JPS63139268A - System for searching wide frequency band noise source - Google Patents

Abstract

PURPOSE:To search a wide frequency band noise source and to measure the azimuth thereof by one receiving sensor, by constituting the title system of a frequency analyzing part, a phase comparing part, an integration part, a synthetic part and an RMS calculation part. CONSTITUTION:A frequency analyzing part 1 analyzes the frequencies of the NS signal 7 having directionality of COS theta, EW signal 8 having directionality of Sin theta and OMNI signal outputted from one receiving sensor A phase comparing part 2 respectively compares the phases of the frequency spectra of the NS signal 10, EW signal 11 and OMNI signal 12 subjected to frequency analysis and applies a positive code to the frequency spectra of the NS signal and EW signal 14 after frequency analysis when said phases are same and applies a negative code to said spectra when the phases are reverse. An integration part 3 integrates the output thereof at every frequency spectrum to obtain NS integral output 15 and EW integral output 16 and a synthetic part 4 synthesizes the results thereof over a definite frequency range. When the RMS of NS synthetic output 17 and EW synthetic output 18 is calculated by an RMS calculation part 5, the level 19 of a noise source and the approximate azimuth 20 thereof can be calculated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used in a sound source detection device that processes acoustic signals received by a wave receiving sensor and detects the sound source. Concerning the detection of occurrences.

[Conventional technology]

Conventionally, the wide-frequency band noise source detection method of Jin-no-Komo detects a sound source 27t received by a receiver A28 and a receiver B29 placed at two different positions as shown in FIG. It was detected by passing it through the correlator 23. Receiving wave sensor? The acoustic signals received by A28 and receiver sensor B29 are expressed by equations (1) and (2), respectively. .

Receiving sensor A receiving signal 24=Nmu(t) +5(t)
(1) Receiving sensor B receiving signal 25 =N e(
t) +5(t) (t-τ)+1) and (2), Mmu(ri) and Na(ri) are underwater noise, and 5(t) is the noise generated at 270.

8 people (t), NB (t), and 5 (t) are noise and have no correlation with each other. Further, τ in equation (2) is the time difference between when the noise generated by the noise source 27 reaches the wave receiving sensor A28 and the wave receiving sensor B29. The correlation output 26 becomes (3)2.

T Correlation output 26=? , (8 people < t-1) + S (t
−i ) 1・(NB(t)+5(t−τmonthdt
(In Equation 31 (3), when the integration time ゛i' is lengthened, the correlation output 26 approaches the noise generated by the sound source 27070 when the time lag base of the correlation is equal to τ, and when the time lag j is different from τ, the correlation output 26 approaches 0. In the conventional wide frequency band noise source detection method, a sound source 270 detector tube that generates noise by changing the correlation time lag and detecting the peak of the correlation output 26 has been used.

The sound source 27C10,000 is the wave receiving sensor A28 and the wave receiving sensor B
It can be determined geometrically by using the distance @ determined from the distance of No. 29 and the time 2gt of the correlation.

[Problems to be Solved by the Invention] The conventional wide frequency band noise source detection method described above requires at least two receiver sensors to perform correlation processing on noise from noise sources received simultaneously from two different locations. The distance must be greater than the distance at which the correlation between the incoming underwater noises disappears, and less than the distance at which the noise from the noise source does not lose its correlation during underwater propagation. Furthermore, since the direction of the noise source is a function of the distance between the two wave receiving sensors, there is a drawback in that it is operationally limited in that the distance must be accurately determined at all times.

[Means for solving problems]

The wide frequency band noise source and detection method of the present invention is to frequency-analyze the NS signal with the directivity of CO8θ and the EW multiplied signal 0MN1 signal with the directivity of Sinθ output from one wave receiving sensor. Analyzed nine NS
and a phase comparison unit that compares the phases of the frequency spectra of the EWi signal and the 0MN1 signal and assigns a positive sign if they are in phase and a negative sign if they are in opposite phase to each frequency spectrum of the NS and EWI signals after frequency analysis. An inspection section that integrates the output for each frequency spectrum, a synthesis section that synthesizes the frequency spectra over a certain frequency range, and an RMS of the output of the N81 composite value and the EV false signal composite value.
It has an RMS calculation section that calculates t.

〔Example〕

FIG. 1 is a block diagram of one embodiment of the present invention.

When the noise source 21 that generates noise and the wave receiving sensor 22 are arranged as shown in FIG. 2, the NS signal 7 of the wave receiving sensor 22
．． The EW signal 8.0AaN1 false code 9 is expressed as in equations (4), (5), and (6).

NS signal? = NN 5(t) +5(t) CO8
θ (4) EW signal 8 = Nx t) + 5(t)
Sinθ (5) and OMN1 signal 9 = N□M
Nx(t)+5(t) (61(4) formula,
In equations (5) and (6), NN5(8Ngw(t)
, OoMsx(t) is underwater noise, 5(t) is noise source 21
θ is the direction seen from the wave receiving sensor of the mf source 21.

The frequency analysis output of the frequency analysis unit 1 ONS signal, EWm number, and OMN1 signal is expressed by formula (7), +a), +97.

NS wave number analysis output 10=NNsi(t)+5i(t)
CO8θ (force EW frequency analysis output 11 = Nmwf(
t) 10S 1(t) S i nθ (8) OMN1
Frequency analysis output 12=NoMsxgt)+5i(t)
(9) In equations (7), (8), and (9), Nnai(
t″KNgwi(t), NOMN 11(t) is the first frequency spectrum of underwater noise, and 5i(t) is the first frequency spectrum of noise generated by the noise source 210.

The phase comparator 2 compares the phases of the NS frequency analysis output 1O5EW frequency analysis output 11 and the 0MN1 frequency analysis output 12 for each valley spectrum, and obtains the symbol KNsi(t).
, Kxvi(t) t-give [asi(t), Kg
wi(t) is 1 when the phase is in-phase and -1 when the phase is out-of-phase.

The output Fi(10) of the phase comparator 2 is expressed by equation (11).

NS phase comparison output 13=KNsi(t) 1Nssi(
t) 15i(t) cogθl (10) 15i(
t) sin θ% (11) When the output of the phase comparator 2 is integrated by the detector 3 for NS, EW, the output is (1
2), it becomes equation (13).

NS integral output 1s=4J": KNsi(t)lNNsi
(t)+5i(t)coai91 dt (12)
EW integral output 16 = -ffoKxwi(t) l N
mwi(t) 15t(t) sin# l dt
(13) When this output is further synthesized in the synthesis section 4 over a constant frequency band for each N5SEW, the output is (14)
.

It becomes (15).

NS composite output 17=,Σ f,” Km s 1(t)
l NN a 1(t)1L +5L(t)cos#%dt (14)+5i(t
) sin θ1cit (15) Σ paste, u indicates the spectrum number of the lower limit frequency and the spectrum number of the upper limit frequency of the frequency band to be synthesized.Here, if the integration time Ti is lengthened and the number of spectra to be synthesized is increased u-L+lt-(1
4) Equation (15) is approximated by (16) and (17).

During NS synthesis output K eo11θ (16) EV
Combined output K sin# (17) NS combined output 17 and EV combined output 181 kRMS calculation unit 7 R
MSt - When calculated, equation (18) is output as a noise source level of 19. Jb during RMS output = 5j doors] 7 stones 100 g = K
K is a constant determined by the noise 5(t) of the noise source 21, the integration time T1, the number of synthesized spectra u-L+l, and the ID tightening sound source 21.
When there is no noise source 21, and when the spectrum of the frequency band that the noise source 21 does not have is synthesized, it is approximated to butterfly 0.

A noise source O approximation direction 19 is obtained from the output of the synthesis section 4 in a paternal calculation section 8 .

The quadrant is determined based on the signs of equations (16) and (17), and the orientation Δθ within the quadrant is determined using equation (19).

Based on the quadrant and Δθ, determine the approximate azimuth θ of the noise source.

[Effect of idea]

As explained above, the present invention has the advantage that it is possible to detect a wide frequency band noise source and measure the direction using one receiving sensor, so that it can be operated without requiring a plurality of receiving sensors.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a layout diagram of a sound source and a directional sonograph when detecting objects according to the present invention, Fig. 3 is a block diagram of a conventional method; FIG. 4 is a diagram showing the arrangement of an Ot source and a sonograph when detection is performed using a conventional method. l... Frequency analysis section, 2... Phase comparison section, 3... Verification section, 4... Synthesis section, 5
... RMS calculation section, 6 ... Direction calculation section, 7 ... NS signal, 8 ..., EW flaw signal 9 ... -0MN1 signal, 10...NS frequency analysis output, 11...EW frequency analysis output, 1
2・・・・・・・・・0MN11i1 wave number analysis output, 1
3...N8 phase ratio rescue power, 14...E
W phase comparison output, 15...NS integral output, 16
...i! Jw integral output, 17...NS
Combined output, 1g...EW combined output, 19...
... Noise source level, 20 ... Noise source approximate direction, 21 ... Noise source, 22 ... Wave receiving sensor, 23 ... Correlator, 24... Receiving sensor A received signal, 25... Receiving sensor B receiving signal, 26... Correlation output, 27... Noise source, 28- ---... Receiving sensor A, 29...
Receiving sensor B. Yoshioiri Patent Attorney Uchihara Jiku"', Meku, \lノ'

Claims (1)

[Claims] In a method for detecting broadband noise sources existing underwater, an NS signal with a COSQ directionality and an EW signal with a Sinθ directionality are output from one wave receiving sensor.
Frequency analysis of signal and omnidirectional OMN1 signal Frequency division Red part and frequency analyzed NS and signal EW signal and OM
A phase comparator section compares the phases of each frequency spectrum of the N1 signal and assigns a positive sign if the phase is the same, and a negative sign if the phase is opposite to each frequency spectrum of the NS and EW signals after frequency analysis. Consists of an inspection section that integrates each frequency spectrum, a synthesis section that synthesizes the results into a frequency spectrum over a certain frequency range, and an RMS calculation section that calculates the RMS of the outputs of the combined value of the NS signal and the combined value of the EW signal. A wide frequency band noise source detection method characterized by: