Sound source position measurement method, sound source position measurement device, damage detection method, abnormality detection method, terminal device for sound source position measurement, sound source position measurement system, program for sound source position measurement, and recording medium

Abstract

To provide a sound source position measurement method, a sound source position measuring device, a damage detection method, an abnormality detection method, a terminal device for measuring a sound source position, a sound source position measurement system, a program for measuring a sound source position, a terminal system, a program for a terminal device, and a recording medium capable of detecting only a position of an actual sound source by removing an imaginary sound source.SOLUTION: A sound source position measuring device includes: a sound source position calculation portion 11 calculating a sound source position for each measurement range from a sound wave received in multiple measurement ranges while moving the positions of the measurement ranges; a travel distance calculation portion 12 calculating travel distance of the positions of the measurement ranges and travel distance of the calculated sound source positions; and an imaginary sound source determination portion 13 comparing the calculated travel distance of the positions of the measurement ranges with travel distance of the sound source positions, and determining sound source positions having travel distance different from travel distance of the positions of the measurement ranges as imaginary sound sources from the inside of the sound source positions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sound source position measurement method, a sound source position measurement device, a damage detection method, an abnormality detection method, a terminal device for sound source position measurement, a sound source position measurement system, a terminal system, a program for sound source position measurement, a program for a terminal device, and a recording medium that can remove virtual sound sources and detect only the position of a real sound source.

Background Art

[0002] In a plant or the like, for example, it is necessary to quickly detect that a corrosion hole has occurred in a pipe or that a device such as electrical equipment has deteriorated or been damaged, and to perform repairs or the like. In order to detect these, it is generally performed to measure sound waves emitted when gas leaks from a corrosion hole in a pipe or sound waves emitted when corona discharge or the like occurs in electrical equipment.

[0003] As a technique for measuring sound waves and detecting the direction of a sound source, for example, Patent Document 1 describes receiving sound waves radiated from a sound source using a large number of microphone arrays, performing processing on the received sound waves by a beamforming method, and specifying the direction of the sound source.

[0004] Further, Patent Document 2 discloses a sound source direction calibration device that measures sound waves while dynamically changing the search range of a sound source and visualizes the gas leakage position of a pipe from a distance.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when obtaining a sound pressure map using a microphone array, since the arrival direction of the sound wave is specified as the sound source position, the sound wave directly arriving from the same sound source and the sound wave arriving after reflection are detected as different sound source positions on the sound pressure map. That is, this sound wave arriving after reflection is a virtual sound source, making it difficult to specify the sound source position of the actual sound source.

[0007] On the other hand, for example, when a harmful gas is leaking, it is preferable to perform inspection work automatically and safely using a mobile robot such as a drone. However, in this case, the microphone array also detects the noise generated by a moving body such as a mobile robot as a sound source. This noise is not an actual sound source to be detected originally, and is detected as a virtual sound source, making it difficult to specify the sound source position of the actual sound source.

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a sound source position measurement method, a sound source position measurement device, a damage detection method, an abnormality detection method, a terminal device for sound source position measurement, a sound source position measurement system, a terminal system, a program for sound source position measurement, a program for a terminal device, and a recording medium that can remove virtual sound sources and detect only the position of the actual sound source.

Means for Solving the Problems

[0009] In order to solve the above-described problems and achieve the object, [1] The sound source position measurement method according to the present invention includes a sound source position calculation step of calculating a sound source position for each of a plurality of measurement ranges from sound waves received in the plurality of measurement ranges while moving the position of the measurement range, a movement amount calculation step of calculating a movement amount of the position of the measurement range and a movement amount of the calculated sound source position, and a virtual sound source determination step of determining a virtual sound source from among the sound source positions using the calculated movement amount of the position of the measurement range and the movement amount of the sound source position. The virtual sound source determination step includes a step of comparing the calculated movement amount of the sound source position and the calculated movement amount of the position of the measurement range, and a step of determining a sound source position having a movement amount different from the movement amount of the position of the measurement range as a virtual sound source.

[0010] [2] Also, in the sound source position measurement method [1] according to the present invention, it includes a sound wave receiving step of receiving sound waves from the plurality of measurement ranges while moving the position within the measurement range.

[0011] [3] Also, in the sound source position measurement method [2] according to the present invention, the sound wave receiving step includes a step of acquiring information regarding the positions of the plurality of measurement ranges for each of the measurement ranges, and the movement amount calculation step includes, from among the information regarding the positions of the plurality of measurement ranges acquired in the sound wave receiving step, the information regarding the position of the first measurement range and the information regarding the position of the second measurement range after moving from the first measurement range, a step of calculating the movement amount of the position of the measurement range.

[0012] [4] Also, in the sound source position measurement method [2] according to the present invention, the sound wave receiving step includes a step of imaging the measurement range as a plurality of images while changing time, and the movement amount calculation step includes a step of calculating the movement amount from among the plurality of images imaged in the sound wave receiving step, from the image taken at the first time and the image taken at the second time after the first time.

[0013] In order to solve the above-described problems and achieve the object, [5] the damage detection method according to the present invention measures a leak sound from a pipe using any one of the sound source position measurement methods [1] to [4] above to detect damage to the pipe.

[0014] In order to solve the above-described problems and achieve the object, [6] the abnormality detection method according to the present invention measures an abnormal sound from a machine using any one of the sound source position measurement methods [1] to [4] above to detect an abnormality of the machine.

[0015] In order to solve the above-described problems and achieve the object, the sound source position measuring apparatus according to the present invention [7] calculates the sound source position for each of the plurality of measurement ranges from sound waves received in the plurality of measurement ranges while moving the position of the measurement range, a movement amount calculation unit that calculates the movement amount of the position of the measurement range and the movement amount of the calculated sound source position, and compares the calculated movement amount of the position of the measurement range and the movement amount of the sound source position, and determines, as a virtual sound source, a sound source position having a movement amount different from the movement amount of the position of the measurement range among the sound source positions.

[0016] [8] Further, in the sound source position measuring apparatus according to the present invention, the sound source position measuring apparatus of [7] above includes a first communication unit, and the first communication unit acquires information regarding the received sound wave and information regarding the position of the measurement range, and / or outputs information regarding the virtual sound source from the virtual sound source determination unit.

[0017] [9] Further, in the sound source position measuring apparatus [7] or [8] according to the present invention, a sound wave receiving unit that receives sound waves from the plurality of measurement ranges while moving the position of the measurement range is provided.

[0018]

[10] Further, in the sound source position measuring apparatus [9] according to the present invention, moving means for moving at least the sound wave receiving unit is provided.

[0019] In order to solve the above-described problems and achieve the object,

[11] a terminal device for sound source position measurement according to the present invention includes a moving device that receives sound waves in a plurality of the measurement ranges while moving the position of the measurement range, and a third communication unit that communicates with a sound source position measurement device, an operation unit that operates the moving means of the moving device via the third communication unit, and means for acquiring information on a virtual sound source output from the sound source position measurement device via the third communication unit and displaying the information on a display unit in a predetermined format. The terminal device for sound source position measurement is characterized in that the information on the virtual sound source is obtained by the sound source position measurement device from information on the sound waves received by the moving device and information on the position of the measurement range. Here, more specifically, the information on the virtual sound source is obtained by the sound source position measurement device executing a process of calculating the sound source position for each measurement range from the information on the sound waves received by the moving device, executing a process of calculating the amount of movement of the position of the measurement range from the information on the position of the measurement range and the amount of movement of the sound source position from the calculated sound source position, comparing the calculated amount of movement of the position of the measurement range with the amount of movement of the sound source position, and executing a process of determining, as a virtual sound source, a sound source position having a movement amount different from the amount of movement of the position of the measurement range among the sound source positions.

[0020]

[12] Further, in a terminal device for sound source position measurement according to the present invention, there are provided a third communication unit that communicates with a moving device that receives sound waves in a plurality of the measurement ranges while moving the position of the measurement range, an operation unit that operates the moving means of the moving device via the third communication unit, and any one of the sound source position measurement devices of [7] to

[10] above.

[0021] In order to solve the above-described problems and achieve the object,

[13] a sound source position measurement system according to the present invention includes the sound source position measurement device of [9] or

[10] above and the terminal device of

[11] above, and measures the sound source position.

[0022]

[14] Further, in the sound source position measurement system according to the present invention, there is provided a sound source position measurement system including the sound source position measurement device of [8] above, a moving device, and a terminal device. The moving device includes a sound wave receiving unit that receives sound waves from the plurality of measurement ranges while moving the position within the measurement range, a moving unit that moves the sound wave receiving means, and means for sending information regarding the received sound waves and information regarding the position of the measurement range to the sound source position measurement device via a second communication unit. The terminal device includes an operation unit that operates the moving unit via a first communication unit, and means for acquiring information regarding the virtual sound source output from the sound source position measurement device via a third communication unit and displaying the information on a display unit in a predetermined format.

[0023]

[15] Further, in the sound source position measurement system according to the present invention, there is provided a sound source position measurement system including the terminal device and the moving device of

[12] above, which measures the sound source position. The moving device includes a sound wave receiving unit that receives sound waves from the plurality of measurement ranges while moving the position within the measurement range, a moving unit that moves the sound wave receiving means, and means for sending information regarding the received sound waves and information regarding the position of the measurement range to the sound source position measurement device via a second communication unit.

[0024] In order to solve the above-described problems and achieve the object,

[16] the terminal system according to the present invention is a terminal system for measuring the sound source position, including the terminal device and the moving device of

[11] above. The moving device includes a sound wave receiving unit that receives sound waves from the plurality of measurement ranges while moving the position within the measurement range, and a moving unit that moves the sound wave receiving means.

[0025] In order to solve the above-described problems and achieve the object,

[17] the damage detection method according to the present invention uses information regarding the virtual sound source output from the virtual sound source determination unit of the sound source position measurement device according to any one of the above inventions [7] to

[10] to measure the leakage sound from the pipe and detect the damage of the pipe.

[0026] In order to solve the above-described problems and achieve the object, the anomaly detection method according to the present invention

[18] measures abnormal sounds from a machine by using information regarding a virtual sound source output from the virtual sound source determination unit of the sound source position measurement apparatus according to any one of the above-described inventions [7] to

[10] , and detects an anomaly of the machine.

[0027] In order to solve the above-described problems and achieve the object, the sound source position measurement program according to the present invention

[19] is a sound source position measurement program used for a sound source position measurement apparatus according to any one of the above [7] to “10”, and is configured such that functions of the sound source position calculation unit, the movement amount calculation unit, and the virtual sound source determination unit can be executed by a computer.

[0028] In order to solve the above-described problems and achieve the object, the recording medium according to the present invention

[20] is a recording medium that records a sound source position measurement program used for a sound source position measurement apparatus according to any one of the above [7] to “10”, and is configured such that functions of the sound source position calculation unit, the movement amount calculation unit, and the virtual sound source determination unit can be executed by a computer.

[0029] In order to solve the above-described problems and achieve the object, the terminal device program according to the present invention

[21] is a terminal device program used for the terminal device for sound source position measurement according to the above

[11] or

[12] , and is configured such that functions of an operation unit of the terminal device, functions of a third communication unit, and information regarding a virtual sound source output from the sound source position measurement apparatus are acquired via the third communication unit and displayed on a display unit in a predetermined format by a computer.

[0030] In order to solve the above-described problems and achieve the object, the recording medium according to the present invention

[22] is a recording medium that records a terminal device program used for the terminal device for sound source position measurement according to the above

[11] or

[12] , and is configured such that functions of an operation unit of the terminal device, functions of a third communication unit, and information regarding a virtual sound source output from the sound source position measurement apparatus are acquired via the third communication unit and displayed on a display unit 5 in a predetermined format by a computer.

Advantages of the Invention

[0031] According to the present invention, it is possible to remove the virtual sound source and detect only the position of the actual sound source.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0033] A sound source position measurement method, a sound source position measurement device, a damage detection method, an abnormality detection method, a terminal device for sound source position measurement, a sound source position measurement system, a program for sound source position measurement, a terminal system, a program for a terminal device, and a recording medium according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments, and the constituent elements in the following embodiments include those that can be replaced by those skilled in the art and are easy, or those that are substantially the same.

[0034] <Overall Configuration> FIG. 1 is a functional block diagram showing the configuration of a sound source position measurement device 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing the external configuration of the sound source position measurement device 1 shown in FIG. 1. As shown in FIG. 1, the sound source position measurement device 1 includes a sound wave receiving unit 2 which is a means for receiving a sound source, a position information measurement unit 3, an operation unit 4, a display unit 5, a storage unit 6, and a control unit 7.

[0035] The sound wave receiving unit 2 receives a sound wave and outputs information regarding the sound wave. Here, the information regarding the sound wave indicates at least the amplitude and time of the received sound wave. The sound wave receiving unit 2 is, for example, a microphone (acoustic sensor) array. The array arrangement of the microphones preferably has an arrangement in which it is difficult to generate grating lobes. Also, the measurement frequency of the microphones used may be one type or a combination of multiple types.

[0036] The position information measurement unit 3 measures information regarding the position in the measurement range for each measurement range. Examples of the information regarding the position in the measurement range include coordinates, distance, angle, etc. In the case of this embodiment, the position information measurement unit 3 includes a sensor 3a and a position information calculation unit 3b. The sensor 3a includes, for example, a camera, an acceleration sensor, an angular acceleration sensor, a barometer, or a GPS. The position information calculation unit 3 calculates information regarding the position in the measurement range from the information measured by the sensor 3a. However, depending on the type of the sensor 3a, it may not be necessary.

[0037] When the sensor 3a is a camera, the position information calculation unit 3b calculates the coordinates (x, y) of feature points appropriately selected from the image captured by the camera. As a method for automatically selecting feature points and their coordinates from images with different positions, for example, feature amount extraction algorithms such as AKAZE (Accelerated-KAZE), SIFT (Scale-Invariant Feature Transform), and SURF (Speeded Up Robust Features) can be used.

[0038] Also, when the sensor 3a is an acceleration sensor, the position information calculation unit 3b calculates the relative distance based on an arbitrary measurement range by integrating the measured acceleration. When the sensor 3a is an angular acceleration sensor, the position information calculation unit 3b calculates the relative angle based on an arbitrary measurement range by integrating the measured angular acceleration. When the sensor 3a is a GPS, the position information calculation unit 3b measures the measured longitude and latitude, and the physical quantity calculation unit 3b calculates the relative distance based on an arbitrary measurement range from the longitude and latitude. When a total station or motion capture is used for the sensor 3a, there is no particular need for the position information calculation unit 3b, and the measured coordinates (x, y, z) can be used as they are. That is, the position coordinates of the position information measurement unit 3 are used as the coordinates (x, y, z) of the measurement range as they are.

[0039] Here, when the camera is used as the sensor 3a, it is preferable that the field of view range of the camera is arranged to include the measurement range of the sound wave receiving unit 2. Also, it is preferable that the position information measurement unit 3 and the sound wave receiving unit 2 are synchronized. In the present embodiment, a camera is adopted as the sensor 3a of the position information measurement unit 3.

[0040] The operation unit 4 is an input device that performs various operations using various operation buttons and the like. The display unit 5 is an output device such as a liquid crystal display or an organic EL display that displays various information. Note that the operation unit 4 and the display unit 5 may be a touch panel type input / output device. In the present embodiment, as shown in FIG. 2, a sensor 3a that is a camera is disposed on the surface of the housing 1a, and the sound wave receiving units 2 are arranged in an array around the sensor 3a. On the other hand, the back surface of the housing 1a is the surface on the operator side, and the operation unit 4 and the display unit 5 are disposed.

[0041] The control unit 7 is a control unit that controls the entire sound source position measuring device 1, and includes a sound source position calculation unit 11, a movement amount calculation unit 12, a virtual sound source determination unit 13, and an output processing unit 14. The control unit 7 stores programs corresponding to these functional units in a storage device such as a non-volatile memory or a magnetic disk device, loads these programs into the memory, and executes them with the CPU to execute the corresponding processes.

[0042] The storage unit 6 is a storage device such as a non-volatile memory, and the sound source position data calculated by the sound source position calculation unit 11 and the position information measurement data measured by the position information measurement unit 3 are stored as pair data DP1 to DPN that form pairs for each measurement range. Note that when the position of the measurement range is moved and the time is changed, it may be stored as pair data DP1 to DPN that form pairs for each time instead of for each measurement range. Note that the time is preferably as close as possible, and even more preferably substantially continuous. Also, the control unit 7 and the storage unit 6 are housed in the housing 1a. In other words, the position information measurement data is data obtained by digitizing information regarding the position of the measurement range.

[0043] The sound source position calculation unit 11 calculates the sound source position for each measurement range from the sound waves received by the sound wave receiving unit 2. The sound source position calculation unit 11 calculates the sound source position by aperture synthesis of the received sound waves for all channels of the microphone array, and generates a sound pressure map. The sound source position data calculated by the sound source position calculation unit 11 is stored in the storage unit 6. In addition to the aperture synthesis method, other methods such as the MUSIC (Multiple Signal Classification) method, the acoustic intensity method, and the acoustic holography method can also be used for the calculation of the sound source position.

[0044] The movement amount calculation unit 12 calculates the movement amount of the position in the measurement range and the movement amount of the calculated sound source position. The movement amount calculation unit 12 calculates the movement amount of the position between measurement ranges with different positions based on the position information measurement data measured by the position information measurement unit 3. The movement amount calculation unit 12 calculates the movement amount of the sound source position on the sound pressure map in a measurement range at a position different from the measurement range measured by the position information measurement unit 3. As a method for calculating the movement amount of the position in the measurement range from the position information measurement data, for example, image matching techniques such as cross-correlation and template matching, Visual-SLAM (Simultaneous Localization and Mapping) technology, a gradient method for estimating the movement amount from the intensity change of the image, or an optical flow method can be used.

[0045] The virtual sound source determination unit 13 is a virtual sound source determination means that determines a virtual sound source from the calculated sound source positions using the movement amount of the position between the measurement ranges and the movement amount of the sound source position. The virtual sound source determination unit 13 determines a sound source position having a movement amount different from the movement amount of the position between the measurement ranges as a virtual sound source.

[0046] Here, as shown in FIG. 3, the virtual sound source is a sound source indicating a detection position other than the original detection position of the sound wave that directly arrives at the sound wave receiving unit 2 from the sound source SS via the path L1. The detection position of the sound wave that arrives via the path L1 is the position of the actual sound source. The detection position of the sound wave that arrives via the reflected path L2 is determined to be the position of the virtual sound source. Also, the detection position of the sound wave of the external noise that arrives via the path L3 different from the path L1 is also determined to be the position of the virtual sound source.

[0047] The output processing unit 14 generates information regarding the virtual sound source. Then, the generated information regarding the virtual sound source is output to the display unit 5. For example, a composite image is generated by superimposing a sound pressure map (sound source position image) from which the virtual sound source is removed and a visible image obtained by imaging a visual field range including the measurement range of this sound pressure map, and output to the display unit 5. Alternatively, the output processing unit 14 may generate the position of the sound source position measuring device and the direction of the actual sound source, and output them to the display unit 5.

[0048] <An example of sound source position measurement processing> FIG. 4 is an explanatory diagram showing an example of sound source position measurement processing. Here, the sensor 3a of the position information measurement unit 3 is a camera. Also, the information regarding the position of the measurement range will be described as the position of the feature point CA selected from the image captured by the camera and the time when the image was captured.

[0049] As shown in FIG. 4(a), first, at time t, the position information measurement unit 3 acquires the image D1 of the i-th measurement range. This image D1 has a feature point CA at the connection part of the pipe 101. And at this time t, the sound wave receiving unit 2 receives the sound wave, and the sound pressure map M1 of the same i-th measurement range is generated by the sound source position calculation unit 11. Four sound sources SA, SB, SC, and SD where a sound pressure equal to or higher than a predetermined value is detected are detected in this sound pressure map M1.

[0050] Thereafter, at time t+1, the position information measurement unit 3 acquires the image D2 of the (i+1)-th measurement range. This image D2 has the feature point CA at the connection part of the pipe 101. And at this time t+1, the sound wave receiving unit 2 receives the sound wave, and the sound source position calculation unit 11 generates the sound pressure map M2 of the same (i+1)-th measurement range. In this sound pressure map M2, three sound sources SA, SB, and SD where the sound pressure of a predetermined value or more is detected are detected, and the sound source SC has disappeared.

[0051] Thereafter, the movement amount calculation unit 12 calculates the movement amount of the position of the measurement range from the position of the feature point CA of the image D1 and the position of the feature point CA of the image D2. As a result, the movement amount is calculated as "3". Also, the movement amount calculation unit 12 calculates the movement amounts of the sound sources SA, SB, SC, and SD on the sound pressure map M1 and the sound sources SA, SB, and SD on the sound pressure map M2. As a result, the movement amount of the sound source SA is "3", the movement amount of the sound source SB is "0", the movement amount of the sound source SC is "infinity" because the sound source SC has disappeared, and the movement amount of the sound source SD is calculated as "5".

[0052] Then, the virtual sound source determination unit 13 determines the sound sources SB and SD on the sound pressure map M2, which have a movement amount different from that of the feature point CA of the image D2, as virtual sound sources. The output processing unit 14 removes the sound sources SB and SD on the sound pressure map M2, generates a sound pressure map M2' with only the sound source SA remaining as the actual sound source, and generates a composite image DD obtained by superimposing this sound pressure map M2' and the image D2, and outputs it to the display unit 5. Note that the measurement range of the sound pressure map M2 only needs to be within the imaging range of the image D2. Also, the pair of the image D1 and the sound pressure map M1, and the pair of the image D2 and the sound pressure map M2 correspond to the pair data DP1 to DPN shown in FIG. 1. For example, the image D1 and the time t at the time of its imaging correspond to the position information measurement data, the sound pressure map M1 corresponds to the sound source position data, and the pair of the image D1 and the sound pressure map M1 corresponds to DP1.

[0053] Note that these paired data are acquired while moving the position within the measurement range and changing the time, and the sound source position may be measured based on the paired data with time advancing or retreating, or the sound source position may be measured between the paired data even if the time does not change. Note that when the feature points in the image exceed the measurement range (imaging range), the movement amount may be obtained by integrating the movement amount of the paired data after the position of the measurement range has moved.

[0054] <Sound source position measurement processing procedure> The sound source position measurement processing procedure to be described hereinafter, particularly steps S108 to S110 which are the determination processing of virtual sound sources, is the most important technical feature in the present invention. The inventors measured a simulated sound source in an anechoic chamber using a conventional sound source position measurement device (one that does not use the sound source position measurement processing procedure to be described hereinafter). Then, it was newly found that depending on the measurement conditions, a sound source was also measured at a position where there was originally no sound source. In this specification, the sound source measured at a position where there is no sound source is called a virtual sound source. As described above, the inventors consider that the generation of virtual sound sources is due to various reflected sounds from the surrounding situation.

[0055] The inventors who obtained this new finding further measured the sound source position using a sound source position measurement device under a variety of measurement conditions, and found that the position of the virtual sound source moves together with the sound source position measurement device, while the position of the original sound source does not move. In other words, when measuring the sound source position for a plurality of the measurement ranges while moving the measurement range, it became clear that a sound source having the same movement amount as the movement amount of the position of the measurement range is a real sound source, and a sound source having a movement amount different from the movement amount of the position of the measurement range is a virtual sound source.

[0056] FIG. 5 is a flowchart showing an example of the sound source position measurement processing procedure. First, the position information measurement unit 3 acquires and generates a first image of the measurement range at a first time (step S101). At the same time, the sound source position calculation unit 11 generates a first sound source map in the same measurement range (step S102).

[0057] Thereafter, the position of the measurement range is moved (step S103). Then, the position information measurement unit 3 acquires and generates a second image of the measurement range at the next second time in the same manner as the first image (step S104). Thereafter, the movement amount calculation unit 12 calculates the movement amount (image movement amount) from the first image to the second image using feature points (step S105). At the same time, the movement amount calculation unit 12 calculates the movement amount of the sound source (sound source movement amount) from the sound source position on the first sound pressure map and the sound source position on the second sound pressure map (step S107).

[0058] Thereafter, the virtual sound source determination unit 13 determines whether the movement amount of the sound source position on the second sound pressure map is the same as the image movement amount (step S108). Note that the determination of whether the sound source movement amount and the image movement amount are the same is made based on whether the difference is within a predetermined value. If the sound source movement amount is not the same as the image movement amount (step S108: No), this sound source is deleted from the second sound pressure map as a virtual sound source (step S109), and the process proceeds to step S110. On the other hand, if the sound source movement amount is the same as the image movement amount (step S108: Yes), the process proceeds to step S110 to determine whether there is a next sound source on the second sound pressure map.

[0059] If there is a next sound source (step S110: Yes), the process proceeds to step S108 and the above processing is repeated. On the other hand, if there is no next sound source (step S110: No), a composite image obtained by superimposing the second image and the second sound pressure map from which the virtual sound source has been removed is output to the display unit 5 (step S111), and this process ends.

[0060] In this embodiment, by comparing the movement amounts of the positions of the measurement ranges, a sound pressure map of only the actual sound sources from which the virtual sound sources have been removed can be obtained, so that the actual sound sources can be detected with high accuracy even at a distance. Further, when a camera is used as the position information measurement unit 3, a composite image obtained by superimposing the sound pressure map of only the actual sound sources and the captured image can be displayed, facilitating the identification of the positions of the actual sound sources.

[0061] <Modification Example 1> FIG. 6 is a functional block diagram showing the configuration of a sound source position measurement system 50 which is a modification example 1 of the embodiment of the present invention. In this modification example 1, the sound source position measurement device 1 shown in FIG. 1 is mounted on a moving device 22. In this case, the moving means of the moving device 22 is, for example, a drone. The drone is suitable for detecting the leakage position of harmful gas.

[0062] Note that the sound source position measurement device 1 shown in FIG. 1 and the sound source position measurement device 21 of the modification example 1 have the same functions and effects. Since the same reference numerals are given to the same devices, detailed description thereof is omitted. The first communication unit 31 of the sound source position measurement device 21 communicates with the third communication unit 33 of the terminal device 23 under the control of the control unit 7. Note that the terminal device 23 will be described in detail in the modification example 2.

[0063] FIG. 7 is a schematic diagram showing a state in which the moving device 22 of the modification example 1 uses a drone as the moving means. In this case, since the drone has a lot of noise due to the wings, a noise cover 40 is provided for the sound source position measurement device 21. If the frequency band of the noise of the drone is known, the sound wave receiving unit 2 may detect the sound wave through a filter that removes this noise frequency band.

[0064] <Modification Example 2> FIG. 8 is a functional block diagram showing the configuration of a sound source position measurement system 50 which is a modification example 2 of the embodiment of the present invention. In this modification example 2, the moving device 22 is provided with moving means so as to be movable. The moving device 22 is equipped with a sound wave receiving unit 2, a position information measuring unit 3, and a second communication unit 32. Further, the sound source position measurement device 21 deletes the sound wave receiving unit 2, the position information measuring unit 3, the operation unit 4, and the display unit 5 of the sound source position measurement device 1 shown in FIG. 1, and is provided with a first communication unit 31.

[0065] Further, the terminal device 23 has an operation unit 4, a display unit 5, and a third communication unit 33. The moving device 22 and the sound source position measurement device 21 are connected by wire or wirelessly, and the sound source position measurement device 21 and the terminal device 23 are connected via wire, wirelessly, a network (including the Internet), or a combination of these methods.

[0066] Note that the moving means of the mobile device 22 is, for example, a drone. The terminal device 23 may control the movement of the mobile device 22. In the inspection of water pipes and water storage tanks where no harmful gas or the like leaks from the sound source, it is also possible to use a trolley that travels manually as the mobile device 22. With these mobile devices 22, the inspection work efficiency can be improved by automating or semi-automating the inspection even in a wide inspection range.

[0067] The mobile device 22 is equipped with a control unit (not shown) that includes a drone (moving means), a camera (sensor 3a), a microphone (sound wave receiving unit 2), and a second communication unit 32 for information transmission. This control unit executes the calculation of position information by the position information calculation unit 3b, the control of the moving means according to the operation unit 4, the control of the sound wave receiving unit 2, the control of the second communication unit, and the storage of information related to sound waves and position information in a recording medium. In addition, this control unit also has a recording medium for storing programs for executing information, control, etc. For example, this control unit is a small computer itself with a communication interface, and the sensor 3a and the sound wave receiving unit 2 are attached to the small computer, and they are directly mounted on the drone.

[0068] The output from the sound wave and the position information calculation unit 3b of the mobile device 22 may be wirelessly sent to the sound source position measuring device 21, but it is also possible to save it in a recording medium such as an SD card, a solid state drive (SSD), or a hard disk drive (HDD), and move the information stored in the recording medium after measurement.

[0069] On the other hand, the terminal device 23 controls the movement of the mobile device 22 via the moving means. The sound source position measuring device 21 performs processes such as the calculation of the sound source position, the calculation of the movement amount, the determination process of the virtual sound source, the output process, and the storage process. Note that the output destination of the composite image is the terminal device 23.

[0070] The terminal device 23 has a control unit (not shown) that includes an operation unit 4 and a third communication unit 33. This control unit has a recording medium that stores programs for executing information for output, control, etc. The terminal device 23 is equipped with a computer and is realized by, for example, a smartphone or a tablet.

[0071] In addition, in Modification 2, it is assumed that the moving device 22 and the terminal device 23 are near the operator, and the sound source position measuring device 21 is in a remote location. Also, the terminal device 23 is operated while being carried by the operator, and the moving device 22 can move to a location away from the operator to collect data. In this case, the operator with the terminal device 23 can move only the moving device 22 from a safe location to a dangerous area such as a gas leak area. As a result, the situation within the dangerous area can be measured while ensuring the safety of the operator. Also, it is suitable when the moving device 22 is equipped with a moving means that does not rely on human power, such as a drone, and the load carried by the moving means can be reduced.

[0072] <Modification 3> FIG. 9 is a functional block diagram showing the configuration of a sound source position measurement system 50 according to Modification 3 of the embodiment of the present invention. In this Modification 3, the terminal device 23 is equipped with the sound source position measuring device 21. The moving device 22 and the terminal device 23 exchange information via a second communication unit 32 and a first communication unit 31, respectively. The moving device 22 and the terminal device 23 are connected via wire, wirelessly, via a network (including the Internet), or by combining these methods. Modification 3 is suitable when the moving device 22 is equipped with a moving means that does not rely on human power, such as a drone, and the load carried by the moving means can be reduced.

[0073] In addition, a flight test of the sound source position measuring device 1 using a drone was conducted. When a simulated leak sound source was placed on the ground and the drone detected the leak sound source from above while moving horizontally, the reflected sound of the drone was always erroneously detected separately from the leak sound source. However, in this embodiment, since the reflected sound (virtual sound source) of the drone moves with the drone and the actual sound source does not move, only the actual sound source could be detected.

[0074] In addition, since the frequency of the leakage sound varies depending on the hole diameter and the internal pressure, the user can comprehensively detect corrosion holes by arbitrarily setting the range of the band-pass filter with the operation button.

[0075] Note that the moving device 22 is capable of moving in any one or more of the air, on land, on an object, or in a liquid. Specifically, in addition to the trolley and the drone described above, an Automatic Guides Vehicle (AGV for short) or an Autonomous Mobile Robot (AMR for short), a walking robot, a crawler robot, a snake-shaped underwater robot, an inspection pig, or an inspection robot can be mentioned.

[0076] <Damage Detection Method> The sound source position measurement method according to the above-described embodiments and modifications can be applied to, for example, a damage detection method for detecting damage to a pipe by measuring a leakage sound from the pipe.

[0077] <Abnormality Detection Method> The sound source position measurement method according to the above-described embodiments and modifications can be applied to, for example, an abnormality detection method for detecting an abnormality of a machine by measuring an abnormal sound from the machine.

[0078] Note that the sound source position calculation unit, the movement amount calculation unit, and the virtual sound source determination unit that constitute the sound source position measurement device may realize these functions by a sound source position measurement program configured to be executable by a computer, or a recording medium recording the sound source position measurement unit program may be provided. Further, the terminal device may realize the functions of the operation unit and the third communication unit of the terminal device, and acquiring information regarding the virtual sound source output from the sound source position measurement device via the third communication unit and displaying it on the display unit in a predetermined format, by a terminal device program configured to be executable by a computer, or a recording medium recording the terminal device program may be provided.

[0079] As described above, the method for measuring the sound source position, the sound source position measuring device, the damage detection method, the abnormality detection method, the terminal device for measuring the sound source position, the sound source position measuring system, the terminal system, the program for measuring the sound source position, the program for the terminal device, and the recording medium according to the present invention have been specifically described by the embodiments and modifications for carrying out the invention. However, the gist of the present invention is not limited to these descriptions and should be broadly interpreted based on the descriptions in the claims. Needless to say, various changes and modifications based on these descriptions are also included in the gist of the present invention.

Explanation of Signs

[0080] 1, 21 Sound source position measuring device 1a Housing 2 Sound wave receiving unit 3 Position information measuring unit 3a Sensor 3b Position information calculation unit 4 Operation unit 5 Display unit 6 Storage unit 7 Control unit 11 Sound source position calculation unit 12 Movement amount calculation unit 13 Virtual sound source determination unit 14 Output processing unit 22 Moving device 23 Terminal device 31 First communication unit 32 Second communication unit 33 Third communication unit 40 Noise cover 50 Sound source position measuring system 101 Pipe CA Feature point D1, D2 Images DD Composite image DP1~DPN Pair data L1~L3 Routes M1, M2, M2´ Sound pressure maps SA, SB, SC, SD, SS Sound sources

Claims

1. A sound source position calculation step of calculating a sound source position for each of the plurality of measurement ranges from sound waves received in the plurality of measurement ranges while moving the position of the measurement range; A movement amount calculation step of calculating a movement amount of the position of the measurement range and a movement amount of the calculated sound source position; A virtual sound source determination step of determining a virtual sound source from among the sound source positions using the calculated movement amount of the position of the measurement range and the movement amount of the sound source position; comprising: The virtual sound source determination step includes: a step of comparing the calculated movement amount of the sound source position with the calculated movement amount of the position of the measurement range; a step of determining a sound source position having a movement amount different from the movement amount of the position of the measurement range as a virtual sound source; A sound source position measurement method.

2. The sound source position measurement method according to claim 1, further comprising a sound wave reception step of receiving sound waves from a plurality of the measurement ranges while moving the position of the measurement range.

3. The sound wave reception step includes a step of acquiring information regarding the positions of the plurality of measurement ranges for each of the measurement ranges, The movement amount calculation step includes a step of calculating a movement amount of the position of the measurement range from information regarding the position of a first measurement range and information regarding the position of a second measurement range after moving from the first measurement range among information regarding the positions of the plurality of measurement ranges acquired in the sound wave reception step. The sound source position measurement method according to claim 2.

4. The sound wave reception step includes a step of imaging the measurement range as a plurality of images while changing time, The movement amount calculation step includes a step of calculating a movement amount from an image taken at a first time and an image taken at a second time after the first time among the plurality of images imaged in the sound wave reception step. The sound source position measurement method according to claim 2.

5. A damage detection method for measuring a leak sound from a pipe using the sound source position measurement method according to any one of claims 1 to 4 and detecting damage to the pipe.

6. An abnormality detection method for measuring an abnormal sound from a machine using the sound source position measurement method according to any one of claims 1 to 4 and detecting an abnormality of the machine.

7. A sound source position calculation unit that calculates a sound source position for each of the plurality of measurement ranges from sound waves received in the plurality of measurement ranges while moving the position of the measurement range; A movement amount calculation unit that calculates a movement amount of the position of the measurement range and a movement amount of the calculated sound source position; Compare the amount of movement of the position within the calculated measurement range with the amount of movement of the sound source position, and determine, from among the sound source positions, a sound source position having an amount of movement different from that of the position within the measurement range as a virtual sound source using a virtual sound source determination unit. A sound source position measurement device comprising the same. **Claim 8** The sound source position measurement device according to claim 7 includes a first communication unit. The first communication unit acquires information regarding the received sound wave and information regarding the position of the measurement range, and / or outputs information regarding the virtual sound source from the virtual sound source determination unit. A sound source position measurement device. **Claim 9** The sound source position measurement device according to claim 7 includes a sound wave reception unit that receives sound waves from the plurality of measurement ranges while moving the position of the measurement range. **Claim 10** The sound source position measurement device according to claim 9 includes moving means for moving at least the sound wave reception unit. **Claim 11** A third communication unit that communicates with a moving device that receives sound waves in a plurality of the measurement ranges while moving the position of the measurement range; An operation unit that operates the moving means of the moving device via the third communication unit; The sound source position measurement device according to claim 7; A terminal device for measuring a sound source position, comprising the same. **Claim 12** A sound source position measurement system that includes the sound source position measurement device according to claim 10 and a terminal device, and measures a sound source position, wherein the terminal device includes a third communication unit that communicates with the moving means and the sound source position measurement device; an operation unit that operates the moving means via the third communication unit; means for acquiring information regarding the virtual sound source output from the sound source position measurement device via the third communication unit and displaying the information on a display unit in a predetermined format. A sound source position measurement system comprising the same. **Claim 13** A sound source position measurement system that includes the sound source position measurement device according to claim 8, a moving device, and a terminal device, wherein the moving device includes a sound wave reception unit that receives sound waves from the plurality of measurement ranges while moving the position of the measurement range; moving means for moving the sound wave reception unit; means for sending information regarding the received sound wave and information regarding the position of the measurement range to the sound source position measurement device via a second communication unit; and includes the terminal device includes an operation unit that operates the moving means via a first communication unit; means for acquiring information regarding the virtual sound source output from the sound source position measurement device via a third communication unit and displaying the information on a display unit in a predetermined format. A sound source position measurement system comprising

14. A sound source position measurement system comprising the terminal device and the mobile device according to claim 11, for measuring the sound source position, wherein the mobile device a sound wave receiving unit that receives sound waves from the plurality of measurement ranges while moving the position within the measurement range; moving means for moving the sound wave receiving unit; means for sending information regarding the received sound wave and information regarding the position of the measurement range to the sound source position measuring device via a second communication unit; A sound source position measurement system comprising

15. A damage detection method using the sound source position measurement device according to any one of claims 7 to 10, the method comprising measuring a leakage sound from a pipe using information regarding a virtual sound source output from the virtual sound source determination unit to detect damage to the pipe.

16. An abnormality detection method using the sound source position measurement device according to any one of claims 7 to 10, the method comprising measuring abnormal sound from a machine using information regarding a virtual sound source output from the virtual sound source determination unit to detect an abnormality in the machine.

17. A sound source position measurement program used in the sound source position measurement device according to claim 7, wherein the functions of the sound source position calculation unit, the movement amount calculation unit, and the virtual sound source determination unit are configured to be executable by a computer.

18. A recording medium recording the sound source position measurement program used in the sound source position measurement device according to claim 7, wherein the functions of the sound source position calculation unit, the movement amount calculation unit, and the virtual sound source determination unit are configured to be executable by a computer.

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