| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus 2 for surely and easily identifying a sound source of an abnormal sound produced in a tire. SOLUTION: The apparatus 2 includes a large number of microphones 4, an acoustic holography device 6, a rotary encoder 8, a computer 10, and a monitor 12. The microphones 4 are adjacent to a tire. Noise generated by the rotation of the tire is continuously measured by the microphones 4. Each of the microphones 4 sends a signal to the acoustic holography device 6. The acoustic holography device 6 analyzes the frequency of each signal and computes sound pressure at a specific frequency. Furthermore, the acoustic holography device 6 computes image data on sound-pressure distribution in accordance with sound pressure in each microphone 4. The rotary encoder 8 puts out a pulse signal corresponding to the angle of rotation of the tire. The computer 10 associates time-based data on sound-pressure distribution images with time-based data on angles of rotation. COPYRIGHT: (C)2009,JPO&INPIT
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