JP7238516B2 - Sonar device and target detection method using the same - Google Patents

Description

The present invention relates to a sonar device and a target detection method using the same.

Sonars mounted on ships are required to search for targets in the sea at long distances or to search small targets with high accuracy at short distances, and specialized equipment has been developed for each.

Patent Document 1 and Non-Patent Document 1 disclose a cylindrical sonar.

In addition, as a technology related to a cross-fan beam type underwater image sonar that uses a transmitter and a receiver in which a transmitting array and a receiving array are arranged orthogonally, for example, Patent Document 2 discloses a group of transmitters and the transmitters. A sonar system comprising a group of detectors and a group of orthogonally arranged receivers, transmitting a transmitted sound whose frequency varies from F1 to F2 over time PW, and identifying and displaying a target according to the signal received from the receiver group. is disclosed. In Patent Document 1, the frequency of the transmitted sound is changed from F1 to F2 over time PW, and the direction of the transmitted wave beam is changed from +θ degrees to −θ degrees.

Furthermore, in Patent Document 3, a transmission line array composed of an array of a plurality of wave-transmitting elements, a receiving line array composed of an array of a plurality of wave-receiving elements arranged orthogonally to the transmission line array, a first means for transmitting positively varying frequencies and negatively varying frequencies from the transmission line array to a target as transmission signals; A sonar system is disclosed with second means for identifying and displaying targets based on the directionally varying frequency and the negatively varying frequency. The transmission line array includes first and second transmission line arrays juxtaposed. With respect to a plane spanned by a normal vector of the plane of each transmission line array and a longitudinal vertical axis in the plane of the transmission line array, the first means rotates clockwise with respect to the normal vector. and a counterclockwise second angle, from one of the first and second angles to the other angle during the period in which the frequencies of the transmission signals from the first and second transmission line arrays change. The vertical azimuth of the transmission beam is changed immediately.

Japanese Patent Application Laid-Open No. 2003-232848 JP-A-10-132930 JP 2015-222226 A

ANTI SUBMARINE WARFARE UMS 4110 Low Frequency Active and Passive Bow Mounted Sonar (BMS) for Medium to Large Platforms, [Search: March 4, 2019] Internet (URL: http://www.thales7seas.com/html_2014/products /424/thales_UMS_4110.pdf)

In recent years, there has been a need for sonar equipment that can be mounted on small vessels and the like and that can search for both near and far targets. In order to search for long-range and close-range targets, either purpose-specific sonar equipment is required. For example, a low-frequency sonar is used when focusing on long-distance detection performance, and a high-frequency sonar or the like is used when focusing on short-distance detection performance. In this case, it is necessary to carry multiple sonar units to search for both near and far targets. However, space considerations do not allow for the mounting of multiple sonar devices to search for both near and far targets. In this case, it is necessary to choose between responding to long-range or close-range targets.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above circumstances, and its object is to provide a sonar apparatus and method that are space-saving and capable of searching for both long-range and short-range targets. That's what it is.

According to one aspect of the present invention, the sonar device includes a plurality of low-pass sensors arranged vertically stacked in multiple stages and arranged so that the side opposite to the acoustic surface defines a hollow section in a cross section orthogonal to the vertical stacking direction. It has a hollow three-dimensional transducer array consisting of frequency transducers. In the sonar device, the hollow three-dimensional transducer array is provided with one or more longitudinally extending regions lacking the low-frequency transducers, and the longitudinally extending In the area, one or more first transmitter arrays are provided, each of which is composed of a plurality of high-frequency transmitters stacked vertically in multiple stages to form a line array. Further, a sonar device is disposed on one end side of the one or more first transmitter arrays along the circumferential direction of the hollow three-dimensional shape perpendicular to the longitudinal direction of the first transmitter arrays. a first wave receiver array consisting of a plurality of high frequency wave receivers arranged in the same direction;

According to one aspect of the present invention, a plurality of low-frequency transducers are arranged in a hollow three-dimensional shape to form a transducer array, and the hollow three-dimensional transducer array includes the low-frequency transducers and having one or more longitudinally extending regions, wherein a plurality of high frequency transmitters are arranged in said one or more longitudinally extending regions One or more transmitter arrays are provided, and one end side of the one or more first transmitter arrays is perpendicular to the longitudinal direction of the first transmitter arrays and along the outer edge of the hollow part. using a sonar having a first receiver array consisting of a plurality of radio frequency receivers arranged in parallel,
detecting the target underwater by transmitting a sound wave from the low-frequency transducer of the transducer array and then receiving a reflected sound from the target;
transmitting sound waves from the high-frequency transmitter while changing the vertical direction of the transmission beam;
There is provided a target detection method using a sonar for receiving echoes of the transmitted sound wave with the high-frequency wave receiver and acquiring three-dimensional information of the underwater target.

According to the present invention, a space-saving sonar device is provided that is capable of searching for both long-range and short-range targets.

1 is a diagram illustrating the configuration of a sonar device according to an exemplary embodiment of the invention; FIG. (A), (B), and (C) are a schematic perspective view, a side section, and a cross section of the transducer array device of the first exemplary embodiment of the present invention. FIG. 2 illustrates an exemplary embodiment of the invention; 1A and 1B are diagrams illustrating exemplary embodiments of the present invention; FIG. 1A and 1B are diagrams illustrating exemplary embodiments of the present invention; FIG. FIG. 4 is a diagram illustrating a high frequency receiver of an exemplary embodiment of the invention; (A) and (B) are a schematic perspective view and a side cross-sectional view of a transducer array device according to a second exemplary embodiment of the present invention. (A) and (B) are a schematic perspective view and a side cross-sectional view of a transducer array device according to a third exemplary embodiment of the present invention. (A) and (B) are a schematic perspective view and a cross-sectional view of a transducer array device according to a fourth exemplary embodiment of the present invention. 1 illustrates a computer-implemented sonar device as an exemplary embodiment of the present invention; FIG.

Exemplary embodiments of the invention are described. According to one aspect of the present invention, the sonar apparatus is a transmission/reception system in which a cross-fan beam type sonar suitable for high-precision searching of short-range targets is embedded in a cylindrical sonar suitable for searching long-range targets. A device array device (20 in FIGS. 1 and 2A) is provided. According to one aspect of the present invention, the transducer array devices (20 in FIGS. 2A, 7A, 8A, and 9) are vertically stacked in multiple stages, and vertically stacked. Hollow three-dimensional transmission/reception consisting of a plurality of low-frequency transducers (21) disposed so as to define a hollow portion (25 in FIG. 2(C)) on the opposite side of the acoustic surface in a cross section perpendicular to the stage direction. It has a wave array. A plurality of low-frequency transducers (21) are disposed along part or all of the hollow portion (25 in FIG. 2(C)) on the opposite side of the acoustic surface.

According to one aspect of the present invention, the transducer array device (20 in FIGS. 2A, 7A, 8A, and 9) has a hollow three-dimensional transducer array. , lacking the low-frequency transducer (21) (24 in FIG. 2(C)), and provided with one or a plurality of longitudinally extending regions, and in the longitudinally extending region , a first transmitter array (high-frequency transmitter array) consisting of a plurality of high-frequency transmitters stacked vertically in multiple stages to form a line array (Figs. 2(A), 7(A), 8( A), 201) in FIG. 9), or one or more.

According to one aspect of the present invention, the transducer array apparatus (20 in FIGS. 2A, 7A, 8A, and 9) further includes the one or more first A plurality of high-frequency wave receivers (23) arranged along the circumferential direction of the hollow three-dimensional shape perpendicular to the first wave transmitter array (201) on one end side of the wave transmitter array (201) of (202 in FIGS. 2A, 7A, 9, and 202A in FIG. 8A).

According to one aspect of the present invention, the hollow portion of the cross-section perpendicular to the stacking direction of the low-frequency transducers (21) vertically stacked in multiple stages is circular or substantially circular (Fig. 2 ( 25) of C). In this case, the transducer array has, for example, a cylindrical shape. In one embodiment of the present invention, the hollow portion (25 in FIG. 2(C)) having a cross section perpendicular to the vertical stacking direction is not limited to a circular shape, but is horseshoe-shaped, semi-circular, arc-shaped, elliptical (or its shape). part), or a combination of any of these and a straight line. Further, the hollow portion (25 in FIG. 2(C)) may not have the same area or shape along the vertical stacking direction of the low-frequency transducers (21).

According to one aspect of the present invention, one end of the region lacking the low-frequency transducer (21) and extending in the longitudinal direction is one end of the hollow three-dimensional shape in the longitudinal direction, and the other end of the region is , the other longitudinal end of the hollow three-dimensional shape, and the first transmitter array (201) extends from one end to the other longitudinal end of the hollow three-dimensional shape (for example, a cylinder). (Fig. 2(A)).

According to one aspect of the present invention, the plurality of radio frequency receivers (23) of the first receiver array may be arranged at a predetermined angle of elevation or inclination (FIG. 7(B)).

According to another aspect of the present invention, on the other end side of the one or more first transmitter arrays (201) opposite to the one end of the first transmitter array (201) A second receiver array (202B in FIG. 8) consisting of a plurality of high-frequency receivers (23B in FIG. 8A) arranged along the outer edge of the hollow portion perpendicular to the longitudinal direction there is The plurality of high-frequency wave receivers (23B) of the second wave receiver array (202) may be arranged at a predetermined elevation angle or depression angle (FIG. 8(B)).

According to another aspect of the present invention, one end of the region lacking the low-frequency transducer (21) and extending in the longitudinal direction is one end of the hollow three-dimensional shape in the longitudinal direction, and the other end of the region does not reach the other longitudinal end of the hollow three-dimensional shape, the first transmitter array (201) is arranged in the region, and the longitudinal direction of the hollow three-dimensional shape extends from the other end of the gap. In the area between the other ends, one or more stages of the low-frequency transducers (21) are arranged (Fig. 9).

<First embodiment>
FIG. 1 is a diagram illustrating the configuration of a sonar device 1 according to an embodiment of the invention. The configuration of FIG. 1 is also applied to second to fourth embodiments described below. Referring to FIG. 1, the transducer array device 20 of the sonar device 1 includes a plurality of low-frequency transducers 21 for interconverting acoustic energy and electrical energy, and a plurality of high-frequency transducers 21 for converting electrical energy into acoustic energy. It comprises a wave device 22 and a plurality of high frequency wave receivers 23 for converting acoustic energy into electrical energy.

The transmitter/receiver 10 includes a low-frequency transmitter/receiver 11 , a high-frequency transmitter 12 , a high-frequency receiver 13 , and a sonar controller 14 . The low-frequency transmitter/receiver 11 generates a transmission signal for the low-frequency transmitter/receiver 21 and performs reception processing. The high frequency transmitter 12 generates a transmission signal for the high frequency transmitter 22 . The high frequency receiver 13 performs reception processing for the high frequency receiver 23 . The sonar control device 14 performs overall control processing of the sonar device 1 such as generation of transmission timing.

FIG. 2A is a perspective view schematically illustrating the outline of the transducer array device 20. FIG. FIG. 2B is a diagram illustrating a cross section A (side cross section) of FIG. 2A, and FIG. 2C illustrates a cross section B of FIG. It is a figure to do. As shown in FIG. 2(A), a plurality of low-frequency transducers 21 are arranged in N stages in the vertical direction of the figure, M pieces (L groups of adjacent m pieces each) in the circular direction, and a hollow columnar (cylindrical) shape. are placed in Although not particularly limited, in the example of FIG. 2, N is 6, M is 30, m is 5, and L is 6 (six groups of five adjacent pixels).

The high-frequency transmitter 22 and the high-frequency receiver 23 are smaller in size than the low-frequency transmitter-receiver 21 and arranged more densely than the low-frequency transmitter-receiver 21 .

As shown in FIG. 2(B), in cross section A, a high-frequency wave receiver 23 is arranged on the lower end side of the row of low-frequency wave transducers 21 . Although not particularly limited, in the example of FIG. 2B, the low-frequency transducer 21 and the high-frequency transducer 23 are arranged flush with each other with the radially outer side of the cylinder as the acoustic surface (vibration surface). The high-frequency wave receivers 23 are arranged annularly in a line along the circumferential direction at the lower end of the cylinder (FIG. 2(A)).

As shown in FIG. 2(C), in a cross section B (a cross section perpendicular to the stacking direction of the low frequency transducers 21), the opposite side of each of the plurality of low frequency transducers 21 to the acoustic surface is a circular hollow. A portion (hollow region) 25 is defined. That is, a plurality of low-frequency transducers (21) are disposed along part or all of the hollow portion 25 on the opposite side of the acoustic surface. In the cross section B, the plurality of high-frequency transmitters 22 are arranged at predetermined intervals in the circumferential direction of the circular hollow portion 25 on the side opposite to the respective acoustic surfaces. In the example of FIG. 2(C), the cross section B has regions (gap) 24 in which the low-frequency transducers 21 are not arranged at intervals of 60 degrees (six at 360 degrees). For example, one high-frequency transmitter 22 is arranged in the region (gap) 24 . That is, in the section B, the plurality of high-frequency transmitters 22 are evenly arranged in all directions at intervals of 60 degrees in the circumferential direction of the circular hollow portion 25 .

Referring to FIG. 2(A), the cylindrical transducer array lacks the low frequency transducer 21 (24 in FIG. 2(C)), and the vertically extending region is a cylinder (hollow Three-dimensional shape) are provided along the circumferential direction. A high-frequency transmitter array 201 composed of a plurality of high-frequency transmitters 22 stacked vertically to form a line array is arranged in each region extending in the longitudinal direction. Six high-frequency transmitter arrays 201 are provided along the circumferential direction of a cylinder (hollow solid). A high-frequency wave receiver array 202 composed of a plurality of high-frequency wave receivers 23 is arranged perpendicular to the high-frequency wave transmitter array device 201 along the circumferential direction of a cylinder (hollow solid), for example, in an annular shape.

In FIG. 2(C), the width of the region (gap) 24 is the width without one low-frequency transducer 21. However, in FIG. 2(C), the region (gap) 24 is not limited to one low-frequency transducer 21 . Also, depending on the width (size) of the area (gap) 24, the number of high-frequency transmitters 22 arranged in the area (gap) 24 is not limited to one. In addition, the hollow portion 25 defines the arrangement form of the low-frequency transducers 21 in a cross section B (a cross section orthogonal to the vertical stacking direction of the low-frequency transducers 21). It goes without saying that a member (distribution cable, etc.) may be arranged (inserted).

The high-frequency transmitters 22 are smaller in size than the low-frequency transmitters/receivers 21 and arranged more densely than the low-frequency transmitters/receivers 21 along the longitudinal direction. In addition, the high-frequency transducers 23 are smaller in size than the low-frequency transducers 21, and are arranged more densely than the low-frequency transducers 21 along the circulating direction. Although the classification of low frequency and high frequency differs depending on the application of the fish finder, etc., when targeting the low frequency of 15 kHz (kiloHertz) to the high frequency of 200 kHz, the low frequency may be 50 to 100 kHz or less. In some cases, the low frequency is 200 Hz to 5 kHz and the high frequency is 15 to 10 kHz. The lower the frequency, the better the long-distance propagation, but the noise such as reverberation increases, the directivity is dull, the azimuth accuracy decreases, and the size of the transducer also increases.

FIG. 3 is a diagram schematically illustrating the arrangement of the high-frequency transmitter array 201 of the high-frequency transmitter 22 and the high-frequency receiver array 202 of the high-frequency receiver 23 of FIG. 2(A). , a high-frequency transmitter array 201-1 composed of a plurality of high-frequency transmitters 22 arranged in a row, and a high-frequency transmitter array 201-2 composed of a plurality of high-frequency transmitters 22 arranged in a row. are arranged in parallel in the vertical direction (longitudinal direction). High frequency transmitter arrays 201-1 and 201-2 correspond to two adjacent high frequency transmitter arrays 201 in FIG. 2(A). A high-frequency wave receiver array 202 consisting of a plurality of high-frequency wave receivers 23 is arranged horizontally (transversely) with respect to the high-frequency transmitter arrays 201-1 and 201-2 so that the axes of the arrays intersect at 90 degrees, for example. are placed. A plurality of low-frequency transducers 21 are arranged in the area between the high-frequency transducer arrays 201-1 and 201-2, but are omitted in FIG.

FIG. 4 is a diagram schematically showing an outline of a beam shape in the cross-fan-beam high-frequency sonar illustrated in FIG. In FIG. 4(A), reference numeral 201 corresponds to the high-frequency transmitter array 201 in which the high-frequency transmitters 22 are arranged in a vertical line in FIG. 2(C). Reference numerals 101 and 102 denote transmission fan beams transmitted from the high-frequency wave transmitter array 201, which have wide directivity in the horizontal direction and narrow directivity in the vertical direction. As shown in FIG. 4A, the axis 106 (the normal vector of the line array for transmission) in the front direction of the high-frequency transmitter array (line array) 201 and the vertical axis 106 of the high-frequency transmitter array (line array) 201 With respect to the plane subtended by axis 104, the beam at angle _.theta.L clockwise with respect to axis 106 is indicated by reference numeral 101, and the beam at angle _.theta.H counterclockwise with respect to axis 106 is indicated by reference numeral . During transmission, the transmission azimuth gradually changes from beam 101 to beam 102, for example, as indicated by a dashed arrow.

The high-frequency transmitter 12 in FIG. 1 generates a transmission signal to be transmitted from the high-frequency transmitter array 201, and phase-controls the generated transmission signal by a phase controller (not shown) for each transmission channel. That is, phase control is performed for each of the plurality of high-frequency transmitters 22 of the high-frequency transmitter array 201 . A transmission signal for each transmission channel is amplified by an amplifier (not shown) and supplied to each high frequency transmitter 22 of each high frequency transmitter array 201 . A plurality of transmission amplifiers (not shown) are provided corresponding to the plurality of high frequency transmitters 22 of the high frequency transmitter array 201 . As a result, the transmission fan beams shown in FIG. 4A are output from the RF transmitter arrays 201-1 and 201-2 of FIG. 3, respectively.

In FIG. 4B, reference numeral 202 denotes a high-frequency wave receiver array 202 in which the high-frequency wave receivers 23 of FIG. For the sake of simplicity, the radio frequency receiver array 202 is represented by a linear array instead of an annular (arcuate) array). Reference numeral 103 denotes a receiving fan beam generated by the high-frequency wave receiver array 202, which has wide directivity in the vertical direction and narrow directivity in the horizontal direction. As schematically shown in FIG. 4B, a plurality of beams are generated in the horizontal direction as the reception fan beam 103 in the signal processing of the reception signal.

5A and 5B are diagrams schematically showing transmission signals generated by the high-frequency transmission section 12. FIG. The high-frequency transmitter 12 transmits a frequency-swept and vertical-direction-swept signal. In FIGS. 5A and 5B, 50 and 51 represent the frequencies and transmission azimuths of transmission beams transmitted from the high-frequency transmitter array. Transmission from multiple RF transmitter arrays may be performed simultaneously. 5A and 5B, the time axes (horizontal axes) are the same. In FIG. 5A, fs and fe are frequencies. In FIGS. 5A and 5B, ts and te are times. In FIG. 5B, θ _L and θ _H are transmission azimuths and correspond to θ _L and θ _H in FIG. 4A, respectively.

Referring to FIG. 5A, the frequency 50 of the transmission signal is frequency-modulated such that it continuously (linearly) rises from the sweep start frequency fs to the sweep end frequency fe as the time ts changes to te. (up chirp). Further, referring to FIG. 5B, the transmission direction 51 is phase-controlled so that it varies linearly from θL to θH.

In the example of FIG. 5A, the polarities of the frequency modulation rate of change (time rate of change) are both positive values, but the present invention is not limited to such control. Also, a frequency-increasing modulated wave (up-chirp waveform) and a frequency-decreasing modulated wave (down-chirp waveform) may be transmitted simultaneously or sequentially. The transmission signal is not limited to chirp modulation that changes at a continuous frequency, but frequency hopping (FH) using discrete frequencies may be used, or phase encoding such as Baker code may be used. may

Referring to FIG. 1 again, the low-frequency transmitter/receiver 11 performs an omnidirectional search using a cylindrical array according to the transmitting/receiving processing method of a general sonar for long-distance target searching.

As illustrated in FIG. 4B, the high-frequency receiver 13 generates a plurality of beams in the horizontal direction and performs reception processing with a cross-fan three-dimensional sonar. In the high-frequency receiver 13, reception processing is performed on reflected sounds due to transmission signals from high-frequency transmitter arrays 201 (line arrays) mounted in different directions (six directions in FIG. 2A) on the horizontal plane. By doing so, omnidirectional three-dimensional information can be obtained.

FIG. 6 is a diagram illustrating an example of the configuration of the high-frequency receiver 13 of FIG. 1. As shown in FIG. In the high-frequency receiver 13, the signal separator 131 separates the replica signal (part of the transmitted signal), which is a sample of the transmitted signal transmitted by the high-frequency wave transmitter 22, from the received data received by the high-frequency wave receiver 23. Calculate the cross-correlation of (replica correlation processing). The cross-correlation value reaches the maximum value (peak) at the time when the replica signal and the received signal are most similar, that is, at the time when the echo is received. The signal separator 131 determines the vertical direction of the transmission signal from the peak of the cross-correlation value, and separates and extracts the reflected sound of the transmission signal transmitted in the vertical direction.

The aperture synthesis processing unit 132 performs aperture synthesis processing (virtual acoustic array directivity synthesis processing) on the plurality of received signals extracted by the signal separation unit 131 to obtain a horizontal signal as shown in FIG. Generate directional receive beams. Note that the virtual acoustic array consists of a transmitter array in which transmitters are arranged at predetermined intervals (for example, intervals of several wavelengths), and a receiver array in which receivers are arranged at intervals of, for example, half a wavelength. consists of a receiver array with Transmitting signals from each transmitter are received by each receiver and subjected to signal processing, so that a virtual acoustic array is formed by interpolating between transmitters with wide intervals by the receivers. The resolution in the azimuth direction depends on the beam width determined by the antenna aperture length for the wavelength of the frequency used. By using a receiver array consisting of M receivers and a transmitter array consisting of N transmitters, the signal of a virtual acoustic array in which M×N elements are spatially arranged can be obtained. Obtainable. As a result, the desired directivity can be achieved with the number of elements that is a fraction of the required number.

The Doppler/azimuth calculation unit 133 calculates each of the plurality of reception fan beams generated by the aperture synthesis processing unit 132, which are transmitted by, for example, the high-frequency transmitter array 201 (eg, 201-1 and 201-2 in FIG. 3). Echoes from the transmitted signals are compared to calculate the target Doppler and the actual azimuth. As for the Doppler/azimuth calculation unit 133, the description of Patent Document 2 is referred to.

The three-dimensional imaging unit 134 performs threshold processing for comparing the target information calculated by the Doppler/azimuth calculation unit 133 with the display conditions, and as a result of the threshold processing, from the pixels that satisfy the display conditions, display data is obtained. , and three-dimensionally displayed on the display device 303 .

The vertical and horizontal azimuths of the echoes are calculated from the azimuth calculation of the received signal by the signal separation unit 131 and the horizontally arranged reception fan beam obtained by the aperture synthesis processing unit 132 . Furthermore, by calculating the distance to the echo from the time difference between the transmission time of the transmission signal and the reception time of the echo, the three-dimensional position of the echo can be localized. Also, the velocity of the echo can be calculated from the result of Doppler calculation.

<Second embodiment>
A second exemplary embodiment of the invention will now be described. FIG. 7 is a diagram illustrating the transducer array device 20 in the second embodiment. FIG. 7(A) is a perspective view schematically illustrating the entire transducer array device 20 of FIG. 1, and FIG. 7(B) schematically illustrates the cross section A of FIG. 7(A). It is a diagram.

In the second embodiment, unlike the first embodiment, the high-frequency wave receiver 23A has an acoustic surface with a predetermined dip (in a state of being directed obliquely downward in FIG. 7(B)). They are arranged in a circle.

According to the second embodiment, by inclining the acoustic surface of the high-frequency wave receiver 23A downward in the figure, it is possible to widen the downward viewing angle in the high-frequency sonar.

<Third Embodiment>
A third illustrative embodiment of the invention will now be described. FIG. 8 is a diagram illustrating the transducer array device 20 in the third embodiment. FIG. 8(A) is a perspective view schematically illustrating the entire transducer array device 20 of FIG. 1, and FIG. 8(B) schematically illustrates the cross section A of FIG. 8(A). It is a diagram.

In the third embodiment, the transducer array device 20 of the second embodiment includes a second high-frequency receiver array 202B on the upper end side in addition to the high-frequency receiver array 202A on the lower end. ing. That is, the second high-frequency wave receiver array 202B is composed of a plurality of high-frequency wave receivers 23B arranged in an annular shape perpendicular to the longitudinal direction of the high-frequency wave transmitter array 201 and along the circumferential direction of the cylinder.

As shown in FIG. 8(B), the high-frequency wave receiver 23B is arranged in an annular shape with its acoustic surface at a predetermined elevation angle (a state in which it faces obliquely upward in FIG. 8(B)). By tilting the acoustic surface of the high-frequency wave receiver 23B upward, the upper viewing angle can be expanded in the high-frequency sonar.

<Fourth Embodiment>
A fourth exemplary embodiment of the present invention will now be described. FIG. 9A is a perspective view schematically illustrating the transducer array device 20 according to the fourth embodiment. In the fourth embodiment, the height of the line array (high-frequency transmitter array) 201 composed of the high-frequency transmitters 22 does not occupy the entire height of the cylindrical array composed of the low-frequency transducers 21. . The high-frequency transmitter array 201 has a height from the lower end (high-frequency receiver 23 side) to the n-stage (<N) low-frequency transmitter-receiver 21 . In the example of FIG. 8, the high-frequency transmitter array 201 has a height from the high-frequency receiver 23 side to the third stage (<N=6) low-frequency transmitter-receiver 21 . Above the high-frequency transmitter array 201, the fourth to sixth low-frequency transmitter-receivers 21 are vertically stacked.

Section B in FIG. 9A is the same as in FIG. 2C. As shown in FIG. 9B, cross section C in FIG. 9A is such that a plurality of low-frequency transducers 21 are arranged so as to define the edge (circumference) of hollow portion 25 (circle). , and the gap 24 in FIG. 2(C) does not exist.

According to the fourth embodiment, side lobes are reduced in the directional characteristics of the cylindrical transducer array composed of the low-frequency transducers 21 as compared with the first to third embodiments. Therefore, sensor performance can be improved. The intensity of the acoustic signal emitted from the transmitter (transducer/receiver) varies depending on the direction, and the beam with the highest acoustic level is called the main lobe. The characteristic that decreases and then increases again is called a side lobe. In the fourth embodiment, as in the second embodiment, the acoustic surface of the high-frequency wave receiver 23 has a predetermined dip (in a state in which it faces obliquely downward in FIG. 7(B)). Alternatively, they may be arranged in an annular shape.

In the first to fourth embodiments, the transducer array composed of the low-frequency transducers 21 has a cylindrical shape, but the three-dimensional shape is of course not limited to a cylindrical shape. A hollow three-dimensional shape such as a part of a cylinder (the cross section of the hollow part is not a circle but an arc, a semicircle, an ellipse, etc.), or a horseshoe-shaped cross section (the cross section of the hollow part is a combination of an arc and a straight line, etc.). Even if there is, it is feasible. Further, the cross section of the hollow portion may be configured such that the area differs between the upper end portion and the lower end portion of the hollow solid, or in the vertical stacking direction of the low-frequency transducers 21 .

FIG. 10 is a diagram for explaining an example in which the transmitting/receiving device 10 (the sonar control device 14) of FIG. Computer 300 comprises processor 301 , memory 302 , display device 303 and interface 304 . The memory 302 stores programs to be executed by the processor 301 . The memory 302 may be semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), or EEPROM (Electrically Erasable and Programmable ROM), or HDD (Hard Disk Drive), USB (Universal Serial Bus), CD (Compact Disc), DVD (Digital Versatile Disc), or other storage device. The interface 304 may connect the processor 301 to the transducer array device 20 of FIG. 1 via signal lines, control lines and the like. Alternatively, when the sonar control device 14 of FIG. 1 is configured by the computer 300, the interface 304 connects the processor 301 to the low frequency transducer 21, high frequency transducer 22, and high frequency transducer 23 of FIG. may The computer 300 may further include a communication interface for wireless or wired communication connection with an external device. The program held in the memory 302 may be, for example, a program (command group, data) for causing the processor 301 to execute the functions and processes of the transmitting/receiving device 10 (the sonar control device 14) of FIG. For example, the processor 301 transmits sound waves from the low-frequency transducer 21 of the transducer array and then receives the reflected sound from the target to detect the target in the water. A program is provided for executing a process of transmitting sound waves while changing the direction, and a process of receiving echoes of the transmitted sound waves by the high-frequency wave receiver 23 and acquiring three-dimensional information of the underwater target.

The disclosures of Patent Documents 1 to 3 and Non-Patent Document 1 mentioned above are incorporated herein by reference. Within the framework of the full disclosure of the present invention (including the scope of claims), modifications and adjustments of the embodiments and examples are possible based on the basic technical concept thereof. Also, various combinations and selections of various disclosure elements (including each element of each claim, each element of each embodiment, each element of each drawing, etc.) are possible within the scope of the claims of the present invention. . That is, the present invention naturally includes various variations and modifications that can be made by those skilled in the art according to the entire disclosure including claims and technical ideas.

1 Sonar Device 10 Transceiver 11 Low Frequency Transceiver 12 High Frequency Transmitter 13 High Frequency Receiver 14 Sonar Control Device 20 Transducer Array Device 21 Low Frequency Transducer 22 High Frequency Transmitter 23, 23A, 23B High Frequency Receiver 24 Gaps (areas devoid of low frequency transducers)
25 Hollow part 50 Transmission signal frequency 51 Transmission signal azimuth (transmission azimuth)
131 Signal separation unit 132 Aperture synthesis processing unit 133 Doppler/azimuth calculation unit 134 Three-dimensional imaging unit 201, 201-1, 201-2 High-frequency transmitter arrays 202, 202A, 202B High-frequency receiver array 300 Computer 301 Processor 302 memory 303 display device 304 interface

Claims (10)

A hollow three-dimensional transducer composed of a plurality of low-frequency transducers stacked vertically in multiple stages and arranged so that the opposite side of the acoustic surface defines a hollow portion in a cross section perpendicular to the direction of the vertically stacked layers. with an array,
The hollow three-dimensional transducer array is provided with one or more longitudinally extending regions lacking the low-frequency transducers,
One or a plurality of first transmitter arrays composed of a plurality of high-frequency transmitters stacked vertically in a plurality of stages and forming a line array in the region extending in the longitudinal direction,
moreover,
A plurality of high-frequency receivers arranged along the circumferential direction of the hollow three-dimensional shape perpendicular to the longitudinal direction of the first transmitter array on one end side of the one or more first transmitter arrays. A sonar device comprising a first receiver array comprising a wave detector. The hollow portion having a cross section orthogonal to the vertical stacking direction is circular,
2. A sonar apparatus as recited in claim 1, wherein said transducer array is cylindrically shaped. 2. A sonar apparatus according to claim 1, wherein said hollow portion of cross-section perpendicular to said stack direction comprises a horseshoe shape, a semi-circle, an arc, an ellipse, or a combination of any of these with a straight line. One end of the region is one end of the hollow three-dimensional shape in the vertical direction,
The other end of the region is the other end in the vertical direction of the hollow three-dimensional shape,
3. A sonar apparatus according to claim 1, wherein said first transmitter array extends from one longitudinal end to the other longitudinal end of said hollow three-dimensional shape. 5. A sonar apparatus according to claim 4, wherein said plurality of radio frequency receivers of said first receiver array are arranged at a predetermined elevation angle or depression angle. In the circumferential direction of the hollow three-dimensional shape, orthogonal to the longitudinal direction of the first transmitter array, on the other end side opposite to the one end of the one or more first transmitter arrays 6. A sonar device as claimed in claim 4 or 5, comprising a second receiver array comprising a plurality of radio frequency receivers arranged along the second receiver array. 7. A sonar apparatus according to claim 6, wherein said plurality of radio frequency receivers of said second receiver array are arranged at a predetermined elevation angle or depression angle. One end of the region is one end of the hollow three-dimensional shape in the vertical direction,
the other end of the region does not reach the other end of the hollow three-dimensional shape in the vertical direction,
the first transmitter array is disposed in the region;
1. A region between the other end of the region and the other end of the hollow three-dimensional shape in the vertical direction is provided with one or more stages of the low-frequency transducers. 4. The sonar device of any one of Claims 1-3. means for detecting an underwater target by transmitting a sound wave from the low-frequency transducer of the transducer array and then receiving a reflected sound from the target;
means for transmitting sound waves from the high-frequency transmitter while changing the vertical direction of the transmission beam; means for receiving the sound waves by the high-frequency receiver;
means for obtaining three-dimensional information of the underwater target;
9. A sonar device as claimed in any one of claims 1 to 8, comprising: A plurality of low-frequency transducers are arranged in a hollow three-dimensional shape to form a transducer array,
the hollow solid-shaped transducer array has one or more longitudinally extending regions devoid of the low-frequency transducers;
One or more first transmitter arrays each having a plurality of high-frequency transmitters disposed in one or more of the longitudinally extending regions;
A plurality of high-frequency wave receivers disposed along the outer edge of the hollow portion perpendicular to the longitudinal direction of the first wave transmitter array on one end side of the one or more first wave transmitter arrays. using a sonar having a first receiver array consisting of
detecting the target underwater by transmitting a sound wave from the low-frequency transducer of the transducer array and then receiving a reflected sound from the target;
transmitting sound waves from the high-frequency transmitter while changing the vertical direction of the transmission beam;
A method of detecting a target using sonar, wherein the echo of the transmitted sound wave is received by the high-frequency wave receiver, and three-dimensional information of the target in the water is acquired.

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