JP6832507B2 - Manufacturing method of microphone array device, microphone array system and microphone array device - Google Patents

Description

The present disclosure includes a microphone array system for picking up a sound, a method of manufacturing a microphone array system and a microphone array device.

Conventionally, there is known a system in which an image is captured by a camera in a predetermined area and sound is picked up by a microphone array (see Patent Document 1). The microphone array is installed on the ceiling or stand in the room, and forms directivity in the direction toward the sound collecting position to collect sound.

JP 2015-209241

Many conventional cameras are waterproof outdoor cameras. On the other hand, the conventional microphone array is often installed downward on the ceiling, and is a specification for indoor use, and waterproofness is not considered. Therefore, when the microphone array is used outdoors, for example, when it is installed on the ground or on a stand and used in an upward state, water intrusion due to rainfall or the like is expected. Therefore, as a specification for outdoor use, it is necessary to improve the waterproofness of the microphone array.

The present disclosure has been made in view of the above circumstances, and provides a microphone array device, a microphone array system, and a method for manufacturing a microphone array device capable of improving the waterproofness of the microphone array.

Microphone array system of the present disclosure provides a microphone array system for picking up an omnidirectional sound, the housing having a plurality of holes are formed face, it is inserted into the plurality of holes, a surface of the housing A plurality of microphone elements attached so as to be exposed from the front side, a plurality of rubber members surrounding the side surfaces and the back surface of the plurality of microphone elements, and a pressing member for pressing the rubber member from the back side of the surface of the housing. When, with the inner wall of the front Kiana, said from the back side of the housing towards the front side are formed on the reduced diameter tapered, sidewalls of the rubber member is formed in a tapered shape along the inner wall of the bore The surface of the housing and the sound collecting surface of the microphone element are located on the same plane in a state where the inner wall of the hole and the side wall of the rubber member face each other and come into contact with each other .

The method for manufacturing a microphone array device of the present disclosure is a method for manufacturing a microphone array device that collects sound in all directions, and the plurality of microphones are formed on a plurality of rubber members surrounding the side surfaces and the back surface of the plurality of microphone elements. The side wall of the rubber member abuts on the inner wall of the hole in the hole formed on the surface of the housing of the microphone array device, and the microphone element is exposed on the surface of the housing from the front side. The rubber member is pressed by a pressing member from the back side of the surface of the housing so that the surface of the housing and the sound collecting surface of the microphone element are flush with each other, and the inner wall of the hole is the inner wall of the housing. It is formed in a tapered shape with a reduced diameter from the back side to the front side, and the side wall of the rubber member is formed in a tapered shape along the inner wall of the hole, and the inner wall of the hole and the side wall of the rubber member are formed. in opposite to abutting state, the sound pickup face surface and the microphone element of the casing it is coplanar.

According to the present disclosure, the waterproofness of the microphone array can be improved.

A block diagram showing a system configuration of a directional control system equipped with the omnidirectional microphone array device of the first embodiment. External view of omnidirectional microphone array device Explanatory drawing of an example of the principle of forming directivity in the direction θ with respect to the sound picked up by an omnidirectional microphone array device. Perspective view showing the appearance of the omnidirectional microphone array device Exploded view showing the inside of the housing of the omnidirectional microphone array device An assembled exploded view showing a method of mounting the microphone element by enlarging the mounting location shown in FIG. Cross-sectional view schematically explaining how to attach the microphone element Cross-sectional view showing a state in which the microphone element is attached to the housing Perspective view showing the appearance of the sound source detection unit in a use case Block diagram showing the schematic configuration of an unmanned aerial vehicle detection system including multiple sound source detection units in a use case Cross-sectional view showing the waterproof structure of the microphone element of the comparative example

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

The microphone array of the following embodiment is applied to, for example, an omnidirectional microphone array device mounted on a directional control system and capable of collecting sound from all directions.

(First Embodiment)
[Configuration, etc.]
FIG. 1 is a block diagram showing a system configuration of a directional control system 10 on which the omnidirectional microphone array device 2 of the first embodiment is mounted. The directional control system 10 includes an omnidirectional microphone array device 2, camera devices C11, ..., C1n, a directional control device 3, and a recorder device 4.

The omnidirectional microphone array device 2 collects sound in a sound collecting area in which the directional control system 10 is installed, and collects sound emitted by a person as an example of a sound source existing in the sound collecting area, for example.

The omnidirectional microphone array device 2 has a ring-shaped housing having an opening formed in the center, and collects sound from a direction (omnidirectional) of 360 ° around the installation position of the omnidirectional microphone array device 2. Make a sound. A ring shape (see FIG. 2) will be described as an example of the cross-sectional shape of the housing of the omnidirectional microphone array device 2, but the shape is not limited to this shape, and may be, for example, a circular shape or a rectangular shape.

In the omnidirectional microphone array device 2, a plurality of microphone units 22 are arranged concentrically along the circumferential direction of the microphone housing. The microphone unit 22 has a built-in microphone element 22m. As the microphone element 22m, for example, an omnidirectional high-quality sound compact electret condenser microphone (ECM: Electret Condenser Microphone) is used.

In the directional control system 10, the omnidirectional microphone array device 2, the directional control device 3, and the recorder device 4 are connected to each other via a network NW. The network NW may be a wired network (for example, an intranet or the Internet) or a wireless network (for example, a wireless LAN (Local Area Network)).

The camera devices C11, ..., C1n are fixedly installed on, for example, the ground, the floor, or a stand. The camera devices C11, ..., C1n have a function as a surveillance camera in, for example, a surveillance system.

The camera devices C11, ..., C1n perform a zoom function (for example, zoom-in processing, zoom-out processing) and an optical axis movement function (pan, tilt) by remote control from a monitoring control room (not shown) connected to the network NW. It is used to capture a predetermined image.

Information on the installation position and direction of each camera device is registered in the directivity control device 3. The pan / tilt / zoom information is transmitted to the directivity control device 3 at any time, and the positional relationship between the image position and the directivity direction is always associated with each other.

Further, for example, when the camera device C11 is an omnidirectional camera, the panorama is obtained by performing a predetermined distortion correction process on the image data (that is, the omnidirectional image data) showing the omnidirectional image in the sound collection region or the omnidirectional image data. The converted and generated plane image data is transmitted to the directional control device 3 or the recorder device 4 via the network NW. Hereinafter, a case where the camera device C11 is an omnidirectional camera will be described as an example.

When an arbitrary position is designated by the user in the image displayed on the display device 36, the camera device C11 receives the coordinate data of the designated position in the image from the direction control device 3 and receives the coordinate data of the designated position from the camera device C11. , Calculate the data of the distance and direction (including horizontal angle and vertical angle; the same applies hereinafter) to the audio position in the real space corresponding to the specified position (hereinafter, simply abbreviated as "audio position") and directivity. It is transmitted to the control device 3.

Since the distance and direction data calculation processing in the camera device C11 is a known technique, the description thereof will be omitted. Further, since the camera devices C11, ..., C1n have substantially the same configurations, they are collectively referred to as the camera device CA when it is not necessary to distinguish them.

The omnidirectional microphone array device 2 is connected to the network NW and has microphone elements 221,222, ..., 22n arranged at equal intervals, and a predetermined signal with respect to the sound data of the sound picked up by each microphone element. It is configured to include at least a control unit (not shown) for performing processing. When it is not necessary to distinguish the microphone elements 221, 222, ..., 22n, they are collectively referred to as the microphone elements 22m.

The omnidirectional microphone array device 2 transmits the voice data of the voice picked up by the microphone element 22m of each microphone unit 22 to the directional control device 3 or the recorder device 4 via the network NW.

Further, the omnidirectional microphone array device 2 detects (measures) ambient environmental parameters (for example, at least temperature among temperature, humidity, atmospheric pressure, wind direction and wind speed) at the time of collecting sound, and measures the measured values of each environmental parameter. It is included in the same packet PKT as the voice data and transmitted to the directivity control device 3 or the recorder device 4.

The directivity control device 3 uses the voice data transmitted from the omnidirectional microphone array device 2 and the measured values of the environmental parameters, and the directivity corresponding to the position (designated position) designated by the operation unit 32 by the user's operation. The sound velocity Vs (see FIG. 3) used when forming directivity in the direction (see below) is calculated (corrected). The directivity control device 3 forms the directivity of the voice data in the directivity direction (θMAh, θMAv) by using the calculated (corrected) sound velocity Vs.

As a result, the directivity control device 3 can relatively increase the volume level of the sound picked up from the directivity directions (θMAh, θMAv) in which the directivity is formed, as compared with the volume level of the sound picked up from the other direction. .. Since the method of calculating the directivity direction (θMAh, θMAv) is a known technique, detailed description thereof will be omitted in the present embodiment.

The directional control device 3 may be a stationary PC (Personal Computer) connected to the network NW and installed in a monitoring system control room (not shown), or a user-portable mobile phone, tablet terminal, or smartphone. It may be a data communication terminal such as.

The directivity control device 3 has a configuration including at least a communication unit 31, an operation unit 32, a signal processing unit 33, a display device 36, a speaker device 37, and a memory 38. The signal processing unit 33 has a configuration including at least a directivity direction calculation unit 34a and an output control unit 34c.

The communication unit 31 receives the packet PKT transmitted from the omnidirectional microphone array device 2 via the network NW and outputs the packet PKT to the signal processing unit 33.

The operation unit 32 is a user interface (UI: User Interface) for notifying the signal processing unit 33 of the content of the user's operation, and is a pointing device such as a mouse or a keyboard, for example. Further, the operation unit 32 may be arranged using, for example, a touch panel or a touch pad that is arranged corresponding to the screen of the display device 36 and can be operated by a user's finger or a stylus pen.

The operation unit 32 is designated by the user's operation with respect to the image displayed on the display device 36 (that is, the image captured by one of the camera devices C11, ..., C1n; the same applies hereinafter). Coordinate data indicating the position (that is, the position where the volume level of the sound output from the speaker device 37 is desired to be increased or decreased) is acquired and output to the signal processing unit 33.

The signal processing unit 33 is configured by using, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a DSP (Digital Signal Processor), and is for controlling the operation of each unit of the directional control device 3 as a whole. It performs control processing, data input / output processing with other parts, data calculation (calculation) processing, and data storage processing.

The directivity direction calculation unit 34a indicates the coordinates (θMAh, θMAh,) indicating the directivity direction from the omnidirectional microphone array device 2 toward the audio position corresponding to the designated position in response to the user's position designation operation from the image displayed on the display device 36. θMAv) is calculated. Since the specific calculation method of the directivity direction calculation unit 34a is a known technique as described above, detailed description thereof will be omitted.

The directivity direction calculation unit 34a uses the distance and direction data from the installation position of the camera device C11 to the voice position, and the directivity direction coordinates (θMAh, θMAv) from the installation position of the omnidirectional microphone array device 2 to the voice position. Is calculated.

For example, when the housing of the omnidirectional microphone array device 2 and the camera device C11 are integrally mounted so as to surround the housing of the camera device C11, the direction from the camera device C11 to the voice position (horizontal angle, The vertical angle) can be used as the directional coordinates (θMAh, θMAv) from the omnidirectional microphone array device 2 to the voice position.

When the housing of the camera device C11 and the housing of the omnidirectional microphone array device 2 are mounted apart from each other, the directional direction calculation unit 34a uses the data of the calibration parameters calculated in advance and the camera. The directional coordinates (θMAh, θMAv) from the omnidirectional microphone array device 2 to the voice position are calculated using the data in the direction (horizontal angle, vertical angle) from the device C11 to the voice position.

The calibration is an operation in which the directivity direction calculation unit 34a of the directivity control device 3 calculates or acquires predetermined calibration parameters required for calculating the coordinates (θMAh, θMAv) indicating the directivity direction. , It is assumed that it has been performed in advance by a known technique.

Of the coordinates (θMAh, θMAv) indicating the directional direction, θMAh represents the horizontal angle of the directional direction from the omnidirectional microphone array device 2 toward the voice position, and θMAv is the directional direction from the omnidirectional microphone array device 2 toward the voice position. Represents a vertical angle.

The voice position is the position of the actual monitoring target or sound picking target corresponding to the designated position designated by the user's finger or the stylus pen in the image displayed on the display device 36 by the operation unit 32.

The output control unit 34c controls the operations of the display device 36 and the speaker device 37. For example, the output control unit 34c causes the display device 36 to display the image data transmitted from the camera device C11 in response to the user's operation, and displays the voice data included in the packet PKT transmitted from the omnidirectional microphone array device 2. It is output from the speaker device 37.

Further, the output control unit 34c forms the directivity of the audio data picked up by the omnidirectional microphone array device 2 in the directivity direction indicated by the coordinates (θMAh, θMAv) calculated by the directivity direction calculation unit 34a. Directivity may be formed in the omnidirectional microphone array device 2.

The display device 36 displays image data transmitted from, for example, the camera device C11 on the screen under the control of the output control unit 34c, for example, in response to a user operation.

The speaker device 37 outputs the voice data included in the packet PKT transmitted from the omnidirectional microphone array device 2 or the voice data in which the directivity is formed in the directivity directions (θMAh, θMAv) calculated by the direction direction calculation unit 34a. To do. The display device 36 and the speaker device 37 may be configured separately from the directivity control device 3.

The memory 38 is configured by using, for example, a RAM (Random Access Memory), functions as a work memory during operation of each part of the directional control device 3, and further stores data necessary for operation of each part of the directional control device 3. Remember.

The recorder device 4 stores the voice data and the environmental parameter data PDT included in the packet PKT transmitted from the omnidirectional microphone array device 2 in association with, for example, the image data transmitted from the camera device C11.

When the directional control system 10 includes a plurality of camera devices, the recorder device 4 includes image data transmitted from each camera device and audio data included in the packet PKT transmitted from the omnidirectional microphone array device 2. And the environment parameter data PDT may be stored in association with each other.

FIG. 2 is an external view of the omnidirectional microphone array device 2. The omnidirectional microphone array device 2 has a disk (perforated disk) -shaped housing 21 in which an opening 21a having a predetermined diameter is formed at the center. A plurality of microphone units 22 are concentrically arranged at predetermined intervals on the surface of the housing 21. Note that FIG. 2 schematically shows the appearance of the housing 21, and a more detailed appearance is shown with reference to FIG.

FIG. 3 is an explanatory diagram of an example of the principle of forming directivity in the direction θ with respect to the sound picked up by the omnidirectional microphone array device 2. In FIG. 3, for example, the principle of the directivity forming process using the delay sum method will be briefly described.

The sound wave emitted from the sound source 80 has a certain angle (incident) with respect to the microphone elements 221, 222, 223, ..., 22 (n-1), 22n built in the microphone unit 22 of the omnidirectional microphone array device 2. Angle = (90-θ) [degree]). The incident angle θ shown in FIG. 3 may be a horizontal angle θMAh or a vertical angle θMAv in the sound collecting direction from the omnidirectional microphone array device 2 toward the sound position.

The sound source 80 is, for example, a subject of a camera device that exists in a direction in which the omnidirectional microphone array device 2 collects sound, and exists in a direction of a predetermined angle θ with respect to the surface of the housing 21 of the omnidirectional microphone array device 2. .. Further, the interval d between the microphone elements 221, 222, 223, ..., 22 (n-1), and 22n is constant.

The sound wave emitted from the sound source 80 first reaches the microphone element 221 and is picked up, then reaches the microphone element 222 and is picked up, similarly, is picked up one after another, and finally reaches the microphone element 22n. Is picked up.

The direction from the positions of the microphone elements 221, 222, 223, ..., 22 (n-1), 22n of the omnidirectional microphone array device 2 toward the sound source 80 is from each microphone element of the omnidirectional microphone array device 2. It is the same as the direction toward the voice position corresponding to the designated position designated by the user on the screen of the display device 36.

Here, the arrival time difference τ1, τ2, τ3 is from the time when the sound wave reaches the microphone elements 221, 222, 223, ..., 22 (n-1) to the time when the sound wave finally reaches the microphone element 22n, which is picked up. , ..., τn-1 occurs. Therefore, when the voice data collected by the respective microphone elements 221, 222, 223, ..., 22 (n-1), 22n is added as it is, the sound data is added with the phase shifted. Volume levels weaken overall.

Note that τ1 is the time difference between the time when the sound wave reaches the microphone element 221 and the time when the sound wave reaches the microphone element 22n, and τ2 is the time when the sound wave reaches the microphone element 222 and the sound wave reaches the microphone element 22n. Similarly, τn-1 is the time difference between the time when the sound wave reaches the microphone element 22 (n-1) and the time when the sound wave reaches the microphone element 22n.

In the directivity forming process of the present embodiment, A / D converters 241,242, 243, ..., 24 (A / D converters 241,242, 243, ..., 24 ( At n-1) and 24n, the analog audio signal is converted into a digital audio signal. Further, the digital audio signal is a delay device 251,252, 253, ..., 25 (n-1), which is provided corresponding to each of the microphone elements 221, 222, 223, ..., 22 (n-1), 22n. A predetermined delay time is added at 25n. The outputs of the delay devices 251, 252, 253, ..., 25 (n-1), 25n are added by the adder 26.

When the directivity forming process is performed in the omnidirectional microphone array device 2, delayers 251,252,253, ..., 25 (n-1), 25n are provided in the omnidirectional microphone array device 2. When the directivity forming process is performed in the directivity control device 3, delayers 251,252,253, ..., 25 (n-1), 25n are provided in the directivity control device 3.

Further, in the directivity forming process shown in FIG. 3, the delay devices 251,252, 253 ..., 25 (n-1), 25n are the respective microphone elements 221, 222, 222, ..., 22 (n-1). After giving a delay time corresponding to the arrival time difference at 22n and aligning the phases of all the sound waves, the adder 26 adds the audio data after the delay processing.

As a result, the omnidirectional microphone array device 2 or the directivity control device 3 is directed in the direction of the angle θ with respect to the sound picked up by the microphone elements 221, 222, 223, ..., 22 (n-1), 22n. Directivity can be formed.

For example, in FIG. 3, the delay times D1, D2, D3, ..., D (n-1), and Dn given by the delay devices 251,252, 253 ..., 25 (n-1), and 25n are reached, respectively. It corresponds to the time difference τ1, τ2, τ3, ..., τ (n-1) and is shown by the mathematical formula (1).

L1 is the difference in sound wave reach between the microphone element 221 and the microphone element 22n. L2 is the difference in sound wave reach between the microphone element 222 and the microphone element 22n. L3 is the difference in sound wave reach between the microphone element 223 and the microphone element 22n, and similarly, L (n-1) is the difference in sound wave reach between the microphone element 22 (n-1) and the microphone element 22n. Is. Vs is the speed of sound of sound waves. The sound velocity Vs may be calculated by the omnidirectional microphone array device 2 or may be calculated by the directivity control device 3 (see below). L1, L2, L3, ..., L (n-1) are known values. In FIG. 3, the delay time Dn set in the delay device 25n is 0 (zero).

In the directivity forming process, the delay time Di (integer of i = 1 to n, n is an integer of 2 or more) given to the sound data of the sound picked up by each microphone element is as shown in the mathematical formula (1). In addition, it is inversely proportional to the speed of sound Vs.

Further, as will be described later, the speed of sound Vs changes depending on the temperature, humidity (water vapor pressure), atmospheric pressure, or wind speed as needed. Therefore, in order to form highly accurate directivity, the environmental parameters (for example, temperature, water vapor pressure (humidity), atmospheric pressure, wind speed) when each microphone element picks up sound are used to obtain accurate sound velocity Vs. It needs to be converted (corrected).

As described above, the omnidirectional microphone array device 2 or the directional control device 3 has delay times D1, D2, D3, ..., Which are given by the delay devices 251,252,253, ..., 25 (n-1), 25n. Change Dn-1, Dn.

As a result, the omnidirectional microphone array device 2 or the directional control device 3 has the sound picked up by the respective microphone elements 221, 222, 223, ..., 22 (n-1), 22n built in the microphone unit 22. The directivity of the voice data can be easily and arbitrarily formed.

FIG. 4 is a perspective view showing the appearance of the omnidirectional microphone array device 2. The housing 21 of the omnidirectional microphone array device 2 is formed in a perforated disk shape by combining the front case 21z with the back case 21y so as to overlap each other.

An opening 21a is formed in the central portion of the front case 21z as described above. A camera device CA is inserted and attached to the opening 21a. A plurality of microphone elements 22m are arranged in the circumferential direction on the peripheral edge of the front case 21z. Both the front case 21z and the back case 21y are made of a plastic material such as metal or plastic. The front case 21z and the back case 21y may be made of the same material or different materials.

FIG. 5 is an exploded view showing the inside of the housing 21 of the omnidirectional microphone array device 2. In FIG. 5, the back case 21y is removed and the back side of the front case 21z is shown. The back of the camera device CA is located at the center of the back side of the front case 21z. Further, a plurality of mounting points pa of the microphone element 22m are provided on the peripheral edge portion on the back side of the front case 21z.

FIG. 6 is an assembled exploded view showing a method of mounting the microphone element 22m by enlarging the mounting location pa shown in FIG. A waterproof film 48 (see FIG. 7) is attached to the sound collecting surface of the microphone element 22 m. The waterproof film 48 is a sheet having both waterproofness and moisture permeability, for example, typified by Gore-Tex (registered trademark), which allows water vapor to pass through but does not allow rain to pass through.

A through hole 41 is formed in the bottom surface of the front case 21z, which is the mounting location pa of the microphone element 22m. The inner wall 41z (see FIG. 7) of the through hole 41 is formed in a tapered shape so that the hole narrows (the opening narrows) from the back side to the front side of the front case 21z, as will be described later.

The microphone element 22m is housed in a rubber member. This rubber member includes a microphone rubber 42, or a microphone rubber 42 and a microphone holder 43. A microphone element 22m housed in a rubber member is inserted into the through hole 41. The rubber member is, for example, silicon rubber. Further, when a plurality of microphone elements 22m and rubber members (four in FIG. 6) are inserted into the plurality of through holes 41, the microphone holding rubber 45 is pressed so as to press these microphone elements 22m together. The sheet metal 46 is attached to the bottom surface of the front case 21z via the sheet metal 46. The sheet metal 46 is screwed with, for example, a female screw (not shown) formed on the bottom surface of the front case 21z by a male screw 47, and is fixed to the bottom surface of the front case 21z. As a result, the microphone element 22m is fixed to the front case 21z.

FIG. 7 is a cross-sectional view schematically illustrating how to attach the microphone element 22m. As described above, the inner wall 41z of the through hole 41 of the front case 21z is formed in a tapered shape so that the opening narrows from the back side to the front side of the front case 21z.

The microphone rubber 42 has a truncated cone shape in which an opening is formed so that the microphone element 22m is internally fitted and the sound collecting surface of the microphone element 22m is exposed. The material of the microphone rubber 42 is, for example, rubber having excellent elasticity.

Like the microphone rubber 42, the microphone holder 43 is made of rubber having excellent elasticity and has a tubular shape. The microphone holder 43 is arranged on the back of the microphone rubber 42, and when pressed in the axial direction together with the microphone rubber 42, it elastically deforms and comes into close contact with the microphone element 22 m. As a result, the microphone rubber 42 and the microphone holder 43 can suppress the intrusion of water from the side surface of the microphone element 22m.

Further, a notch 43z (see FIG. 6) is formed on the side wall of the microphone holder 43. The notch 43z serves as an escape port for excess rubber that is a part of the microphone holder 43 when the microphone holder 43 is excessively compressed. As a result, the microphone holder 43 can be deformed to some extent.

The microphone holding rubber 45 is made of a rubber having excellent elasticity, and has a function as a spacer when the sheet metal 46 presses the microphone rubber 42 against the front side of the front case 21z. On the surface of the microphone holding rubber 45, a convex portion 45z that fits with the engaging hole 46z formed on the surface of the sheet metal 46 is formed. The microphone holding rubber 45 and the sheet metal 46 are integrated by fitting the engaging hole 46z and the convex portion 45z.

The sheet metal 46 presses the microphone rubber 42 and the microphone holder 43 toward the front side of the front case 21z via the microphone holding rubber 45. Further, when a waterproof resin member is used instead of the sheet metal 46, the omnidirectional microphone array device 2 can secure the waterproof property even if the microphone holding rubber 45 is omitted.

Further, a plurality of screw holes 46y are formed on the surface of the sheet metal 46. The male screw 47 is screwed with a female screw formed in the bottom surface of the front case 21z so as to insert these screw holes 46y, and the sheet metal 46 is fixed to the front case 21z. In FIG. 6, the sheet metal 46 fixes the four microphone elements 22m to the front case 21z as described above.

FIG. 8 is a cross-sectional view showing a state in which the microphone element 22m is attached to the front case 21z. The microphone rubber 42 and the microphone holder 43 are pressed toward the front case 21z side by the sheet metal 46 via the microphone holding rubber 45 and are in a contracted state. In this state, the inner wall 42y of the microphone rubber 42 is in close contact with the side surface of the microphone element 22m, and the side wall (outer wall) 42z of the microphone rubber 42 is in close contact with the inner wall 41z of the through hole 41. Further, the upper surface of the microphone holder 43 is in close contact with the back surface of the microphone element 22m.

Therefore, in the omnidirectional microphone array device 2, for example, when the omnidirectional microphone array device 2 is installed outdoors upward, even if it rains, the omnidirectional microphone array device 2 is located between the side wall 42z of the microphone rubber 42 and the inner wall 41z of the through hole 41. It is possible to suppress the ingress of water. Further, the omnidirectional microphone array device 2 can prevent water from entering between the inner wall 42y of the microphone rubber 42 and the side surface of the microphone element 22m.

As a result, the omnidirectional microphone array device 2 can prevent water from entering the inside of the front case 21z, particularly the terminal surface side of the microphone element 22m. The terminal surface of the microphone element 22m is a surface opposite to the sound collecting surface of the microphone element 22m. Therefore, the omnidirectional microphone array device 2 can protect various electronic components including the microphone element 22 m from water droplets. Further, by using rubber in the omnidirectional microphone array device 2, it is possible to improve not only waterproofness but also vibration-proofness and dustproofness.

Further, the notch 43z serves as an escape port for excess rubber that is a part of the microphone holder 43 when the microphone holder 43 is excessively compressed. As a result, the microphone holder 43 can be deformed to some extent. On the other hand, as described above, a waterproof film 48 is attached to the sound collecting surface of the microphone element 22 m in order to maintain waterproofness, so that waterproofness is ensured.

Further, if the sound collecting surface of the microphone element 22m is recessed from the surface of the front case 21z, a dent may be formed, water may collect on the sound collecting surface of the microphone element 22m, and sound propagation may deteriorate. .. As a result, the characteristics of the sound deteriorate. Further, if the sound collecting surface of the microphone element 22m protrudes from the surface of the front case 21z, the sound collecting characteristics may deteriorate.

Further, even if the sound collecting surface of the microphone element 22m protrudes from the surface of the front case 21z, the sound collecting characteristics may be similarly deteriorated.

On the other hand, in the omnidirectional microphone array device 2, the microphone element 22m is attached so that the surface of the front case 21z and the surface of the microphone element 22m are flush with each other. That is, when the microphone element 22m is fitted into the through hole 41 of the front case 21z via the microphone rubber 42, the surface of the front case 21z and the sound collecting surface of the microphone element 22m are aligned on the same plane (same height). .. As a result, the omnidirectional microphone array device 2 can suppress deterioration in sound collection performance.

In FIGS. 7 and 8, the microphone holder 43 is in contact with the side surface of the microphone element 22 m and the inner wall of the microphone rubber 42, the terminal surface side of the microphone element 22 m is in contact with the microphone holder 43, and the microphone holder 43 and the microphone holding rubber 45 are in contact with each other. It is illustrated that they come into contact with. Instead, the side surface and the back surface of the microphone element 22 m may be housed in contact with the microphone holder 43, and the side surface and the back surface of the microphone holder 43 may be housed in contact with the microphone rubber 42.

(Use Case)
Next, an example of a use case of the omnidirectional microphone array device 2 will be shown. The omnidirectional microphone array device 2 is used by being mounted on the sound source detection unit UD, for example.

FIG. 9 is a perspective view showing the appearance of the sound source detection unit UD. The sound source detection unit UD includes an omnidirectional microphone array device 2, an omnidirectional camera CA, a PTZ camera CZ, and a support 70 that mechanically supports these.

The support base 70 includes a tripod 71, two rails 72 fixed to the top plate 71a of the tripod 71, and a first mounting plate 73 and a second mounting plate 74 attached to both ends of the two rails 72, respectively. And have a combined structure. The first mounting plate 73 functions as a baffle plate.

The first mounting plate 73 and the second mounting plate 74 are mounted so as to straddle the two rails 72, and have substantially the same flat surface. Further, the first mounting plate 73 and the second mounting plate 74 are slidable on the two rails 72, and are adjusted and fixed at positions separated or close to each other.

The first mounting plate 73 is, for example, a disk-shaped plate material. An opening 73a is formed in the center of the first mounting plate 73. The housing 21 of the omnidirectional microphone array device 2 is accommodated and fixed in the opening 73a.

The second mounting plate 74 is, for example, a substantially rectangular plate material. An opening 74a is formed in a portion near the outside of the second mounting plate 74. The PTZ camera CZ is accommodated and fixed in the opening 74a.

As shown in FIG. 9, the optical axis L1 of the omnidirectional camera CA housed in the housing 21 of the omnidirectional microphone array device 2 and the optical axis L2 of the PTZ camera CZ mounted on the second mounting plate 74 are It is set so that they are parallel to each other in the initial installation state.

The tripod 71 is supported by a ground contact surface with three legs 71b, and the position of the top plate 71a can be moved in the direction perpendicular to the ground contact surface by manual operation, and the top plate 71a can be moved in the pan direction and the tilt direction. The orientation of the plate 71a can be adjusted. As a result, the sound collecting area of the omnidirectional microphone array device 2 (in other words, the imaging area of the omnidirectional camera CA) can be set in any direction.

FIG. 10 is a block diagram showing a schematic configuration of an unmanned aerial vehicle detection system 5 including a plurality of sound source detection units UD. The unmanned aerial vehicle detection system 5 detects an unmanned aerial vehicle intended by the user as a detection target.

The unmanned aerial vehicle is, for example, a drone that autonomously flies using a GPS (Global Positioning System) function, a radio-controlled helicopter that is radio-controlled by a third party, and the like. The unmanned aerial vehicle is used, for example, for aerial photography of a target, transportation of supplies, and the like.

The unmanned aerial vehicle detection system 5 includes a plurality of sound source detection units UD, a monitoring device 8, and a monitor 50. The plurality of sound source detection units UD are interconnected with the monitoring device 8 via the network NW. Each sound source detection unit UD has an omnidirectional microphone array device 2, an omnidirectional camera CA, and a PTZ camera CZ.

In the sound source detection unit UD, the omnidirectional microphone array device 2 picks up the omnidirectional sound in the sound collecting area where the own device is installed in an omnidirectional state. The sound to be picked up by the omnidirectional microphone array device 2 broadly includes, for example, mechanical operating sounds such as drones, sounds emitted by humans and the like, and other sounds. Further, the sound to be picked up is not limited to the sound in the audible frequency range (that is, 20 Hz to 23 kHz), and may include a low frequency sound lower than the audible frequency and an ultrasonic sound exceeding the audible frequency.

The omnidirectional microphone array device 2 transmits the sound data of the sound obtained by collecting the sound of each microphone element 22 m to the monitoring device 8 via the network NW.

The number of microphone elements in the omnidirectional microphone array device 2 may be 32, or may be another number (for example, 16, 64, 128).

An omnidirectional camera CA that substantially matches the volume of the opening is housed inside the opening formed in the center of the housing 21 (see FIG. 9) of the omnidirectional microphone array device 2. That is, the omnidirectional microphone array device 2 and the omnidirectional camera CA are integrally arranged. The omnidirectional camera CA is a camera equipped with a fisheye lens capable of capturing an omnidirectional image of the imaging area which is the sound collecting space.

In the present embodiment, both the sound collecting area and the imaging area may be a common monitoring area, and the spatial size (for example, volume) of the sound collecting area and the imaging area may not be the same. For example, the volume of the sound collecting area may be larger or smaller than the volume of the imaging area. In short, it is sufficient that the sound collecting area and the imaging area have a common volume portion.

The omnidirectional camera CA functions as, for example, a surveillance camera capable of capturing an imaging area in which a sound source detection unit UD is installed. That is, the omnidirectional camera CA has an angle of view of, for example, 180 ° in the vertical direction and 360 ° in the horizontal direction, and images a monitoring area, which is a hemisphere, as an imaging area.

In each sound source detection unit UD, the omnidirectional camera CA and the omnidirectional microphone array device 2 are arranged coaxially by fitting the omnidirectional camera CA inside the opening of the housing 21.

In this way, the optical axis of the omnidirectional camera CA coincides with the central axis of the housing of the omnidirectional microphone array device 2, so that the imaging area and the sound collecting area in the axial circumferential direction (that is, the horizontal direction) are abbreviated. It becomes the same, and the position of the subject in the image and the position of the sound source to be picked up can be expressed in the same coordinate system (for example, the coordinates indicated by (horizontal angle, vertical angle)).

Each sound source detection unit UD is attached so that, for example, the upward direction in the vertical direction is the sound collecting surface and the imaging surface in order to detect the unmanned aerial vehicle dn flying from the sky.

The monitoring device 8 forms directivity (that is, beamforming) with an arbitrary direction as the main beam direction based on the user's operation with respect to the omnidirectional sound picked up by the omnidirectional microphone array device 2. , The sound in the directivity direction can be emphasized.

The monitoring device 8 processes the captured image to generate an omnidirectional image using the image captured by the omnidirectional camera CA. The omnidirectional image may be generated by the omnidirectional camera CA instead of the monitoring device 8.

The plurality of sound source detection units UD and the monitoring device 8 have a communication interface and are connected to each other via a network NW so that data communication is possible. The network NW may be a wired network (for example, an intranet, the Internet, a wired LAN (Local Area Network)), or a wireless network (for example, a wireless LAN).

The sound source detection unit UD and the monitoring device 8 may be directly connected to each other without going through the network NW. Further, the monitoring device 8 and the monitor 50 are installed in the monitoring room RM where users such as observers are resident.

[Action / effect, etc.]
FIG. 11 is a cross-sectional view showing a waterproof structure of the microphone element 122 of the comparative example. In the comparative example, the microphone rubber 142 is formed in a cylindrical O-ring. The front case 121z is provided with a straight through hole 141 (not tapered).

When the microphone element 122 is attached to the front case 121z, the microphone rubber 142 is fitted on the side surface of the microphone element 122, and the microphone element 122 is inserted into the through hole 141 via the microphone rubber 142.

In this case, a slight gap may occur between the inner wall of the microphone rubber 142 and the side surface of the microphone element 122, and between the side wall of the microphone rubber 142 and the inner wall of the through hole 141 due to aging or the like. Further, even when no gap is formed, when rain rd falls and water pressure is applied in the vicinity of the microphone element 122, water easily enters the inside of the front case 21z straight through these gaps.

On the other hand, the microphone array system of the present embodiment includes a housing 21, a plurality of microphone elements 22m, a plurality of rubber members, and a pressing member. A plurality of through holes 41 are formed on the surface of the front case 21z of the housing 21. The plurality of microphone elements 22m are inserted through the plurality of through holes 41 and attached to the surface of the front case 21z so as to be exposed from the front side. The plurality of rubber members surround the side surfaces and the back surface of the plurality of microphone elements 22 m. The pressing member presses the rubber member from the back side of the surface of the front case 21z. The surface of the front case 21z and the sound collecting surface of the microphone element 22m are located on the same plane. The inner wall 41z of the through hole 41 is formed in a tapered shape whose diameter is reduced from the back side to the front side of the front case 21z. The side wall of the microphone rubber 42 is formed on a tapered surface along the inner wall 41z of the through hole 41.

The microphone array system is, for example, an omnidirectional microphone array device 2. The rubber member is, for example, a microphone rubber 42, or a microphone rubber 42 and a microphone holder 43. The pressing member is, for example, a microphone holding rubber 45 or a sheet metal 46. The through hole 41 is an example of a hole.

As a result, the inner wall 42y of the microphone rubber 42 is in close contact with the side surface of the microphone element 22m, and the side wall 42z of the microphone rubber 42 is in close contact with the inner wall 41z of the through hole 41. The upper surface of the microphone holder 43 is in close contact with the back surface of the microphone element 22 m.

Therefore, when the microphone array system is installed outdoors upward, it is possible to prevent water from entering between the side wall 42z of the microphone rubber 42 and the inner wall 41z of the through hole 41 even if it rains rd. Further, the microphone array system can prevent water from entering between the inner wall 42y of the microphone rubber 42 and the side surface of the microphone element 22m. Further, the microphone array system can prevent water from entering the inside of the housing 21, particularly the terminal surface side of the microphone element 22 m.

Further, in the microphone array system, since the surface of the front case 21z and the sound collecting surface of the microphone element 22m are located on the same plane, it is possible to suppress the accumulation of water on the sound collecting surface of the microphone element 22m. As a result, the microphone array system can suppress the performance deterioration of the microphone element 22m due to the accumulation of water on the sound collecting surface. Further, by using a rubber member in the microphone array system, it is possible to improve not only waterproofness but also vibration-proofness and dustproofness.

Further, when the rubber member is pressed toward the front case 21z side by the pressing member, the side wall 42z of the tapered microphone rubber 42 easily adheres to the inner wall 41z of the through hole 41 formed in a tapered shape. Therefore, the adhesion between the side wall 42z of the microphone rubber 42 and the inner wall 1z of the through hole 41 is improved. Further, the adhesion between the sound collecting surface of the microphone holder 43 and the back surface of the microphone element 22 m is improved.

Further, the microphone holder 43 may be formed in a tubular shape, and a notch 43z may be formed on the side wall thereof. The notch 43z serves as an escape port for excess rubber that is a part of the microphone holder 43 when the microphone holder 43 is excessively compressed. As a result, the terminal surface of the microphone element 22 m can be protected from a short circuit or deterioration.

Further, an opening 21a may be formed at the center of the surface of the front case 21z. A camera device CA may be attached to the opening 21a. The plurality of microphone elements 22m may be arranged in the circumferential direction on the peripheral edge of the surface of the front case 21z.

As a result, the microphone array system can monitor a predetermined area by using the image pickup information together with the sound collection information, and can improve the monitoring performance. Further, when the camera device CA having excellent waterproof performance is used, the waterproofness around the microphone element 22 m can be improved, and a microphone array system for outdoor use having a simple configuration can be provided.

The present embodiment can also be regarded as a method for manufacturing an array microphone system. In this manufacturing method, a plurality of microphone elements 22m are housed in a plurality of rubber members surrounding the side surfaces and the back surface of the plurality of microphone elements 22m. Further, the side wall 42z of the rubber member abuts on the inner wall 41z of the through hole 41 with the through hole 41 formed on the surface of the front case 21z of the microphone array system, and the microphone element 22m is exposed from the front side on the surface of the front case 21z. Press from the back side of the surface of the front case 21z so that the surface of the front case 21z and the sound collecting surface of the microphone element 22m are flush with each other. The inner wall 41z of the through hole 41 is formed in a tapered shape with a diameter reduced from the back side to the front side of the front case 21z, and the side wall 42z of the rubber member is formed in a tapered shape along the inner wall 41z of the through hole 41. Has been done.

This makes it easy to manufacture a highly waterproof microphone array system.

Although the embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, which naturally belong to the technical scope of the present invention. Understood.

The present disclosure includes a microphone array device capable of improving the waterproof property of the microphone array system, it is useful in the production method and the like of the microphone array system and a microphone array device.

2 Omnidirectional microphone array device 3 Directional control device 4 Recorder device 5 Unmanned vehicle detection system 8 Monitoring device 10 Directional control system 21 Housing 21a Opening 21z, 121z Front case 21y Back case 26 Adder 31 Communication unit 32 Operation Unit 33 Signal processing unit 34a Directivity calculation unit 34c Output control unit 36 Display device 37 Speaker device 38 Memory 41,141 Through hole 41z Inner wall 42,142 Microphone rubber 42y Inner wall 42z Side wall 43 Microphone holder 43z Notch 45 Microphone holding rubber 45z Convex part 46 Sheet metal 46y Screw hole 46z Engagement hole 47 Male screw 48 Waterproof film 50 Monitor 70 Support stand 71 Tripod 71a Top plate 71b Leg 72 Rail 73 First mounting plate 74 Second mounting plate 221,222, ..., 22n, 22m, 122 Microphone Elements 241,242, ..., 24n A / D converter 251,252, ..., 25n Delayers C11, C1n, CA Camera device (omnidirectional camera)
CZ PTZ camera L1, L2 optical axis NW network pa mounting location rd rain UD sound source detection unit

Claims (6)

A microphone array device that collects sound in all directions.
A housing with a surface with multiple holes and
A plurality of microphone elements inserted through the plurality of holes and attached to the surface of the housing so as to be exposed from the front side.
A plurality of rubber members surrounding the side surfaces and the back surface of the plurality of microphone elements,
A pressing member that presses the rubber member from the back side of the surface of the housing is provided .
Before the inner wall of Kiana is formed in the housing reduced diameter tapered toward the front side from the back side of,
The side wall of the rubber member is formed in a tapered shape along the inner wall of the hole.
The surface of the housing and the sound collecting surface of the microphone element are located on the same plane in a state where the inner wall of the hole and the side wall of the rubber member face each other and come into contact with each other .
Microphone array device . The surface of the microphone element provided with the sound collecting hole is covered with a waterproof film that has both waterproofness and moisture permeability.
The microphone array device according to claim 1. The surface of the front case of the housing and the surface provided with the sound collecting holes of the microphone element are arranged obliquely with respect to the installation surface on which the support base for supporting the microphone array device is installed.
The microphone array device according to claim 1 or 2 . The pressing member presses the plurality of rubber members corresponding to each of the plurality of microphone elements.
The microphone array device according to any one of claims 1 to 3. The microphone array device according to any one of claims 1 to 4.
Equipped with a camera device,
An opening is provided in the center of the surface of the housing.
The camera device was attached to the opening.
Microphone array system. It is a manufacturing method of a microphone array device that collects sound in all directions.
The plurality of microphone elements are housed in a plurality of rubber members surrounding the side surfaces and the back surface of the plurality of microphone elements.
The side wall of the rubber member abuts on the inner wall of the hole in the hole formed on the surface of the housing of the microphone array device, the microphone element is exposed on the surface of the housing from the front side, and the surface of the housing is exposed. The rubber member is pressed by the pressing member from the back side of the surface of the housing so that the sound collecting surface of the microphone element and the sound collecting surface of the microphone element are flush with each other.
The inner wall of the hole is formed in a tapered shape with a diameter reduced from the back side to the front side of the housing.
The side wall of the rubber member is formed in a tapered shape along the inner wall of the hole.
In the state sidewalls are in contact with opposite those of the inner wall and the rubber member of the hole, and sound pickup plane surface and the microphone element of the casing you are coplanar,
Manufacturing method of microphone array device.