of the optimized spiral array is best, side lobe level lower, and thus has better spatial resolution.3. Conventional beamforming algorithm is researched, the beam control and weighting influence on beam pattern is analyzed. And then introduce MVDR algorithm and MUSIC subspace algorithm, and give simulation comparison with the conventional beamforming algorithm.4. Introduce acoustic imaging positioning system based on the spiral array separately from the hardware system and software implementation and test various performance indicators. The experimental results indicate that the acoustic imaging system has high spatial resolution and strong capability of eliminating ghost images. It can be applied widely into many fields such as localization and separation of noise sources, machine condition monitoring, noise reduction
【Key words】 Spiral array; CBF; Acoustic imaging; Sound source localization;