| Project/Area Number |
07555052
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
設計工学・機械要素・トライボロジー
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| Research Institution | TOKYO INSTITUTE OF THCHNOLOGY |
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Principal Investigator |
UMEZAWA Kiyohiko Precision and Intelligence Laboratory, Tokyo Institute of Technology, Professor, 精密工学研究所, 教授 (60016780)
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| Co-Investigator(Kenkyū-buntansha) |
OHSHIMA Shun-ichi Precision and Intelligence Laboratory, Tokyo Institute of Technology, Research A, 精密工学研究所, 助手 (30262322)
HOUJOH Haruo Precision and Intelligence Laboratory, Tokyo Institute of Technology, Professor, 精密工学研究所, 教授 (40108238)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥13,600,000 (Direct Cost: ¥13,600,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1996: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥11,000,000 (Direct Cost: ¥11,000,000)
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| Keywords | Measurement / Sound / Real-time / Machinery Noise / Acoustic Holography / Near Acoustic Holography / Microphone Array / 音 |
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| Research Abstract |
A real-time 2-D holographic acoustic measurement system is constructed. The system consists of 10 by 10 microphones which are attached to tensioned steel wire and arranged squarely in equal spacing analog circuits and data acquisition system. The effect of the insertion of this 2-D microphone array near the sound source is examined experimentally by means of single scanning microphone. It is shown that the insertion effect of the array don't give the serious error to the estimated result of sound source location.
Since this system realizes the simultaneous measurement of complex sound pressure distribution by all microphones over the aperture, incoherent, temporal-and spatial-varying sound field such as machinery noise source can be grasped. This advantage is confirmed experimentally by means of loud speakers.
Two kinds of holographic process, near-field acoustic holography and acoustic holography, was examined for locating sound sources by simulation to know the advantageous characteristics. And the methodology of locating sound sources combining two holographic processes is proposed for machinery noise, which consiste of applying conventional acoustic holography for wide-view, closing up microphone arrey to objective point of noise souce and applying near-field acousticholography for precise-view. It is to say that, this method can be realized by the real-time measurement syste. Another method is also proposed which is like stereograph realized by multi-position measurement. Experimental tests of proposed method applied to actual machine are presented.
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