A single-microphone sound source direction finding and positioning device

Abstract

The present invention belongs to the technical field of sound source positioning, specifically a single-microphone sound source direction finding and positioning device, including a shell, the shell is set as a hollow polyhedron, each face of which is provided with an acoustic switch connected to the external space of the shell, a microphone is installed inside the shell, and sound-absorbing cotton is filled between the microphone and the inner wall of the shell. The acoustic switch includes a holder, a suspension diaphragm is arranged inside the holder, and a permanent magnet and an iron core are connected to the holder in sequence; a coil is also attached to the suspension diaphragm near the end of the iron core, and the coil is connected to an external analog circuit through a connecting line. Only a single microphone is used. Compared with the traditional array-type sound source positioning system that needs to arrange multiple or even dozens of instrument-level microphones, this invention has a simple structure, low cost, and is easy to use, and the threshold for use is not high; and because the number of microphones is small, it is convenient to process the collected data, and the processing speed is fast, which greatly reduces the burden on the system.

Description

Technical Field

[0001] The invention belongs to the technical field of sound source positioning, and in particular relates to a single-microphone sound source direction finding and positioning device. Background Art

[0002] With the acceleration of industrialization and urbanization, noise pollution has become a serious environmental problem, affecting people's quality of life and health. In the process of dealing with various noises, it is usually necessary to identify the noise source by determining its location before taking appropriate measures to reduce the noise. On the other hand, industrial equipment failures may also produce abnormal noises, and noise source location technology can be used as a method for equipment fault diagnosis. Therefore, noise source location technology has important applications in environmental noise monitoring, industrial equipment fault diagnosis, traffic noise management and other fields.

[0003] Traditional noise source localization methods mainly rely on acoustic sensor arrays, which measure the arrival time difference or phase difference of sound waves between different sensors and use various algorithms to calculate the location of the noise source. By superimposing visual images, the distribution of noise sources can be displayed on the image. Therefore, array-based sound source localization equipment is also called an acoustic camera.

[0004] The microphone arrays that make up the sound source localization equipment can generally be divided into linear arrays, uniform arrays, circular arrays, spiral arrays and random arrays. Regardless of the type of array, the sound source localization system relies on the coordinated work of multiple or even dozens of microphones to determine the location of the noise source by measuring the arrival time difference or phase difference of the sound waves between different sensors. These systems have solved the problem of noise source localization to a certain extent, but there are still some significant limitations. First, the traditional array-type sound source localization system requires the deployment of multiple or even dozens of instrument-level microphones (or microphones), which makes it more expensive.

[0005] At the same time, each sensor needs to be precisely arranged into a specific geometric shape, which not only increases the design and installation complexity of the system, but also increases the hardware cost and maintenance cost. In addition, the relative errors of these sensors need to be calibrated, making their use process quite complicated. Due to the large number of microphones, a lot of data will be generated in the process of collecting sound field data. Processing and analyzing multiple sensor data requires complex algorithms and high computing resources. Especially when the number of sensors increases, the complexity of data processing and computing requirements increase exponentially, increasing the burden on the system. The complexity of these data processing also makes the traditional array sound source localization system often respond slowly when dealing with dynamically changing noise sources. The real-time changes in the position of the noise source require a lot of data processing and calculations, and it is difficult for traditional systems to quickly track and locate moving noise sources. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes a single-microphone sound source direction finding and positioning device, which only uses a single microphone. Compared with the traditional array sound source positioning system that requires the deployment of multiple or even dozens of instrument-level microphones, the invention has a simple structure, low cost, and is easy to use, with a low threshold for use. In addition, due to the small number of microphones, it is convenient to process the collected data, and the processing speed is fast, which greatly reduces the burden on the system.

[0007] The single-microphone sound source direction finding and positioning device of the present invention comprises a shell, which is arranged as a hollow polyhedron, each face of which is provided with an acoustic switch connected to the outer space of the shell, a microphone is installed inside the shell, and sound-absorbing cotton is filled between the microphone and the inner wall of the shell.

[0008] The acoustic switch comprises a holder, a suspension diaphragm is arranged in the holder, and a permanent magnet and an iron core are connected to the holder in sequence; a coil is also attached to the suspension diaphragm near the end of the iron core, and the coil is connected to an external analog circuit through a connecting wire.

[0009] The suspension diaphragm is also provided with a dust cover to cover the iron core.

[0010] The beneficial effects of the present invention are:

[0011] Compared with the prior art, the present invention uses an acoustic switch array that is in an acoustic conduction state or cutoff state in a certain time sequence, so that the sound waves are transmitted from multiple surfaces of the device to the microphone inside the device one by one and receive the detection sound wave signal, thereby judging the size of the sound waves entering from different directions at different times. By identifying the size of the sound wave amplitude detected in different time periods, the center line connecting the microphone and the surface with the largest corresponding sound wave can be determined as the direction of the detected sound source. The present invention only uses a single microphone. Compared with the traditional array-type sound source positioning system that requires the deployment of multiple or even dozens of instrument-level microphones, the present invention has a simple structure, low cost, and is easy to use, and the threshold for use is not high; and because the number of microphones is small, it is convenient to process the collected data, and the processing speed is fast, which greatly reduces the burden on the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0013] Figure 1 Schematic diagram of the overall structure of the sound source direction finding and positioning device in the embodiment;

[0014] Figure 2 A half-section schematic diagram of a sound source direction finding and positioning device in an embodiment;

[0015] Figure 3 A cross-sectional schematic diagram of an acoustic switch in an embodiment;

[0016] Figure 4 This is a schematic diagram of a detection test in the embodiment;

[0017] Figure 5 This is a test result diagram of the test 1 in the embodiment;

[0018] Figure 6 This is a schematic diagram of the second detection test in the embodiment;

[0019] Figure 7 This is a test result diagram of the second test in the embodiment;

[0020] 1-shell, 2-acoustic switch, 21-holder, 22-suspension diaphragm, 23-permanent magnet, 24-iron core, 25-coil, 26-dust cover, 201-acoustic switch one, 202-acoustic switch two, 203-acoustic switch three, 204-acoustic switch four, 205-acoustic switch five, 206-acoustic switch six, 3-microphone, 4-sound-absorbing cotton, 5-analog circuit, 6-sound source. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] Example 1

[0023] See also Figures 1 to 3 As shown, a single-microphone sound source direction finding and positioning device includes a shell 1, which is configured as a hollow hexahedron, and each surface of the shell 1 is provided with an acoustic switch connected to the external space of the shell 1. The acoustic switch includes a retaining frame 21, and a suspension diaphragm 22 is provided in the retaining frame 21. A permanent magnet 23 and an iron core 24 are connected to the retaining frame 21 in sequence; a coil 25 is also attached to the end of the suspension diaphragm 22 near the iron core 24, and the coil 25 is connected to an external analog circuit 5 through a connecting line. By juxtaposing the suspension diaphragm with the electric coil 25 and the magnetic field with the analog circuit 5, the acoustic impedance of the acoustic switch is artificially increased or decreased to achieve the effect of the acoustic switch.

[0024] A microphone 3 is installed inside the housing 1, and sound-absorbing cotton 4 is filled between the microphone 3 and the inner wall of the housing 1. The distance between the microphone 3 and each sound switch is consistent.

[0025] The acoustic switch array is in an acoustic conduction state or cutoff state according to a certain time sequence, so that the sound waves are transmitted from multiple surfaces of the device to the microphone 3 inside the device one by one and receive the detection sound wave signal, so as to judge the size of the sound waves entering from different directions at different times. By identifying the size of the sound wave amplitude detected in different time periods, the center line connecting the microphone 3 and the surface with the largest corresponding sound wave can be determined as the direction of the detected sound source 6. Only a single microphone 3 is used. Compared with the traditional array-type sound source 6 positioning system that requires the arrangement of multiple or even dozens of instrument-level microphones 3, the invention has a simple structure, low cost, and is easy to use, and the threshold for use is not high; and because the number of microphones 3 is small, it is convenient to process the collected data, and the processing speed is fast, which greatly reduces the burden on the system.

[0026] In order to prevent dust from entering the interior of the acoustic switch and affecting the detection performance, a dust cover 26 is provided on the suspension diaphragm 22 to cover the iron core 24 .

[0027] Example 2

[0028] Test 1:

[0029] like Figure 4 As shown, in the single-microphone 3 sound source 6 direction finding and positioning device, a stable sound source 6 is placed at a certain distance, and the approximate relative direction of the sound source 6 and the device is determined by detecting the sound pressure transmitted to the internal microphone 3 through the sound switch 1 201 to the sound switch 6 206 on each side.

[0030] Test results such as Figure 5 As shown, the ordinate represents the sound power, and the abscissa 1-6 represents the sound switches corresponding to one to six. The line graph shows that the sound power passing through the sound switch three 203 is the largest, that is, the sound source 6 is in the direction corresponding to the sound switch three 203.

[0031] Example 3

[0032] Test 2:

[0033] exist Figure 4 Based on the direction finding, the device is moved to a certain position and angle. The original position is represented by a dotted line, and the new position is represented by a solid line. Figure 6 shown.

[0034] The direction of the sound source 6 is determined again by detecting the sound pressure of the sound switch 1 201 to the sound switch 6 206 transmitted to the internal microphone 3 from each side, and then Figure 7It can be seen that the acoustic power passing through the acoustic switch 204 is the largest, that is, the sound source 6 is in the direction corresponding to the acoustic switch 204. The intersection of the second measured direction and the extension line of the first measured direction is the approximate position of the sound source 6. If you want to improve the accuracy of the direction, you can narrow the range by performing multiple position changes. You can also set the device to a multi-faceted structure such as an octahedron or a dodecahedron to increase the number of detection surfaces and acoustic switches, and further improve the accuracy of direction measurement.

[0035] In summary, the two tests have proved that the device has strong direction finding and positioning functions, and has certain feasibility and practicality.

[0036] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the invention to only the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification.

Claims

1. A single-microphone sound source direction finding and positioning device, characterized in that: The invention comprises a shell (1), wherein the shell (1) is configured as a hollow polyhedron, each face of which is provided with an acoustic switch (2) which is connected to the outer space of the shell (1), a microphone (3) is installed inside the shell (1), and sound-absorbing cotton (4) is filled between the microphone (3) and the inner wall of the shell (1); the acoustic switch (2) comprises a retaining frame (21), a suspension diaphragm (22) is arranged inside the retaining frame (21), and a permanent magnet (23) and an iron core (24) are connected to the rear of the retaining frame (21) in sequence; a coil (25) is also attached to the end of the suspension diaphragm (22) close to the iron core (24), and the coil (25) is connected to an external analog circuit (5) through a connecting line. A stable sound source (6) is placed at a certain distance from the single-microphone sound source direction finding and positioning device, and the relative direction between the sound source (6) and the single-microphone sound source direction finding and positioning device is determined by detecting the magnitude of the sound pressure transmitted from each surface through the sound switch 1 (201) to the sound switch 6 (206) to the internal microphone (3); on the basis of the direction finding, the device is moved to a certain position and angle, and the direction of the sound source (6) is determined again by detecting the magnitude of the sound pressure transmitted from each surface through the sound switch 1 (201) to the sound switch 6 (206) to the internal microphone (3), and the second determination direction is the intersection of the second determination direction and the extension line of the first determination direction, which is the position of the sound source (6).

2. The single microphone (3) sound source (6) direction finding and positioning device according to claim 1, characterized in that: The suspension diaphragm (22) is also provided with a dust cover (26) to cover the iron core (24).

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