CN112788479B - Pickup array, pickup device and pickup performance optimization method - Google Patents

Abstract

Disclosed are a sound pickup array, a sound pickup apparatus, and a sound pickup performance optimization method. The adapter array includes a plurality of adapters, the adapter include directional first direction pickup advance sound passageway and directional with the back sound passageway of the opposite second direction pickup of first direction, a plurality of adapters are set up to, and the first direction that advances the sound passageway and points to of different adapters is the form of assembling. Therefore, the distance between the diaphragms of the sound pick-up can be reduced by adjusting the placing structure of the sound pick-up in the sound pick-up array, so that the high-frequency cut-off frequency of the sound pick-up array is extended, and the directional characteristic (such as high-frequency resolution) of the sound pick-up array is improved.

Description

Pickup array, pickup device and pickup performance optimization method

Technical Field

The present disclosure relates to the field of sound pickup array technologies, and in particular, to a sound pickup array, a sound pickup apparatus using the sound pickup array, and a sound pickup performance optimization method.

Background

In order to obtain a high-quality sound signal, a microphone array is widely used in various devices equipped with sound pickup devices, such as a voice interaction device supporting Automatic Speech Recognition (ASR) and an audio/video conference system.

In general, picking up a "best quality" sound Signal means that the acquired Signal has the greatest Signal-to-Noise Ratio (SNR), the least Reverberation (reverbration), and wider Frequency band (Frequency Response Range) information.

In many microphone array technologies, the physical size between two physical microphones determines the upper limit of the high frequency cut-off frequency, and reducing the microphone spacing also has a positive impact on the array directional Resolution (Resolution).

Therefore, a solution capable of reducing the microphone pitch to improve the sound pickup performance is required.

Disclosure of Invention

One technical problem to be solved by the present disclosure is to provide a scheme capable of reducing a sound pickup interval to improve sound pickup performance.

According to a first aspect of the present disclosure, there is provided a microphone array comprising: the sound pick-up comprises a forward sound channel pointing to a first direction for picking up sound and a backward sound channel pointing to a second direction opposite to the first direction for picking up sound, and the sound pick-up is set to be in a convergent shape in the first direction pointing to the forward sound channels of different sound pick-up.

Optionally, the first directions in which the forward sound channels of the different microphones are directed intersect at a point.

Optionally, the angle between two adjacent microphones is set to a first angle, which is substantially equal to 360 ° divided by the number of microphones of the microphone array.

Optionally, the plurality of microphones are at the same level.

Optionally, the plurality of microphones is at least three microphones.

Optionally, the microphone is a directional microphone.

Optionally, the microphone array further comprises: and the displacement device is used for adjusting the position of the sound pickup.

Optionally, the microphone array further comprises: and the switching device is used for switching the sound pickup which is put into use or switching the working state of the forward sound channel and/or the backward sound channel of the sound pickup.

According to a second aspect of the present disclosure, there is provided a microphone array comprising: the sound pick-up comprises a forward sound channel pointing to a first direction for picking up sound and a backward sound channel pointing to a second direction opposite to the first direction for picking up sound, the sound pick-ups are arranged at different levels, and the forward sound channels of the different sound pick-ups are parallel to the first direction pointed by the sound pick-ups.

Optionally, the plurality of microphones is at least three microphones.

Optionally, the microphone is a directional microphone.

According to a third aspect of the present disclosure, there is also provided a voice interaction device, including: a microphone array as described in the first or second aspect of the present disclosure.

According to a fourth aspect of the present disclosure, there is also provided a sound pickup apparatus including: a microphone array as described in the first or second aspect of the present disclosure.

According to a fifth aspect of the present disclosure, there is also provided a conference system including: a sound pickup apparatus according to a third aspect of the present disclosure.

According to a sixth aspect of the present disclosure, there is also provided a method of optimizing sound pickup performance of a sound pickup array, wherein the sound pickup array includes a plurality of sound pickups including a forward sound channel that is directed to pickup in a first direction and a backward sound channel that is directed to pickup in a second direction opposite to the first direction, the method including: the plurality of sound collectors are arranged such that first directions in which the forward sound channels of the different sound collectors are directed converge.

Optionally, the first directions in which the forward sound channels of the different microphones are directed intersect at a point.

Optionally, the angle between two adjacent microphones is set to a first angle, which is substantially equal to 360 ° divided by the number of microphones of the microphone array.

Optionally, the method further comprises: the plurality of microphones are set to be at the same level.

Optionally, the plurality of microphones is at least three microphones.

Optionally, the microphone is a directional microphone.

According to a seventh aspect of the present disclosure, there is also provided a method of optimizing sound pickup performance of a sound pickup array, wherein the sound pickup array includes a plurality of sound pickups including a forward sound channel that is directed to pickup in a first direction and a backward sound channel that is directed to pickup in a second direction opposite to the first direction, the method including: the plurality of microphones are arranged at different levels, and the first directions in which the forward sound channels of the different microphones are directed are parallel.

Optionally, the plurality of microphones is at least three microphones.

Optionally, the microphone is a directional microphone.

Therefore, the distance between the diaphragms of the sound pick-up can be reduced by adjusting the placing structure of the sound pick-up in the sound pick-up array, so that the high-frequency cut-off frequency of the sound pick-up array is extended, and the directional characteristic (such as high-frequency resolution) of the sound pick-up array is improved.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in greater detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.

Fig. 1 shows an internal structure diagram of a directional microphone.

Fig. 2 shows a schematic diagram of the path difference I generated by sound incident from front and rear.

Fig. 3 shows a polar response diagram of a Unidirectional Microphone (uni directional Microphone).

Fig. 4 shows a schematic diagram of three sound pickup devices, in which the sound pickup devices are arranged such that their sound paths are directed outward to pick up sound and their sound paths are directed toward the center of a circle to pick up sound.

Fig. 5 shows a schematic perspective view of the microphone array shown in fig. 4.

Fig. 6 illustrates a schematic diagram of a case where the back sound channel picks up sound outward and the front sound channel points to the center of a circle to pick up sound based on the present disclosure by taking three sound pickups as an example.

Fig. 7 shows a schematic diagram of the high frequency response of a microphone with a diaphragm of 1cm diameter.

Fig. 8 shows a schematic diagram of the high frequency response of a 2cm diameter circle on which the diaphragm of the microphone lies.

Fig. 9 shows a frequency response comparison graph when the diameter of the circle on which the diaphragm of the microphone is located is 1cm and 2cm, respectively.

Fig. 10 is a schematic diagram illustrating five sound pickup devices, in which the sound pickup device according to the present disclosure is configured such that a rear sound path is directed outward to pick up sound and a front sound path is directed to a circle center to pick up sound.

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

A Microphone refers to a device for picking up sound, and may be, for example, but not limited to, a Microphone (Microphone). Microphones can be divided into directional microphones and non-directional microphones. Directional microphones, such as electret directional microphones, are much more sensitive to sound coming from the front than to sound coming from the back. The directional pickup is provided with two openings, i.e., a forward sound channel and a backward sound channel, at both ends of the diaphragm. The forward sound channel may refer to a forward sound hole, and the backward sound channel may refer to a backward sound hole. The vibration of the diaphragm depends on the pressure difference across it according to the phase relationship. The damping (such as an acoustic filter) arranged at the front end of the sound inlet channel plays a time delay role, so that the sound transmitted from the back can reach the diaphragm from the front sound channel and the back sound channel simultaneously and be offset, and the polar diagram of the directional sound pick-up is heart-shaped.

Taking the directional Microphone as an example of a directional Microphone, the directional Microphone can be classified into, but not limited to, a Cardioid directional Microphone (cardiac Microphone), a sub-Cardioid directional Microphone (subcardiac Microphone), a transcardiac directional Microphone (supercardioid Microphone), a hypercardiac directional Microphone (Hypercardioid Microphone), and a Dipole directional Microphone (Dipole Microphone).

Fig. 1 shows an internal structure diagram of a directional microphone.

As shown in fig. 1, the directional microphone may be composed of, but not limited to, a Front Cavity C (Front Cavity), a rear Cavity D (Back Cavity), a forward sound channel a, a backward sound channel B, a Diaphragm E (Diaphragm), a damper F (Damp), an amplifier circuit (not shown in the figure), and the like.

The directional pickup may have various structural dimensions, such as 1045 and 6030, taking the directional pickup as a directional microphone. Of these 45, 30 characterize the thickness dimension information, i.e. 4.5mm and 3.0mm respectively.

The volume of the front sound cavity C of the sound pickup determines the high-frequency cut-off frequency of the sound pickup, and the smaller the volume, i.e. the smaller the sound capacitance, the smaller the value of the equivalent capacitor C, and the higher the cut-off frequency, so that the diaphragm E of the sound pickup is positioned close to the front sound cavity C, i.e. the position of the diaphragm E of the sound pickup in front of the front sound cavity C. The front sound cavity and the rear sound cavity D jointly form the band-pass frequency response characteristic of the sound pick-up.

The sound enters from the sound inlet channel A of the sound pick-up and is diffracted into the sound inlet channel B, and then the sound inlet channel B and the damping F jointly act on the diaphragm E. As shown in fig. 2, sound is incident through the front diaphragm and diffracted to the sound inlet channel behind the microphone, and a certain Acoustic path difference I (Acoustic path) is incident from the front and from the back. The phase difference caused by diffraction and the sound pressure difference caused by damping together form a directional beam pattern (BeamPattern).

Fig. 3 shows a polar response diagram of a Unidirectional Microphone (uni directional Microphone). The description of the polarity response diagram is omitted here.

When the pickup array formed based on the directional pickup is adopted for omnidirectional pickup, the energy attenuation of signals is generated between every two pickups. Taking a sound pickup device in a conference system as an example, this may cause that the sound is suddenly loud and weak when speaking at different angles, which affects the conference experience.

The loss of the angle can be compensated by forming a virtual microphone by more than two microphones, but the cut-off frequency of the high frequency is limited by the physical distance between the microphones, and the Resolution (Resolution) of the high frequency directivity is worse as the cut-off frequency of the high frequency is lower as the distance is larger. Wherein the physical spacing between pickups may be characterized by the distance between the diaphragms of the pickups.

The directional pickup is based on the physical structure of the directional pickup (hereinafter referred to as pickup), the minimum distance between the pickups is optimized by adjusting the placement mode of the pickup, the high-frequency cut-off frequency is improved, and the voice distortion caused by aliasing of the high-frequency is prevented. The aliasing distortion is high frequency domain aliasing that causes a low cut-off frequency and a low high frequency resolution.

In the present disclosure, the sound pickup includes a forward sound channel that is directed to a first direction for sound pickup and a backward sound channel that is directed to a second direction opposite to the first direction for sound pickup, where the first direction may be regarded as a sound pickup direction of the forward sound channel and the second direction may be regarded as a sound pickup direction of the backward sound channel. For the structure of the sound pickup, the above description in conjunction with fig. 1 can be referred to, and the details are not repeated here.

The present disclosure proposes that the plurality of sound collectors may be arranged such that the first direction in which the forward sound channels of the different sound collectors are directed is convergent.

The present disclosure states "convergence" as opposed to "divergence". The first directions pointed by the forward sound channels of different sound pickups are convergent, that is, the first directions pointed by the forward sound channels of different sound pickups are not divergent. More specifically, the sound pickup directions (i.e., the first directions) of the forward sound channels of the different sound pickups may intersect at one or more points, preferably at one point.

The plurality of forward sound channels and the plurality of backward sound channels may be included in each sound pickup, and the first direction in which the forward sound channels of different sound pickups according to the present disclosure are directed may refer to a first direction in which the forward sound channels at the same distributed positions in different sound pickups are directed, for example, may refer to a first direction in which the forward sound channels in different sound pickups are directed near an intermediate position (for example, at a dotted line in fig. 1).

According to the physical structure of the sound pickup (for example, the structure shown in fig. 1), the diaphragms of the sound pickup are arranged near the front sound cavities, and the sound advancing channels are also arranged near the front sound cavities, so that the distance between the diaphragms of different sound pickups, that is, the distance between the sound pickups, can be reduced in the case that the sound pickup directions (i.e., the first direction) of the sound advancing channels of different sound pickups converge.

In this disclosure, can set up the adapter ring shape to make the pickup direction of the advancing sound channel of different adapters intersect in a bit, the contained angle between two adjacent adapters this moment is set up to first contained angle, and first contained angle can be equallyd equal to 360 substantially and divide by adapter quantity. Wherein the number of microphones may be set to at least three. And multiple pickups may preferably be at the same level to avoid comb filtering of high frequencies due to sound reflections at different heights. The plurality of microphones may be at the same level, which means that the plurality of microphones are at the same level when the microphone array is put into use.

Take three annularly arranged pickups as an example: fig. 4 is a schematic diagram showing the sound pickup with the forward sound channel facing outwards and the backward sound channel pointing to the circle center; FIG. 5 is a schematic view of the three-dimensional arrangement of the structure of FIG. 4; fig. 6 shows a schematic diagram of a rear sound channel picking up sound outwards and a front sound channel pointing to a circle center to pick up sound according to the present disclosure.

Reference numeral 10 shown in fig. 4 to 6 denotes the side of the sound pickup where the sound path advances, and 20 denotes the side of the sound pickup where the sound path advances backward.

When the forward sound channel of the sound pick-up is picked up outwards and the backward sound channel points to the circle center, the diameter of the circle where the diaphragm of the sound pick-up is located is recorded as D1, when the backward sound channel of the sound pick-up is picked up outwards and the forward sound channel points to the circle center, the diameter of the circle where the diaphragm of the sound pick-up is located is recorded as D2, and D1 is obviously larger than D2. Taking 1045 microphone as an example, the diameter of the circle where the microphone diaphragm is located can be reduced from 18mm to 10mm by pointing the forward sound channel of the microphone to the center of the circle for sound pickup.

The distance between the diaphragms of the sound pick-up is positively correlated with the diameter of a circle where the diaphragm of the sound pick-up is located, namely the smaller the diameter of the circle where the diaphragm of the sound pick-up is located, the smaller the distance between the diaphragms of the sound pick-up is. Therefore, the placing mode of the sound pick-up is adjusted, the minimum distance between the sound pick-up can be optimized, the high-frequency cut-off frequency is improved, and the voice distortion caused by aliasing of the high-frequency is prevented.

Fig. 7 shows a schematic diagram of the high frequency response of a microphone with a diaphragm of 1cm diameter.

Fig. 8 shows a schematic diagram of the high frequency response of a 2cm diameter circle on which the diaphragm of the microphone lies.

As can be seen from fig. 7 and 8, the diameter of the circle on which the diaphragm of the microphone is located is reduced, so that the high-frequency response is improved, and the index of the high-frequency directional resolution is optimized.

Fig. 9 shows a frequency response comparison graph when the diaphragm of the microphone is located in a circle having a diameter of 1cm and 2cm, respectively.

As can be seen from fig. 9, reducing the diameter of the circle on which the diaphragm of the microphone is located improves the directional resolution, and optimizes the high-frequency cutoff frequency.

The present disclosure may be applied to a sound pickup array composed of more (three or more) sound pickups, and as shown in fig. 10, the present disclosure may be applied to a sound pickup array composed of five sound pickups. The five sound pickups may be arranged in a ring shape, and the sound pickup directions of the forward sound channels of the different sound pickups are directed to the same point (i.e., the position of the center of the circle).

As an alternative, the first directions in which the forward sound channels of the different microphones are directed may also be parallel, for example, the different microphones may be placed vertically, so that the projections of the diaphragms of the different microphones on the horizontal plane are located at the same point, which may also reduce the distance between the diaphragms of the microphones, but at this time the different microphones are at different horizontal heights, so that the high frequency may cause comb filtering due to sound wave reflection.

In summary, the present disclosure can reduce the distance between the diaphragms of the microphone by adjusting the placement structure of the microphones in the microphone array, so that the Cut-Off Frequency (Cut-Off Frequency) of the microphone array is extended, and the directional characteristic (Beam Pattern) of the microphone array, such as the high Frequency Resolution (Resolution), is improved.

The present disclosure may therefore be embodied as a microphone array that may include a plurality of microphones including a forward sound path that is directed to a first direction to pick up sound and a backward sound path that is directed to a second direction, opposite the first direction, to pick up sound. The plurality of sound collectors are arranged such that the first directions in which the forward sound channels of the different sound collectors are directed converge. Wherein the plurality of microphones may be at least three microphones. Preferably, the first directions in which the forward sound channels of the different microphones are directed intersect at a point. The angle between two adjacent pickups is set to a first angle substantially equal to 360 divided by the number of pickups the array has. The plurality of pickups are at the same level. For details related to the scheme, see the above description, and are not repeated herein.

The present disclosure may also be embodied as a microphone array that may include a plurality of microphones including a forward sound channel that is directed to a first direction to pick up sound and a backward sound channel that is directed to a second direction opposite to the first direction to pick up sound. The plurality of microphones are arranged so that, at different levels, the first directions in which the forward sound channels of the different microphones are directed are parallel. For details related to the scheme, see the above description, and are not repeated herein.

The microphone array of the present disclosure may further include a displacement device for adjusting where the microphone is located. That is, the positions of the sound collectors in the sound collector array can be adjusted by the displacement means, so that the positional arrangement of the sound collectors having the best sound collecting performance can be determined by adjusting the positions of the sound collectors. Taking the three annularly arranged microphones shown in fig. 4 as an example, the positions of the three microphones can be adjusted by the displacement means so that the three microphones are located on a circle with a larger diameter.

The microphone array of the present disclosure may also include a switching device. The switching device may be used to select the sound pickup to be put into use, for example, the sound pickup array may include a plurality of sound pickups arranged in a ring shape, and the number of sound pickups participating in sound pickup may be selected by the switching device, for example, 3 sound pickups may be selected to participate in sound pickup, and 6 sound pickups may also be selected to participate in sound pickup. And/or the switch device can also be used for switching the working state of the forward sound channel and/or the backward sound channel of the sound pick-up, and switching the working state of the forward sound channel and/or the backward sound channel, namely controlling the on or off of the forward sound channel and/or the backward sound channel of the sound pick-up under the action of the switch device.

The present disclosure may also be embodied as a voice interaction device, which may include the microphone array mentioned above. The voice interaction device may include, but is not limited to, various devices supporting voice interaction, such as a smart speaker, a smart phone, a vehicle, etc., which integrate a microphone array.

The present disclosure may also be realized as a sound pickup apparatus, which may include the above-mentioned sound pickup array.

The present disclosure can also be realized as a conference system based on the sound pickup apparatus described above, which may be an audio/video conference system.

The present disclosure may also be realized as a method of optimizing sound pickup performance of a sound pickup array, wherein the sound pickup array includes a plurality of sound pickups including a forward sound channel that points to pickup in a first direction and a backward sound channel that points to pickup in a second direction opposite to the first direction, the method including: the plurality of sound collectors are arranged such that first directions in which forward sound channels of different sound collectors are directed converge. Preferably, the first directions in which the forward sound channels of the different microphones are directed intersect at a point. The angle between two adjacent pickups is set to a first angle substantially equal to 360 divided by the number of pickups the array has. The plurality of pickups are at the same level. For details related to the scheme, see the above description, and are not repeated herein.

The present disclosure may also be realized as a method of optimizing sound pickup performance of a sound pickup array, wherein the sound pickup array includes a plurality of sound pickups including a forward sound channel that picks up sound in a first direction and a backward sound channel that picks up sound in a second direction opposite to the first direction, the method including: the plurality of microphones are arranged at different levels, and the first directions in which the forward sound channels of the different microphones are directed are parallel. For details related to the scheme, see the above description, and are not repeated herein.

The microphone array, the voice interaction apparatus, the sound pickup apparatus, the conference system, and the method of optimizing the sound pickup performance of the microphone array according to the present disclosure have been described in detail above with reference to the accompanying drawings.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems and methods according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (13)

1. A pickup array, comprising:

a plurality of pickups, the pickups include the preceding sound channel of directional first direction pickup and the directional back sound channel of second direction pickup opposite with the first direction, a plurality of pickups are at least three pickups, the pickups are directive sound pickups, the pickups still include preceding sound chamber and diaphragm, the diaphragm all is close to the setting of preceding sound chamber with the preceding sound channel,

the plurality of sound collectors are arranged in a manner that the first directions pointed by the forward sound channels of different sound collectors converge so as to reduce the distance between the diaphragms of different sound collectors.

2. The pickup array of claim 1,

the first directions in which the forward sound channels of the different microphones are directed intersect at a point.

3. The pickup array of claim 2,

an angle between two adjacent microphones is set to a first angle substantially equal to 360 degrees divided by the number of microphones of the microphone array.

4. The pickup array of claim 1,

the plurality of microphones are at the same level.

5. The pickup array of claim 1, further comprising:

and the displacement device is used for adjusting the position of the sound pickup.

6. The pickup array of claim 1, further comprising:

switching means for selecting a sound pickup to be put into use, and/or for switching an operating state of a forward sound channel and/or a backward sound channel of the sound pickup.

7. A voice interaction device, comprising:

a pick-up array as claimed in any one of claims 1 to 6.

8. A sound pickup apparatus comprising:

a pick-up array as claimed in any one of claims 1 to 6.

9. A conferencing system, comprising:

the sound pickup device according to claim 8.

10. A method of optimizing pickup performance of a pickup array, wherein the pickup array includes a plurality of pickups, the pickups include a forward sound path that points to a first direction pickup and a backward sound path that points to a second direction pickup opposite to the first direction, the plurality of pickups are at least three pickups, the pickups are directional pickups, the pickups further include a front sound cavity and a diaphragm, the diaphragm and the forward sound path both being disposed proximate to the front sound cavity, the method comprising:

the plurality of sound collectors are arranged such that the first directions in which the sound-feeding channels of the different sound collectors are directed converge, so as to reduce the distance between the diaphragms of the different sound collectors.

11. The method of claim 10, wherein,

the first directions in which the forward sound channels of the different microphones are directed intersect at a point.

12. The method of claim 10, wherein,

an angle between two adjacent microphones is set to a first angle substantially equal to 360 degrees divided by the number of microphones of the microphone array.

13. The method of claim 10, further comprising:

the plurality of microphones are disposed at the same level.

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