A sound source orientation device, orientation method, sound source positioning system and positioning method

Abstract

The present invention provides a sound source orientation device, an orientation method, a sound source positioning system and a positioning method, wherein the sound source orientation device comprises: a circuit board; an FPGA chip mounted on the circuit board; a differential microphone array mounted on the circuit board and coupled to the FPGA chip, wherein the differential microphone array comprises four omnidirectional microphones distributed at equal intervals, and the four differential microphone arrays form a circle. The present invention improves the integration of the sound source orientation device by arranging an FPGA chip in the sound source orientation device; in addition, the present invention arranges four omnidirectional microphones distributed at equal intervals on the circuit board, simplifies the calculation of the azimuth angle obtained by the sound source orientation device by optimizing the position of the data collection device, and improves the processing speed.

Description

Technical Field

[0001] The present invention relates to the field of speech signal processing, and in particular to a sound source orientation device, an orientation method, a sound source localization system and a localization method. Background Art

[0002] Sound source localization is a branch of passive target localization technology. It has attracted more and more attention due to its potential in sound source separation, sound source tracking and speech enhancement. With the development of digital signal processing and array signal processing technology, sound source localization systems based on microphone arrays have been applied to audio and video conferencing, security monitoring and intelligent robot positioning in noisy environments.

[0003] However, in the existing sound source localization technology, due to the complex structure of the sound source localization system, there is a problem of low system integration; and due to the large amount of calculation of the sound source localization, there is a problem of slow processing speed.

[0004] Therefore, it is urgent to solve the problems of low system integration and slow processing speed due to large amount of calculation when locating the sound source in the prior art. Summary of the invention

[0005] In view of this, it is necessary to provide a sound source orientation device, an orientation method, a sound source localization system and a positioning method to solve the problems of low system integration and slow processing speed due to large calculation amount when localizing the sound source in the prior art.

[0006] In order to solve the above problems, the present invention provides a sound source directional device, including: a circuit board; an FPGA chip, mounted on the circuit board; a differential microphone array, mounted on the circuit board and coupled to the FPGA chip, wherein the differential microphone array includes four omnidirectional microphones distributed at equal intervals, and the four differential microphone arrays form a circle.

[0007] In order to solve the above problems, the present invention also provides a sound source orientation method based on a sound source orientation device, and the sound source orientation method comprises:

[0008] Acquire four sound signals of the sound source based on four omnidirectional microphones;

[0009] Preprocessing the four sound signals to obtain four target sound signals;

[0010] Determine the center point sound pressure signal, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal of the four omnidirectional microphones according to the four target sound signals, wherein the center points of the four omnidirectional microphones coincide with the center of the circle surrounded by the differential microphone array;

[0011] According to the sound pressure signal of the center point, the horizontal axis vibration velocity signal of the center point, and the vertical axis vibration velocity signal of the center point, the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point are obtained;

[0012] The azimuth of the sound source is determined based on the horizontal axis sound intensity at the center point and the vertical axis sound intensity at the center point.

[0013] Among them, the four sound signals include an average sound pressure signal and a vibration velocity signal. According to the four target sound signals, the center point sound pressure signal, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal of the four omnidirectional microphones are obtained, including;

[0014] According to the four sound pressure signals in the four target sound signals, the center point sound pressure signal is calculated by using a preset sound pressure signal standardization formula and a center point sound pressure signal formula;

[0015] According to the four vibration velocity signals in the four target sound signals, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal are calculated through the preset sound wave motion equation, the center point horizontal axis vibration velocity signal formula and the center point vertical axis vibration velocity signal formula to obtain the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal.

[0016] Wherein, the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point are obtained according to the sound pressure signal of the center point, the horizontal axis vibration velocity signal of the center point, and the vertical axis vibration velocity signal of the center point, including:

[0017] Performing Fourier transformation on the sound pressure signal of the center point, the horizontal axis vibration velocity signal of the center point, and the vertical axis vibration velocity signal of the center point to obtain the sound pressure signal after Fourier transformation of the center point, the horizontal axis vibration velocity signal after Fourier transformation of the center point, and the vertical axis vibration velocity signal after Fourier transformation of the center point;

[0018] The horizontal axis sound intensity at the center point and the vertical axis sound intensity at the center point are obtained according to the sound pressure signal after Fourier transformation of the center point, the horizontal axis vibration velocity signal after Fourier transformation of the center point and the vertical axis vibration velocity signal after Fourier transformation of the center point.

[0019] Among them, the four sound signals are preprocessed to obtain four target sound signals, including:

[0020] Parts of a preset frequency range are extracted from the four sound signals to obtain four target sound signals.

[0021] Before acquiring four sound signals of the sound source based on four omnidirectional microphones, the method further includes:

[0022] A rectangular coordinate system is established, with the center of the circle surrounded by the differential microphone array as the origin of the rectangular coordinate system, and the direction of any omnidirectional microphone as the horizontal axis direction, wherein the distance between the omnidirectional microphone and the origin of the rectangular coordinate system is half of the preset diameter.

[0023] In order to solve the above technical problems, the present invention also provides a sound source localization system, comprising: a plurality of the above sound source directional devices which are not arranged in the same straight line, for obtaining a plurality of azimuth angles of the sound source; a control device, coupled to the plurality of sound source directional devices, for determining the position of the sound source according to the plurality of azimuth angles.

[0024] In order to solve the above technical problems, the present invention also provides a sound source localization method based on a sound source localization system, the sound source localization method comprising:

[0025] For multiple sound source directional devices that are not arranged in the same straight line, the sound source directional methods of the sound source directional devices are respectively adopted to obtain multiple azimuth angles of the sound source;

[0026] respectively obtaining distances between a plurality of sound source directional devices;

[0027] The position of the sound source is determined according to multiple azimuth angles of the sound source and the distances between multiple sound source directional devices.

[0028] The multiple azimuths of the sound source include a first azimuth, a second azimuth and a third azimuth, and the multiple sound source directional devices include a first sound source directional device, a second sound source directional device and a third sound source directional device; after obtaining the multiple azimuths of the sound source, the method further includes:

[0029] Establishing a polar coordinate system, taking the center point of the first sound source directional device as the origin of the polar coordinate system, and taking the direction of the center point of the second sound source directional device as the horizontal axis direction;

[0030] A first polar azimuth, a second polar azimuth, and a third polar azimuth of the first azimuth, the second azimuth, and the third azimuth in the polar coordinate system are obtained respectively.

[0031] The method of determining the position of the sound source according to multiple azimuths of the sound source and distances between multiple sound source directional devices includes:

[0032] Acquire a first polar azimuth and a second polar azimuth, and a distance between a first sound source directional device and a second sound source directional device, wherein the first sound source directional device corresponds to the first polar azimuth, and the second sound source directional device corresponds to the second polar azimuth;

[0033] Obtaining a first distance between the sound source and the first sound source directional device according to the first polar azimuth, the second polar azimuth, and the distance between the first sound source directional device and the second sound source directional device;

[0034] Determine whether the first distance exists, and if so, determine the position of the sound source; if not, discard the second polar azimuth and its corresponding second sound source directional device, and obtain the third polar azimuth and the distance between the third sound source directional device and the first sound source directional device;

[0035] According to the first polar azimuth, the third polar azimuth and the distance between the first sound source directional device and the third sound source directional device, a second distance between the sound source and the first sound source directional device is obtained to determine the position of the sound source.

[0036] The beneficial effects of adopting the above embodiment are:

[0037] In the sound source orientation device and orientation method provided by the present invention, an FPGA chip is added to the original circuit board to replace the original complex control module structure, thereby effectively improving the integration of the sound source orientation device; in addition, four omnidirectional microphones distributed at equal intervals are arranged on the circuit board, and the distribution position of the differential microphone array is optimized, thereby simplifying the calculation of the azimuth angle obtained by the sound source orientation device and improving the processing speed.

[0038] Furthermore, the sound source localization system and localization method provided by the present invention include multiple sound source directional devices that are not arranged in the same straight line, and multiple azimuths of the sound source are obtained through the multiple sound source directional devices, and then the position of the sound source is calculated based on the multiple azimuths. In particular, in order to avoid the situation where the multiple azimuths obtained are in the same straight line with the sound source, so that the position of the sound source cannot be obtained, the sound source localization system and localization method provided by the present invention need to include multiple sound source directional devices that are not arranged in the same straight line. The present invention utilizes the sound source localization system and localization method to obtain the position of the sound source, and based on the high integration of the sound source directional device, the sound source localization system also has the advantage of high integration. In addition, the sound source localization system obtains the azimuth through the sound source directional device to obtain the sound source localization, and the calculation method is simple and the reliability is high, so it has a high processing speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic structural diagram of an embodiment of an orientation device provided by the present invention;

[0040] Figure 2 A schematic flow chart of an embodiment of a sound source orientation method based on a sound source orientation device provided by the present invention;

[0041] Figure 3 A schematic diagram of the structure of an embodiment of a sound source localization system provided by the present invention;

[0042] Figure 4 A schematic flow chart of an embodiment of a sound source localization method based on a sound source localization system provided by the present invention. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0044] The present invention provides a sound source orientation device, an orientation method, a sound source localization system and a localization method, which are described in detail below.

[0045] In order to improve the integration of the sound source directional device, the present application introduces an FPGA chip to process the sound signal, which effectively improves the processing speed of the sound source directional device and reduces energy consumption.

[0046] like Figure 1 As shown, Figure 1 This is a structural schematic diagram of an embodiment of a sound source orientation device provided by the present invention, and the sound source orientation device includes:

[0047] Circuit board 101;

[0048] FPGA chip 102, mounted on a circuit board;

[0049] The differential microphone array 103 is mounted on a circuit board and coupled to the FPGA chip, wherein the differential microphone array includes four omnidirectional microphones that are equally spaced and arranged to form a circle.

[0050] In this embodiment, four omnidirectional microphones form a circle, and each omnidirectional microphone is equivalent. The angle and position of the sound source directional device can be adjusted arbitrarily according to needs without affecting the measurement of the sound source azimuth; and the measurement using multiple omnidirectional microphones can reduce errors and improve accuracy; finally, in this embodiment, an FPGA chip is used to process the sound signal of the sound source. Based on the characteristics of FPGA chips with high integration, fast computing speed and low energy consumption, the sound source directional device in this embodiment has the advantages of high system integration, fast processing speed and low energy consumption.

[0051] In order to solve the above technical problems, the present invention also provides a sound source orientation method based on the sound source orientation device.

[0052] like Figure 2 As shown, Figure 2 A flow chart of an embodiment of a sound source orientation method based on a sound source orientation device provided by the present invention, wherein the sound source orientation method based on the sound source orientation device includes:

[0053] Step S201: acquiring four sound signals of a sound source based on four omnidirectional microphones;

[0054] Step S202: pre-processing the four sound signals to obtain four target sound signals;

[0055] Step S203: determining the center point sound pressure signal, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal of the four omnidirectional microphones according to the four target sound signals, wherein the center points of the four omnidirectional microphones coincide with the center of the circle surrounded by the differential microphone array;

[0056] Step S204: obtaining the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point according to the sound pressure signal of the center point, the horizontal axis vibration velocity signal of the center point, and the vertical axis vibration velocity signal of the center point;

[0057] Step S205: Determine the azimuth of the sound source according to the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point.

[0058] In an embodiment of the present invention, first, the sound signals of the sound source are collected simultaneously by four omnidirectional microphones on the circuit board; secondly, the four sound signals are preprocessed to obtain four target sound signals; then, based on the four target sound signals, the center point sound pressure signal, the center point horizontal axis velocity signal and the center point vertical axis velocity signal are obtained by calculation, wherein the center points of the four omnidirectional microphones coincide with the center point of the circle surrounded by the differential microphone array; next, based on the center point sound pressure signal, the center point horizontal axis velocity signal and the center point vertical axis velocity signal, the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point are obtained; finally, based on the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point, the azimuth of the sound source is determined.

[0059] In this embodiment, the sound signal of the sound source is collected by four omnidirectional microphones distributed at equal intervals, and then the acquired sound signal of the sound source is processed by using an FPGA chip, thereby effectively improving the processing speed of the sound source orientation.

[0060] In order to unify the measurement data during the process of collecting the sound signal of the sound source, it is also necessary to establish a rectangular coordinate system after determining the position of the sound source directional device.

[0061] As a preferred embodiment, the rectangular coordinate system in the present application takes the center of the circle surrounded by the differential microphone array as the origin of the rectangular coordinate system, and the direction of a certain omnidirectional microphone is the horizontal axis direction, wherein the distance between the omnidirectional microphone and the origin of the rectangular coordinate system is half of the preset diameter.

[0062] In other embodiments, the coordinate system may be established in other ways, the origin and horizontal axis direction of the coordinate system may be determined according to other standards, and other coordinate systems may be established as needed, such as a polar coordinate system, a spatial coordinate system, etc.

[0063] Furthermore, in order to avoid the influence of external factors such as environment or measurement error on the measurement results.

[0064] As a preferred embodiment, in the present application, after acquiring four sound signals, they are preprocessed to obtain four target sound signals; wherein, the preprocessing of the four sound signals includes: extracting parts of the four sound signals within a preset frequency range to obtain four target sound signals; wherein, the preset frequency range includes [300Hz, 3000Hz].

[0065] Furthermore, the four sound signals of the sound source acquired by the four omnidirectional microphones include an average sound pressure signal and a velocity signal; in order to obtain the center point sound pressure signal, the center point horizontal axis velocity signal and the center point vertical axis velocity signal based on the four sound pressure signals and four velocity signals measured.

[0066] As a preferred embodiment, according to the structure of the sound source directional device in the present application, the present application obtains a preset sound pressure signal standardization formula, a center point sound pressure signal formula, a sound wave motion equation, a center point horizontal axis vibration velocity signal formula and a center point vertical axis vibration velocity signal formula through analysis, experiments and other methods; and realizes that according to the measured sound pressure signal and vibration velocity signal, the center point sound pressure signal, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal can be obtained through calculation.

[0067] As a preferred embodiment, the sound pressure signal normalization formula in step S203 of the present application is:

[0068] P i (t)αs(t-τ)+n i (t), i = 1, 2, 3, 4

[0069] The formula for the center point sound pressure signal is:

[0070]

[0071] The equation of motion for sound waves is:

[0072]

[0073] The formula of the horizontal axis vibration velocity signal at the center point is:

[0074]

[0075] The formula of the center point vertical axis vibration velocity signal is:

[0076]

[0077] Among them, s(t) is the signal of the sound source, α is the propagation attenuation of the sound source signal to the microphone, τ is the time delay from the sound source signal to the microphone, and n i (t) is the additive noise signal received by the microphone, P is the sound pressure signal, v(t is the vibration velocity signal, ρ is the medium density, is the gradient operator and D is the diameter of the circle.

[0078] Through the above formula, after obtaining the sound signals of the sound source collected by four omnidirectional microphones with equal spacing, on the one hand, the sound pressure signals in the sound signals of the sound source collected by the four omnidirectional microphones are extracted, and the four sound pressure signals are standardized so that the four sound pressure signals can be expressed by a unified formula; then, the sound pressure signal of the center point is obtained by using the formula of the sound pressure signal of the center point. On the other hand, the velocity signal in the sound signal of the sound source collected by the four omnidirectional microphones is extracted, and the velocity signal of the center point is obtained by using the equation of sound wave motion, and then, the horizontal axis velocity signal formula of the center point and the vertical axis velocity signal formula of the center point are used to obtain the component of the velocity signal of the center point on the horizontal axis and the component of the velocity signal of the center point on the vertical axis.

[0079] Furthermore, after obtaining the sound pressure signal of the center point, the horizontal axis vibration velocity signal of the center point and the vertical axis vibration velocity signal of the center point, the horizontal axis sound intensity and the vertical axis sound intensity of the center point must be obtained to improve the calculation of the azimuth of the sound source.

[0080] As a preferred embodiment, in step S204 of the present application, the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point are obtained according to the center point sound pressure signal, the center point horizontal axis vibration velocity signal, and the center point vertical axis vibration velocity signal, including:

[0081] The sound pressure signal at the center point, the horizontal axis vibration velocity signal at the center point and the vertical axis vibration velocity signal at the center point are subjected to Fourier transform to obtain the sound pressure signal after Fourier transform at the center point, the horizontal axis vibration velocity signal after Fourier transform at the center point and the vertical axis vibration velocity signal after Fourier transform at the center point.

[0082] Then, according to the sound pressure signal after Fourier transform of the center point, the horizontal axis vibration velocity signal after Fourier transform of the center point and the vertical axis vibration velocity signal after Fourier transform of the center point, the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point are calculated through the horizontal axis sound intensity relationship formula and the vertical axis sound intensity relationship formula.

[0083] Among them, the horizontal axis sound intensity relationship is:

[0084]

[0085] The vertical axis sound intensity relationship is:

[0086]

[0087] Among them, I represents sound intensity, P represents the sound pressure signal after Fourier transform, V represents the vibration velocity signal after Fourier transform, * represents conjugate operation, and Re represents the real part.

[0088] Finally, after obtaining the horizontal axis sound intensity at the center point and the vertical axis sound intensity at the center point, the azimuth of the sound source can be obtained.

[0089] As a preferred embodiment, in step S205 of the present application, after obtaining the horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point, the azimuth angle of the sound source can be obtained by the azimuth angle formula; wherein the azimuth angle formula is:

[0090]

[0091] where θ is the azimuth angle of the sound source.

[0092] Acquiring the azimuth of the sound source in the above manner not only effectively utilizes the structural characteristics of the sound source directional device, but also does not require adjusting the parameters of the center point sound signal formula when arbitrarily adjusting the angle and position of the sound source directional device; and after acquiring the sound signal of the sound source collected by the four omnidirectional microphones, the azimuth of the sound source is obtained by calculation, which effectively utilizes the calculation function of the FPGA chip and improves the processing speed. In other words, through the above method, it is achieved that only four omnidirectional microphones are needed to measure the sound signal of the sound source to obtain the azimuth of the sound source.

[0093] Furthermore, based on the above-mentioned sound source orientation device, in order to obtain the position of the sound source, the present application also provides a sound source positioning system.

[0094] As a preferred embodiment, Figure 3 As shown, Figure 3 This is a structural schematic diagram of an embodiment of a sound source localization system provided by the present invention. The sound source localization system includes a first sound source orientation device 301, a second sound source orientation device 302, a third sound source orientation device 303 and a control device 304 which are not arranged in the same straight line.

[0095] In this embodiment, the positions of the first sound source orientation device 301 , the second sound source orientation device 302 and the third sound source orientation device 303 are fixed, and the distance data is stored in the control device 304 .

[0096] In the process of locating the sound source, the azimuth of the sound source is respectively obtained by the first sound source directional device 301, the second sound source directional device 302 and the third sound source directional device 303, and transmitted to the control device 304. The control device 304 obtains the distance between the sound source and a certain sound source directional device based on the above three azimuths and the distance data of the corresponding sound source directional devices, and through the relationship between the distances between multiple sound source directional devices and their corresponding obtained azimuths.

[0097] In other embodiments, the sound source localization system may further include other numbers of sound source directional devices, the sound source directional devices may further be movable, and the position of the sound source may be obtained based on other sound source directional devices or based on other reference objects.

[0098] Based on the structure of the sound source localization system, in order to solve the above technical problems, the present invention also provides a sound source localization method of the sound source localization system.

[0099] like Figure 4 As shown, Figure 4 A flow chart of an embodiment of a sound source localization method based on a sound source localization system provided by the present invention, wherein the sound source localization method of a sound source directional device includes:

[0100] Step S401: for a plurality of sound source directional devices that are not arranged in the same straight line, respectively adopt the sound source directional method of the sound source directional device to obtain a plurality of azimuth angles of the sound source;

[0101] Step S402: respectively obtaining the distances between a plurality of sound source directional devices;

[0102] Step S403: Determine the position of the sound source according to the multiple azimuth angles of the sound source and the distances between the multiple sound source directional devices.

[0103] In an embodiment of the present invention, first, according to the multiple sound source directional devices described above, using the sound source directional method of the sound source directional device, multiple azimuths of the sound source in this embodiment are obtained; wherein the multiple sound source directional devices are not on the same straight line. In other embodiments, other numbers of azimuths of the sound source can also be obtained.

[0104] Then, the distances between two of the multiple sound source directional devices are obtained and recorded one by one.

[0105] Finally, the position of the sound source is determined according to the multiple azimuths of the sound source and the distances between the multiple sound source directional devices.

[0106] That is to say, based on the above positioning method, when the distances between multiple sound source directional devices and the azimuths of the sound sources measured therein are obtained, the positions of the sound sources can be obtained through calculation.

[0107] In the actual measurement process, when the horizontal axis directions in the rectangular coordinate systems of multiple sound source directional devices are different, the multiple azimuth angles obtained by measurement are easily confused, resulting in inaccurate positioning results.

[0108] As a preferred embodiment, in order to avoid the above situation, after obtaining multiple azimuth angles of the sound source, the present application further includes:

[0109] Establishing a polar coordinate system, taking the center point of the first sound source directional device as the origin of the polar coordinate system, and taking the direction of the center point of the second sound source directional device as the horizontal axis direction;

[0110] Then, a first polar azimuth, a second polar azimuth, and a third polar azimuth of the first azimuth, the second azimuth, and the third azimuth in the polar coordinate system are obtained respectively.

[0111] After obtaining the first polar azimuth, the second polar azimuth and the third polar azimuth, the calculation can be improved by combining the distances between the multiple sound source directional devices to obtain the position of the sound source.

[0112] In other embodiments, the coordinate system may be established in other ways, the origin and horizontal axis direction of the coordinate system may be determined according to other standards, and other coordinate systems may be established as needed, such as a rectangular coordinate system, a spatial coordinate system, etc.

[0113] In order to determine the position of the sound source, the present application proposes an embodiment to obtain the distance between the sound source and the center point of the first sound source directional device by calculation.

[0114] As a preferred embodiment, the present application uses three sound source directional devices to obtain the azimuth of the sound source, wherein the first sound source directional device, the second sound source directional device and the third sound source directional device are not on the same straight line; the distance between the first sound source directional device and the second sound source directional device is L 12 , the distance between the first sound source directional device and the third sound source directional device is L 13 , the distance between the second sound source directional device and the third sound source directional device is determined as L 23 In addition, the first polar azimuth, the second polar azimuth and the third polar azimuth of the first sound source directional device, the second sound source directional device and the third sound source directional device in the polar coordinate system are θ1, θ2 and θ3 respectively.

[0115] According to the first polar azimuth angle θ1, the second polar azimuth angle θ2 and the distance L between the first sound source directional device and the second sound source directional device 12 , a first distance between the sound source and the center point of the first sound source directional device is calculated by a first positioning formula, wherein the first positioning formula is:

[0116]

[0117] In particular, when the sound source, the first sound source directional device and the second sound source directional device are in the same straight line, the above positioning formula becomes invalid. In order to compensate for the distortion of the test result caused by this situation, in this embodiment, after obtaining the first distance, the following is further included:

[0118] Determine whether the first distance exists. If so, determine the location of the sound source. If not, discard the first distance and obtain the third polar azimuth θ3 and the distance L between the first sound source directional device and the third sound source directional device. 13 ;

[0119] According to the first polar azimuth θ1, the third polar azimuth θ3 and the distance L between the first sound source directional device and the third sound source directional device 13 , a second distance between the sound source and the center point of the first sound source directional device is calculated by a second positioning formula, wherein the second positioning formula is:

[0120]

[0121] In the above manner, the distance between the sound source and the center point of the first sound source directional device can be determined.

[0122] In other embodiments, other numbers of sound source directional devices may be obtained to determine the sound source positioning through calculation. The center point position of the first sound source directional device may be defined as a certain fixed point position by adjusting the formula parameters, thereby ultimately obtaining the distance between the sound source and the certain fixed point position.

[0123] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A sound source localization method according to a sound source localization system, characterized in that: The sound source localization system comprises: a plurality of sound source orientation devices which are not arranged in the same straight line, the sound source orientation device comprising: a circuit board; an FPGA chip mounted on the circuit board; a differential microphone array mounted on the circuit board and coupled to the FPGA chip, wherein the differential microphone array comprises four omnidirectional microphones distributed at equal intervals, and the four differential microphone arrays form a circle; The sound source localization method comprises: For the multiple sound source orientation devices that are not arranged in the same straight line, a sound source orientation method is adopted respectively to obtain multiple azimuths of the sound source; wherein the sound source orientation method comprises: obtaining four sound signals of the sound source based on the four omnidirectional microphones; preprocessing the four sound signals to obtain four target sound signals; according to the four target sound signals, determining the center point sound pressure signal, the center point horizontal axis velocity signal and the center point vertical axis velocity signal of the four omnidirectional microphones, wherein the center points of the four omnidirectional microphones coincide with the center point of the circle surrounded by the differential microphone array; according to the center point sound pressure signal, the center point horizontal axis velocity signal and the center point vertical axis velocity signal, obtaining the center point horizontal axis sound intensity and the center point vertical axis sound intensity; according to the center point horizontal axis sound intensity and the center point vertical axis sound intensity, determining the azimuth of the sound source; respectively obtaining the distances between the plurality of sound source directional devices; Determine the position of the sound source according to the multiple azimuths of the sound source and the distances between the multiple sound source directional devices; The multiple azimuths of the sound source include a first azimuth, a second azimuth and a third azimuth, the multiple sound source directional devices include a first sound source directional device, a second sound source directional device and a third sound source directional device, and after obtaining the multiple azimuths of the sound source, the method further includes: Establish polar coordinate system; Respectively obtaining a first polar azimuth, a second polar azimuth, and a third polar azimuth of the first azimuth, the second azimuth, and the third azimuth in the polar coordinate system; The step of determining the position of the sound source according to the multiple azimuth angles of the sound source and the distances between the multiple sound source directional devices comprises: Acquire a first polar azimuth and a second polar azimuth, and a distance between the first sound source directional device and the second sound source directional device, wherein the first sound source directional device corresponds to the first polar azimuth, and the second sound source directional device corresponds to the second polar azimuth; Obtaining a first distance between the sound source and the first sound source directional device according to the first polar azimuth, the second polar azimuth, and the distance between the first sound source directional device and the second sound source directional device; Determine whether the first distance exists, and if so, determine the position of the sound source; if not, discard the second polar azimuth and the second sound source directional device corresponding thereto, and obtain the third polar azimuth and the distance between the third sound source directional device and the first sound source directional device; According to the first polar azimuth, the third polar azimuth and the distance between the first sound source directional device and the third sound source directional device, a second distance between the sound source and the first sound source directional device is obtained to determine the position of the sound source.

2. The sound source localization method according to claim 1, characterized in that: The four sound signals each include a sound pressure signal and a vibration velocity signal; the center point sound pressure signal, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal of the four omnidirectional microphones are obtained according to the four target sound signals, including; According to the four sound pressure signals in the four target sound signals, the center point sound pressure signal is calculated by a preset sound pressure signal standardization formula and a center point sound pressure signal formula to obtain the center point sound pressure signal; According to the four vibration velocity signals in the four target sound signals, the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal are calculated by the preset sound wave motion equation, the center point horizontal axis vibration velocity signal formula and the center point vertical axis vibration velocity signal formula to obtain the center point horizontal axis vibration velocity signal and the center point vertical axis vibration velocity signal.

3. The sound source localization method according to claim 2, characterized in that: The step of obtaining the horizontal axis sound intensity at the center point and the vertical axis sound intensity at the center point according to the center point sound pressure signal, the center point horizontal axis vibration velocity signal, and the center point vertical axis vibration velocity signal comprises: Performing Fourier transformation on the sound pressure signal of the center point, the horizontal axis velocity signal of the center point, and the vertical axis velocity signal of the center point to obtain the sound pressure signal after Fourier transformation of the center point, the horizontal axis velocity signal after Fourier transformation of the center point, and the vertical axis velocity signal after Fourier transformation of the center point; The horizontal axis sound intensity of the center point and the vertical axis sound intensity of the center point are obtained according to the sound pressure signal after Fourier transformation of the center point, the horizontal axis velocity signal after Fourier transformation of the center point and the vertical axis velocity signal after Fourier transformation of the center point.

4. The sound source localization method according to claim 1, characterized in that: The preprocessing of the four sound signals to obtain four target sound signals includes: Parts of the preset frequency range are extracted from the four sound signals to obtain the four target sound signals.

5. The sound source localization method according to claim 1, characterized in that: The method of obtaining four sound signals of a sound source based on the four omnidirectional microphones also includes: A rectangular coordinate system is established, with the center of the circle surrounded by the differential microphone array as the origin of the rectangular coordinate system, and the direction where any omnidirectional microphone is located as the horizontal axis direction, wherein the distance between the omnidirectional microphone and the origin of the rectangular coordinate system is half of the preset diameter.

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