Noise reduction appliance

Abstract

To provide a noise reduction appliance which reduces noise generated in a building and leaking to the outside of the building, by combining an active noise canceller and opening adjustment of an opening part in a plant.SOLUTION: A noise reduction device 10 which is used to reduce the magnitude of a generation noise from a sound source O in a factory F at a predetermined position outside of a factory F includes: speakers 12a, 12b for outputting an output sound with respect to the noise which is the generation noise which has gone out of the factory; a reference microphone 14 for measuring the sound before going out of the factory F as a noise; and a control computer 20 for executing the processing of setting an opening of an opening part K provided at a place facing the outdoors in the factory F. The control computer 20 executes prediction processing for predicting the magnitude of the noise in the case where the speakers 12a, 12b output the output sound, and setting processing for, in the case where the prediction value of the magnitude of the noise has exceeded a specified value, setting the opening of the opening part K by an opening / closing member U so that the magnitude of the noise becomes equal to or less than the specified value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sound reduction facility, and more particularly to a sound reduction facility for reducing sound that is generated inside a building and leaks outside the building. [Background technology]

[0002] Buildings are usually provided with openings such as windows for ventilation and lighting. However, openings can be entrances and exits for sound, and for example, noise generated inside a building may leak outside the building through the openings, affecting the environment around the building. Therefore, from the viewpoint of suppressing noise, technologies have been developed to set the number of openings in a building and to control the opening and closing of the openings.

[0003] For example, according to the technology described in Patent Document 1, from the perspective of evaluating the noise level entering a building through the building's air intakes, the location and number of openings provided in the building, as well as the soundproofing function added to the openings, are evaluated. Moreover, according to the technology described in Patent Document 2, sounds around a building are monitored by a sonic receiver, and if the sound volume exceeds a certain level, the openings of the building are automatically closed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-211895 A [Patent Document 2] Japanese Utility Model Application Publication No. 3-80882 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, if the openings of a building are completely sealed off in order to reduce noise, it becomes difficult to ensure sufficient ventilation within the building, which may cause a loss of comfort within the building. Therefore, there is a demand for technology that can ensure sufficient ventilation within the building while suppressing the noise leaking outside the building to a certain level or below.

[0006] Therefore, the present invention has been made in consideration of the above-mentioned problems, and its object is to provide a sound reduction system that can suppress sound leaking outside the building while ensuring ventilation within the building. [Means for solving the problem]

[0007] The above-mentioned problems are solved by the sound reduction equipment of the present invention, which is used to reduce the volume of sound generated inside a building at a specified position outside the building, and which comprises an output device that outputs an output sound in response to sound generated outside the building, and a processing execution device that executes processing to set the opening degree of an opening provided in a location of the building facing the outdoors, and the processing execution device executes a prediction process that predicts the volume of the output sound when the output device outputs the output sound, and a setting process that sets the opening degree of the opening so that the volume will be equal to or less than the specified value when the predicted value of the volume exceeds a specified value. In the sound reduction equipment of the present invention configured as described above, the sound (noise) that is emitted from inside the building to the outside of the building is reduced by the output sound from the output device, and when the sound cannot be reduced sufficiently by the output sound alone, the opening size of the opening is reduced. This makes it possible to suppress sound leaking outside the building while ensuring the amount of ventilation inside the building by making the opening size of the opening as large as possible in the building.

[0008] Furthermore, in the sound reduction equipment of the present invention, a plurality of output devices may be provided, and the process execution device may predict, in the prediction process, the volume of the output sound when each of the plurality of output devices outputs the output sound. According to the above configuration, it is possible to more effectively reduce the sound (noise) that goes from inside the building to outside the building by the sound (output sound) that is output from each of the multiple output devices.

[0009] In addition, in the sound reduction equipment of the present invention, when the volume of a sound generated within a building measured exceeds a reference value, the output device may output an output sound, and the processing execution device may execute a prediction process. According to the above configuration, the output device and the processing execution device are operated when the impact of sound radiating from inside the building to outside the building on the surrounding area of ​​the building becomes relatively large, so that these devices can be used rationally.

[0010] In the sound reduction equipment of the present invention, the output device may output an output sound that is generated in response to a generated sound measured within the building. According to the above configuration, it is possible to more effectively reduce the sound that is output from the output device and goes outside the building from inside the building.

[0011] Furthermore, in the sound reduction equipment of the present invention, the processing execution device, in the setting process, calculates the above-mentioned magnitude corresponding to the opening degree of the opening, for each opening degree, and sets the opening degree when the calculated value of the magnitude is equal to or less than a specified value. According to the above configuration, when the sound (noise) leaking outside the building cannot be sufficiently reduced by the output sound alone, the noise level at a predetermined position outside the building is calculated multiple times by changing the opening degree of the opening, and the opening degree at which the calculated noise level is equal to or less than a specified value is found. This makes it possible to appropriately set the opening degree of the opening that can suppress the noise leaking outside the building to a specified value or less while ensuring the maximum possible ventilation volume inside the building.

[0012] The sound reduction equipment of the present invention may further include a detector that detects sound outside the building at a position closer to the building than the predetermined position while the output device is outputting the output sound. In this case, the processing execution device may predict the loudness of the generated sound at the predetermined position based on the loudness of the sound detected by the detector in the prediction process. Furthermore, when the predicted loudness value exceeds a specified value, the processing execution device may set the opening degree of the opening according to the loudness of the sound detected by the detector in the setting process. According to the above configuration, it is possible to more appropriately predict the noise level at a given position outside the building, and to more appropriately set the opening degree of the opening that can suppress the noise leaking outside the building to a specified value or less.

[0013] In the sound reduction equipment of the present invention, the process execution device may be a controller that controls the output device. According to the above configuration, the processing execution device has a function for controlling the output device, so that the number of devices that make up the sound reduction equipment can be reduced compared to a configuration in which a separate controller is provided to control the output device.

[0014] Furthermore, in the sound reduction equipment of the present invention, the processing execution device may predict the size when the opening degree is a first opening degree in the prediction process. Then, when the size when the opening degree is the first opening degree exceeds a specified value, the processing execution device may execute a setting process to set the opening degree of the opening to a second opening degree smaller than the first opening degree. According to the above configuration, the opening degree of the opening in the building is set as large as possible, and when the noise cannot be sufficiently suppressed by the output sound from the output device alone, the opening degree is set smaller to reduce (soundproof) the noise leaking outside the building. This makes it possible to suppress the noise leaking outside the building while ensuring the amount of ventilation inside the building by setting the opening degree of the opening in the building as large as possible. Effect of the Invention

[0015] According to the sound reduction equipment of the present invention, it is possible to maximize the opening size of the openings in a building to ensure the amount of ventilation within the building, while suppressing noise generated within the building that leaks outside the building. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing the inside of a building in which a sound reduction system according to a first embodiment of the present invention is used. [Diagram 2] FIG. 2 is a diagram showing the arrangement positions of output devices in a building according to the first embodiment of the present invention. [Diagram 3] 1 is a block diagram showing an example of the configuration of a sound reduction facility according to a first embodiment of the present invention. [Figure 4] 5A to 5C are diagrams illustrating an example of the operation of the sound reduction equipment according to the first embodiment of the present invention. [Diagram 5] FIG. 11 is a diagram showing the inside of a building in which sound reduction equipment according to a second embodiment of the present invention is used. [Figure 6] FIG. 11 is a block diagram showing an example of the configuration of a sound reduction facility according to a second embodiment of the present invention. [Figure 7] 10A to 10C are diagrams illustrating an example of the operation of the sound reduction equipment according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, each device (apparatus) is illustrated in a simplified and schematic manner for ease of understanding. Also, the size (dimension) of the device (apparatus) and the interval between the devices (apparatus) shown in the drawings may differ from the actual size (dimension) of the device (apparatus). In addition, in this specification, the concept of "device" includes a single device that performs a specified function by itself, and also includes a combination of multiple devices that are distributed and exist independently but work together to perform a specified function.

[0018] <<First embodiment of the present invention>> Hereinafter, one embodiment of the present invention (hereinafter referred to as the first embodiment) will be described. The first embodiment relates to a technology for suppressing the volume of sounds generated inside a building that can be heard outside the building to below a predetermined level while ensuring the amount of ventilation inside the building, and in particular, to a technology for suppressing the volume of the sounds generated at a predetermined position on the construction site of the building to below a certain level.

[0019] In the first embodiment, the building is, for example, a factory or a building (hereinafter, simply referred to as a factory F) in which people and movable equipment are arranged and predetermined work is performed. The factory F as a building has a structure in which the interior space is covered by an exterior wall, a roof, etc. The building to which the present invention is applicable is not limited to a factory, but may be a building other than a factory, such as a house or a facility.

[0020] The specified location of the building construction site is the boundary location of the factory F site (hereinafter referred to as the site boundary line), and the site boundary line is a location determined in accordance with regulations such as the Building Standards Act and the contract terms at the time of land purchase, etc. The specified position on the construction site of the building is not limited to the site boundary line, but may be, for example, a position a specified distance away from the exterior wall of the building.

[0021] In the first embodiment, a sound reduction equipment according to an example of the present invention (hereinafter, sound reduction equipment 10) can be used to reduce the volume of sound generated within a factory F when it leaks outside the factory F and is heard at the boundary line of the premises, specifically, the sound pressure and volume at the boundary line of the premises. Here, the sound generated within the factory F refers to sound generated from a sound source present within the factory F, and corresponds to, for example, the voices of people present within the factory F, work sounds, operating sounds of movable equipment installed within the factory F, and sounds generated from other sound sources such as audio equipment placed within the factory F. In addition, there may be multiple sources of generated sound within the factory F, and in that case, the sound reduction equipment 10 reduces the sound (generated sound) generated from each of the multiple different sound sources and leaking outside the factory F.

[0022] In the following explanation, sound generated within factory F that leaks outside of factory F will also be referred to as "noise," and the volume of sound generated within factory F that leaks outside factory F and can be heard at the site boundary will also be referred to as the "noise volume."

[0023] (Example of configuration of sound reduction equipment according to the first embodiment) In the first embodiment, the sound reduction equipment 10 can use both an active noise canceller (ANC) and adjustment of the opening of an opening in the factory F as a means for reducing the volume of noise. ANC is a technology that outputs a sound with the same sound pressure (same amplitude) and opposite phase from an output device such as a speaker to actively cancel out the noise by interference with this output sound, making it difficult to hear. In the first embodiment, a plurality of speakers as output devices are installed on the outer wall of the factory F, and more specifically, as shown in Figs. 1 and 2, two speakers 12a, 12b are installed on the outer wall surface of the factory F that faces the site boundary line.

[0024] Among the exterior walls of the factory F, an exterior wall facing the site boundary line is provided with an entrance as an opening K of the factory F and a shutter as an opening / closing member U for opening and closing the entrance. In this embodiment, the two speakers 12a, 12b are attached above the shutter and are disposed at opposite positions to each other with the shutter in between, as shown in FIG. The number and installation positions of the speakers as output devices are not particularly limited, but are preferably set appropriately depending on the specifications of the building and the characteristics of the noise to be reduced.

[0025] Adjusting the opening degree of an opening K in a factory F refers to adjusting the opening degree of an opening provided in a location of the factory F facing the outdoors, specifically, an opening for ventilation or lighting provided in the outer wall and roof of the factory F, or an entrance (front door) to the factory F. To explain in more detail, the opening in the factory F is provided with an opening / closing member U that can be opened and closed freely, as shown in Figs. 1 and 2. The opening / closing member U is a device that adjusts the opening degree of the opening K, such as a shutter, door, window, etc., and is an electric opening / closing member in this embodiment.

[0026] In the first embodiment, the opening / closing member U can be remotely controlled, and the opening degree (open / closed position) of the opening K is adjusted by the control. A known device can be used as the remotely controllable electric opening / closing member U. The opening degree of the opening K is the ratio of the open area to the total area (opening area) of the opening K when it is open, that is, the opening rate, and the opening degree is 0(%) in the fully closed state and 100(%) in the fully open state.

[0027] The number of openings K and opening / closing members U provided in the factory F is not particularly limited, and may be only one, or may be two or more. Furthermore, when multiple openings K are provided in the factory F, the opening / closing members U installed in some of the openings K may be models that do not support remote control, i.e., manual opening / closing members.

[0028] Next, a configuration example of the sound reduction equipment 10 according to the first embodiment will be described with reference to Fig. 3. In the first embodiment, the sound reduction equipment 10 includes two speakers 12a and 12b, a reference microphone 14, and a control computer 20, as shown in Fig. 3.

[0029] The two speakers 12a, 12b are speakers for ANC, and as described above, output sound in response to sound (i.e., noise) generated within the factory F that leaks out of the factory F. The two speakers 12a, 12b are installed at different positions on the exterior wall surface of the factory F, more specifically, on the exterior wall surface facing the site boundary line. The two speakers 12a, 12b output output sound toward the site boundary line, in other words, the output sound is output in the same direction as the noise propagating toward the site boundary line.

[0030] The reference microphone 14 is an instrument that measures sounds generated within the factory F, i.e., sounds before going outside the factory F as noise, and specifically, measures sound pressure (volume), frequency, phase, waveform, etc., as characteristics of the generated sounds. In the first embodiment, the reference microphone 14 is placed at a predetermined position within the factory F, more specifically, near the location where the two speakers 12a and 12b are installed, i.e., near the outer wall located on the site boundary side of the factory F (see FIG. 1). In other words, in the first embodiment, the reference microphone 14 is placed between the sound source O of the generated sound (including the noise emitted into the factory F) and the site boundary in the propagation path of the generated sound. The measurement results by the reference microphone 14 are transmitted to the control computer 20.

[0031] The control computer 20 functions as a controller that controls the two speakers 12a and 12b. The control computer 20 is configured by a control circuit or a general-purpose computer, and includes a processor 21 as shown in FIG. 3. The processor 21 may include a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array) whose circuit configuration can be changed after manufacture, and a dedicated electric circuit having a dedicated circuit configuration for executing a specific process such as an ASIC (Application Specific Integrated Circuit). In addition, a processor that realizes all the functions mounted on the control computer 20 with one IC (Integrated Circuit) chip, such as an SoC (System on Chip), may also be used. The hardware that configures the above processor may be an electric circuit (Circuitry) that combines circuit elements such as semiconductor elements.

[0032] When the loudness of the sound generated in the factory F measured by the reference microphone 14 exceeds a reference value, the control computer 20 controls the two speakers 12a, 12b to output an output sound from at least one of the two speakers 12a, 12b. More specifically, when the loudness of the sound generated by the reference microphone 14 exceeds a reference value, the control computer 20 generates an output sound (strictly speaking, waveform data of the output sound) according to the measurement result by the reference microphone 14. Here, the reference value can be set to any value, but it is preferable to set it based on the allowable limit level of the loudness of noise audible at the boundary line of the premises, for example.

[0033] Then, the control computer 20 outputs the generated output sound from at least one of the speakers 12a, 12b. In other words, each of the two speakers 12a, 12b outputs the output sound generated by the control computer 20 in response to the generated sound measured by the reference microphone 14 in the factory F. The control computer 20 can also output sound from the two speakers 12a, 12b simultaneously. In this case, the sound pressure and frequency of the sound output from the two speakers 12a, 12b are the same between the speakers, but the phases of the sounds differ between the speakers because the installation positions of the two speakers 12a, 12b are different from each other. As a result, the sound output from the two speakers 12a, 12b complementarily contribute to noise reduction (silencing), and the sound output from both speakers can effectively reduce the volume of the noise.

[0034] In addition, the procedure by which the control computer 20 controls each speaker 12a, 12b to output the output sound, in particular the method of determining the output conditions for the output sound and outputting the output sound according to the output conditions, may be a method adopted in general ANC. Furthermore, when output sounds are output simultaneously from the two speakers 12a, 12b, the control computer 20 may control each of the two speakers 12a, 12b individually. That is, an output sound may be generated for each speaker, and the output sound corresponding to each speaker 12a, 12b may be output from each speaker 12a, 12b.

[0035] In the first embodiment, the control computer 20 has a function as a controller that controls the speakers 12a, 12b, as well as a function as a process execution device that executes a process for setting the opening degree of the opening K provided in the factory F. The control computer 20 as a process execution device executes a prediction process, a setting process, and an opening / closing process.

[0036] The prediction process is a process for predicting the loudness of noise when the speaker outputs an output sound. Specifically, the process predicts the loudness of noise when one of the two speakers 12a, 12b outputs an output sound, and the loudness of noise when both speakers output an output sound. In the prediction process, the number of speakers that output the output sound is used as a parameter to simulate the propagation and attenuation of the generated sound (noise) from inside the factory F to the site boundary line, and calculate the sound pressure level of the noise on the site boundary line. In the simulation, the sound insulation performance and area of ​​the exterior walls in each direction of the factory F, the distance from the sound source O to the site boundary line, the opening degree of the opening K provided in the factory F, the characteristics of the output sound from each speaker 12a, 12b, and the measured sound pressure of the generated sound by the reference microphone 14 are used as input values.

[0037] In the first embodiment, when the volume of the sound generated in the factory F measured by the reference microphone 14 exceeds a reference value, the control computer 20 executes a prediction process. The opening degree of the opening K (hereinafter referred to as the first opening degree) set as an input value for simulation in the prediction process can be set to any value, and when multiple openings K are provided in the factory F, the first opening degree is set (input) for each opening K. That is, in the prediction process, the control computer 20 predicts the volume of the noise when the opening degree of the opening K is the first opening degree. The first opening degree is set to a value equal to or less than 100%, and is usually set to, for example, 100 to 50%.

[0038] The setting process is a process for setting the opening degree of the opening K so that the noise level becomes equal to or lower than a specified value when the predicted value of the noise level in the prediction process, more specifically, the predicted value of the noise level when both of the two speakers 12a, 12b output sound, exceeds a specified value. Here, the specified value is the allowable limit level of the noise level audible at the boundary line of the premises, and is, for example, a regulated value (control value) set forth in a law, regulation, or ordinance, etc., which is applied in the area to which the premises of the factory F belongs.

[0039] In the setting process, the opening degree of the opening K is set to be smaller than the first opening degree set in the prediction process, specifically, set to a second opening degree smaller than the first opening degree. In addition, when a plurality of openings K are provided in the factory F, the opening degree is set for each opening K in the setting process. The procedure for setting the second opening degree will be described. The opening degree of the opening K is used as a parameter, and a simulation similar to that of the prediction process is performed while changing the opening degree, and the loudness of the noise is calculated for each opening degree. In this simulation, the loudness of the noise when both of the two speakers 12a and 12b output the output sound is calculated. Then, the opening degree when the calculated value of the loudness of the noise is equal to or less than a specified value is set as the second opening degree. To explain in more detail, the largest opening degree among the opening degrees at which the calculated value of the loudness of the noise is equal to or less than a specified value is set as the second opening degree.

[0040] The opening / closing process is a process in which, when the setting process is executed and a second opening degree is set as the opening degree of an opening K, the opening / closing member U installed for that opening K is remotely controlled to change the opening degree of that opening K to the second opening degree. Note that, when multiple openings K are provided and an opening degree is set for each opening K in the setting process, the opening / closing process remotely controls the opening / closing member U corresponding to each opening K to change the opening degree of each opening K to the second opening degree corresponding to each opening K.

[0041] The control computer 20 is configured to be able to execute the above processes, and specifically, as shown in FIG. 3, includes a memory 22, a storage 23, a communication interface 24, an input device 25, and an output device 26. The memory 22 is configured by semiconductor memories such as a Read Only Memory (ROM) and a Random Access Memory (RAM).

[0042] The storage 23 is configured by, for example, a flash memory, a hard disc drive (HDD), a solid state drive (SSD), a flexible disc (FD), a magneto-optical disc (MO disc), a compact disc (CD), a digital versatile disc (DVD), a secure digital card (SD card), or a universal serial bus memory (USB memory). The storage 23 stores various information required for executing the above-mentioned prediction process, setting process, and opening and closing process, and specifically, stores information for a simulation performed in the prediction process. The information for the simulation includes a simulation model regarding the propagation and attenuation of sound generated in the factory F until it reaches the site boundary line, and numerical data required as input values ​​for the simulation (specifically, acoustic characteristics of the exterior walls, etc. in the factory F, and numerical values ​​related to other specifications and designs of the factory F, etc.). The storage 23 may be built into the computer body constituting the control computer 20, or may be attached to the computer body in an external form. Alternatively, the storage 23 may be configured by an external server (for example, a database server or a file server) present on the network.

[0043] The communication interface 24 may be, for example, a network interface card or a communication interface board. The control computer 20 can communicate data with other devices connected to the Internet or a mobile communication line via the communication interface 24. The control computer 20 can also remotely control devices to be controlled in the factory F (specifically, the speakers 12a, 12b and the opening / closing member U, etc.) via the communication interface 24.

[0044] The input device 25 is configured by, for example, a keyboard, a mouse, a touch panel, etc. Furthermore, the input device 25 may be a device that accepts voice input. The output device 26 includes a display or other indicator, and the indicator displays the opening degree of the opening K set in the setting process described above (more specifically, the second opening degree) and the noise level when set to that opening degree.

[0045] Furthermore, in the computer constituting the control computer 20, as software, a program for an operating system (OS) and an application program for executing the above-mentioned processes are installed.

[0046] (Operation example of sound reduction equipment according to the first embodiment) Next, an operation example of the sound reduction equipment 10 according to the first embodiment will be described with reference to Fig. 4. Note that in the following description of the operation example of the sound reduction equipment 10, the information processing flow (hereinafter, sound reduction flow) executed by the above-mentioned control computer 20 will be mainly described.

[0047] The sound reduction flow according to the first embodiment proceeds according to the flow shown in Fig. 4, and each step in the flow is executed by the processor 21 of the control computer 20. In the sound reduction flow, first, a user who is a user of the sound reduction equipment 10 inputs information related to the initial settings, and the processor 21 accepts the user's input operation (S001). In the initial settings, the above-mentioned reference values ​​and specified values ​​are input. In addition, in the initial settings, information used as input values ​​in the simulation in the prediction process, specifically, the sound insulation performance and area of ​​the exterior walls located in each direction of the factory F, and the distance from the sound source O to the site boundary line, are set.

[0048] Furthermore, when the sound reduction flow is started, the reference microphone 14 installed in the factory F measures the volume (sound pressure) of the sound generated in the factory F, and the processor 21 receives the measurement result of the reference microphone 14 (S002). The processor 21 also determines whether the volume (sound pressure) of the sound generated in the factory F exceeds a reference value based on the received measurement result (S003). If the volume of the sound generated in the factory F is equal to or less than the reference value, the sound reduction flow ends at that point.

[0049] On the other hand, when the loudness of the sound generated in the factory F exceeds the reference value, the ANC speaker outputs the output sound, and the processor 21 of the control computer 20 executes a prediction process to predict the loudness of the noise. More specifically, the processor 21 executes a prediction process to predict the loudness of the sound generated in the factory F when it goes outside the factory F and is heard at the boundary line of the premises, that is, the loudness of the noise (S004). More specifically, in the prediction process, a simulation is performed using various input values ​​set during initial setup, and the loudness of the noise when the output sound is output from one of the two speakers 12a, 12b and the loudness of the noise when the output sound is output from both the two speakers 12a, 12b are predicted.

[0050] When performing a simulation in the prediction process, the opening degree of the opening K provided in the factory F is set to a first opening degree, and the first opening degree is determined, for example, based on an input operation of the first opening degree by a user. In addition, the characteristics of the output sound from each speaker 12a, 12b (specifically, frequency, phase, amplitude, waveform, etc.) are set based on the control conditions when the control computer 20 controls the speakers 12a, 12b. In the prediction process, a simulation is performed based on the set first opening degree, the set characteristics of the output sound, and the loudness (sound pressure) of the generated sound measured by the reference microphone 14, and the loudness of the noise under these conditions is predicted. More specifically, the total noise transmission loss on the exterior wall surface of the factory F, the amount of sound reduction by the output sound from the speaker, and the amount of sound attenuation up to the site boundary line are calculated, and the loudness of the noise (sound pressure level) at the site boundary line is calculated from these results.

[0051] If the predicted noise level is equal to or lower than the specified value (Yes in S005), the processor 21 of the control computer 20 controls the speakers 12a, 12b to output the output sound based on the control conditions set when the simulation was performed in step S003 (S006). To explain in more detail, if the noise level when the output sound is output from one of the two speakers 12a, 12b is equal to or lower than the specified value in the prediction process, in step S006, the one speaker is controlled to output the output sound only from that speaker. On the other hand, if the loudness of the noise when the output sound is output from one of the two speakers 12a, 12b exceeds the specified value and the loudness of the noise when the output sound is output from both of them is equal to or less than the specified value, in step S006, both speakers 12a, 12b are controlled to output the output sound from each speaker.

[0052] On the other hand, if the predicted noise level exceeds the specified value (No in S005), the processor 21 executes a setting process to set the opening degree of the opening K, specifically, sets the opening degree of the opening K to a second opening degree smaller than the first opening degree set during the prediction process (S007). To explain in more detail, in the setting process, as described above, a simulation similar to that of the prediction process is performed while changing the opening degree using the opening degree of the opening K as a parameter, and the noise level is calculated for each opening degree. Then, the opening degree when the calculated value of the noise level is equal to or less than the specified value is set as the second opening degree. The set second opening degree is stored in the memory 22 of the control computer 20.

[0053] When the opening degree of the opening K is set to the second opening degree by the execution of the setting process, the processor 21 executes the opening / closing process and controls the opening / closing member U to change the opening degree of the opening K to the second opening degree (S008). Then, the process proceeds to step S006, where the processor 21 controls the two speakers 12a and 12b to output the output sound from each of the speakers 12a and 12b.

[0054] Then, the processor 21 repeatedly executes the series of steps from S004 onwards while the volume of the sound generated within the factory F exceeds the reference value (S009), and ends the sound reduction flow when the volume of the generated sound becomes equal to or below the reference value. In addition, when steps S004 and onwards are repeated, in the second or subsequent prediction processes, the noise level may be predicted by reducing the sound insulation performance of the exterior walls of factory F (in other words, by increasing the safety factor) compared to the previous prediction process. Also, once the noise level at the site boundary is maintained at a level below the specified value, the opening degree of the opening K is maintained at the same opening degree and the output sound is output from the speakers 12a and 12b under the same control conditions. In this case, only step S006 may be continuously performed, while the other steps may be omitted. Also, in step S003, if the volume (sound pressure) of the sound generated within factory F exceeds a reference value and the difference between the volume of the generated sound and the reference value exceeds a threshold value (e.g., 15 dB), steps S004 and S005 may be omitted and the process may proceed to step S007, i.e., the step of executing the setting process.

[0055] As described above, in the first embodiment, sound output control of the ANC speaker and adjustment of the opening degree of the opening K are used in combination to reduce the volume of sound (noise) generated within the factory F that is heard outside the factory F and at the boundary line of the premises. In such a configuration, normally, in order to ensure the amount of ventilation (airflow) in the factory F, the opening degree of the opening K is made as large as possible while the volume of the noise is reduced by the output sound from the speaker. On the other hand, if the noise level cannot be sufficiently reduced by the sound output from the speaker alone, ANC is used and the opening of the opening K is made smaller. This reduces the amount of ventilation inside the factory F, but it is possible to sufficiently and effectively reduce the noise level heard at the boundary line of the premises.

[0056] <<Second embodiment of the present invention>> In the first embodiment, a prediction process is executed to predict the loudness of a sound generated in the factory F when it goes outside the factory F and is heard at the boundary line of the premises, that is, the loudness of the noise. In the prediction process according to the first embodiment, the loudness of the noise is predicted based on the opening degree of the opening K, the characteristics of the output sound from each of the speakers 12a and 12b, and the loudness of the generated sound measured by the reference microphone 14. Here, it is naturally preferable that the loudness of the noise can be predicted with higher accuracy. If the loudness of the noise can be predicted with higher accuracy, more appropriate control and adjustment can be performed when reducing the noise by controlling the sound output of the ANC speaker and adjusting the opening degree of the opening K.

[0057] Therefore, hereinafter, as a second embodiment of the present invention, a configuration capable of improving the prediction accuracy of the noise volume compared to the first embodiment will be described with reference to Figs. 5 to 7. Note that, for the second embodiment, differences from the first embodiment will be mainly described, and descriptions of commonalities with the first embodiment will be omitted as appropriate. Also, in Figs. 5 and 6, among the components of the sound reduction equipment 10X according to the second embodiment, those common to the first embodiment will be given the same reference numerals as in the first embodiment.

[0058] The configuration of the sound reduction equipment 10X according to the second embodiment is the same as that of the sound reduction equipment 10 according to the first embodiment, except that, as shown in Figs. 5 and 6, an error microphone 16 is further provided. The error microphone 16 corresponds to a detector, and detects noise during ANC operation, i.e., while the speakers 12a and 12b are outputting output sounds. To explain in more detail, the error microphone 16 is disposed outside the factory F at a position closer to the factory F than the boundary line of the premises, as shown in Fig. 5, and detects residual noise at that position. The residual noise is a sound that can be detected at the position where the error microphone 16 is disposed when the noise is reduced by the output sounds from the speakers 12a and 12b, and more specifically, is a noise silencing deviation (error).

[0059] In the second embodiment, as described above, the error microphone 16 is placed at a position closer to the factory F than the site boundary line. More specifically, as shown in FIG. 5, the error microphone 16 is placed at a position closer to the exterior wall surface of the factory F than the site boundary line and, more precisely, the exterior wall surface on which the speakers 12a and 12b are installed. If the error microphone 16 is placed at such a position, the noise volume at the site boundary line can be detected more appropriately than when the error microphone 16 is placed on the site boundary line. This is because, by placing the error microphone 16 in a position closer to the point that is the original sound receiving point, the residual noise at each part of the vertical plane (imaginary plane) including the sound receiving point can be identified from the detection result at the installation position.

[0060] The detection result of the error microphone 16, i.e., a signal corresponding to the volume of the noise (residual noise) detected by the error microphone 16, is transmitted to the control computer 20. The control computer 20 executes a prediction process based on the detection result of the error microphone 16, and also executes a setting process based on the detection result of the error microphone 16 when the predicted value of the noise volume exceeds a specified value.

[0061] Specifically, in the prediction process, the control computer 20 predicts the noise volume at the site boundary line based on the volume of the residual noise detected by the error microphone 16. More specifically, in the prediction process according to the second embodiment, as in the first embodiment, the prediction process predicts the noise volume when an output sound is output from one of the two speakers 12a, 12b, and the noise volume when an output sound is output from both the two speakers 12a, 12b. Also, in the prediction process according to the second embodiment, as in the first embodiment, the opening degree of the opening K is set to a first opening degree, and the noise volume according to the set first opening degree is predicted.

[0062] When the predicted value of the noise level is equal to or lower than a specified value, the control computer 20 controls the speakers 12a and 12b to output the output sound. At this time, the control computer 20 controls the speakers 12a and 12b based on the level of the residual noise detected by the error microphone 16. Specifically, the control computer 20 sets the range, step size, leakage, etc. of the band pass filter and parameters to be set when controlling the speakers 12a and 12b according to the level of the residual noise detected by the error microphone 16. As for the control method, a general ANC control method using an error microphone can be adopted, and for example, a fluctuation control method, a feedback control method, a feedforward control method, etc. can be used.

[0063] In addition, in the setting process, the control computer 20 sets the opening degree of the opening K based on the magnitude of the residual noise detected by the error microphone 16, specifically, sets it to a second opening degree smaller than the first opening degree set in the prediction process. Then, when the second opening degree is set as the opening degree of the opening K, the control computer 20 executes the opening / closing process and remotely controls the opening / closing member U installed for the opening K to change the opening degree of the opening K to the second opening degree.

[0064] In the second embodiment, when the predicted value of the noise level exceeds a specified value, the control computer 20 repeatedly performs sound output control, setting processing, and opening / closing processing of the ANC speaker. Furthermore, each time the opening degree of the opening K changes, the control computer 20 calculates the noise level based on the detection result of the error microphone 16. As a result, the second opening degree, which is the opening degree of the opening K, is adjusted to an opening degree at which the calculated value of the noise level is equal to or less than the specified value, and more precisely, is set to the largest opening degree at which the noise level is equal to or less than the specified value.

[0065] Next, as an operation example of the sound reduction equipment 10 according to the second embodiment, an information processing flow shown in FIG. 7, that is, a sound reduction flow according to the second embodiment, will be described. As can be seen from FIG. 7, the sound reduction flow of the second embodiment includes an additional step (S013) of receiving the detection result of error microphone 16, but is generally the same as the sound reduction flow of the first embodiment (S011, S012, S014 to S020).

[0066] In the second embodiment, as described above, the prediction process, the sound output control of the ANC speaker, and the setting process are executed based on the detection result of the error microphone 16 (S014, S017, S018). That is, in the prediction process, the loudness of the noise at the site boundary is predicted based on the loudness of the residual noise detected by the error microphone 16. Furthermore, when controlling the speakers 12a and 12b to output the output sound, the speakers 12a and 12b are controlled according to the control conditions (control parameters) set according to the loudness of the residual noise detected by the error microphone 16. Furthermore, in the setting process, the opening degree of the opening K is set based on the loudness of the residual noise detected by the error microphone 16, and more specifically, each time the opening degree changes, the loudness of the noise at the site boundary is calculated based on the loudness of the residual noise detected by the error microphone 16, and an opening degree (second opening degree) at which the calculated value is equal to or less than a specified value is set.

[0067] In the sound reduction flow of the second embodiment, while the volume of sound generated within factory F exceeds a reference value (S019), the series of steps from S014 onwards are repeatedly performed, and the sound reduction flow ends when the volume of the generated sound falls below the reference value. In addition, when steps from S015 onwards are repeated, in the second or subsequent prediction process, the noise level may be predicted by reducing the sound insulation performance of the exterior walls of factory F (in other words, by increasing the safety factor) compared to the previous prediction process. Also, once the noise level at the site boundary is maintained at a level below the specified value, the opening degree of the opening K is maintained at the same opening degree and the output sound is output from the speakers 12a and 12b under the same control conditions. In this case, only step S017 may be continuously performed, while the other steps may be omitted. Furthermore, in step S014, if the volume (sound pressure) of the sound generated within factory F exceeds a reference value and the difference between the volume of the generated sound and the reference value exceeds a threshold value (e.g., 15 dB), steps S015 and S016 may be omitted and the process may proceed to step S018, i.e., the step of executing the setting process.

[0068] As described above, in the second embodiment, prediction processing, sound output control of the ANC speaker, and setting processing are performed based on the detection result of the error microphone 16, so these processing and control can be performed with higher accuracy. In this respect, the second embodiment is more advantageous. On the other hand, in the first embodiment, since the detection result of the error microphone 16 is not used, the prediction process, the sound output control of the ANC speaker, and the setting process can be executed more simply, and the load of the process and control can be reduced. In this respect, the first embodiment is more advantageous.

[0069] <<Other embodiments>> Although specific embodiments of the sound reduction equipment and the noise reduction method using said equipment of the present invention have been described above, the above-mentioned embodiments are merely examples for facilitating understanding of the present invention and do not limit the present invention. In other words, the present invention may be modified or improved without departing from the spirit of the present invention. In addition, the present invention naturally includes its equivalents.

[0070] To explain more specifically, for example, in the above embodiment, the controller that controls the speakers 12a and 12b and the process execution device that executes the prediction process, the setting process, and the like are configured as one computer, specifically, the control computer 20. However, this is not limited to this, and the controller and the process execution device may be configured as separate devices (computers).

[0071] In the above embodiment, the prediction process predicts the noise level when the output sound is output from both the two speakers 12a and 12b, and when the predicted value exceeds the regulation value, the setting process is executed to set the opening degree of the opening K to a smaller second opening degree. In the above embodiment, after the opening degree of the opening K is changed to the second opening degree, the output sound continues to be output from both the two speakers 12a and 12b. That is, in the above-mentioned first and second embodiments, the opening degree adjustment of the opening K and the sound output control of the ANC speaker are used simultaneously, but this is not limited to this. For example, when the opening degree of the opening K is adjusted (reduced), the output of the output sound from the ANC speaker may be interrupted, in other words, the opening degree adjustment of the opening K may be performed alone. [Explanation of symbols]

[0072] 10,10X Sound Reduction Equipment 12a, 12b Speaker (output device) 14 Reference Microphone 16 Error microphone (detector) 20 Control computer (processing execution device, controller) 21 Processors 22 Memory 23. Storage 24 Communication Interface 25 Input Devices 26 Output Devices F Factory (building) K opening O sound source S Opening and closing member

Claims

1. A sound reduction system used to reduce the volume of a sound generated in a building at a predetermined location outside the building, comprising: an output device that outputs an output sound in response to the generated sound that has gone outside the building; a processing execution device that executes a process for setting an opening degree of an opening portion provided in a portion of the building facing the outdoors, The process execution device includes: A prediction process for predicting the volume of the output sound when the output device outputs the output sound; and when the predicted value of the magnitude exceeds a specified value, a setting process is executed to set an opening degree of the opening so that the magnitude becomes equal to or smaller than the specified value.

2. A plurality of the outputs are provided, The sound reduction facility according to claim 1 , wherein the process execution device predicts, in the prediction process, the magnitude of the sound when each of the plurality of output devices outputs the output sound.

3. 2. The sound reduction facility according to claim 1, wherein, when the loudness of the generated sound measured in the building exceeds a reference value, the output device outputs the output sound and the processing execution device executes the prediction processing.

4. The sound reduction facility according to claim 1 , wherein the output device outputs the output sound that is generated in response to the generated sound measured in the building.

5. 2. The sound reduction equipment according to claim 1, wherein the processing execution device, in the setting process, calculates the size corresponding to the opening degree of the opening for each opening degree, and sets the opening degree when the calculated value of the size is equal to or smaller than the specified value.

6. a detector that detects a sound at a position outside the building closer to the building than the predetermined position while the output device is outputting the output sound; The process execution device, in the prediction process, predicts a loudness of the generated sound at the predetermined position based on a loudness of the sound detected by the detector; 2. The sound reduction equipment according to claim 1, wherein when the predicted value of the sound level exceeds the specified value, the processing execution device sets the opening degree of the opening based on the sound level detected by the detector in the setting process.

7. The sound reduction equipment according to claim 1 , wherein the processing execution device is a controller that controls the output device.

8. 2. The sound reduction equipment according to claim 1, wherein the processing execution device, in the prediction process, predicts the size when the opening degree of the opening is a first opening degree, and, if the size when the opening degree of the opening is the first opening degree exceeds the specified value, executes the setting process to set the opening degree of the opening to a second opening degree smaller than the first opening degree.

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