著者

英 慎平 上保 徹志 土田 悠太 篠原 寿広 中迫 昇

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. C, 電子・情報・システム部門誌 = The transactions of the Institute of Electrical Engineers of Japan. C, A publication of Electronics, Information and System Society (ISSN:03854221)

巻号頁・発行日

vol.129, no.11, pp.2027-2033, 2009-11-01

被引用文献数

3

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In many engineering fields, distance to target is very important and fundamental information. Acoustical signal often plays an essential role in measurement of distance. Though there are distance measurement methods using a time delay between transmitted and reflected waves, it is difficult to measure short distance because the reflected waves are often buried in the transmitted wave for short distance. Recently, a method for measuring the short distance has been proposed using standing wave. We applied the fundamental principle of this method to the estimation of short distance using audible sound as a transmitted wave. This method enabled us to obtain range spectrum from power spectrum of composite sound, but it required Fourier Transfom twice. This paper introduces the chirp signal, which is a signal such that the frequency changes with lapse of time, as a transmitted wave, and an interference arises due to the superposition of transmitted and reflected waves. Since the period of power fluctuation for the composite sound is inversely proportional to the distance between microphone and target, we propose a new distance estimation method by using chirp signal as a transmitted wave. Finally, we also confirm the validity of the proposed method through computer simulation and by experiment in an actual sound field.