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Research on "Invisible Noise Barrier"

“隐形隔音屏障”研究

基本信息

批准号：
02805065
负责人：
HASEBE Masaki
金额：
$ 0.96万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02805065/
关键词：
Active Noise Control Barrier LMS 適応制御 LMSアルゴリズム音場制御

项目摘要

The basic idea to control the traffic noise by this active noise control method is to use a network of microphones and secondary sources. This network of the secondary sources is just the "Invisible Noise Barrier". In our case, the primary source corresponds to the individual vehicle or a small portion of traffic flow and the network of the secondary sources is rather transparent state than the usual noise barrier.(1)The theory to treat the complex three-dimensional sound field is needed.(2)ln order to follow up the changes of the condition of propagation path of sound, the adaptability must be included in the filter system. It is shown by the JMC theory that a source-free volume can be shielded against noise from outside by cancellation sources along its surface. In order to demonstrate the "Invisible Noise Barrier" system in our laboratory, an experimental setup was constructed as the simplified model of the barrier- system. The main control filter is constructed by a DSP(digital sig … More nal processor)system(Lorry Plus ; by Mtt Co.)of which purchase was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture.Simulated results agree with the measured results in a broad sence. The level of sound pressure field behind the tripole sound sources were reduced around the error microphone. The size of the reduced area increases as the distance between each tripole increases. However, when the distance is 0.6 lambda, some high pressure region penetrates the reduced pressure area. This means that there exists the best condition about the distance between each tripole. In this experiment, the maximum number of tripole sound source was three. As the numerical simulation, we can carry out some calculations. In the case of 17 tripoles and the distance between each tripole, 0.2 lambda, the size of reduced area becomes half-horizontal plane. This shows the meaning which Jessel have already spoken out. We can, however, only discrete secondary sound sources as the tripole, there remains problem how to distribute such discrete tripoles in order to cancel the distributed noise field as the best condition. Less

这种有源噪声控制方法控制交通噪声的基本思想是使用麦克风和次级源的网络。这个次级声源网络就是“无形的噪音屏障”。在我们的例子中，主要声源对应于单个车辆或一小部分交通流，而次要声源的网络是相当透明的状态，而不是通常的噪音屏障。（1）需要处理复杂三维声场的理论。(2)ln为了跟踪声音传播路径条件的变化，滤波系统必须具有适应性。JMC理论表明，无源体积可以通过沿其表面沿着的抵消源屏蔽来自外部的噪声。为了在实验室演示“隐形声屏障”系统，我们构建了一个实验装置作为屏障系统的简化模型。主控滤波器由DSP（数字信号处理器）构成 ...更多信息 nal处理器）系统（Lorry Plus ; Mtt Co.）其中10台是由文部科学省科学研究补助金资助购置的，模拟结果与实测结果在广泛意义上是一致的。在误差传声器周围，三极声源后的声压场水平降低。减小区域的大小随着每个三极之间的距离的增加而增加。然而，当距离为0.6 λ时，一些高压区域穿透减压区域。这就意味着每个三极之间的距离存在一个最佳条件。在本实验中，三极声源的最大数量为三个。作为数值模拟，我们可以进行一些计算。在17个三极和每个三极之间的距离为0.2 λ的情况下，减小面积的大小变为半水平面。这就说明了杰塞尔已经讲出来的意思。然而，我们只能将离散的次级声源作为三极，仍然存在如何分布这样的离散三极以消除分布式噪声场作为最佳条件的问题。少