SOUND SOURCE PROBING METHOD

• Main Author: TSUJII MASAMUNE
• Format: Patent
• Language: English; Japanese
• Published: 18.06.2020
• Subjects: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

To provide a sound source probing method with which the effect of dark noise is reduced.SOLUTION: The sound source probing method includes: sequentially measuring sound pressure at a plurality of measurement positions using a moving microphone; starting and finishing measurement on the basis of a prescribed reference signal when measuring at each measurement position by the moving microphone; measuring sound pressure using a stationary microphone the position of which is fixed in synchronism with measurement at each measurement position by the moving microphone; finding a phase difference between the frequency analysis data of measured data of the moving microphone at each measurement position and the frequency analysis data of measured data of the stationary microphone corresponding thereto; finding a phase difference, among phase differences between the frequency analysis data of measured data of the moving microphone at each measurement position, that is attributable to a difference in measurement position; and finding a sound pressure distribution in the ground contact portion of a tire by acoustic holography using the phase difference attributable to a difference in measurement position.SELECTED DRAWING: Figure 1 【課題】暗騒音の影響を低減した音源特定方法を提供する。【解決手段】移動マイクロホンを用いて複数の測定位置において順番に音圧を測定し、移動マイクロホンによる各測定位置での測定にあたり、所定のレファレンス信号に基づき測定を開始及び終了し、位置が固定された固定マイクロホンを用いて、移動マイクロホンによる各測定位置での測定と同期させて音圧を測定し、各測定位置における移動マイクロホンの測定データの周波数分析データと、それに対応する固定マイクロホンの測定データの周波数分析データとの位相差を求め、それにより、各測定位置における移動マイクロホンの測定データの周波数分析データの間の位相差のうちの測定位置の違いに起因する位相差を求め、前記の測定位置の違いに起因する位相差を使用して音響ホログラフィを用いてタイヤの接地部分における音圧分布を求める。【選択図】図１