Sound wave information output device, sound wave information output method, and recording medium

Abstract

In order to make it possible to improve the accuracy of verifying whether a generated sound wave is a known sound wave, this sound wave information output device: estimates, on the basis of the generation of a sound wave of interest, which is a sound wave transmitted in water, a transmission source velocity, which is the movement direction and movement speed of a transmission source that emits the generated sound wave, which is the generated sound wave of interest; verifies whether the generated sound wave is a known sound wave on the basis of the transmission source velocity, an actual reception frequency, which is the reception frequency of the generated sound wave in a reception device that has received the generated sound wave, a reception device velocity, which is the movement direction and movement speed of the reception device, and information relating to the transmission frequency of the known sound wave, which is said known sound wave; and outputs sound wave information including information relating to a verification result indicating whether the generated sound wave is the known sound wave.

Description

SOUND WAVE INFORMATION OUTPUT DEVICE, SOUND WAVE INFORMATION OUTPUT METHOD, AND RECORDING MEDIUM

[0001] The present disclosure relates to a sound wave information output device, a sound wave information output method, and a recording medium.

[0002] It is being considered to communicate using acoustic waves underwater. Hereinafter, communication using acoustic waves underwater will be referred to as underwater acoustic communication.

[0003] Because radio waves are significantly attenuated underwater, sound waves are more suitable for communication than radio waves in deep water.

[0004] Recently, a method has been known in which a control device on land or on water communicates with an underwater communication device via a base station floating on the water surface. In this method, the communication between the base station and the underwater communication device is carried out by underwater acoustic communication. In addition, the communication between the base station and the control device is carried out by radio wave communication or wired communication.

[0005] Furthermore, a related technique is disclosed in Japanese Patent Laid-Open No. 2003-222999.

[0006] Japanese Patent Application Laid-Open No. 2003-121544

[0007] Underwater, sound waves other than those transmitted from a communication device or a base station may be generated, and there may be cases where it is desired to verify whether the generated sound waves are known sound waves.

[0008] However, when at least one of the source of the generated sound waves and the detection device that detects the generation of the sound waves is moving, the reception frequency of the sound waves at the detection device will be different from the transmission frequency of the sound waves at the source. Also, when at least one of the source of sound waves and the detection device is moving, even if the transmission frequency of the sound waves at the source is constant, the reception frequency at the detection device will change depending on the speed of movement. Therefore, when determining whether a sound wave is known by comparing the reception frequency at the detection device, there is a possibility that the generated sound wave will not be considered a known sound wave even if it is a known sound wave, and there is also a possibility that the generated sound wave will be considered a known sound wave even if it is an unknown sound wave. Note that the above problem was discovered by the inventor of the present application.

[0009] In view of the above-mentioned problems, the object of the present disclosure is to provide an acoustic information output device, an acoustic information output method, and a recording medium that enable improved accuracy in determining whether a generated acoustic wave is a known acoustic wave.

[0010] In one aspect of the present disclosure, the sound wave information output device comprises: a speed estimation means for estimating a source speed, which is the direction and speed of movement of a source that emits a generated sound wave, based on the generation of a target sound wave, which is a sound wave transmitted underwater; a comparison means for comparing whether the generated sound wave is a known sound wave based on the source speed, the actual received frequency, which is the reception frequency of the generated sound wave at a receiving device that receives the generated sound wave, the receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmission frequency of a known sound wave, which is a known sound wave; and an output means for outputting sound wave information including information on the comparison result as to whether the generated sound wave is a known sound wave.

[0011] In another aspect of the present disclosure, a method for outputting acoustic information estimates a source speed, which is the direction and speed of movement of a source that emits a generated sound wave, based on the generation of a target sound wave, which is a sound wave transmitted underwater, and verifies whether the generated sound wave is a known sound wave based on the source speed, the actual received frequency, which is the reception frequency of the generated sound wave at a receiving device that receives the generated sound wave, the receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmission frequency of a known sound wave, which is a known sound wave, and outputs acoustic information including information on the comparison result as to whether the generated sound wave is a known sound wave.

[0012] In another aspect of the present disclosure, a sound wave information output program recorded on a computer-readable recording medium causes a computer to realize the following: a speed estimation function that estimates the source speed, which is the direction and speed of movement of the source that emits the generated sound wave, based on the generation of the target sound wave, which is a sound wave transmitted underwater; a comparison function that compares whether the generated sound wave is a known sound wave based on the source speed, the actual received frequency, which is the reception frequency of the generated sound wave at the receiving device that receives the generated sound wave, the receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmission frequency of a known sound wave, which is a known sound wave; and an output function that outputs sound wave information including information on the comparison result as to whether the generated sound wave is a known sound wave.

[0013] According to the above-described aspects of the present disclosure, it is possible to improve the accuracy of checking whether a generated sound wave is a known sound wave.

[0014] FIG. 1 is a diagram illustrating an example of the configuration of a sonic information output device of the present disclosure. FIG. 2 is a diagram illustrating an example of the operation flow of a sonic information output device of the present disclosure. FIG. 3 is a diagram illustrating an example of the configuration of a communication system including a sonic information output device of the present disclosure. FIG. 4 is a diagram illustrating an example of the configuration of a sonic information output device of the present disclosure. FIG. 5 is a diagram illustrating an example of known sonic information. FIG. 6 is a diagram illustrating another example of the configuration of a sonic information output device of the present disclosure. FIG. 7 is a diagram illustrating the relationship between the emission source speed and the receiving device speed. FIG. 8 is a diagram illustrating an example of an image showing sonic information. FIG. 9 is a diagram illustrating an example of the configuration of a communication system including a sonic information output device of the present disclosure. FIG. 10 is a diagram illustrating an example of the configuration of a sonic information output device of the present disclosure. FIG. 11 is a diagram illustrating an example of the hardware configuration of the present disclosure.

[0015] First Embodiment A first embodiment of the present disclosure will be described. A specific example of the sound wave information output device 10 in the first embodiment is a sound wave information output device 20 in a second embodiment described later.

[0016] 1 shows an example of the configuration of a sound wave information output device 10. The sound wave information output device 10 includes a speed estimation unit 11, a matching unit 12, and an output unit 13.

[0017] The velocity estimation unit 11 estimates the velocity of a source based on the generation of a target sound wave. The target sound wave is a sound wave transmitted underwater. The velocity of the source is the direction and speed of movement of the source that emits the generated sound wave. The generated sound wave is the generated target sound wave.

[0018] The comparison unit 12 compares whether the generated sound wave is a known sound wave based on information on the source speed, actual received frequency, receiving device speed, and transmission frequency of the known sound wave. The actual received frequency is the reception frequency of the generated sound wave at the receiving device that receives the generated sound wave. The receiving device speed is the movement direction and speed of the receiving device. The known sound wave is a known sound wave. Note that the reception frequency is the frequency received (observed) by the receiving device for the sound wave received by the receiving device.

[0019] The output unit 13 outputs the sound wave information. The sound wave information is information about the generated sound wave. The sound wave information also includes information about the result of checking whether the generated sound wave is a known sound wave.

[0020] Next, FIG. 2 shows an example of the operation flow of the sound wave information output device 10.

[0021] The velocity estimation unit 11 estimates the velocity of the source based on the generation of the target sound wave (step S101).

[0022] The collator 12 collates whether the generated sound wave is a known sound wave based on the information on the speed of the source, the actual receiving frequency, the receiving device speed, and the transmission frequency of the known sound wave (step S102).

[0023] The output unit 13 outputs the sound wave information (step S103).

[0024] As described above, in the first embodiment of the present disclosure, the sonic information output device 10 includes a speed estimation unit 11, a matching unit 12, and an output unit 13. The speed estimation unit 11 estimates the source speed based on the generation of a target sound wave. The target sound wave is a sound wave transmitted underwater. The source speed is the direction and speed of movement of the source that emits the generated sound wave. The generated sound wave is the generated target sound wave. The matching unit 12 matches whether the generated sound wave is a known sound wave based on information about the source speed, the actual received frequency, the receiving device speed, and the transmission frequency of the known sound wave. The actual received frequency is the reception frequency of the generated sound wave at the receiving device that receives the generated sound wave. The receiving device speed is the direction and speed of movement of the receiving device. The known sound wave is a known sound wave. The output unit 13 outputs sonic information. The sonic information includes information about the matching result of whether the generated sound wave is a known sound wave.

[0025] As a result, the sound wave information output device 10 estimates the speed of the sound source and performs matching based on the estimated speed of the sound source, which improves the matching accuracy for sound sources whose speed is unknown. As a result, it becomes possible to improve the matching accuracy for determining whether the generated sound waves are known sound waves.

[0026] Second Embodiment Next, a second embodiment of the present disclosure will be described. A specific example of the sound wave information output device 10 in the first embodiment is a sound wave information output device 20 in the second embodiment.

[0027] 3 shows an example of the configuration of a communication system 71 including the sonic information output device 20. The communication system 71 includes the sonic information output device 20, a base station 60, and wireless communication devices 50-i (i is an integer from 1 to N, and N is an integer equal to or greater than 1).

[0028] The base station 60 is located on the water and is capable of wireless communication with the wireless communication device 50-i using acoustic waves.

[0029] The wireless communication device 50-i exists underwater. The wireless communication device 50-i can perform wireless communication using sound waves with a base station 60. The wireless communication device 50-i can communicate with the sound wave information output device 20 via the base station 60. The wireless communication devices 50-1 to 50-N may be collectively referred to as wireless communication devices 50.

[0030] Furthermore, the frequency that the wireless communication device 50-i uses for wireless communication using sound waves with the base station 60 will be referred to hereinafter as the operating frequency. Note that the wireless communication using sound waves may be communication using band signals. In this case, the operating frequency may be a frequency band. When the wireless communication is communication using band signals, the term "frequency" refers to a "frequency band."

[0031] The sonic information output device 20 is connected to a base station 60. The sonic information output device 20 is located on water or on land. The sonic information output device 20 can communicate with the base station 60 wirelessly via radio waves or via wire.

[0032] 4 shows an example of the configuration of the sound wave information output device 20. The sound wave information output device 20 includes a speed estimation unit 21, a matching unit 22, an output unit 23, and a detection unit 24.

[0033] The detection unit 24 detects the generation of target sound waves. Target sound waves are sound waves transmitted underwater. Furthermore, target sound waves are sound waves that are the target of outputting sound wave information, which will be described later. The type of sound waves that are the target of outputting sound wave information is set in advance. For example, the target sound waves may be sound waves transmitted underwater. Furthermore, the target sound waves may be sound waves that are not used in wireless communication between the base station 60 and the wireless communication device 50. Furthermore, the target sound waves may be interference waves. If the target sound waves to be detected are interference waves, the detection unit 24 detects the generation of interference waves in the wireless communication performed by the wireless communication device 50. The detection unit 24 can detect the generation of target sound waves using any method. Examples of methods for detecting target sound waves will be described later. Furthermore, the generated target sound waves will hereinafter be referred to as generated sound waves.

[0034] The interference waves are sound waves that can interfere with sound-based wireless communication between the base station 60 and the wireless communication device 50 located underwater. For example, interference waves can be waves with frequencies close to the frequency used for wireless communication by the wireless communication device 50. In the case of sound-based wireless communication, interference waves can also be sound waves used in communications by other operators, natural sounds, sounds of construction work being carried out on water, on land, or underwater, and sounds emitted by ships.

[0035] The speed estimation unit 21 estimates the source speed based on the generation of the target sound waves. The source speed is the direction of movement and speed of movement of the source that emits the generated target sound waves (generated sound waves). The source is an object that emits sound waves. For example, a device that communicates by sound waves, an underwater creature, construction equipment, a ship, etc. can also be a source. The speed estimation unit 21 considers that the target sound waves have been generated when the detection unit 24 detects the generation of the target sound waves. An example of a method for estimating the source speed will be described later. Note that estimating the source speed based on the generation of the target sound waves includes estimating the source speed based on the reception of the target sound waves.

[0036] The matching unit 22 matches whether the generated sound wave is a known sound wave based on information on the source speed, actual receiving frequency, receiving device speed, and transmission frequency of the known sound wave. The actual receiving frequency is the receiving frequency of the generated sound wave at the receiving device that received the generated sound wave. The receiving device speed is the moving direction and speed of the receiving device. The known sound wave is a known sound wave. The receiving device is a device that received the generated sound wave. The receiving device is a base station 60, a wireless communication device 50, or an information collection device described below. The receiving frequency is the frequency received (observed) by the receiving device for the sound wave received by the receiving device. Examples of matching methods will be described below.

[0037] The information about the known sound waves is stored in advance in a storage means (not shown) inside or outside the sound wave information output device 20. Hereinafter, the information about the known sound waves may be referred to as known sound wave information. The known sound wave information includes at least information about the transmission frequency of the known sound waves at the source of the known sound waves. The storage means may store information about one or more known sound waves. Furthermore, the information about the transmission frequency may include spectral information indicating the frequency spectrum. The spectral information indicates the correspondence between the frequency and intensity of the sound waves.

[0038] Figure 5 shows an example of known sound wave information. In the example shown in Figure 5, information about three sound waves is stored in the storage means as known sound wave information. A sound wave ID (identification) is identification information assigned to each known sound wave. A transmission frequency is also associated with each known sound wave. Two or more transmission frequencies may be associated with one known sound wave. For example, if the transmission frequency is an estimated value, two or more frequencies that may be the transmission frequency of the known sound wave may be associated with one known sound wave. Furthermore, if the source that emits the known sound waves is known, information about the source may be stored for each known sound wave. For example, if the source of the known sound waves is a ship, a ship ID that can identify each individual ship may be stored.

[0039] The output unit 23 outputs sound wave information. The sound wave information is information about the generated sound wave. The sound wave information includes information about the collation result as to whether the generated sound wave is a known sound wave or not. A method for outputting the sound wave information will be described later.

[0040] Next, a method for detecting the generation of target sound waves will be described. The detection unit 24 may detect, as the target sound waves, the generation of interference waves in wireless communication performed by the wireless communication device 50. There are two methods for detecting target sound waves: a method for detecting based on sound waves received by the base station 60, and a method for detecting based on sound waves received by the wireless communication device 50.

[0041] First, a method for detecting target sound waves based on sound waves received by the base station 60 will be described.

[0042] In this case, the base station 60 transmits information about the received sound waves to the sound wave information output device 20. The sound wave information includes information about the direction of arrival of the sound waves and information about the frequency of the sound waves (the reception frequency at the base station 60). Note that if the target sound waves are sound waves that are not used in communication with the wireless communication devices 50-1 to 50-N, the base station 60 does not need to transmit sound wave information about the sound waves that are used in communication with the wireless communication devices 50-1 to 50-N. Also, if the target sound waves are interference waves, the base station 60 does not need to transmit sound wave information about sound waves with frequencies that do not affect the frequencies used by the wireless communication devices 50-1 to 50-N.

[0043] For example, the detection unit 24 of the sound wave information output device 20 can determine that a target sound wave has been generated when the base station 60 receives any of the following sound waves: A sound wave that arrives from a direction in which no wireless communication device 50-1 to 50-N is present A sound wave that arrives from a direction in which no wireless communication device 50-1 to 50-N is present, but has a frequency that is different from the frequency used by a wireless communication device that is present in that direction A sound wave that has unknown identification information Furthermore, the detection unit 24 can determine, for example, that, of the above sound waves, a sound wave with a frequency that affects the frequency used by the wireless communication devices 50-1 to 50-N is an interference wave.

[0044] Next, a method for detecting target sound waves based on sound waves received by the wireless communication device 50-i will be described.

[0045] In this case, the wireless communication device 50-i transmits information about the received sound waves to the sound wave information output device 20 via the base station 60. The sound wave information includes information about the direction of arrival of the sound waves and information about the frequency of the sound waves (the reception frequency at the wireless communication device 50-i). Note that if the target sound waves are sound waves that are not used in communication with the wireless communication devices 50-1 to 50-N, the wireless communication device 50-i does not need to transmit sound wave information about the sound waves that are being used in communication with the base station 60. Also, if the target sound waves are interference waves, the wireless communication device 50-i does not need to transmit sound wave information about sound waves with frequencies that do not affect the frequencies used by the wireless communication devices 50-1 to 50-N.

[0046] Furthermore, if the wireless communication device 50-i is affected by interference waves, it cannot communicate using the original frequency it was using. Therefore, when it is unable to communicate using the original frequency it uses, the wireless communication device 50-i communicates with the base station 60 using one of the spare frequencies that is not affected by interference waves.

[0047] The detection unit 24 of the sound wave information output device 20 can determine that a target sound wave has been generated when the wireless communication device 50-i receives the target sound wave. Also, the detection unit 24 can determine that an interference wave has been generated when the wireless communication device 50-i receives a sound wave that may interfere with the wireless communication by sound waves between the base station 60 and the wireless communication device 50.

[0048] The detection unit 24 may detect the target sound waves based on sound waves received by an information acquisition device (not shown). The information acquisition device may be mounted on, for example, an unmanned underwater vehicle (UUV) used for information acquisition. In this case, the information acquisition device can detect the target sound waves in a manner similar to the method of detecting the target sound waves based on sound waves received by the wireless communication device 50-i.

[0049] Next, an example of a method for estimating the source velocity will be described.

[0050] For example, the speed estimation unit 21 may estimate the speed of the source using position information of a ship that is present within a predetermined range from the receiving device. The predetermined range is, for example, a range within which the receiving device is likely to receive sound waves emitted from that range. The predetermined range may be fixed and determined in advance. The speed estimation unit 21 may receive ship position information from a server (not shown) that provides ship position information. The information provided from the server may be, for example, information from an AIS (Automatic Identification System). The ship position information may also be ship position information visually confirmed by a land-based observer. The ship position information may also include a history of past position information. The speed estimation unit 21 may further receive ship identification information from the server.

[0051] When using the ship's position information, the speed estimation unit 21 may estimate the ship that is the source of the generated sound waves, for example, based on the ship's position information and the arrival direction of the generated sound waves, which is the arrival direction of the generated sound waves relative to the receiving device that received the generated sound waves.

[0052] For example, the speed estimation unit 21 may estimate a ship present in the direction of arrival of the generated sound waves as the source of the generated sound waves. When two or more ships are present in the direction of arrival of the generated sound waves, the speed estimation unit 21 may estimate two or more ships as candidate sources. Furthermore, the speed estimation unit 21 may exclude a ship that is no longer present in the direction of arrival of the generated sound waves from the candidate sources based on changes over time in the direction of arrival of the generated sound waves.

[0053] Furthermore, the speed estimation unit 21 may estimate the ship that is the source of the generated sound waves, for example, based on the ship's position information and the position of the source of the generated sound waves. The speed estimation unit 21 may estimate, for example, that a ship that is present within a predetermined range from the position of the source of the generated sound waves is the source emitting the generated sound waves. When two or more ships are present within a predetermined range from the position of the source of the generated sound waves, the speed estimation unit 21 may narrow down the ships that are estimated as candidate sources based on changes in the position of the source over time. Furthermore, the speed estimation unit 21 may estimate two or more ships as candidate sources.

[0054] The position of the source is estimated by a source position estimation unit 35. The source position estimation unit 35 estimates the position of the source (source position) that emits the generated sound wave detected by the detection unit 24. FIG. 6 shows an example of the configuration of a sound wave information output device 30 that includes the source position estimation unit 35. The sound wave information output device 30 includes the source position estimation unit 35 in addition to the speed estimation unit 21, the matching unit 22, the output unit 23, and the detection unit 24. The method for estimating the source position will be described later.

[0055] The speed estimation unit 21 uses the movement speed of the ship estimated as the source as the source speed. For example, the speed estimation unit 21 can estimate the source speed based on changes over time in the position of the ship estimated as the source. The speed estimation unit 21 may also use information on the movement speed of the ship included in information from the AIS as information on the source speed. When two or more ships are estimated as candidate sources, the speed estimation unit 21 may use the movement speed of each of the candidate sources as a candidate source speed.

[0056] Note that the source may not be a ship. Therefore, the speed estimation unit 21 may not be able to identify the ship that is the source. For example, there may be cases where no ship is present in the direction from which the generated sound waves are coming. Therefore, when the speed estimation unit 21 is unable to identify the ship that is the source, it may be better to estimate the source speed using another method.

[0057] For example, the velocity estimation unit 21 may estimate the velocity of the source based on the change over time of the source position estimated by the source position estimation unit 35. The velocity estimation unit 21 may also estimate the velocity of the source based on the change over time of the direction of arrival of the generated sound wave.

[0058] Next, a method for estimating the position of the transmission source will be described. The position of the transmission source is estimated by the transmission source position estimator 35.

[0059] For example, the detection unit 24 receives information about generated sound waves received by the base station 60 from the base station 60. The information about the generated sound waves includes information about the direction of arrival and frequency (received frequency) of the generated sound waves. The detection unit 24 also receives information about generated sound waves received by the wireless communication device 50-i from the wireless communication device 50-i. The source position estimation unit 35 then estimates the position of the source using information about generated sound waves that are estimated to be generated from the same source, among the information about the generated sound waves received by the detection unit 24. For example, the source position estimation unit 35 can determine the position of the source as the intersection of a line extending from the position of the device (receiving device) that received the generated sound waves to the direction of arrival of the generated sound waves. Note that the source position estimation unit 35 may also consider generated sound waves with similar received frequencies, generated sound waves with the same identification information included in the sound waves, sound waves with similar frequency spectrum shapes, etc. to be generated sound waves from the same source.

[0060] The position of the wireless communication device 50-i may be measured based on an inertial sensor provided in the wireless communication device 50-i.

[0061] Furthermore, the speed estimation unit 21 can estimate the position of the wireless communication device 50-i, for example, based on the direction of arrival of the sound waves emitted by the wireless communication device 50-i relative to the base station 60. For example, the speed estimation unit 21 receives information on the direction of arrival of the sound waves emitted by the wireless communication device 50-i from the base station 60. The speed estimation unit 21 also receives information on the vertical position (depth) of the wireless communication device 50-i from the wireless communication device 50-i via the base station 60. The speed estimation unit 21 can then estimate the position of the wireless communication device 50-i based on the information on the direction of arrival and the information on the vertical position (depth). In this case, the wireless communication device 50-i is equipped with a pressure (depth) sensor.

[0062] The source position estimation unit 35 may further estimate the location of the source based on the received signal level of the generated sound wave. In this case, the information on the generated sound wave further includes information on the received signal level at the device that received the generated sound wave.

[0063] Next, an example of the matching method will be described. The matching unit 22 matches whether the generated sound wave is a known sound wave based on information on the speed of the source, the actual receiving frequency, the receiving device speed, and the transmission frequency of the known sound wave. The actual receiving frequency is the receiving frequency of the generated sound wave at the receiving device that receives the generated sound wave. The known sound wave is a known sound wave. The receiving device is a wireless communication device 50, a base station 60, or an information acquisition device.

[0064] The matching method includes a method of matching the reception frequency and a method of matching the transmission frequency.

[0065] First, a method for verifying the reception frequency will be described. In the method for verifying the reception frequency, the verification unit 22 first calculates an estimated reception frequency. The estimated reception frequency is the reception frequency of a known sound wave in the receiving device. Then, the verification unit verifies the estimated reception frequency with the actual reception frequency.

[0066] It is possible that information on two or more known sound waves is stored in the storage means. In this case, the collation unit 22 calculates an estimated reception frequency for each of the known sound waves whose information is stored in the storage means.

[0067] In addition, the speed estimation unit 21 may estimate the speed of the source based on the position information of the ship. In addition, the position information of the ship may be associated with the identification information of the ship. In this case, the matching unit 22 may calculate an estimated reception frequency for known sound waves associated with the identification information of the ship estimated as the source by the speed estimation unit 21, among the known sound waves whose information is stored in the storage means.

[0068] The collation unit 22 can calculate the estimated reception frequency fe, for example, using the following formula (1): where f0 is the transmission frequency of the known sound wave, Vc is the speed of sound, r is the speed of the receiving device, and t is the speed of the source of the generated sound wave.

[0069]

[0070] The collation unit 22 uses the component of the source speed t0 (vector) in the direction of the straight line from the source to the receiving device as the source speed t. If the direction of travel of the source with respect to the straight line from the source to the receiving device is θt, the source speed t is calculated by the following equation (2). Note that the collation unit 22 can determine the direction of the straight line from the source to the receiving device from information on the direction of arrival of the generated sound wave at the receiving device. The source speed t0 is estimated by the speed estimation unit 21.

[0071]

[0072] Furthermore, the collation unit 22 uses the component of the receiving device speed r0 (vector) in the direction of the straight line from the transmission source to the receiving device as the speed r of the receiving device. If the direction of travel of the receiving device relative to the straight line from the transmission source to the receiving device is θr, the speed r of the receiving device is calculated by the following equation (3). Note that the receiving device speed r0 is acquired by the receiving device and transmitted to the ultrasonic information output device 20.

[0073]

[0074] FIG. 7 also shows the relationship between source rate and receiver rate.

[0075] The collation unit 22 also estimates the sound speed Vc and calculates the estimated reception frequency fe using the estimated sound speed Vc. The method for estimating the sound speed will be described later.

[0076] Furthermore, when the speed estimation unit 21 estimates two or more speeds as candidates for the transmission source speed, the collation unit 22 calculates an estimated reception frequency fe for each of the candidate transmission source speeds. Then, the collation unit 22 sets each of the calculated estimated reception frequencies as a candidate for the estimated reception frequency.

[0077] The collation unit 22 then compares the estimated reception frequency with the actual reception frequency. If the estimated reception frequency and the actual reception frequency are similar, the collation unit 22 determines that the generated sound wave is a known sound wave. For example, if the difference between the estimated reception frequency and the actual reception frequency is smaller than a predetermined value, the collation unit 22 determines that the two are similar. If two or more estimated reception frequencies have been calculated as candidates for the estimated reception frequency, the collation unit 22 determines that the two are similar if there is an estimated reception frequency whose difference between the estimated reception frequency and the actual reception frequency is smaller than a predetermined value.

[0078] Next, a method for verifying the transmission frequency will be described. In the method for verifying the transmission frequency, the verification unit 22 first estimates the transmission frequency of the sound wave generated at the source. Then, the verification unit 22 verifies the estimated transmission frequency with the transmission frequency of the known sound wave.

[0079] The collation unit 22 can calculate the transmission frequency f0 of the sound wave generated at the transmission source, for example, using the following equation (4): where f is the reception frequency of the generated sound wave at the receiving device, Vc is the speed of sound, r is the speed of the receiving device, and t is the speed of the transmission source.

[0080]

[0081] Furthermore, when the speed estimation unit 21 estimates two or more speeds as candidates for the sound source speed, the collation unit 22 calculates the transmission frequency f0 of the sound wave generated at the sound source for each of the candidate sound source speeds. Then, the collation unit 22 sets each of the calculated transmission frequencies as a candidate for the transmission frequency of the generated sound wave.

[0082] The collation unit 22 then compares the estimated transmission frequency of the generated sound wave with the transmission frequency of the known sound wave. The collation unit 22 determines that the generated sound wave is a known sound wave when the estimated transmission frequency of the generated sound wave and the transmission frequency of the known sound wave are similar. For example, the collation unit 22 determines that the two are similar when the difference between the estimated transmission frequency of the generated sound wave and the transmission frequency of the known sound wave is smaller than a predetermined value. When two or more transmission frequencies have been calculated as candidates for the transmission frequency of the generated sound wave, the collation unit 22 determines that the two are similar when there is a transmission frequency for which the difference between the estimated transmission frequency of the generated sound wave and the transmission frequency of the known sound wave is smaller than a predetermined value.

[0083] In addition, when the source of the sound waves is a ship, changing the speed of the ship's movement may change the rotation speed of the screw, which may change the transmission frequency of the sound waves emitted by the ship. Therefore, the storage means may store information on the transmission frequency as known sound wave information, associated with the speed of the source or the speed of movement of the source (the speed component of the source speed). In this case, information on one or more transmission frequencies is stored in the storage means for one known sound wave.

[0084] When information on transmission frequencies associated with speed components of the source velocity is stored in the storage means as known sound wave information, the matching unit 22 may use, for matching, the transmission frequencies of the known sound waves associated with the speed components of the source velocity estimated by the velocity estimation unit 21. Note that the source velocity estimated by the velocity estimation unit 21 may hereinafter be referred to as the estimated source velocity.

[0085] Furthermore, if the transmission frequency corresponding to the speed component of the estimated source speed is not stored in the storage means, the matching unit 22 may estimate the transmission frequency corresponding to the speed component of the estimated source speed for the known sound wave and use the estimated transmission frequency as the transmission frequency of the known sound wave for matching. For example, if two or more transmission frequencies are stored for one known sound wave in association with the speed components of the source speed, the matching unit 22 can estimate the transmission frequency corresponding to the speed component of the estimated source speed for the known sound wave using the correspondence between the speed components of the source speed and the transmission frequency. The matching unit 22 can estimate the transmission frequency corresponding to the speed component of the estimated source speed using any method, such as interpolation or extrapolation.

[0086] Furthermore, when the spectral information of the known sound wave is stored in the storage means, the matching unit 22 may perform matching using the spectral information as information on the transmission frequency. For example, the matching unit 22 may detect a peak frequency from the frequency spectrum indicated by the spectral information and use the detected peak frequency as the transmission frequency of the known sound wave.

[0087] Next, a method for estimating the speed of sound will be described.

[0088] Regarding the speed of sound around the receiving device, for example, the speed of sound in the ocean depends on the water temperature, pressure (depth), and salinity. Therefore, the matching unit 22 may estimate the vertical and horizontal sound speed distributions based on at least one of the water temperature and salinity around the receiving device. The matching unit 22 may receive information (water temperature, salinity, etc.) acquired by an information acquisition device (not shown) from the information acquisition device, and estimate the vertical and horizontal sound speed distributions based on the received information.

[0089] The information acquisition device acquires information about the depth of the information acquisition device. Also, the information acquisition device acquires information about at least one of the water temperature and salinity concentration around the information acquisition device. For example, the information collection device is equipped with a depth sensor and acquires information about the depth of the information acquisition device. Also, for example, the information acquisition device is equipped with a water temperature sensor and acquires information about the water temperature around the information acquisition device. Also, for example, the information acquisition device is equipped with a salinity concentration sensor and acquires information about the salinity concentration around the information acquisition device. Note that the information acquisition device may be a wireless communication device 50-i.

[0090] It should be noted that the Global Navigation Satellite System (GNSS) cannot be used underwater to determine the location of the information acquisition device. Therefore, the matching unit 22 may estimate the location of the information acquisition device based on the direction of arrival of sound waves emitted by the information acquisition device relative to the base station 60. For example, the matching unit 22 receives information on the direction of arrival of sound waves emitted by the information acquisition device from the base station 60. The matching unit 22 also receives information on the vertical position (depth) of the information acquisition device from the information acquisition device via the base station 60. The matching unit 22 can then estimate the location of the information acquisition device based on the information on the direction of arrival and the information on the vertical position (depth).

[0091] Alternatively, the collation unit 22 may receive information from an information server (not shown). The information server may estimate the current water temperature and salinity at a predetermined location based on, for example, information on past water temperature and salinity.

[0092] The matching unit 22 can also receive information about the vertical position (depth) of the wireless communication device 50-i from the wireless communication device 50-i. The wireless communication device 50-i is equipped with a pressure (depth) sensor and acquires information about the vertical position (depth) of the wireless communication device 50-i. The matching unit 22 also estimates the position of the wireless communication device 50-i in the same manner as described above.

[0093] Next, the sound wave information will be described. The sound wave information includes information regarding the matching result. The matching result is information as to whether the generated sound wave is a known sound wave. The sound wave information may include information indicating the matching result. Furthermore, if the matching result indicates that the generated sound wave is a known sound wave, the sound wave information may include information about known sound waves with similar frequencies in the frequency matching. The output unit 23 can output information about at least one or more items of the known sound wave information stored in the storage means as information about the known sound wave. For example, it can output identification information of the known sound wave, a ship ID, etc. Furthermore, if the source of the known sound wave is a ship and the ship ID has been identified, information about the ship may be obtained from the AIS and output.

[0094] In the comparison of reception frequencies, two or more estimated reception frequencies may be similar to the actual reception frequency. In this case, the sound wave information may include information on each of the known sound waves corresponding to the estimated reception frequency similar to the actual reception frequency as information on candidates of known sound waves estimated as the generated sound wave.

[0095] Furthermore, in the comparison of the transmission frequencies, the frequency estimated as the transmission frequency at the source of the generated sound wave may be similar to the transmission frequencies of two or more known sound waves. In this case, the sound wave information may include, as information on candidates for the known sound wave estimated as the generated sound wave, information on each of the known sound waves corresponding to a transmission frequency similar to the frequency estimated as the transmission frequency at the source of the generated sound wave.

[0096] The acoustic wave information may also include information on the velocity of the source. If the position information of a ship is used to estimate the velocity of the source, the acoustic wave information may also include identification information of the ship whose position information was used to estimate the velocity of the source. The acoustic wave information may also include metadata acquired from the generated acoustic waves. The metadata is acquired by the receiving device and transmitted to the acoustic wave information output device 20.

[0097] The sound wave information may also include spectral information of the generated sound waves. The spectral information of the generated sound waves is acquired by the receiving device and transmitted to the sound wave information output device 20.

[0098] Next, a method for outputting sound wave information will be described.

[0099] The output unit 23 may output the sound wave information to a control device (not shown) that controls the base station 60 or the wireless communication device 50. A function equivalent to the control device may be included in the sound wave information output device 20. The control device may then control the base station 60 or the wireless communication device 50 based on the sound wave information. The control device may, for example, take interference avoidance measures against known interference waves. The control device may, for example, implement interference avoidance measures that have been effective in the past against known interference waves.

[0100] The output unit 23 may also output the sound wave information to a storage unit.

[0101] For example, if the result of the comparison indicates that the generated sound wave is an unknown sound wave, the output unit 23 may add the information about the generated sound wave to the known sound wave information by storing the sound wave information about the generated sound wave in the storage means as information about a new known sound wave. Also, if the generated sound wave is known, the output unit 23 may not need to store the information about the generated sound wave in the storage means.

[0102] Furthermore, when the generated sound wave is known, the output unit 23 may update the known sound wave information stored in the storage means with the information on the generated sound wave. For example, assume that the storage means stores information on the number of times the known sound wave has been detected and the time of detection as the known sound wave information. In this case, the output unit 23 may update the information on the number of times the known sound wave has been detected and the time of detection stored in the storage means. The information on the detection time can be stored in the storage means one or more times for one known sound wave.

[0103] The control device may take interference avoidance measures using information on the number of times the known sound waves are detected and the time of detection. For example, the control device may predict the time of occurrence of the known sound waves based on the time of detection of the known sound waves, and take interference avoidance measures based on the predicted time of occurrence. For example, if the known sound waves are generated at a fixed time every day and interference by the known sound waves is predicted, the control device may start interference avoidance measures for at least one of the wireless communication device 50 and the base station 60 before the generation of the known sound waves. Also, for example, the control device may take interference avoidance measures for known sound waves whose detection count exceeds a predetermined number.

[0104] Furthermore, the output unit 23 may estimate the position of the source of the generated sound waves at a predetermined time using information on the estimated source speed and source position. Furthermore, the output unit 23 may predict the reception frequency of the generated sound waves at the wireless communication device 50 based on the position of the source of the generated sound waves at a predetermined time, predict whether or not the generated sound waves will have an effect (interference) on the wireless communication device 50, and output the result. Furthermore, the control device may take measures to avoid interference based on the prediction result.

[0105] The output unit 23 may also output image information for displaying an image on a display means (not shown) as the sound wave information. The image displayed on the display means may be an image showing the source of the generated sound waves superimposed on a map.

[0106] FIG. 8 shows an example of an image showing sound wave information. In FIG. 8, a black circle indicates the position of the wireless communication device. An isosceles triangle indicates the position of the source of the generated sound wave. The apex angle of the isosceles triangle indicates the direction of travel of the source. An open isosceles triangle indicates a known source of the generated sound wave. A black isosceles triangle indicates an unknown source of the generated sound wave. The position of the source of the generated sound wave is estimated by the source position estimation unit 35. In the example of FIG. 8, the sound wave information is shown on a two-dimensional map, but it may also be shown three-dimensionally.

[0107] Furthermore, there is a possibility that two or more known sound waves may be estimated as candidates for the known sound wave corresponding to the generated sound wave. In this case, the image may include information on the two or more known sound waves.

[0108] Furthermore, two or more velocities may be estimated as candidates for the emission source velocity. In this case, information on two or more source velocities may be included in the image as candidates for the emission source velocity.

[0109] The image may also include predicted information about the position of the source of the generated sound waves at a predetermined time. The position of the source of the generated sound waves at a predetermined time can be predicted from the source speed estimated by the speed estimation unit 21 and the source position estimated by the source position estimation unit 35. The predicted position information may take into account errors in the source speed and source position, and may indicate a range of possibilities rather than a pinpoint position.

[0110] In addition, when two or more known sound waves are estimated as candidates for a known sound wave corresponding to one generated sound wave, it may be possible to reduce the number of known sound waves estimated as candidates as the wireless communication device 50 or the source of the known sound waves moves. For example, the direction of arrival of the generated sound waves relative to the receiving device may change, and as a result, one of the ships estimated as the source of the generated sound waves may no longer be located in the direction of arrival of the generated sound waves. Therefore, the sound wave information output device 20 may perform the matching operation again at a predetermined timing, such as at a predetermined time interval, to update the sound wave information. Furthermore, the control device may control the movement of the wireless communication device 50 so as to reduce the number of candidates for the known sound wave.

[0111] Next, an example of the operation flow of the sound wave information output device 20 will be described with reference to FIG.

[0112] The detector 24 detects the generation of a target sound wave.

[0113] When the detection unit 24 detects the generation of a target sound wave, the velocity estimation unit 21 estimates the velocity of the source (step S101).

[0114] The collator 22 collates whether the generated sound wave is a known sound wave based on the information on the speed of the source, the actual receiving frequency, the receiving device speed, and the transmission frequency of the known sound wave (step S102).

[0115] The output unit 23 outputs the sound wave information (step S103).

[0116] As described above, in the second embodiment of the present disclosure, the sonic information output device 20 includes a speed estimation unit 21, a matching unit 22, and an output unit 23. The speed estimation unit 21 estimates the source speed based on the generation of a target sound wave. The target sound wave is a sound wave transmitted underwater. The source speed is the direction and speed of movement of the source that emits the generated sound wave. The generated sound wave is the generated target sound wave. The matching unit 22 matches whether the generated sound wave is a known sound wave based on information about the source speed, the actual received frequency, the receiving device speed, and the transmission frequency of the known sound wave. The actual received frequency is the reception frequency of the generated sound wave at the receiving device that receives the generated sound wave. The receiving device speed is the direction and speed of movement of the receiving device. The known sound wave is a known sound wave. The output unit 23 outputs sonic information. The sonic information includes information about the matching result of whether the generated sound wave is a known sound wave.

[0117] As a result, the sound wave information output device 20 estimates the speed of the sound source and performs matching based on the estimated speed of the sound source, which improves the matching accuracy for sound sources whose speed is unknown. This makes it possible to improve the matching accuracy for determining whether the generated sound waves are known sound waves.

[0118] The matching unit 22 may calculate an estimated reception frequency, which is the reception frequency of the known sound wave at the receiving device, based on the transmission source speed, the receiving device speed, and the transmission frequency of the known sound wave, and determine that the generated sound wave is a known sound wave if the estimated reception frequency and the actual reception frequency are similar.Alternatively, the matching unit 22 may estimate the transmission frequency of the generated sound wave based on the transmission source speed, the actual reception frequency, and the receiving device speed, and determine that the generated sound wave is a known sound wave if the transmission frequency of the known sound wave and the transmission frequency of the generated sound wave are similar.This makes it possible to improve the accuracy of matching between the generated sound wave and the known sound wave.

[0119] The speed estimation unit 21 may also estimate the source speed based on position information of ships present within a predetermined range from the receiving device. The speed estimation unit 21 may also estimate a ship present in the direction from which the generated sound waves arrive at the receiving device as the source of the generated sound waves. This allows the sound wave information output device 20 to estimate the source speed.

[0120] Furthermore, when there are multiple ships in the direction of arrival of the generated sound waves, the speed estimation unit 21 may exclude ships that are no longer in the direction of arrival of the sound source from the candidates for the sound source based on changes over time in the direction of arrival of the generated sound waves, thereby improving the accuracy of estimating the sound source speed.

[0121] The ultrasonic information output device 30 may further include a source position estimation unit 35 that estimates the source position, which is the location of the source. The speed estimation unit 21 may estimate the source speed based on changes in the source position over time. This allows the ultrasonic information output device 30 to estimate the source speed.

[0122] The matching unit 22 may also estimate the speed of sound in water around the receiving device based on the water temperature around the receiving device and use the estimated speed of sound for matching. The matching unit 22 may also estimate the speed of sound based on the salinity concentration around the receiving device. This allows the matching unit 22 to more accurately estimate the speed of sound and perform matching more accurately.

[0123] The target sound waves may also be sound waves that are not used in the sound-based wireless communication between the base station 60 and the underwater wireless communication device 50. In this case, the output unit 23 can output sound wave information about the sound waves that are not used in the sound-based wireless communication between the base station 60 and the underwater wireless communication device 50.

[0124] The target sound wave may also be an interference wave, which is a sound wave that can interfere with the sound-based wireless communication between the base station 60 and the underwater wireless communication device 50. In this case, the output unit 23 can output sound wave information about the interference wave.

[0125] The sonic information output device 20 may also include a detection unit 24 that detects the generation of target sound waves. In this case, the sonic information output device 20 can detect the generation of target sound waves within the sonic information output device 20. Note that the detection of the generation of target sound waves may also be performed outside the sonic information output device 20.

[0126] Third Embodiment Next, a third embodiment of the present invention will be described. A specific example of the sound wave information output device 10 in the first embodiment is a sound wave information output device 40 in the third embodiment.

[0127] 9 shows an example of the configuration of a communication system 72 including a sonic information output device 40. The communication system 72 includes a base station 60, wireless communication devices 50-i (i is an integer from 1 to N, and N is an integer equal to or greater than 1), and sonic information output devices 40-i. The sonic information output devices 40-i are connected to each of the wireless communication devices 50-i. The sonic information output devices 40-1 to 40-N may be collectively referred to as sonic information output devices 40.

[0128] The base station 60 and the wireless communication device 50 are the same as those in the second embodiment, and therefore a description thereof will be omitted.

[0129] The sonic information output device 40-i is connected to the wireless communication device 50-i, and is mounted on the same UUV as the wireless communication device 50-i, for example.

[0130] 10 shows an example of the configuration of the sonic information output device 40-i. The sonic information output device 40-i includes a speed estimation unit 41-i, a matching unit 42-i, an output unit 43-i, and a detection unit 44-i.

[0131] The detection unit 44-i detects the generation of target sound waves. The target sound waves may be sound waves transmitted underwater. Furthermore, the target sound waves may be sound waves not used in the sonic wireless communication between the base station 60 and the wireless communication device 50 located underwater. Furthermore, the target sound waves may be interference waves with the wireless communication performed by the wireless communication device 50-i. The detection unit 44-i can detect the generation of target sound waves using any method. For example, the detection unit 44-i detects the generation of target sound waves based on sound waves received by the wireless communication device 50-i connected to the sonic information output device 40-i. Note that, if the target sound waves are interference waves, the detection unit 44-i does not need to detect as target sound waves sound waves that do not affect the sound waves used in the wireless communication between the wireless communication device 50-i and the base station 60.

[0132] The velocity estimation unit 41-i estimates the velocity of the source based on the generation of the target sound wave. When the generation of the target sound wave is detected by the detection unit 44-i, the velocity estimation unit 41-i considers that the target sound wave has been generated.

[0133] The speed estimation unit 41-i may estimate the source speed using the position information of the ship, as in the second embodiment. The speed estimation unit 41-i can receive the position information of the ship from a server that provides the position information of the ship, via the base station 60 and the wireless communication device 50-i.

[0134] The velocity estimation unit 41-i may also estimate the velocity of the source based on changes over time in the direction of arrival of the target sound wave. The velocity estimation unit 41-i may also estimate the velocity of the source based on changes over time in the position of the source. The sound wave information output device 40 may also include a source position estimation unit, similar to the sound wave information output device 30 (FIG. 6) described in the second embodiment.

[0135] The position of the wireless communication device 50-i may be measured based on an inertial sensor provided in the wireless communication device 50-i.

[0136] The speed estimation unit 41-i can also estimate the position of the wireless communication device 50-i, for example, based on the direction of arrival of sound waves emitted by the base station 60 relative to the wireless communication device 50-i. For example, the speed estimation unit 41-i receives information on the direction of arrival of sound waves emitted by the base station 60 from the wireless communication device 50-i. The speed estimation unit 41-i also receives information on the vertical position (depth) of the wireless communication device 50-i from the wireless communication device 50-i. The speed estimation unit 41-i can then estimate the position of the wireless communication device 50-i based on the information on the direction of arrival, the information on the vertical position (depth), and the position information of the base station 60. In this case, the wireless communication device 50-i is equipped with a pressure (depth) sensor.

[0137] The collation unit 42-i verifies whether the generated sound wave is a known sound wave based on information on the speed of the source, the actual receiving frequency, the speed of the receiving device, and the transmission frequency of the known sound wave. In this embodiment, the receiving device is a wireless communication device 50-i. The collation method is the same as in the second embodiment, so a description thereof will be omitted.

[0138] The output unit 43-i outputs sound wave information. The sound wave information includes information on the result of checking whether the generated sound wave is a known sound wave or not. The output unit 43-i may output the sound wave information to a control device (not shown) connected to the base station 60 via the base station 60 and the wireless communication device 50-i. The method of outputting the sound wave information is the same as in the second embodiment, and therefore description thereof will be omitted.

[0139] Next, an example of the operation flow of the sound wave information output device 40-i will be described with reference to FIG.

[0140] The detector 44-i detects the generation of a target sound wave.

[0141] When the detection unit 24 detects the generation of a target sound wave, the velocity estimation unit 41-i estimates the velocity of the source (step S101).

[0142] The collator 42-i collates whether the generated sound wave is a known sound wave based on the information on the speed of the source, the actual receiving frequency, the receiving device speed, and the transmission frequency of the known sound wave (step S102).

[0143] The output unit 43-i outputs the sound wave information (step S103).

[0144] As described above, in the third embodiment of the present disclosure, the sonic information output device 40-i includes a speed estimation unit 41-i, a matching unit 42-i, and an output unit 43-i. The speed estimation unit 41-i estimates the source speed based on the generation of target sound waves. The target sound waves are sound waves transmitted underwater. The source speed is the direction and speed of movement of the source that emits the generated sound waves. The generated sound waves are the generated target sound waves. The matching unit 42-i verifies whether the generated sound waves are known sound waves based on information on the source speed, the actual received frequency, the receiving device speed, and the transmission frequency of the known sound waves. The actual received frequency is the reception frequency of the generated sound waves at the receiving device that receives the generated sound waves. The receiving device speed is the direction and speed of movement of the receiving device. The known sound waves are known sound waves. The output unit 43-i outputs sonic information. The sound wave information includes information on the result of checking whether the generated sound wave is a known sound wave or not.

[0145] As a result, the sound wave information output device 40-i estimates the speed of the source and performs matching based on the estimated speed of the source, which improves the matching accuracy for sources whose speed is unknown. As a result, it becomes possible to improve the accuracy of matching whether the generated sound waves are known sound waves.

[0146] [Hardware Configuration Example] An example of the configuration of hardware resources for realizing the sonic information output device (10, 20, 30, 40) in each of the above-described embodiments of the present disclosure using one information processing device (computer) will be described. Note that the sonic information output device may be physically or functionally realized using at least two information processing devices. Also, the sonic information output device may be realized as a dedicated device. Also, only some of the functions of the sonic information output device may be realized using an information processing device. Also, at least some of the functions of the sonic information output device may be realized on the cloud.

[0147] 11 is a diagram schematically illustrating an example of the hardware configuration of an information processing device that can realize the sonic information output device according to each embodiment of the present disclosure. The information processing device 90 includes a communication interface 91, an input / output interface 92, a computing device 93, a storage device 94, a nonvolatile storage device 95, and a drive device 96.

[0148] 1 can be realized by a communication interface 91 and a calculation device 93. The speed estimation unit 11 and the matching unit 22 can be realized by the calculation device 93.

[0149] The communication interface 91 is a communication means for the sonic information output device of each embodiment to communicate with an external device via a wired or / and wireless connection. When the sonic information output device is realized using at least two information processing devices, the devices may be connected via the communication interface 91 so as to be able to communicate with each other.

[0150] The input / output interface 92 is a man-machine interface including a keyboard as an example of an input device and a display as an output device.

[0151] The arithmetic unit 93 is realized by a general-purpose central processing unit (CPU), a microprocessor, or other arithmetic processing device, and a plurality of electric circuits. The arithmetic unit 93 is capable of, for example, reading various programs stored in a nonvolatile storage device 95 into the storage device 94 and executing processing in accordance with the read programs.

[0152] The storage device 94 is a memory device such as a RAM (Random Access Memory) that can be accessed by the arithmetic device 93, and stores programs, various data, etc. The storage device 94 may be a volatile memory device.

[0153] The nonvolatile storage device 95 is a nonvolatile storage device such as a ROM (Read Only Memory) or a flash memory, and is capable of storing various programs, data, and the like.

[0154] The drive device 96 is, for example, a device that processes reading and writing of data from and to a recording medium 97, which will be described later.

[0155] The recording medium 97 is any recording medium capable of recording data, such as an optical disk, a magneto-optical disk, or a semiconductor flash memory.

[0156] Each embodiment of the present disclosure may be realized, for example, by configuring an acoustic information output device using the information processing device 90 illustrated in Figure 11 and supplying to this acoustic information output device a program capable of realizing the functions described in each of the above embodiments.

[0157] In this case, the embodiment can be realized by having the arithmetic unit 93 execute a program supplied to the sonic information output device. It is also possible to configure some, but not all, of the functions of the sonic information output device in the information processing unit 90.

[0158] Furthermore, the sonic information output device may be configured so that the program is recorded on the recording medium 97 and is stored in the nonvolatile storage device 95 as appropriate at the shipping stage, operation stage, etc. In this case, the method of supplying the program may be a method of installing the program in the sonic information output device using an appropriate jig at the manufacturing stage before shipping, operation stage, etc. Furthermore, the method of supplying the program may be a general method such as downloading the program from an external source via a communication line such as the Internet.

[0159] Some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0160] (Supplementary Note 1) A sound wave information output device comprising: a speed estimation means for estimating source speed, which is the direction and speed of movement of a source that emits generated sound waves, based on the generation of target sound waves, which are sound waves transmitted underwater; a comparison means for comparing whether the generated sound waves are known sound waves or not, based on the source speed, an actual received frequency, which is the reception frequency of the generated sound waves at a receiving device that receives the generated sound waves, a receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmission frequency of known sound waves, which are known sound waves; and an output means for outputting sound wave information including information on the comparison result as to whether the generated sound waves are known sound waves or not.

[0161] (Appendix 2) The acoustic wave information output device described in Appendix 1, wherein the comparison means calculates an estimated reception frequency, which is the reception frequency of the known acoustic wave at the receiving device, based on the speed of the source, the speed of the receiving device, and the transmission frequency of the known acoustic wave, and determines that the generated acoustic wave is a known acoustic wave if the estimated reception frequency and the actual reception frequency are similar.

[0162] (Appendix 3) The sound wave information output device described in Appendix 1, wherein the comparison means estimates the transmission frequency of the generated sound wave based on the source speed, the actual receiving frequency, and the receiving device speed, and determines that the generated sound wave is a known sound wave if the transmission frequency of the known sound wave is similar to the transmission frequency of the generated sound wave.

[0163] (Supplementary Note 4) The ultrasonic information output device according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the speed estimation means estimates the source speed based on position information of a ship present within a predetermined range from the receiving device.

[0164] (Supplementary Note 5) The sound wave information output device according to Supplementary Note 4, wherein the speed estimation means estimates a ship present in the direction from which the generated sound wave arrives at the receiving device as the source of the generated sound wave.

[0165] (Appendix 6) The sound wave information output device described in Appendix 5, wherein, when there are multiple ships in the direction of arrival of the generated sound waves, the speed estimation means excludes ships that are no longer in the direction of arrival of the sound source from the candidates for the sound source based on changes over time in the direction of arrival of the generated sound waves.

[0166] (Supplementary Note 7) The ultrasonic information output device according to any one of Supplementary Note 1 to Supplementary Note 6, further comprising a source position estimation means for estimating a source position, which is the position of the source, and the velocity estimation means for estimating the source velocity based on a change in the source position over time.

[0167] (Appendix 8) The ultrasonic information output device according to any one of appendices 1 to 7, wherein the comparison means estimates the speed of sound in water around the receiving device based on the water temperature around the receiving device, and uses the estimated speed of sound for the comparison.

[0168] (Supplementary Note 9) The sonic information output device according to Supplementary Note 8, wherein the comparison means further estimates the speed of sound based on a salinity concentration in the vicinity of the receiving device.

[0169] (Supplementary Note 10) The sonic information output device according to any one of Supplementary Notes 1 to 9, wherein the target sound waves are sound waves that are not used in sonic wireless communication between a base station and a wireless communication device located underwater.

[0170] (Supplementary Note 11) The sound wave information output device according to any one of Supplementary Note 1 to Supplementary Note 9, wherein the target sound wave is an interference wave that can interfere with sound wave-based wireless communication between a base station and a wireless communication device located underwater.

[0171] (Supplementary Note 12) The sound wave information output device according to any one of Supplementary Note 1 to Supplementary Note 11, further comprising a detection means for detecting generation of the target sound wave.

[0172] (Supplementary Note 13) A method for outputting sound wave information, comprising: estimating, based on the generation of a target sound wave, which is a sound wave transmitted underwater, a source speed, which is the direction and speed of movement of a source that emits the generated sound wave, which is the generated target sound wave; verifying whether the generated sound wave is a known sound wave based on the source speed, an actual received frequency, which is the reception frequency of the generated sound wave at a receiving device that receives the generated sound wave, a receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmission frequency of a known sound wave, which is a known sound wave; and outputting sound wave information including information on the result of the verification as to whether the generated sound wave is a known sound wave.

[0173] (Appendix 14) An acoustic information output method according to Appendix 13, which calculates an estimated reception frequency, which is the reception frequency of the known acoustic wave at the receiving device, based on the speed of the source, the speed of the receiving device, and the transmission frequency of the known acoustic wave, and determines that the generated acoustic wave is a known acoustic wave if the estimated reception frequency and the actual reception frequency are similar.

[0174] (Supplementary Note 15) The sound wave information output method described in Supplementary Note 13, wherein the transmission frequency of the generated sound wave is estimated based on the source speed, the actual receiving frequency, and the receiving device speed, and if the transmission frequency of the known sound wave and the transmission frequency of the generated sound wave are similar, the generated sound wave is determined to be a known sound wave.

[0175] (Supplementary Note 16) The acoustic information output method according to any one of Supplementary Note 13 to Supplementary Note 15, wherein the source speed is estimated based on position information of a ship present within a predetermined range from the receiving device.

[0176] (Supplementary Note 17) The sound wave information output method according to Supplementary Note 16, wherein a ship present in a direction from which the generated sound wave arrives at the receiving device is estimated as the source of the generated sound wave.

[0177] (Appendix 18) The acoustic information output method described in Appendix 17, wherein, when there are multiple ships in the direction of arrival of the generated sound waves, ships that are no longer in the direction of arrival of the source are excluded from the candidates for the source based on changes over time in the direction of arrival of the generated sound waves.

[0178] (Supplementary Note 19) The sound wave information output method according to any one of Supplementary Note 13 to Supplementary Note 18, further comprising: estimating a source position, which is the position of the source; and estimating a source velocity based on a change in the source position over time.

[0179] (Supplementary Note 20) The ultrasonic information output method according to any one of Supplementary Note 13 to Supplementary Note 19, wherein the speed of sound in water around the receiving device is estimated based on the water temperature around the receiving device, and the estimated speed of sound is used for the matching.

[0180] (Supplementary Note 21) The sound wave information output method according to Supplementary Note 20, further comprising estimating the sound speed based on a salinity concentration around the receiving device.

[0181] (Supplementary Note 22) The sound wave information output method according to any one of Supplementary Note 13 to Supplementary Note 21, wherein the target sound waves are sound waves that are not used in sound wave wireless communication between a base station and a wireless communication device present underwater.

[0182] (Supplementary Note 23) The sound wave information output method according to any one of Supplementary Note 13 to Supplementary Note 21, wherein the target sound wave is an interference wave that can interfere with sound wave-based wireless communication between a base station and a wireless communication device present underwater.

[0183] (Supplementary Note 24) The sound wave information output method according to any one of Supplementary Notes 13 to 23, further comprising detecting generation of the target sound wave.

[0184] (Supplementary Note 25) A computer-readable recording medium having recorded thereon a sound wave information output program that realizes the following in a computer: a speed estimation function that estimates the source speed, which is the direction and speed of movement of the source that emits the generated sound waves, based on the generation of target sound waves, which are sound waves transmitted underwater; a comparison function that checks whether the generated sound waves are known sound waves based on the source speed, the actual reception frequency, which is the reception frequency of the generated sound waves at the receiving device that receives the generated sound waves, the receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmission frequency of known sound waves, which are known sound waves; and an output function that outputs sound wave information including information on the comparison result as to whether the generated sound waves are known sound waves.

[0185] (Appendix 26) A computer-readable recording medium having recorded thereon the sound wave information output program described in Appendix 25, wherein the matching function calculates an estimated reception frequency, which is the reception frequency of the known sound wave at the receiving device, based on the source speed, the receiving device speed, and the transmission frequency of the known sound wave, and determines that the generated sound wave is a known sound wave if the estimated reception frequency and the actual reception frequency are similar.

[0186] (Appendix 27) A computer-readable recording medium having recorded thereon the sound wave information output program described in Appendix 25, wherein the matching function estimates the transmission frequency of the generated sound wave based on the source speed, the actual receiving frequency, and the receiving device speed, and determines that the generated sound wave is a known sound wave if the transmission frequency of the known sound wave is similar to the transmission frequency of the generated sound wave.

[0187] (Appendix 28) A computer-readable recording medium having recorded thereon an acoustic information output program described in any one of Appendices 25 to 27, wherein the speed estimation function estimates the source speed based on position information of ships located within a predetermined range from the receiving device.

[0188] (Supplementary Note 29) A computer-readable recording medium having recorded thereon the acoustic information output program described in Supplementary Note 28, wherein the speed estimation function estimates a ship present in the direction from which the generated acoustic wave arrives at the receiving device as the source of the generated acoustic wave.

[0189] (Appendix 30) A computer-readable recording medium having recorded thereon the acoustic information output program described in Appendix 29, wherein the speed estimation function, when there are multiple ships in the direction of arrival of the generated sound waves, excludes ships that are no longer in the direction of arrival of the source from the candidates for the source based on changes over time in the direction of arrival of the generated sound waves.

[0190] (Appendix 31) A computer-readable recording medium having recorded thereon an acoustic information output program according to any one of Appendices 25 to 30, further comprising a source position estimation function for estimating the source position, which is the location of the source, and the velocity estimation function for estimating the source velocity based on changes in the source position over time.

[0191] (Appendix 32) A computer-readable recording medium having recorded thereon an acoustic information output program according to any one of Appendices 25 to 31, wherein the matching function estimates the speed of sound in water around the receiving device based on the water temperature around the receiving device, and uses the estimated speed of sound for the matching.

[0192] (Supplementary Note 33) The computer-readable recording medium having the sound wave information output program according to Supplementary Note 32 recorded thereon, wherein the collation function further estimates the sound speed based on a salinity concentration around the receiving device.

[0193] (Appendix 34) A computer-readable recording medium having recorded thereon the sound wave information output program described in any one of Appendices 25 to 33, wherein the target sound waves are sound waves that are not used in sound wave wireless communication between a base station and a wireless communication device located underwater.

[0194] (Appendix 35) A computer-readable recording medium having recorded thereon the sound wave information output program described in any one of Appendices 25 to 33, wherein the target sound wave is an interference wave, which is a sound wave that can interfere with sound wave wireless communication between a base station and a wireless communication device located underwater.

[0195] (Supplementary Note 36) A computer-readable recording medium having recorded thereon the sound wave information output program according to any one of Supplementary Notes 25 to 35, further causing a computer to realize a detection function of detecting the generation of the target sound wave.

[0196] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0197] This application claims priority based on Japanese Patent Application No. 2023-150691, filed September 19, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0198] 10, 20, 30, 40, 40-i: sonic wave information output device 11, 21, 41-i: speed estimation unit 12, 22, 42-i: matching unit 13, 23, 43-i: output unit 24, 44-i: detection unit 35: transmission source position estimation unit 50, 50-i: wireless communication device 60: base station 71, 72: communication system 90: information processing device 91: communication interface 92: input / output interface 93: arithmetic unit 94: storage device 95: non-volatile storage device 96: drive device 97: recording medium

Claims

1. A sound wave information output device comprising: a speed estimation means for estimating source speed, which is the direction and speed of movement of a source that emits a generated sound wave, which is a generated target sound wave, based on the generation of a target sound wave, which is a sound wave transmitted underwater; a comparison means for comparing whether the generated sound wave is a known sound wave or not, based on information on the source speed, the actual receiving frequency, which is the receiving frequency of the generated sound wave at a receiving device that receives the generated sound wave, the receiving device speed, which is the direction and speed of movement of the receiving device, and the transmission frequency of a known sound wave, which is a known sound wave; and an output means for outputting sound wave information including information regarding the comparison result as to whether the generated sound wave is a known sound wave or not.

2. The sound wave information output device of claim 1, wherein the comparison means calculates an estimated receiving frequency, which is the receiving frequency of the known sound wave at the receiving device, based on the source speed, the receiving device speed, and the transmission frequency of the known sound wave, and determines that the generated sound wave is a known sound wave if the estimated receiving frequency and the actual receiving frequency are similar.

3. The sound wave information output device of claim 1, wherein the comparison means estimates the transmission frequency of the generated sound wave based on the source speed, the actual receiving frequency, and the receiving device speed, and determines that the generated sound wave is a known sound wave if the transmission frequency of the known sound wave is similar to the transmission frequency of the generated sound wave.

4. An acoustic information output device as described in any one of claims 1 to 3, wherein the speed estimation means estimates the source speed based on position information of ships present within a predetermined range from the receiving device.

5. The sound wave information output device according to claim 4, wherein the speed estimation means estimates a ship present in the direction from which the generated sound wave arrives at the receiving device as the source of the generated sound wave.

6. The sound wave information output device of claim 5, wherein, when there are multiple ships in the direction of arrival of the generated sound wave, the speed estimation means excludes ships that are no longer in the direction of arrival of the sound source from the candidates for the sound source based on changes over time in the direction of arrival of the generated sound wave.

7. The sound wave information output device according to any one of claims 1 to 6, further comprising a source position estimation means for estimating a source position, which is the position of the source, and the speed estimation means estimates the source speed based on a change in the source position over time.

8. A method for outputting sound information, comprising: estimating source speed, which is the direction and speed of movement of a source that emits the generated sound wave, based on the generation of a target sound wave, which is a sound wave transmitted underwater; verifying whether the generated sound wave is a known sound wave based on information on the source speed, the actual receiving frequency, which is the receiving frequency of the generated sound wave at a receiving device that receives the generated sound wave, the receiving device speed, which is the direction and speed of movement of the receiving device, and the transmission frequency of a known sound wave, which is a known sound wave; and outputting sound information including information on the result of the verification as to whether the generated sound wave is a known sound wave.

9. The sound wave information output method of claim 8, further comprising: calculating an estimated reception frequency, which is the reception frequency of the known sound wave at the receiving device, based on the source speed, the receiving device speed, and the transmission frequency of the known sound wave; and determining that the generated sound wave is a known sound wave if the estimated reception frequency and the actual reception frequency are similar.

10. The sound wave information output method of claim 8, further comprising estimating a transmission frequency of the generated sound wave based on the source speed, the actual receiving frequency, and the receiving device speed, and determining that the generated sound wave is a known sound wave if the transmission frequency of the known sound wave is similar to the transmission frequency of the generated sound wave.

11. A method for outputting acoustic information according to any one of claims 8 to 10, wherein the source speed is estimated based on position information of a ship present within a predetermined range from the receiving device.

12. The sound wave information output method according to claim 11, further comprising estimating a ship present in the direction from which the generated sound wave arrives at the receiving device as the source of the generated sound wave.

13. The sound wave information output method described in claim 12, wherein, when there are multiple ships in the direction of arrival of the generated sound wave, ships that are no longer in the direction of arrival of the sound source are excluded from the candidates for the sound source based on changes over time in the direction of arrival of the generated sound wave.

14. A method for outputting sound wave information according to any one of claims 8 to 13, further comprising estimating a source position, which is the position of the source, and estimating a source speed based on a change in the source position over time.

15. A method for outputting ultrasonic information as described in any one of claims 8 to 14, further comprising estimating the speed of sound in water around the receiving device based on the water temperature around the receiving device, and using the estimated speed of sound for the comparison.

16. The method for outputting sound wave information according to claim 15, further comprising estimating the sound speed based on the salinity concentration in the vicinity of the receiving device.

17. The method for outputting sound wave information according to any one of claims 8 to 16, wherein the target sound waves are sound waves that are not used in wireless communication by sound waves between a base station and a wireless communication device present underwater.

18. The method for outputting sound wave information described in any one of claims 8 to 16, wherein the target sound wave is an interference wave, which is a sound wave that can interfere with wireless communication by sound waves between a base station and a wireless communication device present underwater.

19. The sound wave information output method according to any one of claims 8 to 18, further comprising detecting the generation of the target sound wave.

20. A computer-readable recording medium having recorded thereon a sound wave information output program which realizes the following in a computer: a speed estimation function which estimates a source speed, which is the direction and speed of movement of a source that emits a generated sound wave, based on the generation of a target sound wave, which is a sound wave transmitted underwater; a comparison function which checks whether the generated sound wave is a known sound wave based on the source speed, an actual receiving frequency, which is the receiving frequency of the generated sound wave at a receiving device that receives the generated sound wave, a receiving device speed, which is the direction and speed of movement of the receiving device, and information on the transmitting frequency of a known sound wave, which is a known sound wave; and an output function which outputs sound wave information including information on the comparison result as to whether the generated sound wave is a known sound wave.

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