KR101126694B1 - Hull sticking type sonar and ship having the same - Google Patents

Abstract

PURPOSE: A hull-attached sonar and a ship with the same are provided to facilitate the detection of sound wave during the high speed driving of the ship or the stop of the ship. CONSTITUTION: A hull-attached sonar comprises a linear aligning sensor(100) and a signal processing unit(200). The linear aligning sensor is attached to both sides of the hull and senses the sound wave transmitted underwater. The signal processing unit determines the approaching direction and the kind of the sound source, which produces sound source, using the sensing signals. The signal processing unit comprises a multi-beam former(210) and a signal detector(220). The multi-beam former forms the beam for extracting the sound wave inputted at the specific incident angle. The signal detector determines the approaching direction and the kind of the sound source using the beam.

Description

Hull sticking type sonar and ship having the same}

The present invention relates to a hull-mounted sound wave detector and a ship having the same, and more particularly, attached to the side of the ship of various types of sound wave detector to detect the mid- and low-frequency sound, and equipped with the same It is about a ship.

In general, the sonar is mounted on a ship such as a submarine, a submersible, a semi-submersible, or a ship operated in the water or underwater, and detects and detects noise or sound emitted from a remote underwater sound source through one or more underwater acoustic sensors. It is a sound detection equipment used to determine the nature and characteristics of sound sources and the location of sound sources by analyzing the underwater sound signals.

When the ship is equipped with a sound wave detector, the sound wave detector can be used to detect not only fish and the like, but also to identify features and positions of other ships within a detectable range. Can be detected.

On the other hand, in a conventional ship or the like, as shown in Fig. 1 (a), a bottom mounted sonar sound wave detector 10 or Fig. 1 (b) which fixes the sound wave detector to the bottom portion of a ship or the like. As shown in Fig. 2, a towed array sonar 20 such as a towed array sonar system (TAS) was used.

The fixed bottom acoustic wave detector 10 is convenient for daily operation, but is not suitable for medium and low frequency sounds due to its short array length, and for this reason, such as an underwater vehicle in which medium and low frequency sounds are mainly generated. There was a problem that the detection ability is significantly reduced.

In addition, the towed line array sound wave detector 20 is suitable for low and medium frequency detection due to its long array length, but it is difficult to stop the high speed of the ship during towing the tow line array sound wave detector 20, and the water depth is relatively low. The problem is that the use is very limited in the shallow waters, which are shallow and scattered with obstacles such as fishing nets.

The present invention is attached to the side of the hull is capable of providing a low-frequency sound detection, can be utilized even in the offshore sea hull-type sound wave detector and a ship provided with the same.

The hull-mounted sound wave detector according to an embodiment of the present invention includes a line array sensor unit attached to the left and right sides of the hull in the longitudinal direction of the hull and detecting a sound wave propagated underwater to generate a detection signal; And a signal processor for determining the approach direction of the sound source generating the sound wave and the type of the sound source by using the sensed signal.

Here, the display unit may further include a display unit visually indicating the approach direction of the sound source and the type of the sound source.

Here, the line array sensor unit A plurality of acoustic sensors for outputting a sensor signal by detecting the sound wave propagated in the water; And a sensor signal receiver for amplifying and converting the sensor signal to generate the detection signal.

The signal processor may include: a multi-beam shaper configured to form at least one beam for extracting sound waves input at a specific incident angle from among a plurality of sound waves input while forming different incident angles into the hull; It may include a signal detector for determining the approach direction of the sound source and the type of the sound source using the beam.

Here, the multiple beam former may delay the plurality of sensing signals, respectively, for a time set corresponding to the specific incident angle, and form the beam by adding the delayed plurality of sensing signals.

Here, the multi-beam shaper

B _i : beam corresponding to the specific incident angle

W _j : Weight for each acoustic sensor included in the linear array sensor unit

S _j : detection signal of the acoustic sensor

t: hour

τ _i : Time delay corresponding to the specific angle of incidence A beam may be formed using the above equation.

Here, the multi-beam shaper may set τ _{i according} to the geometric arrangement and curvature of the acoustic sensor.

Here, the signal detector may determine that the sound source approaches the direction of the incident angle when the size of the beam is greater than or equal to a preset value.

Here, the signal detector may discriminate the type of the sound source by performing signal processing in a LOFAR and a DEMON method with respect to the beam.

According to another embodiment of the present invention, a ship provided with a ship-mounted sound wave detector includes: the ship-mounted sound wave detector; And the hull-mounted sound wave detector may include a hull attached to the side.

Here, when the sound source is the underwater vehicle, and it is determined that the underwater vehicle approaches the hull, it may further include a deception launch pad for launching a deception machine for disturbing the underwater vehicle.

The hull-mounted sound wave detector according to an embodiment of the present invention and the ship having the same, since the sound wave detector is attached to the side of the hull, it is possible to easily detect the sound waves even during high-speed starting or stopping of the vessel.

The hull-mounted sound wave detector according to an embodiment of the present invention and a vessel provided with the same, the sound wave detector is attached to the side of the hull in the longitudinal direction of the hull, the length of the arrangement is relatively long, according to the sound of medium, low frequency Can be detected effectively.

Figure 1 (a) is a schematic diagram showing a conventional linear fixed sound wave detector, Figure 1 (b) is a schematic diagram showing a state in which a conventional tow-type linear array sound wave detector is connected to the ship.
FIG. 2 is a view illustrating a state in which a hull-type sound wave detector according to an embodiment of the present invention is attached to a ship, and FIG. 2 (a) is a side view and FIG. 2 (b) is a schematic view showing a front view.
Figure 3 is a functional block diagram showing the function of the hull-mounted sound wave detector according to an embodiment of the present invention.
4 is a graph illustrating beam formation according to an embodiment of the present invention.
5 is a graph illustrating a delay time correction according to beam formation and curvature according to an embodiment of the present invention.
6 is a flowchart for distinguishing types of sound sources through signal processing according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing in detail the operating principle of the preferred embodiment of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and like parts are denoted by similar reference numerals throughout the specification.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

2 is a view showing a state in which the hull-mounted sound wave detector according to an embodiment of the present invention is attached to the ship, Figure 3 is a functional block diagram showing the function of the hull-mounted sound wave detector.

Referring to FIG. 3, the hull-mounted sound wave detector according to an embodiment of the present invention may include a linear array sensor unit 100 and a signal processor 200. The linear array sensor unit 100 may include a plurality of acoustic sensors 110 and a sensor signal receiver 120, and the signal processor 200 may include a multiple beam former 210 and a signal detector 220. can do. Here, the display unit 300 may further include a deception launch pad 500.

2 and 3, the hull-mounted sound wave detector according to an embodiment of the present invention will be described.

The line array sensor unit 100 may be attached to the left and right sides of the hull 910 in the longitudinal direction of the hull 910 and may generate a detection signal by detecting sound waves propagated underwater.

2, since the line array sensor unit 100 is attached to the left and right sides of the hull 910 in the longitudinal direction of the hull 910, the arrangement length is longer than that of the conventional bottom fixed sound wave detector. In addition, low frequency sound waves can be detected. In addition, compared to the conventional tow-type line array sound wave detector, since it is attached to the hull 910, it is possible to easily detect sound waves even during high-speed starting or stopping of the vessel 900 and the like.

The line array sensor unit 100 may further include an acoustic sensor 110 and a sensor signal receiver 120.

The acoustic sensor 110 may detect a sound wave propagated underwater and output a sensor signal. The acoustic sensor 110 may detect a sound wave generated by a sound source existing in the water and output the sound wave as a sensor signal which is an electrical signal. The acoustic sensor 110 may be used as long as it can detect the sound wave, it may be a hydrophone (hydrophone). Therefore, a piezoelectric transducer composed of a piezoelectric crystal or ceramic material which is sensitive to pressure can convert a pressure change around the hydrophone generated by an acoustic wave into an electrical signal. A plurality of acoustic sensors 110 may be attached to the hull 910 while forming an arbitrary interval suitable for equal intervals or detection in the longitudinal direction of the hull 910.

The sensor signal receiver 120 may generate the detection signal by amplifying and converting the sensor signal.

The sensor signal output by the acoustic sensor 110 may be an analog signal, and the sensor signal may be inappropriate for signal processing. Therefore, the sensor signal receiver 120 may convert the sensor signal into a digital signal, amplify the digital signal, and convert the sensor signal to be suitable for signal processing.

The signal processor 200 may determine the approach direction of the sound source for generating the sound wave and the type of the sound source using the sense signal.

An approach direction of the sound source may be determined from information such as the size of the sound wave detected by the sound sensor 110, and the type of the sound source may be determined from the frequency distribution of the sound wave. The frequency distribution may vary according to the type of the sound source, and the form of the frequency distribution for each sound source may be stored in a database.

The signal processor 200 may further include a multiple beam former 210 and a signal detector 220.

The multiple beam former 210 may form at least one beam for extracting sound waves input at a specific incident angle from among a plurality of sound waves input while forming different incident angles to the hull 910.

4 and 5 (a) are for explaining beam forming according to an embodiment of the present invention. Hereinafter, the beam forming process will be described with reference to FIGS. 4 and 5 (a).

The incidence angle represents an angle between the traveling direction of the sound wave and the line array sensor unit, and is indicated by θ in FIG.

The multi-beam shaper 210 may form a beam corresponding to the incident angle by setting a delay time of the detection signal according to the incident angle. The beam may be formed in plural in accordance with the incident angle. For example, the multi-beam shaper 210 may arrange at least 32 acoustic sensors and set the incidence angles at 5 ° intervals to form 32 beams simultaneously. Forming 32 beams at 5 ° intervals can detect sound waves approaching the 160 ° range. However, since the acoustic sensor cannot distinguish left and right, the acoustic sensors may be attached to the left and right sides of the hull, respectively, to detect 320 ° by 160 ° each. Specifically, the acoustic sensor attached to the left side may be less covered by the hull and receive less sound waves approaching from the right side, and the sensor attached to the right side may receive less sound waves from the left side. Therefore, the left and right sides can be distinguished by simultaneously checking the left and right sensor signals.

 Fig. 4A is a graph showing a case in which a beam is formed in the 30 ° direction with respect to the hull and there is a sound source approaching in the 30 ° direction. That is, although a plurality of sound waves are input to the acoustic sensor, the sound source having the incidence angle of 30 ° is the largest and most prominent, and thus the sound waves approach the incidence angle 30 °.

As shown in FIG. 4B, the multiple beam former 210 may generate a plurality of beams according to each set incident angle. Therefore, the plurality of sound sources approaching in each direction can be individually identified, and then, the signal processing can be used to determine the type of the individual sound sources.

Here, the part which appears especially larger than the angle of 30 degrees, 50 degree, 70 degree, and 90 degree compared with another angle can be called a main lobe, and the remainder can be called a sublobe. The main lobe can be seen that the sound waves approach at an angle corresponding to the main lobe.

Here, the multiple beam former 210 may delay the plurality of sensing signals, respectively, and add the delayed plurality of sensing signals to form the beam for a time set corresponding to the specific incident angle. FIG. 5A illustrates the beam forming process. Hereinafter, the beam forming process of the multiple beam former 210 will be described with reference to FIG. 5A.

When sound waves are transmitted in a specific direction, a signal may be largely received only in a beam corresponding to the direction. When the beam is formed in each direction by using this characteristic and the direction of the beam in which the signal is received is the largest, the sound source approaches the beam direction. The sound source may be an underwater vehicle.

Among a plurality of sound waves having various incident angles, assuming that a specific sound wave is input while maintaining a specific direction, that is, the incident angle θ, the two neighboring acoustic sensors receive a time difference of Δt while receiving the sound wave. Therefore, when the sound waves are delayed by Δt with respect to the acoustic sensors that are quickly input by Δt, and then the received signals of the two acoustic sensors are added, the sound waves having the incident angle θ are added in the same phase. However, since sound waves having different incidence angles are added to different phases, their magnitude becomes relatively small. The difference in size may appear larger as the number of the acoustic sensors increases. That is, by adding a sound wave after a different time delay, the size of the sound wave for a predetermined specific direction can be made large enough to be distinguished from the size of the sound wave input in the other direction.

의 수식을 통하여 구할 수 있으며, 상기 τ: 시간 지연, D: 음향센서간의 거리 C: 음파의 속도, θ: 입사각일 수 있다. 상기 음향센서간의 거리(D)와 음파의 속도(C)는 상수이므로, 오직 입사각(θ)만이 변수이다. 따라서 상기 시간 지연은 입사각에 따라서 설정될 수 있다.
Where the time delay is

It can be obtained through the equation of, wherein τ: time delay, D: distance between the acoustic sensor, C: the speed of sound waves, θ: the angle of incidence. Since the distance D between the acoustic sensors and the speed C of the sound wave are constant, only the incident angle θ is a variable. Therefore, the time delay may be set according to the incident angle.

Wherein the multi-beam shaper 210,

B _i : beam corresponding to the specific incident angle

W _j : Weight for each acoustic sensor included in the linear array sensor unit

S _j : detection signal of the acoustic sensor

t: hour

τ _i : Time delay corresponding to the specific angle of incidence A beam may be formed using the above equation. Looking at the above equation, the beam corresponding to a specific angle of incidence can be obtained by multiplying the weight for each acoustic sensor by the detection signal of the acoustic sensor delayed by the time delay τ.

Using the beam formed by the above formula, it is possible to determine the approach direction of the sound source, the type of the sound source.

Here, the multi-beam shaper 210 may improve the directional characteristics of the main lobe while appropriately maintaining the level difference between the main lobe and the sublobe, rather than lowering the overall sublobe level. Therefore, by maintaining the level difference between the main lobe and the sublobe at about -30 dB, the main lobe and the sublobe can be distinguished. In order to maintain the level difference at about −30 dB, the weight W may be extracted more precisely through experiments, or the delay time τ may be set in consideration of the curvature of the hull surface to which the acoustic sensor is attached. In addition, various techniques for separating the noise of the ship itself from the noise of the sound source can be utilized.

Here, the multi-beam shaper 210 may set the τ _i differently according to the geometric arrangement and curvature of the acoustic sensor. As shown in FIG. 5 (b), in general, τ _i is set to one fixed constant according to the magnitude of each incidence angle and increases linearly as the incidence angle increases. However, since the acoustic sensor actually attached to the vessel is not exactly attached in a straight line, and the hull is curved, the acoustic sensor may be set differently according to the geometric arrangement and curvature of the acoustic sensor for accurate beam formation.

The signal detector 220 may determine the approach direction of the sound source and the type of the sound source by using the beam.

By using the information about the size of the beam, it is possible to determine the approach direction of the sound source, the type of the sound source can be determined in consideration of the frequency distribution of the beam. Since each sound source generating sound waves in water has a unique tone, the type of the sound source can be determined through the tone.

Here, the signal detector 220 may determine that the sound source approaches the direction of the incident angle when the size of the beam is greater than or equal to a preset value. The multi-beam shaper 210 may form beams individually for a plurality of incidence angles, and the sound source approaches a beam having a size greater than or equal to a predetermined value among the beams in a direction of incidence angle corresponding to the beam. Can be determined.

Here, the signal detector 220 may perform the LOFAR and DEMON signal processing on the beam to distinguish the type of the sound source. Regarding the type discrimination of the sound source, it will be described with reference to FIG.

A beam may be formed using the sensing signal S10 (S20), and LOFAR and DEMON signal processing may be performed on the formed beam.

According to the low frequency signal processing S30, after performing Fourier transform on the beam approaching the hull, a wideband base signal may be extracted to generate a tonal signal for each frequency.

According to the daemon signal processing (S40), the beam approaching the hull may be shifted to a low frequency band, then filtered and Fourier transformed, and the broadband base signal may be extracted to generate an identification signal for each frequency. .

Thereafter, the frequency-specific tonal signal and the frequency-specific identification signal are binarized in a time-frequency domain (S50), and then compared with the tonal frequencies and identification signals of various types of sound sources stored in a reference identification database to compare the type of the sound source. I can figure it out. In this case, when the determined type of the sound source is an underwater vehicle, an alarm signal may be generated (S60 and S70).

When the alarm signal is generated, it is possible to manually generate an alarm (S80) or automatically generate an alarm (S90), and to perform a response to the underwater vehicle.

The display unit 300 may visually indicate the approach direction of the sound source and the type of the sound source. The display unit may utilize a commonly used device such as LCD, LED, CRT for exhibition. The display unit 300 may display an approach direction of a sound source based on the hull as an image, and may display the type of the approaching sound source by using letters or symbols.

Ship 900 having a hull-mounted sound wave detector according to another embodiment of the present invention, as shown in Figure 2, the hull-mounted sound wave detector 100 and the hull according to an embodiment of the present invention The attached sound wave detector may include a hull 910 attached to the side.

Here, the ship 900 provided with the hull-mounted sound wave detector, if it is determined that the sound source detected by the hull-mounted sound wave detector is an underwater vehicle, and the underwater vehicle is approaching the hull, to disturb the underwater vehicle. It may further include a deception launch pad 500 for launching deception.

The deception machine and the launch pad 500 may be used as long as it does not disturb the water vehicle so that the water vehicle does not damage the vessel 900.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those skilled in the art.

10: bottom fixed sound wave detector 20: towed line array sound wave detector
100: pre-array sensor unit 110: acoustic sensor
120: sensor signal receiver 200: signal processing unit
210: multiple beam former 220: signal detector
300: exhibit 500: deception launch pad
900: ship 910: hull

Claims (11)

A line array sensor unit attached to the left and right sides of the hull in the longitudinal direction of the hull and detecting a sound wave propagated underwater to generate a detection signal; And
By using the detection signal, including a signal processing unit for determining the approach direction of the sound source for generating the sound wave and the type of the sound source,
The signal processor
A multiple beam former for forming at least one beam for extracting sound waves input at a specific incident angle from among a plurality of sound waves input while forming different incident angles with the hull; And
And a signal detector for determining the approach direction of the sound source and the type of the sound source by using the beam.
The method of claim 1,
And a display unit for visually indicating an approach direction of the sound source and a type of the sound source.
The method of claim 1, wherein the line array sensor unit
A plurality of acoustic sensors for sensing the sound waves propagating in the water to output a sensor signal; And
And a sensor signal receiver for amplifying and converting the sensor signal to generate the detection signal.
delete The method of claim 3, wherein the multi-beam shaper
And a plurality of delayed sensing signals, respectively, for a set time corresponding to the specific incident angle, and adding the delayed plurality of sensing signals to form the beam.
The method of claim 5, wherein the multi-beam shaper

B _i : beam corresponding to the specific incident angle
W _j : Weight for each acoustic sensor included in the linear array sensor unit
S _j : detection signal of the acoustic sensor
t: hour
τ _i : time delay corresponding to the specific incident angle
Hull-type sound wave detector to form a beam using the above formula.
7. The apparatus of claim 6, wherein the multiple beam former is
And τ _i is set according to the geometric arrangement and curvature of the acoustic sensor.
The method of claim 1, wherein the signal detector
The ship-mounted sound wave detector for determining that the sound source is approaching in the direction of the incident angle when the size of the beam is greater than or equal to a predetermined value.
The method of claim 8, wherein the signal detector
A hull type acoustic wave detector for discriminating the type of the sound source by performing a signal processing of the LOFAR and DEMON method for the beam.
A hull-mounted sound wave detector according to claim 1;
Ship having a hull-mounted sound wave detector including a hull to which the hull-attached sound wave detector is attached to the side.
The method of claim 10,
If the sound source is an underwater vehicle, and the underwater vehicle is determined to approach the hull, the ship provided with a hull-type sound wave detector further comprises a deception launcher to launch a deception machine for disturbing the underwater vehicle.

Images