Three-dimensional microphone array for acquiring sound and pickup device

Abstract

The present invention provides a three-dimensional microphone array for acquiring sound, the microphone array comprising a plurality of sub-microphone arrays for pickup, each sub-microphone array comprising a plurality of microphones, the plurality of microphones being placed on a front surface of a substrate; wherein the orthographic projections of the plurality of microphones in each sub-microphone array in the horizontal plane direction are distributed along the ray direction, and the ray where the orthographic projection of each sub-microphone array is located is emitted to the edge of the substrate by taking the center of the orthographic projection of the substrate in the horizontal plane direction as a source; the front surface of the substrate is in a non-planar shape. Compared with the prior art, the front surface of the substrate is in the non-planar shape, so that the microphone array arranged on the substrate breaks through the planar limitation of a traditional two-dimensional array in a low-cost, simple and convenient mode, non-coplanar three-dimensional layout is achieved, and all-dimensional accurate capture of a sound source in a three-dimensional space is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of microphone arrays, and in particular to a topological arrangement of microphones in space. Background Art

[0002] Microphone arrays play an important role in video conferencing. The speakers need microphones to clearly capture sound signals so that they can be accurately transmitted to other participants. In a meeting, microphones need to be able to distinguish different sound sources and collect everyone's voice as clearly as possible to avoid confusion and mutual interference. For example, when several speakers are speaking and discussing at the same time, microphones can pick up sounds from different directions so that sounds from all directions can be transmitted clearly.

[0003] The existing technical solutions usually use one-dimensional or two-dimensional array microphones combined with sound source localization (DOA) and array beamforming (BF) algorithms for sound localization and collection. Common microphone array topologies include uniform linear array (ULA), circular array, spiral array, cross array, rectangular array, etc. Among them, the one-dimensional array has a simple structure, low cost, and is easy to deploy and implement. It can achieve horizontal positioning and directional sound pickup. It is usually used in devices such as video conferencing all-in-one machines and large conference flat panels deployed in front of the conference room. Compared with the one-dimensional array, the two-dimensional array can obtain richer sound source location information, can achieve 360-degree beam pointing and two-dimensional sound source localization capabilities, and is mostly used in applications such as smart speakers, ceiling microphones, and acoustic imaging. Among the microphones with the above array topology, the one-dimensional array can receive less spatiotemporal information and can only locate the azimuth in the horizontal direction, but cannot obtain information on the pitch angle of the sound source. Although the two-dimensional microphone array improves the shortcoming of the one-dimensional microphone array that can only give the azimuth of the sound source and can calculate the pitch angle, it cannot obtain the distance of the sound source relative to the microphone. In addition, as the pitch angle of the sound source increases, the side lobes of the beam of the planar array will also deteriorate, which will not only cause deviations in the sound source positioning accuracy and resolution at different pitch angles, but also change the clarity and consistency of the sound pickup of the beam. In other words, the array topology of the existing microphone array cannot clearly capture the voices of speakers in all directions in a multi-person discussion scenario.

[0004] Therefore, there is an urgent need for a microphone array that can improve the quality of sound collection and the ability to localize spatial sound sources. Summary of the invention

[0005] The present invention provides a three-dimensional microphone array and a sound pickup device for acquiring sound. The three-dimensional microphone array is composed of a plurality of sub-microphone arrays that are not in the same plane, so as to solve the problem that traditional one-dimensional and two-dimensional microphone arrays cannot capture the sound of speakers in all directions and cannot accurately locate the height of the speaker's voice, thereby greatly improving the quality of sound collection and the ability to locate the sound source in space.

[0006] In order to achieve the above-mentioned object, the present invention provides a three-dimensional microphone array for acquiring sound, the microphone array comprising: a substrate having a front surface and a rear surface; a plurality of sub-microphone arrays for picking up sound, each sub-microphone array comprising a plurality of microphones, and the plurality of microphones are placed on the front surface of the substrate. The orthographic projections of the plurality of microphones in each sub-microphone array in the horizontal plane direction are distributed along the ray direction, and the ray where the orthographic projection of each sub-microphone array is located is emitted to the edge of the substrate with the center of the orthographic projection of the substrate in the horizontal plane direction as the source. The front surface of the substrate has a non-planar shape.

[0007] As a preferred solution, the multiple microphones in the sub-microphone array are not coplanar.

[0008] As a preferred solution, multiple microphones in the sub-microphone array are coplanar.

[0009] As a preferred solution, at least one sub-microphone array arranged in a ring is further placed at the center of the substrate, and the center of the sub-microphone array arranged in a ring coincides with the center of the substrate.

[0010] As a preferred solution, the straight line where the orthographic projection of each sub-microphone array lies is emitted to the edge of the substrate from the annularly arranged sub-microphone array farthest from the center of the substrate as a source.

[0011] As a preferred solution, the non-planar shape of the front surface of the substrate is wavy, and the wavy front surface has a plurality of raised areas arranged in sequence in a first direction (the raised areas are arranged in a straight line or in a ring).

[0012] As a preferred solution, the multiple microphones of the sub-microphone array are placed sequentially along the crests and troughs of the wavy front surface.

[0013] As a preferred solution, the multiple microphones of the sub-microphone array are placed sequentially along the slope of the wavy front surface.

[0014] As a preferred solution, the center of the substrate is higher than the edge of the substrate.

[0015] As a preferred solution, the substrate is formed by splicing a plurality of sub-substrates.

[0016] As a preferred solution, the substrate is formed by splicing a plurality of fan-shaped sub-substrates in pairs.

[0017] As a preferred solution, the microphones in the sub-microphone arrays are arranged in the same manner.

[0018] The present invention also provides a sound pickup device, which at least includes the aforementioned three-dimensional microphone array for acquiring sound. Since the sound pickup device uses a three-dimensional microphone array, the accuracy and sound quality of sound collection in three-dimensional space are greatly improved, especially in scenes with strict requirements on sound positioning, such as concerts, large public speeches, and high-level conferences, etc., it will show excellent expressiveness. The sound pickup device of the present invention can not only achieve three-dimensional precise positioning of the sound source, but also maintain the consistency and clarity of sound collection in a complex sound field environment, providing users with an unprecedented auditory experience.

[0019] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the present invention provides a three-dimensional microphone array for acquiring sound, the microphone array includes a plurality of sub-microphone arrays for picking up sound, each sub-microphone array includes a plurality of microphones, and the plurality of microphones are placed on the front surface of a substrate; wherein the orthographic projections of the plurality of microphones in each sub-microphone array in the horizontal plane direction are distributed along the ray direction, and the ray where the orthographic projection of each sub-microphone array is located is emitted to the edge of the substrate from the center of the orthographic projection of the substrate in the horizontal plane direction as the source; wherein the front surface of the substrate is a non-planar shape. Compared with the prior art, the present application uses the non-planar shape of the front surface of the substrate to enable the microphone array arranged on the substrate to break the planar limitation of the traditional two-dimensional array in a low-cost and simple and convenient manner, realize the non-coplanar three-dimensional layout of the microphone array, and enhance the accurate capture of the sound source in all directions in the three-dimensional space. Since the shape and number of the sub-microphone arrays of the three-dimensional microphone array can be adjusted arbitrarily, that is, they can be flexibly adjusted according to actual needs, which not only improves the adaptability of the entire three-dimensional microphone array, but also ensures that the optimal sound collection efficiency can be achieved in various acoustic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : A schematic diagram of an application scenario of a three-dimensional microphone array for acquiring sound provided by the present invention.

[0021] Figure 2A : A schematic diagram of the stereoscopic structure of an embodiment of a three-dimensional microphone array for acquiring sound provided by the present invention.

[0022] Figure 2B : A schematic diagram of the top view of an embodiment of a three-dimensional microphone array for acquiring sound provided by the present invention.

[0023] Figure 2C : A cross-sectional view of an embodiment at AA in FIG. 2b provided by the present invention.

[0024] Figure 2D : A cross-sectional view of another embodiment at AA in FIG. 2b provided by the present invention.

[0025] Figure 2E : A cross-sectional view of another embodiment at AA in FIG. 2b provided by the present invention.

[0026] Figure 2F : A cross-sectional view of another embodiment at AA in FIG. 2b provided by the present invention.

[0027] Figure 2G : A cross-sectional view of another embodiment at AA in FIG. 2b provided by the present invention.

[0028] Figure 3 : A schematic diagram of the top view of another embodiment of a three-dimensional microphone array for acquiring sound provided by the present invention.

[0029] Figure 4 : A schematic diagram of the top view of another embodiment of a three-dimensional microphone array for acquiring sound provided by the present invention.

[0030] Figure 5 : A structural schematic diagram of a substrate of an embodiment of a three-dimensional microphone array for acquiring sound provided by the present invention. DETAILED DESCRIPTION

[0031] Some of the terms used in this application are described below.

[0032] An array microphone refers to a microphone system composed of multiple microphones (acoustic sensors) arranged according to certain rules. It is a sound pickup device used to collect and process the spatial characteristics of the sound field.

[0033] Microphone refers to an acoustic sensor, which is a transducer that converts sound signals into electrical signals. It mainly realizes the conversion of sound into electrical signals based on the principles of electromagnetic induction, capacitance change, piezoelectric effect, etc. There are dynamic microphones, condenser microphones, electromagnetic microphones, and piezoelectric microphones.

[0034] Other terms

[0035] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0036] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0037] In the description of this application, unless otherwise specified, "plurality" means two or more. The term "at least one" in this application means one or more, and the term "plurality" in this application means two or more.

[0038] It should be understood that the "one embodiment", "an embodiment", "a possible implementation" mentioned in the specification means that the specific features, structures or characteristics related to the embodiment or implementation are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment", "a possible implementation" appearing throughout the specification may not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Embodiment:

[0041] The present invention provides a three-dimensional microphone array and a sound pickup device for acquiring sound. The three-dimensional microphone array is composed of a plurality of sub-microphone arrays that are not in the same plane, so as to solve the problem that traditional one-dimensional and two-dimensional microphone arrays cannot capture the sound of speakers in all directions and cannot accurately locate the height of the speaker's voice, thereby greatly improving the quality of sound collection and the ability to locate the sound source in space.

[0042] Reference Figure 1An application scenario of a three-dimensional microphone array 100 for acquiring sound is shown. The three-dimensional microphone array 100 is generally used in a conference room with a video conferencing function. The three-dimensional microphone array 100 can be placed in the center of the desktop, in front of the speaker, at the edge of the conference room podium, or on the ceiling. Preferably, the three-dimensional microphone array 100 is usually installed on the ceiling of a conference place such as a conference room. Its position is relatively high, and it can cover a larger area, fully capturing the voices of speakers from all directions in the conference room, and can avoid the situation where the sound collection in some areas is poor due to the limited placement of the microphone. It is precisely because of the particularity of its installation position that the three-dimensional microphone array 100 needs to have a strong three-dimensional sound source positioning capability to clearly capture the voices of speakers from all directions, ensuring that the voices of participants can be well picked up no matter how they move or change positions in the conference room, and maintaining the stability and balance of sound collection.

[0043] Reference Figure 2A-2C A stereoscopic view, a top view and a cross-sectional view of an embodiment of a three-dimensional microphone array 100 for acquiring sound are respectively shown. In this embodiment, the three-dimensional microphone array 100 includes a substrate 10, the substrate 10 has a front surface 10a and a rear surface 10b, and a plurality of sub-microphone arrays 20 for picking up sound. Each sub-microphone array includes a plurality of microphones 20a, and the plurality of microphones are placed on the front surface 10a of the substrate 10. The orthographic projections of the plurality of microphones 20a in each sub-microphone array 20 in the horizontal plane direction are distributed along the ray direction, and the ray where the orthographic projection of each sub-microphone array 20 is located is emitted from the center B of the orthographic projection of the substrate in the horizontal plane direction to the edge of the substrate. The front surface 10a of the substrate is a non-planar shape. This embodiment takes the example where the center of the front surface 10a of the substrate is slightly higher than the edge of the substrate, as shown in FIG. Figures 2C to 2D As shown, there is a height difference H between the center B of the substrate and the edge C of the front surface of the substrate, and the height difference H is approximately 3 mm to 3 cm. Because each sub-microphone array 20 includes multiple microphones 20a, and there are height differences between the microphones 20a in the same sub-microphone array 20, at least two or more sub-microphone arrays are not in the same plane in space, forming a three-dimensional sound collection system. By improving the elevation directivity of the microphone array, higher positioning accuracy can be obtained at long distances, thereby greatly improving the sound source positioning capability in three-dimensional space, making it more suitable for use in three-dimensional space.

[0044] In one embodiment, the multiple microphones 20a in each sub-microphone array 20 are coplanar, but there is a height difference between the multiple microphones in each sub-microphone array, and adjacent microphones are arranged at equal intervals or with increasing intervals from the inside to the outside. The arrangement of the microphones in each sub-microphone array can be the same or different. Figure 2CAs shown, the distances between adjacent microphones increase from the inside to the outside. Taking the sub-microphone array 20 including 8 microphones as an example, the horizontal distances between each microphone array and the center B of the substrate are d1 to d8 (not marked in the figure), where d1=0m, d2=0.021m, d3=0.044m, d4=0.065m, d5=0.090m, d6=0.130m, d7=0.170m, d8=0.255m. This embodiment takes the example of 8 microphones in each sub-microphone array 20. The actual number of sub-microphone arrays and microphones in each sub-microphone array 20 can be designed based on the parameter properties of the three-dimensional microphone array, such as white noise gain or directivity. Figure 3 As shown, the microphones in each sub-microphone array 20 are arranged differently, for example, the microphone spacing in at least one sub-microphone array 20 is different from the microphone spacing in its adjacent sub-microphone array.

[0045] In one embodiment, the multiple microphones 20a in each sub-microphone array 20 are not coplanar. Since the substrate 10 is non-planar, such as the substrate is wavy or curved, the multiple microphones 20a are located on different planes. Figure 2E-2G As shown, the front surface 10a of the substrate is wavy or arc-shaped, and the multiple adjacent microphones 20a in each sub-microphone array 20 are arranged at equal intervals or are distributed on the non-planar substrate 10 with increasing intervals from the inside to the outside. Since each microphone is arranged on the uneven substrate plane to form a three-dimensional layout, it can provide three-dimensional information, thereby realizing three-dimensional 360-degree beamforming. The three-dimensional layout of the microphone enables the sound source localization capability to clearly capture the voices of speakers in all directions, ensuring that the voices of participants can be well picked up no matter how they move or change positions in the conference room, and maintaining the stability and balance of sound collection.

[0046] In one embodiment, the non-planar shape of the front surface of the substrate is wavy, and the wavy front surface has a plurality of raised areas arranged in sequence in the first direction, and the raised areas are linear or annularly distributed. Figure 2F As shown, the multiple microphones of the sub-microphone array 20 are sequentially placed along the crests and troughs of the wavy front surface. Figure 2G As shown, multiple microphones of the sub-microphone array 20 are sequentially placed along the slope of the wavy front surface. Since the wavy substrate is a non-flat substrate, most of the microphones on the substrate are not coplanar, thereby realizing a three-dimensional layout of the microphone array in a low-cost manner, breaking the plane limitation of the traditional two-dimensional array. By arranging microphones on a non-flat substrate, it is possible to configure microphones on multiple planes of different heights, so as to achieve the effect of accurately capturing the sound source in all directions in three-dimensional space.

[0047] Reference Figure 4 One specific embodiment of a three-dimensional microphone array 100 for acquiring sound is shown. The difference between this embodiment and the previous embodiment is that at least one annularly arranged sub-microphone array 30' is placed in the center of the substrate, and the center of the annularly arranged sub-microphone array 30' coincides with the center of the substrate. This embodiment takes four circular microphones 30' as an example. The number of sub-microphone arrays 30' actually arranged in annular shapes can be designed based on the parameter properties of the three-dimensional microphone array, such as white noise gain or directivity, to determine the number of sub-microphone arrays and the number of microphones. The straight line where the orthographic projection of each sub-microphone array 20' lies is emitted to the edge of the substrate with the annularly arranged sub-microphone array 30' farthest from the center of the substrate as the source. That is, the arrangement of microphones in each sub-microphone array on the substrate may be different. For example Figure 4 As shown, the fourth ring is the farthest from the center of the substrate, and the straight line of the sub-microphone array 20' is emitted from the edge of the substrate with the microphone of the fourth ring as the source. In addition, the number of microphones in each ring of the sub-microphone array arranged in a ring and the sub-microphone array 30' can be the same or different. The front surface of the substrate in this embodiment is not flat, that is, the front surface of the substrate is wavy, arc-shaped, or there is a height difference H between the substrate center B and the edge C of the front surface of the substrate, so that the two sub-microphones 30' and the microphones in the sub-microphone array 20' are not coplanar, and a three-dimensional layout of the microphone array can be formed at a relatively low cost, so as to achieve accurate capture of the sound source in all directions in three-dimensional space. Since the shape and number of the sub-microphone arrays of the three-dimensional microphone array can be adjusted arbitrarily, the number and arrangement of microphones are allowed to be flexibly adjusted according to actual needs, which not only improves the adaptability of the three-dimensional microphone array for acquiring sound, but also ensures that the optimal sound collection efficiency can be achieved in various acoustic environments.

[0048] Reference Figure 5 One specific embodiment of a three-dimensional microphone array 100 for acquiring sound is shown. The difference between this embodiment and the previous embodiment is that the substrate 10" is formed by splicing a plurality of sub-substrates, and the substrate in this embodiment is formed by splicing a plurality of fan-shaped sub-substrates in pairs. As shown in the figure, the substrate 10" includes a plurality of fan-shaped sub-substrates 10c". This embodiment takes 8 fan-shaped sub-substrates 10c" as an example. The height of each fan-shaped sub-substrate 10c" can be adjusted so that there is a height difference between the center B of the substrate and the edge C of the front surface of the substrate, so that the front surface of the substrate is a non-coplanar surface, and the height difference of each fan-shaped sub-substrate can be freely adjusted, which increases the dynamic adjustability of the three-dimensional microphone configuration strategy and improves the adaptability of the system.

[0049] Reference Figure 1A sound pickup device 100 is provided, and the sound pickup device includes at least one of the three-dimensional microphone arrays for acquiring sound in the aforementioned embodiment. Since the sound pickup device 100 uses the aforementioned three-dimensional microphone array, the accuracy and sound quality of sound collection in three-dimensional space are greatly improved, especially in scenes with strict requirements on sound positioning, such as concerts, large public speeches, and high-level conferences, etc., it will show excellent expressiveness. Through the sound pickup device 100 of the present invention, not only can the three-dimensional precise positioning of the sound source be achieved, but also the consistency and clarity of sound collection can be maintained in a complex sound field environment, providing users with an unprecedented auditory experience.

[0050] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0051] The present invention provides a three-dimensional microphone array for acquiring sound, the microphone array includes a plurality of sub-microphone arrays for picking up sound, each sub-microphone array includes a plurality of microphones, and the plurality of microphones are placed on the front surface of a substrate; wherein the orthographic projections of the plurality of microphones in each sub-microphone array in the horizontal plane direction are distributed along the ray direction, and the ray where the orthographic projection of each sub-microphone array is located is emitted to the edge of the substrate with the center of the orthographic projection of the substrate in the horizontal plane direction as the source; wherein the front surface of the substrate is a non-planar shape. Compared with the prior art, the present application breaks the planar limitation of the traditional two-dimensional array in a low-cost and simple and convenient manner by making the front surface of the substrate a non-planar shape, realizes a non-coplanar three-dimensional layout, and enhances the accurate capture of the sound source in all directions in three-dimensional space. Since the shape and number of the sub-microphone arrays of the three-dimensional microphone array can be adjusted arbitrarily, the number and arrangement of microphones are allowed to be flexibly adjusted according to actual needs, which not only improves the adaptability of the system, but also ensures that the optimal sound collection efficiency can be achieved in various acoustic environments.

[0052] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A three-dimensional microphone array for acquiring sound, the microphone array comprising: a substrate having a front surface and a rear surface; A plurality of sub-microphone arrays for picking up sound, each of the sub-microphone arrays comprising a plurality of microphones, and the plurality of microphones are placed on the front surface of the substrate; The orthographic projections of the plurality of microphones in each of the sub-microphone arrays in the horizontal plane direction are distributed along the ray direction, and the ray where the orthographic projection of each sub-microphone array is located is emitted from the center of the orthographic projection of the substrate in the horizontal plane direction to the edge of the substrate; Wherein, the front surface of the substrate is a non-planar shape.

2. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: The plurality of microphones in the sub-microphone array are not coplanar.

3. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: The plurality of microphones in the sub-microphone array are coplanar.

4. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: At least one sub-microphone array arranged in a ring is also placed at the center of the substrate, and the center of the sub-microphone array arranged in a ring coincides with the center of the substrate.

5. The three-dimensional microphone array for acquiring sound according to claim 4, characterized in that: The straight line where the orthographic projection of each sub-microphone array is located is emitted to the edge of the substrate from the annularly arranged sub-microphone array farthest from the center of the substrate as a source.

6. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: The non-planar shape of the front surface of the substrate is a wave shape, and the wave-shaped front surface has a plurality of convex areas arranged in sequence in a first direction.

7. The three-dimensional microphone array for acquiring sound according to claim 6, characterized in that: The plurality of microphones of the sub-microphone array are sequentially placed along the crests and troughs of the wavy front surface.

8. The three-dimensional microphone array for acquiring sound according to claim 6, characterized in that: The multiple microphones of the sub-microphone array are placed in sequence along the slope of the wavy front surface.

9. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: The center of the substrate is higher than the edge of the substrate.

10. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: The substrate is formed by splicing a plurality of sub-substrates.

11. The three-dimensional microphone array for acquiring sound according to claim 10, characterized in that: The substrate is formed by splicing a plurality of fan-shaped sub-substrates in pairs.

12. The three-dimensional microphone array for acquiring sound according to claim 1, characterized in that: The microphones in each of the sub-microphone arrays are arranged in the same manner.

13. A sound pickup device, characterized in that: At least: A three-dimensional microphone array for acquiring sound as described in claims 1-13.

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