JPH11153660A - Sound source searching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily measure direction and position of even a sound source of non-specific frequency, by obtaining a frequency corresponding to a peak value obtained by high-speed Fourier transform of the output received with two microphones arranged with an interval, and calculating the arrival direction of sound wave from the phase value of frequency obtained at the same time. SOLUTION: High speed Fourier converters 4a and 4e output common peak frequency shown in a frequency region and output common phase value corresponding to the frequency. An azimuth operator 5 calculates difference of phase values of high speed Fourier converters 4a and 4b, and, based on the phase difference, microphone intervals and wavelength of this frequency, propagating direction of sound wave is operated. Based on the two azimuth angle data obtained from two power source direction measuring sensors, two sensors interval distances and the position relation, the sound position is calculated by the triangle method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the direction of arrival of a sound wave mainly emitted in the sea and the position of a sound source.

[0002]

2. Description of the Related Art As an apparatus for examining the characteristics of underwater sound waves, a passive sonar has been conventionally used. The main purpose of this passive sonar is to analyze the frequency of sound waves and measure sound wave intensity.
It is difficult to measure the direction, and the apparatus is complicated and expensive even if the frequency band is limited.

[0003]

SUMMARY OF THE INVENTION As described above, the passive
An object of the present invention is to provide a device that can easily measure the direction and position of a sound source of an unspecified frequency, which has been difficult with a conventional device such as a sonar.

[0004]

In the sound source searching apparatus according to the present invention, a frequency corresponding to a peak value obtained by performing a fast Fourier transform on an output received by two microphones arranged at an interval is obtained. The arrival direction of the sound wave is calculated from the difference between the phase values of the frequencies obtained simultaneously. Further, the above-mentioned means are installed at a predetermined distance from each other, and the position of the sound source is calculated from the arrival angles obtained respectively.

[0005]

As described above, the frequency of the main component can be specified for the sound wave of an unspecified frequency by the fast Fourier transform, and the phase value of the frequency specified in the calculation process of the Fourier transform can be obtained. Therefore, the arrival direction of the sound wave can be easily known from the reception phase difference between the two microphones installed at a predetermined interval. Also, if the arrival directions can be known at two places, the position of the sound source can be easily determined.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a sound source searching apparatus according to claim 1 of the present invention, wherein reference numerals 1a and 1b denote microphones for converting received sound waves into electric signals, 2a, and 2a.
b is an amplifier for amplifying the output of the microphone, 3a,
Reference numeral 3b denotes an A / D converter for converting the amplified analog signal into a digital value, and reference numerals 4a and 4b denote fast Fourier transformers (FFT) for performing a Fourier transform on the digital signal. The fast Fourier transformers 4a and 4b output a common peak frequency indicated in the frequency domain and a phase value corresponding to the frequency. Reference numeral 5 denotes an azimuth calculator which calculates the difference between the phase values of the fast Fourier transformers 4a and 4b, and calculates the direction of arrival of the sound wave based on the phase difference, the microphone interval, and the wavelength at this frequency. Is calculated. If the phase difference is φ, the microphone interval is 1, the wavelength at this frequency is λ, and the arrival direction of the sound wave is θ with reference to the direction shown in FIG. 2, the arrival direction θ of the sound wave is calculated by the following equation. .

## EQU1 ## θ = Sin ⁻¹ (φ · λ / 2πl)

FIG. 3 is a diagram showing a configuration of a sound source search apparatus according to a second aspect. Reference numerals 10a and 10b denote sound source direction measurement sensors, which are constituted by the sound source search device according to claim 1, and are installed at a predetermined distance from each other. 11 is
A position calculator, which is a sound source direction measuring sensor 10a and 1 transmitted through data transmission lines 12a and 12b.
Based on the two azimuth data obtained at 0b, the separation distance between the two sensors, and the positional relationship, the sound source position is calculated by trigonometry.

[0008]

As described above, according to the sound source searching apparatus according to the present invention, the arrival direction and the position of the sound source of the unspecified frequency can be measured while specifying the frequency with a simple and inexpensive apparatus. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a sound source search apparatus according to claim 1 of the present invention.

FIG. 2 is a microphone arrangement diagram for calculating a sound source direction according to the present invention.

FIG. 3 is a diagram showing a configuration of a sound source search device according to claim 2 of the present invention.

[Explanation of symbols]

1a and 1b; microphones 10a and 10b;
Sound source direction measurement sensors 2a and 2b; amplifier 11;
Position calculators 3a and 3b; A / D converters 12a and 12b;
Data transmission lines 4a and 4b; Fast Fourier Transformer 5;

Claims (2)

[Claims] 1. A pair of microphones arranged at a predetermined interval, an amplifier for amplifying signals received by the two paired microphones, and a digital signal for each of the amplified received signals. An A / D converter for converting the digital signal into a Fourier transform, a frequency indicating a peak value obtained as a result thereof, and a fast Fourier converter outputting a phase value corresponding to the frequency; A sound source search device comprising: a direction calculator that calculates a direction of arrival of a sound wave based on a frequency, a difference between respective detection phases, and the predetermined interval. 2. A position calculator for calculating a sound source position based on the directions of arrival of sound waves obtained by a plurality of sound source searching apparatuses according to claim 1 and the predetermined distance, the sound sources being located at a predetermined distance from each other. Sound source searching apparatus characterized by having