JP3546201B2 - Underwater acoustic exploration method and underwater acoustic exploration system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an underwater acoustic exploration method and an underwater acoustic exploration system, and is particularly useful when applied to a case where a return component of a reflected wave to a transmitting side is small due to a shape of a target to which a transmitted sound wave is applied. .
[0002]
[Prior art]
For example, when exploring the seabed topography, sonar using sound is widely used. In particular, recently, a synthetic aperture search device that reproduces and visualizes a search target on a monitor image has been proposed, and its application has been studied. This synthetic aperture exploration device is equipped with a sound wave transmitter and a receiver on an underwater vehicle that sails underwater, and while the underwater vehicle is traveling, it can be used for exploration of the seabed etc. with a transmitter. Along with transmitting sound waves toward the target, the receiver receives the sound waves reflected and returned from the search target, calculates the distance from that time, and reproduces the two-dimensional image of the search target on the monitor. is there.
[0003]
FIG. 4 is an explanatory view conceptually showing the principle of synthetic aperture search in the case where the seafloor is set as a search target. As shown in FIG. 1, an underwater vehicle 1 sails in water 2. In the case shown in FIG. 4, the ship sails from the right to the left in the figure in parallel with the seabed 3. Here, the underwater vehicle 1 is equipped with an acoustic exploration device, and its transducer 4 is attached to the abdomen of the main body, and emits sound waves toward the sea floor 3 and transmits sound waves reflected from the sea floor 3. It is designed to receive waves. In FIG. 4, sound waves are emitted at positions A, B, and C, and reflected waves at the positions A to C are received. That is, the acoustic sounding device visualizes the state of the seabed 3 by processing the information contained in the reflected wave while intermittently emitting sound waves toward the seabed 3 as the underwater vehicle 1 moves underwater. Play back on a monitor (not shown).
[0004]
Here, a sound wave having a predetermined frequency (usually several tens of kHz) is modulated by a pulse from the transmitter, and is intermittently transmitted. In addition, the sensor part of the receiver of the acoustic sounding device has a large number (several tens to one hundred and several tens) of sensing elements arranged in, for example, a lattice shape to form a predetermined plane or curved surface. The entire curved surface receives the reflected wave. In the synthetic aperture exploration method, information on the seabed 3 detected at each of the positions A to C is processed in consideration of the traveling speed and direction of the underwater vehicle 1 and the sound emission interval time, etc. To C are combined. That is, for example, the reference coordinates are formed with the transducer 4 at the position A as the origin, and the coordinates of the positions B and C are adjusted to the origin of the reference coordinates so that the target 5 identified at each of the positions B and C is set at the reference coordinates. It can be converted to a position and represented. By combining the information at the plurality of positions A to C in this manner, the plane or curved surface constituting the sensor is effectively extended in the traveling direction of the underwater vehicle 1, and the extended plane or curved surface It is possible to provide a sensor unit having an effective sensing element corresponding to the curved surface. Incidentally, the greater the number of sensing elements, the higher the search accuracy.
[0005]
[Problems to be solved by the invention]
Although not limited to the synthetic aperture search as described above, an acoustic wave that emits a sound wave from a transmitter of an underwater vehicle and receives a sound wave that is reflected back from a target to be searched and performs predetermined processing. The following problems have arisen in exploration. That is, as shown in FIG. 5, depending on the shape of the target 5, most of the reflected components of the transmission wave D emitted from the transducer 4 of the underwater vehicle 1 traveling in the water 2 are transmitted and received as the reflected wave E. The reflected wave F, which is reflected in a direction irrelevant to the transmitter 4 side and returns to the transmitter / receiver 4, becomes small. In this case, the level of the sound wave due to the reflected wave F received by the transmitter / receiver 4 is small, and it is not possible to obtain sufficiently clear information on the target 5, so that the resolution deteriorates accordingly. Such a phenomenon occurs, for example, when the surface of the target 5 is flat. For example, there is a case where the target 5 on the sea floor 3 to be searched is a flat artificial structure.
[0006]
The present invention has been made in consideration of the above-described circumstances, and regardless of the shape of a target to be searched, an underwater acoustic search that can always receive a reflected wave from the target and obtain good-quality sound search information based on the received wave. It is an object to provide a method and an underwater acoustic sounding system.
[0007]
[Means for Solving the Problems]
The configuration of the present invention that achieves the above object has the following features.
[0008]
1) A transmitter mounted on an underwater vehicle that travels underwater emits sound waves toward the seabed or other exploration target, and receives and processes the reflected waves reflected by the exploration target, thereby processing the target. In the underwater acoustic exploration method for exploring the shape etc.,
A transmitter / receiver is mounted on one of the multiple underwater vehicles traveling in the water while grasping the mutual positional relationship, and a receiver is mounted on the remaining underwater vehicle,
A reflected wave based on the sound wave emitted from the transmitter / receiver, and another receiver together with the transmitter / receiver, receive the wave in synchronization with the reception timing,
Collecting exploration information of an overlapping area of the plurality of underwater vehicles by processing a signal based on the reflected wave for each of the transducers.
[0009]
2) A transmitter mounted on an underwater vehicle that travels underwater emits sound waves toward the object to be searched, such as the sea floor, and receives and processes the reflected waves reflected from the object to be searched, thereby processing the object to be searched. In the underwater acoustic exploration method for exploring the shape etc.,
Each of multiple underwater vehicles moving in water while grasping the mutual positional relationship is equipped with a transducer that emits sound waves of individually assigned frequencies,
A reflected wave based on a sound wave of a unique frequency emitted from each transducer is received by each transducer in synchronization with the reception timing,
Further, each reflected wave is selected for each frequency and for each receiver, and a signal based on the reflected wave is processed for each selected frequency, so that the plurality of underwater vehicles overlap with each other. Collecting each exploration information of the area.
[0010]
3) A transmitter mounted on an underwater vehicle that travels underwater emits sound waves toward the seabed or other exploration target, and receives and processes the reflected waves reflected by the exploration target to process the target. In the underwater acoustic exploration method for exploring the shape etc.,
Each of a plurality of underwater vehicles traveling underwater while grasping the mutual positional relationship is equipped with a transducer that emits sound waves of the same frequency at the assigned unique time,
Collecting exploration information of an overlapping area of the plurality of underwater vehicles by processing a signal based on the reflected wave for each transducer.
[0011]
4) In the underwater acoustic exploration method according to any one of 1) to 3) above,
Generating exploration information based on information of the level of the reflected wave which is the maximum level among the obtained exploration information.
[0012]
5) The underwater acoustic exploration method according to any one of 1) to 3) above,
To average the level of each reflected wave of each obtained search information to generate search information.
[0013]
6) In the underwater acoustic exploration method according to any one of 1) to 5) above,
Send and receive exploration information collected by each underwater vehicle by underwater communication.
[0014]
7) The underwater acoustic search method according to any one of 1) to 6) above,
The exploration method shall be a synthetic aperture exploration method for superimposing and synthesizing exploration information collected at each position on the basis of the reference coordinates while running the underwater vehicle.
[0015]
8) A transmitter mounted on an underwater vehicle that travels underwater, and a reflected wave emitted from the transmitter toward an object to be explored, such as the sea floor, similarly received on the underwater vehicle. And a processing system for a reflected wave to be processed and processed, in an underwater acoustic search system for searching for a shape or the like of a search target based on a reflected wave of a sound wave emitted from the transmitter,
A transducer mounted on one of a plurality of underwater vehicles that sail underwater while grasping their mutual position,
Multiple receivers respectively mounted on the remaining underwater vehicles,
In the transducer and each receiver, the reflected wave based on the sound wave emitted from the transducer is received by synchronizing the respective reception timings, and the reflected wave is transmitted to each transducer or receiver. And a plurality of processing systems that process signals based on the signals and generate respective pieces of search information.
[0016]
9) A transmitter mounted on an underwater vehicle that travels underwater, and a reflected wave that is also mounted on the underwater vehicle and emitted from the transmitter toward an object to be explored, such as the sea floor, is received. And a processing system for a reflected wave to be processed and processed, in an underwater acoustic search system for searching for a shape or the like of a search target based on a reflected wave of a sound wave emitted from the transmitter,
It is mounted on each of a plurality of underwater vehicles that navigate underwater while grasping the mutual positional relationship and emits sound waves of a unique frequency assigned to each, while receiving reflected waves of each sound wave A plurality of transducers,
In each transducer, the reflected wave based on the sound wave emitted from each transducer is received by synchronizing the respective reception timings, and the received reflected wave is separated for each frequency component, and each separated frequency is separated. A plurality of processing systems for processing signals based on reflected waves for each component to generate each piece of search information.
[0017]
10) A transmitter mounted on an underwater vehicle traveling in water, and a reflected wave emitted from the transmitter toward an object to be explored, such as the seabed, similarly received on the underwater vehicle. And a processing system for a reflected wave to be processed and processed, in an underwater acoustic search system for searching for a shape or the like of a search target based on a reflected wave of a sound wave emitted from the transmitter,
A transducer mounted on each of a plurality of underwater vehicles traveling in water while grasping the mutual positional relationship, and transmitting a sound wave of the same frequency at a unique time assigned to each,
In each transducer, a reflected wave based on a sound wave emitted from each transducer is received by synchronizing the respective reception timings, and a signal based on each reflected wave is processed for each transducer and processed. A plurality of processing systems for generating exploration information;
[0018]
11) In the underwater acoustic search system according to any one of the above 8) to 10),
Maximum level image display processing means for inputting each piece of search information obtained by each processing system and generating search information based on the information of the maximum level of the reflected wave.
[0019]
12) In the underwater acoustic search system according to any one of the above 8) to 10),
Average image display processing means for inputting each piece of search information obtained by each processing system and averaging the level of each reflected wave to generate search information.
[0020]
13) In the underwater acoustic search system according to any one of the above 8) to 12),
A transmitter or a receiver for transmitting or receiving each piece of search information obtained by processing in the processing system of each underwater vehicle by underwater communication.
[0021]
14) In the underwater acoustic search system according to any one of the above 8) to 13),
Each processing system processes information based on the reflection signals collected at each position while sailing the underwater vehicle along with the information at each position, and superimposes the exploration information at each position based on the reference coordinates, A synthetic aperture search processing unit that synthesizes these results.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
<First embodiment>
FIG. 1 is an explanatory view conceptually showing the underwater acoustic search method according to the first embodiment of the present invention. As shown in the figure, in this embodiment, two underwater vehicles 1a and 1b are driven in water 2 to perform a predetermined search. Here, among the underwater vehicles 1a and 1b, the underwater vehicle 1a has the transmitter / receiver 4, but the underwater vehicle 1b has only the receiver 6.
[0024]
In this embodiment, sound waves are emitted from the transducer 4 of the underwater vehicle 1a toward the seabed 3 as appropriate while the two underwater vehicles 1a and 1b are running. The transmission at this time is represented by the symbol D in the figure. Then, the reflected wave is received by the transmitter / receiver 4 and the receiver 6 for each transmission. This reception is adjusted by the transmitter / receiver 4 and the receiver 6 of each underwater vehicle 1a, 1b so that their timings coincide.
[0025]
Here, when the transmission wave D hits and reflects on the flat target 5 as shown in FIG. 1, the level of the reflected wave E returning to the direction of the underwater vehicle 1a is very small, The reflected wave F directed toward the body 1b has a sufficiently large sound wave level. Exploration devices mounted on the underwater vehicles 1a and 1b respectively process sound wave signals received via the transmitter / receiver 4 or the receiver 6 to collect information on the seabed 3 including the target 5.
[0026]
The information collected individually by each underwater vehicle 1a, 1b is brought back to the land and subjected to predetermined processing such as comparing the two information during the land operation, thereby reproducing the search results of the seabed 3. On the other hand, information obtained by processing by the underwater vehicle 1b is transmitted to the underwater vehicle 1a by underwater communication, and the underwater vehicle 1a performs predetermined processing such as matching with the processing information, thereby obtaining the seabed. The search results of No. 3 may be collected. Here, as a method of selecting both information, 1) in both information, each pixel (corresponding to a pixel of the sensor unit of the wave transmitter / receiver 4 or the wave receiver 6; the same applies to the following) applies reflected waves F and E A method of comparing the signal levels based on the signal level and selecting a signal having a higher level, 2) a method of averaging and reproducing the signal levels detected for each pixel, and the like can be considered. Whichever method is employed, it is possible to obtain more accurate and higher-resolution information than the information based on the reflected wave F collected by one underwater vehicle 1a. Naturally, after the information collected by the underwater vehicles 1a and 1b is individually and parallelly reproduced, one of them may be selected.
[0027]
The position information of each position received by each underwater vehicle 1a, 1b is separately detected and specified at least in a relative positional relationship, and the position information and the received wave information are integrated. And compose complete exploration information.
[0028]
According to this embodiment, the target 5 has a special shape such as a flat plate (a shape in which only a reflected wave in a specific direction is particularly large and a reflection component in other directions is extremely small; the same applies hereinafter). However, since the reflected waves E and F are received at different positions, even if the component of the reflected wave F reflected to the transmitter / receiver 4 side does not have a sufficient level, the receiver 6 In many cases, the reflected wave E to be received has a sufficient level. That is, there is a high probability that the reflected waves E and F received at least on one side have a sufficient level. As a result, sufficiently high-quality search information can be obtained.
[0029]
<Second embodiment>
FIG. 2 is an explanatory view conceptually showing the underwater acoustic search method according to the second embodiment of the present invention. As shown in the figure, in this embodiment, two underwater vehicles 1a and 1b are driven in water 2 to perform a predetermined search. Here, each of the underwater vehicles 1a and 1b is equipped with a transducer 4a and 4b. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.
[0030]
In this embodiment, sound waves are emitted from the transducers 4a and 4b of the underwater vehicles 1a and 1b toward the seabed 3 as appropriate while the two underwater vehicles 1a and 1b are traveling. Here, the region where the sound wave is diffused, that is, the search region, is adjusted so as to overlap between the two. In addition, reference symbol D in the figure indicates transmission of the wave of the transducer 4a, and reference symbol G indicates transmission of a wave of the transducer 4b. Then, the reflected waves H and E are received by the transducers 4a and 4b for each transmission. The reception is adjusted by the transmitters / receivers 4a and 4b of the respective underwater vehicles 1a and 1b so that their timings coincide with each other.
[0031]
Here, the following two types of transmission methods by the transmitter / receivers 4a and 4b are considered. One is a method in which sound waves having different transmission frequencies are assigned to the respective transducers 4a and 4b, and reflected waves E and H are separated for each frequency component by passing through a filter on the receiving side. This is a so-called frequency division method. At this time, sound waves (transmitted waves D and G) are simultaneously emitted from the transducers 4a and 4b. Further, the output signal based on each reflected wave contains the frequency components of the transmitted waves D and G of the transducers 4a and 4b, so that when processing the output signal, both components are separated by a filter. Similar processing is performed in parallel for each frequency component. The other is a method in which different transmission timings are alternately assigned to the transmitters / receivers 4a and 4b, and the reception side adjusts the reception timing in synchronization with the assigned transmission timing. This is a so-called time division method. At this time, for example, first, the transmission wave D is emitted from the transmitter / receiver 4a, the reflected wave E and the reflected wave F (see FIG. 1) are simultaneously received by the transmitter / receivers 4b and 4a, and the next transmitted wave is transmitted. A transmission wave G is emitted from the transmitter / receiver 4b at the timing, and the reflected waves H and the like (reflected waves other than H corresponding to the transmitted wave G are not shown) are simultaneously received by the transmitter / receivers 4a and 4b. .
[0032]
When the transmission wave D from the transducer 4a hits and reflects on a flat target 5 as shown in FIG. 2, a reflected wave returning to the underwater vehicle 1a (not shown in FIG. The level of the reflected wave F) is very small, but the level of the reflected wave E toward the underwater vehicle 1b is sufficiently large. Similarly, when the transmission wave G from the transducer 4b hits and reflects on the flat target 5, the level of the reflected wave (not shown) returning to the underwater vehicle 1a is extremely small, The reflected wave H traveling in the direction of the underwater vehicle 1 has a sufficiently large sound level.
[0033]
As described above, in the present embodiment, sound waves are respectively emitted from the transducers 4a, 4b of the two underwater vehicles 1a, 1b having different sailing positions, so that the two transducers 4b, 4a receive the sound waves. There is a high probability that both of the reflected waves E and H have a sufficient level.
[0034]
Processing after the reflected waves E and H are received by the transducers 4b and 4a is performed in the same manner as in the first embodiment based on FIG. In other words, the information collected individually by each underwater vehicle 1a, 1b is brought back to the land, and a predetermined process such as comparing the two information in the land operation is performed. Also, the information obtained by processing by the underwater vehicle 1a, 1b is transmitted to each other by underwater communication, and predetermined processing such as matching the mutual information is performed, thereby reproducing the search result of the seabed 3. You may. Here, as a method of selecting both information, similar to the first embodiment, 1) a method of comparing signal levels for each pixel in both information and selecting a signal having a higher level, 2) A method of averaging the signal level detected for each pixel and reproducing the signal can be considered. Whichever method is employed, it is possible to obtain more accurate and higher-resolution information than the information based on the reflected wave F collected by one underwater vehicle 1a. Of course, after the information collected by the underwater vehicles 1a and 1b is individually reproduced in parallel, one of them may be selected.
[0035]
The position information of each position received by each underwater vehicle 1a, 1b is separately detected and specified at least in the relative positional relationship, as in the first embodiment. The information and the received wave information together form complete exploration information.
[0036]
According to this embodiment, even if the target 5 has a special shape, the reflected waves E and H based on the transmitted waves D and G from different positions are mutually complemented at positions where their levels are sufficiently large. It is possible to receive waves while performing. Therefore, better quality search information can be obtained than in the case of the first embodiment shown in FIG.
[0037]
In the first and second embodiments, the case in which the number of underwater vehicles 1a and 1b is two has been described, but the present invention is not limited to this. It is sufficient if there are a plurality of units, and as the number increases, the accuracy or resolution improves accordingly. Further, the search target may be a sea surface. In this case, the transmitters / receivers 4, 4a, 4b and the receiver 6 are fixed to the upper surfaces of the underwater vehicles 1a, 1b and emit sound waves upward, and receive reflected waves reflected upward. Waves. Further, the underwater vehicles 1a, 1b are not limited to those that independently travel in water, and may also integrally travel with the ship by a method such as being fixed to the bottom of the ship.
[0038]
<Third embodiment>
Of the underwater acoustic search methods as described above, the underwater acoustic search method according to the first embodiment can be realized by an underwater acoustic search system as shown in FIG. This will be described as a third embodiment.
[0039]
FIG. 3 is a block diagram showing the underwater acoustic search system according to the present embodiment, particularly, a processing system for a reflected signal. As shown in the figure, in the present system, a transmitter / receiver 4 (see FIG. 1; the same applies hereinafter) is provided for the underwater vehicle 1a and a receiver 6 (see FIG. 1) for the underwater vehicle 1b. The same applies hereinafter), and has a processing system I mounted on the underwater vehicle 1a and a processing system II mounted on the watercraft 1b. The processing system I includes a sensor unit 11, a sound signal dividing unit 12, an image reproducing unit 13, and an image synthesizing unit 14. Similarly, the processing system II also includes a sensor unit 15, a sound wave signal dividing unit 16, an image reproducing unit 17, and an image synthesizing unit 18.
[0040]
The sensor units 11 and 15 are configured by arranging a large number of sensing elements in a plane, and there is no difference from that shown in FIG. That is, each sensing element receives a sound wave such as a reflected wave and transmits a sound wave signal which is an electric signal corresponding to the level of the sound wave. Therefore, the sound wave signals of the levels corresponding to the reflected waves F and E (see FIG. 1; the same applies hereinafter) are intermittently transmitted from the sensor units 11 and 15 at each time when the transducer 4 transmits. . Here, the underwater vehicle 1a has a transmitter 19 for performing underwater communication, and the underwater vehicle 1b has a transmitter 19 for receiving a predetermined signal transmitted by the transmitter 19. It has a receiver 20. Thus, the reception timings of the two sensor units 11 and 15 are adjusted so that the reception timings of the sensor units 11 and 15 are synchronized.
[0041]
The sound wave signal dividing units 12 and 16 determine the time t at which the sound wave, which is a reflected wave, is received for each transmission time. _n (N = 1, 2,...; The same applies hereinafter) to the image reproducing units 13 and 17 respectively. As a result, the image processing units 13 and 17 transmit the time t _n Information on the reflected waves for each is captured. Further, the image reproducing units 13 and 17 separately detect each time t. _n The target 5 (see FIG. 1; the same applies hereinafter) is adjusted to the reference coordinates based on the information on the position coordinates of the underwater vehicles 1a and 1b. As a result, each time t _n The target 5 converted into the reference coordinates can be reproduced on each virtual image. In this way, the information individually obtained by the processing system I and the processing system II are individually synthesized by the image synthesis units 14 and 18 as they are. That is, a common process associated with the synthetic aperture search is performed in each of the processing systems I and II. As described above, the processing for synthetic aperture search individually performed in each of the processing systems I and II hardly differs from the known processing. However, in the present embodiment, it is devised to further combine the processing results obtained in the respective processing systems I and II to provide information having higher resolution. Specifically, it is as follows.
[0042]
Synthetic aperture search information S obtained as an output signal of image synthesizing section 18 of processing system II ₂ Is transmitted to the processing system I on the underwater vehicle 1a side by underwater communication via the transmitter 21. This sound wave signal is received by the receiver 22 of the processing system I.
[0043]
The processing system I includes a switch 23, an individual image display processor 24, an average image display processor 25, a maximum level image display processor 26, a switch 27, and a monitor 28 as unique components. The switch means 23 generates synthetic aperture search information S obtained as an output signal of the image synthesis unit 14 of the processing system I. ₁ And the synthetic aperture search information S ₂ Or synthetic aperture search information S ₁ Or opening search information S ₂ Is selectively supplied to any one of the individual image display processing unit 24, the average image display processing unit 25, and the maximum level image display processing unit 26. In the individual image display processing unit 24, the synthetic aperture search information S ₁ , S ₂ And display them individually. In the average image display processing unit 25, both synthetic aperture search information S ₁ , S ₂ The display processing is performed by averaging the signal levels detected for each pixel (corresponding to each pixel of the sensor units 11 and 20; the same applies hereinafter). In the maximum level image display processing unit 26, both synthetic aperture search information S ₁ , S ₂ Among them, the signal levels detected for each pixel are compared, and the one with the higher level is selected to perform display processing. The switch means 27 selects one of the pieces of information processed by the individual image display processing section 24, the average image display processing section 25, or the maximum level image display processing section 26 and supplies the selected information to the monitor 28. The monitor 28 reproduces and visualizes any of the information subjected to the display processing.
[0044]
In the underwater acoustic search system according to the third embodiment, the synthetic aperture search information of the underwater vehicle 1b is transmitted to the underwater vehicle 1a by underwater communication between the underwater vehicles 1a and 1b. Although the predetermined selection process is performed by the underwater vehicle 1a, the configuration is not necessarily required. At least, it is sufficient if the system can receive the reflected waves F and E individually from the underwater vehicle 1a and 1b and collect synthetic aperture information based on the reflected waves. In this case, the information collected individually by each underwater vehicle 1a, 1b is brought back to the land, and a predetermined process such as comparing the two information in the land operation is performed.
[0045]
Further, among the underwater acoustic search methods as described above, the underwater acoustic search method according to the second embodiment can also be realized by a reflection signal processing system according to the underwater acoustic search system as shown in FIG. That is, in the case of the time division method (when the transmissions D and G (see FIG. 1; the same applies hereinafter) have the same frequency), the transmitter 19 of the processing system I and the receiver 20 of the processing system II shown in FIG. May be configured as transceivers so that reception timings are synchronized with each other.
[0046]
On the other hand, in the case of the frequency division method (when the transmissions D and G have different frequencies), the sensor unit 11 of the processing system I shown in FIG. Therefore, a filter for selecting signals of both frequencies is provided on the output side of the sensor unit 11, and two processing systems (a sound signal dividing unit 12, an image reproducing unit 13) are provided in correspondence with each filter. And the image combining unit 14). Then, the output signal of the image synthesizing unit 14 of the processing system is configured to be processed and output by the average image display processing unit 25 or the maximum level image display processing unit 26 shown in FIG. Regarding the processing system II, two systems of processing are performed in parallel with exactly the same configuration.
[0047]
An output signal processed by such a parallel processing system of two systems is used as the synthetic aperture search information S in the third embodiment. ₁ And synthetic aperture search information S ₂ If the two kinds of synthetic aperture search information corresponding to the above are supplied to the switch means 23 of FIG. 3 directly or by using underwater communication, the subsequent processing can be performed in exactly the same manner as in the case of the third embodiment. it can. Of course, it is also possible to construct a system for collecting synthetic aperture search information individually for the underwater vehicles 1a and 1b, and to compare the two synthetic aperture search information on land or the like.
[0048]
Further, in the above description, the case where the number of underwater vehicles is two, that is, the number of received signal processing systems is two has been described, but the number is naturally not limited to this. The number of underwater vehicles and the number of transducers and receivers mounted thereon or the number of transducers mounted thereon can be increased as necessary. In this case, the processing system of the received signal may be increased in parallel with the number of underwater vehicles.
[0049]
【The invention's effect】
As described in detail with the above embodiments, the invention described in [Claim 1] emits a sound wave from a transmitter mounted on an underwater vehicle traveling in water toward an exploration target such as the sea floor. Underwater acoustical exploration methods for exploring the shape of the exploration target by receiving and processing the reflected waves reflected by the exploration target. A transmitter / receiver is mounted on one of the running bodies, and a receiver is mounted on the remaining underwater vehicle, and a reflected wave based on a sound wave emitted from the transmitter / receiver is also used in the other receiver together with the transmitter / receiver. By receiving the signals in synchronization with the reception timing, and processing the signal based on the reflected wave for each of the transducers and receivers, each of the exploration information of the area overlapping in the plurality of underwater vehicles To collect,
The reflected wave of the sound wave transmitted by the transducer can be received at a plurality of positions.
As a result, even when the target to be searched has a special shape such as a flat plate and the return component of the reflected wave to the transducer is small, the information of the target to be searched can be collected satisfactorily. Exploration becomes possible.
[0050]
[Claim 2] The invention according to claim 2 is to transmit a sound wave from a transmitter mounted on an underwater vehicle traveling in water to an object to be searched, such as the sea floor, and receive a reflected wave reflected by the object to be searched. In the underwater acoustical exploration method of exploring the shape of the exploration target by performing processing, the frequency of the frequency individually assigned to each of a plurality of underwater vehicles traveling in the water while grasping the mutual positional relationship Equipped with a transducer that emits a sound wave, a reflected wave based on a sound wave of a unique frequency emitted from each transducer, received by each transducer, synchronizing the reception timing, and further receiving each said A reflected wave is selected for each frequency and for each receiver, and by processing a signal based on the reflected wave for each selected frequency, each of the areas overlapping with the plurality of underwater vehicles is processed. Because we collect exploration information,
The reflected wave of the sound wave transmitted by each transducer can be received at a plurality of positions. At this time, the frequency components of the sound waves transmitted by the respective transducers are different from each other, and at the same time, the reflected wave is separated for each frequency on the receiving side, so that it can be distinguished from which transducer the reflected wave is. can do.
As a result, even when the target to be searched has a special shape such as a flat plate and the return component of the reflected wave of the sound wave to the transducer that transmitted the sound wave is small, any one of the transducers is sufficient. A large reflected wave can be received. That is, a search with higher resolution than in the case of the invention described in [Claim 1] becomes possible.
[0051]
[Claim 3] The invention according to claim 3 is to transmit a sound wave from a transmitter mounted on an underwater vehicle traveling in water to a search target such as the sea floor and receive a reflected wave reflected by the search target. In the underwater acoustical exploration method of exploring the shape of the exploration target by processing and processing, in each of a plurality of underwater vehicles traveling in water while grasping the mutual positional relationship, a unique Equipped with a transducer that emits sound waves of the same frequency at the time, by processing the signal based on the reflected wave for each transducer, each exploration information of the area overlapping in the plurality of underwater vehicles To collect,
The reflected wave of the sound wave transmitted by each transducer can be received at a plurality of positions. At this time, since the transmission timings of the sound waves transmitted by the respective transducers are different from each other, it is possible to distinguish which of the transducers is the reflected wave.
As a result, even when the target to be searched has a special shape such as a flat plate and the return component of the reflected wave of the sound wave to the transducer that transmitted the sound wave is small, any one of the transducers is sufficient. A large reflected wave can be received. That is, a search with higher resolution than in the case of the invention described in [Claim 1] becomes possible.
[0052]
According to the invention described in [Claim 4], in the underwater acoustic exploration method according to any one of [Claim 1] to [Claim 3], the level of a reflected wave in each of the obtained search information is Generate exploration information based on the highest level of information,
Exploration information can be generated using the highest resolution information detected at a plurality of positions. As a result, high-resolution search information is obtained as a whole.
[0053]
According to a fifth aspect of the present invention, in the underwater acoustic exploration method according to any one of the first to third aspects, the level of each reflected wave in each of the obtained exploration information is averaged. And generate exploration information,
Exploration information can be generated using information of the average level detected at a plurality of positions. As a result, high-resolution search information is obtained as a whole.
[0054]
According to a sixth aspect of the present invention, in the underwater acoustic exploration method according to any one of the first to fifth aspects, the search information collected by each underwater vehicle by underwater communication is provided. Because we will give and receive
Each exploration information can be concentrated on any underwater vehicle. As a result, high-resolution exploration information can be collected via the underwater vehicle.
[0055]
The invention described in [Claim 7] is an underwater acoustic exploration method according to any one of [Claim 1] to [Claim 6]. Since it is a synthetic aperture search method that superimposes and synthesizes the search information collected at the position based on the reference coordinates,
Higher resolution exploration information can be collected by synthetic aperture exploration.
[0056]
The invention described in [Claim 8] is directed to a transmitter mounted on an underwater vehicle traveling in water, and also mounted on the underwater vehicle, from the transmitter to an object to be explored such as the sea floor. A reflected wave processing system that receives and processes the reflected wave emitted toward the underwater acoustic exploration system for exploring the shape and the like of the exploration target based on the reflected wave of the sound wave emitted from the transmitter, A transducer mounted on one of a plurality of underwater vehicles traveling in water while grasping the mutual positional relationship, a plurality of transducers mounted on each of the remaining underwater vehicles, In each of the wave receiver and each receiver, a reflected wave based on a sound wave emitted from the transmitter / receiver is received by synchronizing the respective reception timings, and a signal based on the reflected wave for each transmitter / receiver or receiver. And a plurality of processing systems for generating each exploration information by processing
The reflected wave of the sound wave transmitted by the transducer can be received at a plurality of positions.
As a result, even when the target to be searched has a special shape such as a flat plate and the return component of the reflected wave to the transducer is small, the information of the target to be searched can be collected satisfactorily. Exploration becomes possible.
[0057]
The invention described in [Claim 9] is directed to a transmitter mounted on an underwater vehicle traveling in water, and also mounted on the underwater vehicle, and from the transmitter to an object to be explored such as the sea floor. A reflected wave processing system that receives and processes the reflected wave emitted toward the underwater acoustic exploration system for exploring the shape and the like of the exploration target based on the reflected wave of the sound wave emitted from the transmitter, It is mounted on each of a plurality of underwater vehicles that navigate underwater while grasping the mutual positional relationship and emits sound waves of a unique frequency assigned to each, while receiving reflected waves of each sound wave A plurality of transducers, each of which transmits and receives a reflected wave based on a sound wave emitted from each of the transducers by synchronizing the respective reception timings, and divides the received reflected wave for each frequency component. Signal based on the reflected wave for each separated frequency component. Since the and a plurality of processing system for generating each search information by processing each
The reflected wave of the sound wave transmitted by each transducer can be received at a plurality of positions. At this time, the frequency components of the sound waves transmitted by the respective transducers are different from each other, and at the same time, the reflected wave is separated for each frequency on the receiving side, so that it can be distinguished from which transducer the reflected wave is. can do.
As a result, even when the target to be searched has a special shape such as a flat plate and the return component of the reflected wave of the sound wave to the transducer that transmitted the sound wave is small, any one of the transducers is sufficient. A large reflected wave can be received. That is, a search with higher resolution than the case of the invention described in [Claim 8] can be performed.
[0058]
The invention described in [Claim 10] includes a transmitter mounted on an underwater vehicle traveling in water, and a transmitter mounted on the underwater vehicle similarly, and from the transmitter, an object to be explored such as a seabed. A reflected wave processing system that receives and processes the reflected wave emitted toward the underwater acoustic exploration system for exploring the shape and the like of the exploration target based on the reflected wave of the sound wave emitted from the transmitter, A transmitter / receiver mounted on each of a plurality of underwater vehicles that navigate underwater while grasping the mutual positional relationship, and emits sound waves of the same frequency at each assigned unique time, and each transmitter / receiver The receiver receives the reflected wave based on the sound wave emitted from each transmitter / receiver by synchronizing the respective reception timings, and processes the signal based on each reflected wave for each transmitter / receiver to obtain each search information. Since it has multiple processing systems to generate
The reflected wave of the sound wave transmitted by each transducer can be received at a plurality of positions. At this time, since the transmission timings of the sound waves transmitted by the respective transducers are different from each other, it is possible to distinguish which of the transducers is the reflected wave.
As a result, even when the target to be searched has a special shape such as a flat plate and the return component of the reflected wave of the sound wave to the transducer that transmitted the sound wave is small, any one of the transducers is sufficient. A large reflected wave can be received. That is, a search with higher resolution than the case of the invention described in [Claim 8] can be performed.
[0059]
The invention described in [Claim 11] is characterized in that in the underwater acoustic exploration system according to any one of [Claim 8] to [Claim 10], each piece of exploration information obtained by each processing system is input, Since the level of the reflected wave has the maximum level image display processing means for generating the search information based on the information of the maximum level,
Exploration information can be generated using the highest resolution information detected at a plurality of positions. As a result, high-resolution search information is obtained as a whole.
[0060]
According to a twelfth aspect of the present invention, in the underwater acoustic exploration system according to any one of the eighth to tenth aspects, each piece of exploration information obtained by each processing system is input, Since it has an average image display processing means for averaging the level of each reflected wave and generating exploration information,
Exploration information can be generated using information of the average level detected at a plurality of positions. As a result, high-resolution search information is obtained as a whole.
[0061]
According to a thirteenth aspect of the present invention, in the underwater acoustic sounding system according to any one of the eighth to twelfth aspects, each of the underwater sounding systems obtained by processing in the processing system of each underwater vehicle is provided. Since it has a transmitter or receiver that transmits or receives exploration information by underwater communication,
Each exploration information can be concentrated on any underwater vehicle. As a result, high-resolution exploration information can be collected via the underwater vehicle.
[0062]
According to a fourteenth aspect of the present invention, in the underwater acoustic exploration system according to any one of the eighth to thirteenth aspects, each of the processing systems is configured to cause the underwater vehicle to sail. A synthetic aperture search processing unit that processes information based on the reflection signals collected at each position together with information at each position, superimposes search information at each position with reference coordinates, and synthesizes these results. So
Higher resolution exploration information can be collected by synthetic aperture exploration.
[Brief description of the drawings]
FIG. 1 is an explanatory view conceptually showing an underwater acoustic search method according to a first embodiment of the present invention.
FIG. 2 is an explanatory view conceptually showing an underwater acoustic search method according to a second embodiment of the present invention.
FIG. 3 is a block diagram showing an underwater acoustic search system (synthetic aperture search system) according to a third embodiment of the present invention, particularly showing a processing system for a reflected signal;
FIG. 4 is an explanatory view conceptually showing the principle of synthetic aperture search when the seabed is set as a search target.
FIG. 5 is an explanatory diagram conceptually showing a search mode by an acoustic sonar according to the related art.
[Explanation of symbols]
1a, 1b Underwater vehicle
2 underwater
3 Seabed
4, 4a, 4b transducer
5 Target
6 receiver
I, II processing system
11, 15 Sensor unit
14, 18 Image synthesis unit
19, 21 transmitter
20, 22 receiver
25 Average image display processing unit
26 Maximum level image display processing unit

Claims (14)

A transmitter mounted on an underwater vehicle that travels underwater emits sound waves toward the seabed and other objects to be searched, and receives and processes the reflected waves reflected by the objects to be searched to form the object to be searched. In the underwater acoustic search method to search for
A transmitter / receiver is mounted on one of the multiple underwater vehicles traveling in the water while grasping the mutual positional relationship, and a receiver is mounted on the remaining underwater vehicle,
A reflected wave based on the sound wave emitted from the transmitter / receiver, and another receiver together with the transmitter / receiver, receive the wave in synchronization with the reception timing,
An underwater acoustic exploration method, comprising: collecting a plurality of pieces of exploration information of an area overlapping with the plurality of underwater vehicles by processing a signal based on a reflected wave for each of the transducers. A transmitter mounted on an underwater vehicle that travels underwater emits sound waves toward the seabed and other objects to be searched, and receives and processes the reflected waves reflected by the objects to be searched to form the object to be searched. In the underwater acoustic search method to search for
Each of multiple underwater vehicles moving in water while grasping the mutual positional relationship is equipped with a transducer that emits sound waves of individually assigned frequencies,
A reflected wave based on a sound wave of a unique frequency emitted from each transducer is received by each transducer in synchronization with the reception timing,
Further, each reflected wave is selected for each frequency and for each receiver, and a signal based on the reflected wave is processed for each selected frequency, so that the plurality of underwater vehicles overlap with each other. An underwater acoustic exploration method characterized by collecting exploration information of an area. A transmitter mounted on an underwater vehicle that travels underwater emits sound waves toward the seabed and other objects to be searched, and receives and processes the reflected waves reflected by the objects to be searched to form the object to be searched. In the underwater acoustic search method to search for
Each of a plurality of underwater vehicles traveling underwater while grasping the mutual positional relationship is equipped with a transducer that emits sound waves of the same frequency at the assigned unique time,
An underwater acoustic exploration method comprising: processing a signal based on a reflected wave for each transducer to collect exploration information of an overlapping area of the plurality of underwater vehicles. In the underwater acoustic exploration method according to any one of claims 1 to 3,
An underwater acoustic exploration method characterized by generating exploration information based on the information of the level of the reflected wave which is the maximum level among the obtained exploration information. In the underwater acoustic exploration method according to any one of claims 1 to 3,
An underwater acoustic exploration method characterized by averaging the level of each reflected wave of each obtained exploration information to generate exploration information. In the underwater acoustic exploration method according to any one of claims 1 to 5,
An underwater acoustic exploration method characterized by transmitting and receiving exploration information collected by each underwater vehicle by underwater communication. In the underwater acoustic exploration method according to any one of [claim 1] to [claim 6],
The underwater acoustic exploration method is characterized in that the exploration method is a synthetic aperture exploration method in which exploration information collected at each position is superimposed and synthesized based on reference coordinates while the underwater vehicle is traveling. A transmitter mounted on an underwater vehicle traveling underwater, similarly mounted on the underwater vehicle, receiving a reflected wave emitted from the transmitter toward an object to be explored, such as the sea floor, A processing system for a reflected wave to be processed, and in an underwater acoustic search system for searching for a shape or the like of a search target based on a reflected wave of a sound wave emitted from the transmitter,
A transducer mounted on one of a plurality of underwater vehicles that sail underwater while grasping their mutual position,
Multiple receivers respectively mounted on the remaining underwater vehicles,
In the transducer and each receiver, the reflected wave based on the sound wave emitted from the transducer is received by synchronizing the respective reception timings, and the reflected wave is transmitted to each transducer or receiver. A plurality of processing systems for processing signals based on the signals and generating respective pieces of search information. A transmitter mounted on an underwater vehicle traveling underwater, similarly mounted on the underwater vehicle, receiving a reflected wave emitted from the transmitter toward an object to be explored, such as the sea floor, A processing system for a reflected wave to be processed, and in an underwater acoustic search system for searching for a shape or the like of a search target based on a reflected wave of a sound wave emitted from the transmitter,
It is mounted on each of a plurality of underwater vehicles that navigate underwater while grasping the mutual positional relationship and emits sound waves of a unique frequency assigned to each, while receiving reflected waves of each sound wave A plurality of transducers,
In each transducer, the reflected wave based on the sound wave emitted from each transducer is received by synchronizing the respective reception timings, and the received reflected wave is separated for each frequency component, and each separated frequency is separated. An underwater acoustic search system, comprising: a plurality of processing systems that respectively process signals based on reflected waves for each component to generate search information. A transmitter mounted on an underwater vehicle traveling underwater, similarly mounted on the underwater vehicle, receiving a reflected wave emitted from the transmitter toward an object to be explored, such as the sea floor, A processing system for a reflected wave to be processed, and in an underwater acoustic search system for searching for a shape or the like of a search target based on a reflected wave of a sound wave emitted from the transmitter,
A transducer mounted on each of a plurality of underwater vehicles traveling in water while grasping the mutual positional relationship, and transmitting a sound wave of the same frequency at a unique time assigned to each,
In each transducer, a reflected wave based on a sound wave emitted from each transducer is received by synchronizing the respective reception timings, and a signal based on each reflected wave is processed for each transducer and processed. An underwater acoustic exploration system, comprising: a plurality of processing systems for generating exploration information. In the underwater acoustic sounding system according to any one of claims 8 to 10,
An underwater acoustic search system comprising a maximum level image display processing means for inputting each piece of search information obtained by each processing system and generating search information based on information of a maximum level of a reflected wave. In the underwater acoustic sounding system according to any one of claims 8 to 10,
An underwater acoustic exploration system comprising an average image display processing means for inputting each exploration information obtained in each processing system and averaging the level of each reflected wave to generate exploration information. In the underwater acoustic sounding system according to any one of claims 8 to 12,
An underwater acoustic search system comprising a transmitter or a receiver for transmitting or receiving each piece of search information obtained by processing in a processing system of each underwater vehicle by underwater communication. In the underwater acoustic sounding system according to any one of [claim 8] to [claim 13],
Each processing system processes information based on the reflection signals collected at each position while sailing the underwater vehicle along with the information at each position, and superimposes the exploration information at each position based on the reference coordinates, An underwater acoustic search system, which is a synthetic aperture search processing unit that synthesizes these results.

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