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研制开发了一种进行声源定位的「实验装置,波的传播特性,可以推知物体的位置,文章介绍了声发射平面定位的原理,自制的实验装置和实验结果。 相似文献
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本文针对声发射技术中的三维定位问题提出一种新的简易实验方案.通过传感器接收的时差信息和空间坐标实现三维立体结构中的声发射源定位,操作和计算简单,降低了实验成本.该实验方法不仅可以直观地实现三维声发射源定位过程,还可以实现声速的测量.本设计加深了学生对物理问题的理解,提高了学生对声发射技术和声源定位技术的兴趣,适合普及. 相似文献
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储罐底板腐蚀是多声源问题,即在不同位置的腐蚀源可能同时发射应力波。这些声源信号有时会重叠被传感器接收,从而影响定位的可靠性。为此本文基于平面声发射源能量定位方法的基本理论,进行了模拟储罐底板定位实验,提出了能量定位系数的修正方法。同时通过对实验数据分析,发现快速独立分量分析(FastICA)方法可以将同种声源混合信号进行有效分离,并且基本保持原有波形特征,相干系数法可以实现对分离后的同源信号进行聚类,进而应用改进能量定位方法对声发射源进行定位,从而对声源辨识,判断事件集中度提供依据。 相似文献
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系统阐述了利用水下爆炸声源作为发射声源,辅助声呐系统实现水下目标定位和目标方位、距离参数估计的方法。研究了目标散射信号的窄波束混响模型,以及混响背景下的目标方位参数的估计方法。对目标参数估计误差进行研究,证明方位参数、距离参数的估计误差近似满足高斯分布,并推导了距离参数估计误差方差的表达式。利用仿真实验对目标距离参数估计误差及其标准差进行研究,得出了一系列提高距离参数估计精度的措施。仿真和湖试数据处理结果显示,在存在一定爆炸声源距离误差的条件下,本文方法可实现对远距离水下目标的准确定位。 相似文献
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综合考虑声音信号的时延和多普勒效应,设计出一种七元非对称麦克风阵列声源定位装置。将该装置应用于对静止声源、不同运动状态的声源的定位,探究了装置对不同声频、三维空间不同位置以及不同运动状态的声源的定位效果。对于静止声源,装置的定位精度约为±2cm,定位范围约为0~70cm。对于运动声源,装置可以得到不同时刻声源的位置和速度,进行拟合后得到的运动参数误差约为3%。以声源定位测量重力加速度为例讨论了声源定位在实验上的扩展。本工作有助于帮助学生理解声学的相关知识,具有很大的实际应用与实验教学价值。 相似文献
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多特征向量约束的自适应环境宽容匹配场算法可用于随机和不确知海洋声传播介质中的声源位置定位。该方法需要对拷贝场复声压的互谱矩阵进行估计。为了克服蒙特卡洛统计方法计算互谱矩阵较为耗时的缺点,文章将起伏介质中的随机或不确知声压表示为以正交的随机多项式为基底的级数,随机多项式基底的输入变量为描述环境随机性或不确知性的随机变量。利用随机多项式展开基底的正交性可快速估计拷贝场复声压互谱矩阵。仿真结果表明:在声源频率较低、浅海海水声速存在随机起伏的条件下,在计算效率上使用随机多项式展开方法估计拷贝场复声压互谱矩阵较蒙特卡洛统计方法可提高一个数量级;在高信噪比下,多特征向量约束匹配场声源定位算法在定位准确率和输出峰均比上优于线性匹配场和对角加载的最小方差匹配场声源定位方法。 相似文献
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Soeta Y Ito K Shimokura R Sato S Ohsawa T Ando Y 《The Journal of the Acoustical Society of America》2012,131(2):1206-1220
In 1965, the Catholic Church liturgy changed to allow priests to face the congregation. Whereas Church tradition, teaching, and participation have been much discussed with respect to priest orientation at Mass, the acoustical changes in this regard have not yet been examined scientifically. To discuss acoustic desired within churches, it is necessary to know the acoustical characteristics appropriate for each phase of the liturgy. In this study, acoustic measurements were taken at various source locations and directions using both old and new liturgies performed in Japanese churches. A directional loudspeaker was used as the source to provide vocal and organ acoustic fields, and impulse responses were measured. Various acoustical parameters such as reverberation time and early decay time were analyzed. The speech transmission index was higher for the new Catholic liturgy, suggesting that the change in liturgy has improved speech intelligibility. Moreover, the interaural cross-correlation coefficient and early lateral energy fraction were higher and lower, respectively, suggesting that the change in liturgy has made the apparent source width smaller. 相似文献
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R. Kinns 《Journal of sound and vibration》1976,44(2):275-289
It is shown how the coherence and phase spectra 0f signals from a closely spaced pair of microphones in the far-field can be used to compute the moments of a line distribution of arbitrarily correlated omni-directional sound radiators. This line source gives a far-field which is equivalent to that of model-scale and full-size turbojet engines in terms of measured power and cross-spectra 0f microphone signals. The necessary spectra can be computed rapidly on a small digital computer and the simplicity of the technique has meant that experiments could be performed in parallel with the usual far-field noise measurements. In this way, it has been possible t0 identify important properties of noise generation by turbojet engines at minimum cost and development and application of more sophisticated techniques has been accelerated. It is shown how the apparent properties of the source distribution may depend markedly on distance from the source to the microphones. Interpretation of results is guided by consideration of simple cases. 相似文献
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为减小声速误差对定位精度的影响,提出了一种基于声速修正的分布式声源定位方法。首先,将声速表示为未知声源位置的函数,逼近风场中的声速场分布,然后将其代入TDOA (Time Differences of Arrival)算法中,构建非线性超定方程组,最后采用粒子群优化算法求解声源位置。对不同风速、不同声源位置及不同测试区域进行仿真,结果表明:修正后的定位精度比修正前有明显提高,尤其对于大范围并且声源靠近测试区域边缘位置的定位系统,改善更加明显;4个节点的定位系统实验结果表明,修正后的定位误差可降至修正前的4l%,该方法能更好的应用于风场中的定位系统。 相似文献
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Ochmann M 《The Journal of the Acoustical Society of America》2004,116(6):3304-3311
The sound field caused by a monopole source above an impedance plane can be calculated by using a superposition of equivalent point sources located along a line in the mirror space below the plane. Originally, such an approach for representing the half-space Green's function was described by Sommerfeld at the beginning of the last century, in order to treat half-space problems of heat conduction. However, the representation converges only for masslike impedances and cannot be used for the more important case of reflecting planes with springlike surface impedances. The singular part of the line integral can be transformed into a Hankel function, which shows that surface waves are contained in the whole solution. Unfortunately, this representation suffers from the lack of validity at certain receiver points and from restrictions on wave number and impedance range to ensure the necessary convergence. The main idea of the present method is to use also a superposition of equivalent point sources, but to allow that these sources can be located at complex source points. The corresponding form of the half-space Green's function is suitable for both masslike and springlike surface impedances, and can be used as a cornerstone for a boundary element method. 相似文献
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A highly efficient frequency-controlled sound source based on a tunable high-Q underwater acoustic resonator is described. The required spectrum width was achieved by transmitting a linear frequency-modulated signal and simultaneously tuning the resonance frequency, keeping the sound source in resonance at the instantaneous frequency of the signal transmitted. Such sound sources have applications in ocean-acoustic tomography and deep-penetration seismic tomography. Mathematical analysis and numerical simulation show the Helmholtz resonator's ability for instant resonant frequency switching and quick adjustment of its resonant frequency to the instantaneous frequency signal. The concept of a quick frequency adjustment filter is considered. The discussion includes the simplest lumped resonant source as well as the complicated distributed system of a tunable organ pipe. A numerical model of the tunable organ pipe is shown to have a form similar to a transmission line segment. This provides a general form for the principal results, which can be applied to tunable resonators of a different physical nature. The numerical simulation shows that the "state-switched" concept also works in the high-Q tunable organ pipe, and the speed of frequency sweeping in a high-Q tunable organ pipe is analyzed. The simulation results were applied to a projector design for ocean-acoustic tomography. 相似文献
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A.G. Sills 《Applied Acoustics》1982,15(3):231-240
A method of predicting sound pressure levels from an explosive source has been developed by the author to assist in the control of artillery firing at Larkhill.Measurements have shown that, for a given charge weight and source to receiver distance, changing meteorological conditions can alter the observed sound intensities by over 30 dB.The method is valid for a wide range of weather conditions and will model observed sound foci including those upwind. The RMS error in the predictions is less than 6 dB for levels of 100 dB or more (peak linear).Application to other types of sound source and corrections for topography are under development. 相似文献
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《声学学报:英文版》2021,(1)
详细阐述了单水听器和水听器阵列进行海豚定距定位的几何模型,以及利用不同接收通道间的时延差计算空间坐标的方法,结合实验数据计算了海豚在水中的三维空间坐标和回声定位信号的声源级,并开展了海豚运动轨迹追踪分析。结果表明,相对于单水听器,水听器阵列对测量环境和海豚行为的限制较少,但对采集设备的同步性和硬件连接有较高要求。误差分析表明水听器阵列在大于3 m的距离,定位误差可降低到5%以下。研究结果为精确计算海豚发声源级及海豚的声呐性能及行为研究提供了技术支撑。 相似文献
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详细阐述了单水听器和水听器阵列进行海豚定距定位的几何模型,以及利用不同接收通道间的时延差计算空间坐标的方法,结合实验数据计算了海豚在水中的三维空间坐标和回声定位信号的声源级,并开展了海豚运动轨迹追踪分析。结果表明,相对于单水听器,水听器阵列对测量环境和海豚行为的限制较少,但对采集设备的同步性和硬件连接有较高要求。误差分析表明水听器阵列在大于3 m的距离,定位误差可降低到5%以下。研究结果为精确计算海豚发声源级及海豚的声呐性能及行为研究提供了技术支撑。 相似文献
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锥形声源的二次谐波声场分布 总被引:1,自引:0,他引:1
本文推导了锥形声源的非线性二次谐波声场分布。理论表明锥形源二次谐波声场沿径向呈Bessel函数分布,且与传播距离无关。另一个重要结论是这种声场的二次谐波束宽刚好为基波的1/2,而非一般情况下的$1 / \\sqrt{2}$倍,此外,我们指出了这种声束在非线性参量B/A成象或测量中潜在的应用价值. 相似文献
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