KR102877565B1 - Apparatus and Method for Noise Reduction - Google Patents

Abstract

The noise reduction device of the present invention comprises: a device communication unit for receiving terminal location information from a mobile communication terminal; a direction control unit for rotating a microphone and a speaker in the direction of the location of the mobile communication terminal based on the terminal location information; a microphone for measuring noise in the direction in which the mobile communication terminal is located by being rotated under the control of the direction control unit; an offset waveform generation unit for analyzing the measured noise and generating an offset waveform of an opposite phase to the noise; and a speaker for outputting the offset waveform in the direction in which the mobile communication terminal is located by being rotated under the control of the direction control unit.

Description

Apparatus and Method for Noise Reduction

The present invention relates to a device and method for reducing noise in a place where multiple noises are generated.

Noise is defined as sound that is unpleasant to the human ear and that is above a standard decibel level (e.g., 60 dB) in the audible frequency range. The loudness of sound depends on the amplitude (amount of sound energy) and is measured in decibels (dB). Sounds with high energy and large amplitude, such as gunshots, are heard loudly, while sounds with low energy and small amplitude, such as whispers, are heard softly. The loudness of sound decreases in inverse proportion to the square of the distance from the source of the sound (e.g., motors, compressors, fans, pumps, etc.). For example, the sound level of normal conversation is about 65 decibels (dB), and the sound of a passing truck is about 90 decibels (dB). Exposure to sounds above 90 decibels (dB) for more than 8 hours can cause hearing damage.

In modern society, people are exposed to a variety of noises throughout their lives. In particular, persistent noise can lead to hearing impairments such as hearing loss and tinnitus, as well as a decreased ability to recognize hazardous situations, putting them at risk for accidents. In particular, workers in industrial settings are exposed to multiple noises generated by motors, compressors, fans, pumps, and other sources for extended periods, making noise a serious safety hazard.

Technologies to eliminate this noise, such as active noise control (ANC), noise canceling, and active noise reduction (ANR), utilize microphones attached to the listener's earphones or headphones to pick up ambient noise and then generate destructive interference waves to cancel it out, thereby blocking the noise. Alternatively, efforts are being made to install noise-reducing devices a certain distance away from the source of noise and output destructive interference waves to reduce the noise.

However, when noise reduction functions are included in earphones or headphones, there are problems with reduced lifespan due to dust and heat, and the discomfort felt when wearing earphones or headphones makes it difficult for workers who work long hours in industrial sites to use them.

The method of reducing noise by installing noise reduction devices at a certain distance from the source of the noise cannot reduce the noise across the entire industrial site due to the characteristic of the wave pattern, which spreads concentrically from the source. Furthermore, when multiple noise sources are simultaneously generated, the perceived noise level (intensity) varies across locations, making it ineffective for noise reduction.

The present invention aims to provide a noise reduction device and a noise reduction method that output a noise cancellation waveform for noise having a large impact at a location based on the real-time location of a worker working for a long time at an industrial site.

The present invention aims to provide a noise reduction device and a noise reduction method capable of receiving feedback on noise measured from a terminal carried by a worker, checking the degree of noise reduction in real time, and precisely correcting a noise cancellation waveform based on the feedback.

A noise reduction device according to one feature of the present invention comprises: a device communication unit for receiving terminal location information from a mobile communication terminal; a direction control unit for rotating a microphone and a speaker in the direction of the location of the mobile communication terminal based on the terminal location information; a microphone that is rotated under the control of the direction control unit to measure noise in the direction in which the mobile communication terminal is located; an offset waveform generation unit for analyzing the measured noise and generating an offset waveform of an opposite phase to the noise; and a speaker that is rotated under the control of the direction control unit to output the offset waveform in the direction in which the mobile communication terminal is located.

The above-mentioned offset waveform generation unit can extract the maximum single noise having the maximum amplitude among the plurality of single noises constituting the measured noise and generate an offset waveform having an opposite phase to the maximum single noise.

The above-mentioned offset waveform generation unit can extract a single noise having the highest decibel among the plurality of single noises constituting the measured noise as the maximum single noise.

The above-mentioned offset waveform generation unit can analyze noise information transmitted from the mobile communication terminal to monitor the degree of noise reduction and correct the output offset waveform so that the noise reduction efficiency reaches a preset level.

A noise reduction method according to another feature of the present invention comprises the steps of: receiving terminal location information from a mobile communication terminal; controlling a rotational direction of a microphone based on the terminal location information to measure noise in a direction in which the mobile communication terminal is located; analyzing the measured noise to generate a cancellation waveform having an opposite phase to the noise; and controlling a rotational direction of a speaker based on the terminal location information to output the cancellation waveform in a direction in which the mobile communication terminal is located.

The step of generating the above-mentioned offset waveform can extract the maximum single noise having the maximum amplitude among the plurality of single noises constituting the measured noise and generate the offset waveform having the opposite phase to the maximum single noise.

The step of generating the above-mentioned offset waveform can extract a single noise having the highest decibel among the plurality of single noises constituting the measured noise as the maximum single noise.

After the step of outputting the above-mentioned offset waveform, the step of determining whether terminal location information and noise information are retransmitted from the mobile communication terminal; and, if the terminal location information and noise information are retransmitted from the mobile communication terminal, the step of analyzing the noise information transmitted from the mobile communication terminal to monitor the degree of noise reduction and correcting the outputting offset waveform so that the noise reduction efficiency reaches a preset level may be further included.

The present invention provides a noise reduction device and a noise reduction method having high noise reduction efficiency by outputting a noise cancellation waveform for noise having a large impact at a location based on the real-time location of a worker working for a long time at an industrial site, and receiving feedback on noise measured from a terminal carried by the worker to confirm the degree of noise reduction.

The present invention provides a noise reduction device and a noise reduction method that can reduce noise at each position of a plurality of workers without requiring a separate noise reduction device, thereby providing high worker satisfaction.

FIG. 1 is a drawing illustrating a noise reduction system according to one embodiment.
Figure 2 is a drawing explaining the mobile communication terminal and noise reduction device of Figure 1.
Figure 3 is an example of noise and offset waveforms.
Fig. 4 is an exemplary diagram illustrating a method for reducing the largest single noise among multiple single noises constituting the noise of Fig. 3.
Fig. 5 is a drawing illustrating a noise reduction method according to one embodiment.

One embodiment of the present invention relates to a device and method for reducing various noises in an industrial site, but is not limited thereto, and any place where various noises exist may be included.

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the attached drawings. The same or similar components will be given the same or similar drawing reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and/or "part" used for components in the following description are given or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

FIG. 1 is a drawing illustrating a noise reduction system according to one embodiment, FIG. 2 is a drawing illustrating a mobile communication terminal and a noise reduction device of FIG. 1, FIG. 3 is an example drawing of a noise cancellation waveform, and FIG. 4 is an example drawing illustrating a method for reducing the largest single noise among a plurality of single noises constituting the noise of FIG. 3.

Referring to Fig. 1, a noise reduction system includes a mobile communication terminal (1) and a noise reduction device (2). Fig. 1 illustrates an industrial site where multiple single noises (N1-Nk) are generated, but the present invention is not limited to industrial sites and can be applied to various places where noise reduction is required. Among the multiple single noises (N1-Nk) illustrated in Fig. 1, the single noise (e.g., N1) that is heard the loudest varies depending on the position of the worker, and when the worker moves, the single noise that is heard the loudest may change (e.g., N1-> N3) depending on the moving position.

Referring to FIG. 2, the mobile communication terminal (1) may include a terminal communication unit (11), a location measurement unit (12), and a noise measurement unit (13). The mobile communication terminal (1) measures the current location in real time or at predetermined intervals and transmits the measured location to the noise reduction device (2). For example, when the mobile communication terminal (1) measures noise at the current location and feeds the measured location back to the noise reduction device (2), the noise reduction device (2) can analyze the feedback information and monitor the noise reduction efficiency. The location of the worker carrying the mobile communication terminal (1) corresponds to the location of the mobile communication terminal (1).

The terminal communication unit (11) can communicate with the noise reduction device (2) by including at least one module among a short-range wireless communication module, a network connection module, a mobile communication module, and a wireless Internet module.

The short-range wireless communication module connects to the noise reduction device (2) via Bluetooth to enable data communication, and information required for the connection can be stored in memory. The network connection module connects to the noise reduction device (2) via WiFi to enable data communication, and information required for the connection can be stored in memory. The mobile communication module can transmit and receive wireless signals with at least one of a base station, an external terminal, and a server in a mobile communication network. The wireless signals can include various types of data according to voice call signals, video call call signals, and text/multimedia message transmission and reception. The wireless Internet module can be built into or external to the mobile communication terminal (1) as a module for wireless Internet access. For example, the wireless Internet module can perform WiFi-based wireless communication or WiFi Direct-based wireless communication.

The location measuring unit (12) can measure the current location of the mobile communication terminal (1) in real time or at predetermined intervals. For example, the location measuring unit (12) may include a GPS module that receives current location information of the mobile communication terminal (1) in real time from a plurality of GPS satellites, and transmits information about the measured location (hereinafter, terminal location information, P) to the noise reduction device (2) via the terminal communication unit (11). For example, the location measuring unit (12) may include a Bluetooth module to measure the current location of the mobile communication terminal (1) in real time or at predetermined intervals, and transmit the terminal location information (P) to the noise reduction device (2) via the terminal communication unit (11).

The noise measuring unit (13) can measure noise in real time or at predetermined intervals at the current location of the mobile communication terminal (1). Referring to FIGS. 1 and 3, noise (A) measured at an arbitrary location is a synthesized state of multiple single noises (N1-Nk) having a single frequency, and the frequency, amplitude, phase, etc. of noise (A) may vary depending on the type of synthesized single noise. Referring to FIGS. 1 and 4, in a certain range of an area where multiple single noises (N1-Nk) are generated, the maximum single noise (Nmax) having the highest decibel (dB) among the multiple single noises (N1-Nk) constituting noise (A) may vary depending on the measurement location.

The noise measurement unit (13) can transmit information (hereinafter, noise information, W) about the measured noise (A) to the noise reduction device (2) through the terminal communication unit (11). For example, the noise measurement unit (13) can transmit a plurality of noise information (W1-Wk) about a plurality of single noises (N1-Nk) constituting the noise (A) to the noise reduction device (2) through the terminal communication unit (11). For example, the noise measurement unit (13) can extract the maximum single noise (Nmax) having the highest decibel (dB) among the plurality of single noises (N1-Nk) constituting the noise (A), and transmit the noise information (W) about the extracted maximum single noise (Nmax) to the noise reduction device (2) through the terminal communication unit (11). The noise information (W) can include at least one piece of information from among phase, amplitude, frequency, and waveform of the measured noise.

The noise reduction device (2), referring to FIG. 2, may include a device communication unit (21), a direction control unit (22), a microphone (23), a cancellation waveform generation unit (24), and a speaker (25). The noise reduction device (2) measures noise (A) in the direction in which the mobile communication terminal (1) is located, outputs a cancellation waveform in the direction in which the mobile communication terminal (1) is located, and then analyzes noise information (W) transmitted from the mobile communication terminal (1) to monitor the degree of noise reduction.

The device communication unit (21) may include at least one module among a short-range wireless communication module, a network connection module, a mobile communication module, and a wireless Internet module to communicate with the terminal communication unit (11). For example, the device communication unit (21) may receive terminal location information (P) and noise information (W) from the terminal communication unit (11) in real time or at predetermined intervals.

The direction control unit (22) controls the rotation module (not shown) based on the terminal location information (P) received from the device communication unit (21) to rotate the microphone (23) and speaker (25) in the direction of the location of the mobile communication terminal (1). For example, the rotation module may include a motor.

A microphone (23) is connected to a rotation module and configured to be rotatable at a predetermined angle. The microphone (23) is rotated under the control of a direction control unit (22) to measure noise (A) in the direction in which the mobile communication terminal (1) is located, and transmits the measured noise (A) to a cancellation waveform generation unit (24). For example, the microphone (23) may include various types of noise measurement devices having a noise measurement function.

The cancellation waveform generation unit (24) can analyze the noise (A) received from the microphone (23) and generate a cancellation waveform of the opposite phase to remove the noise (A). For example, the cancellation waveform generation unit (24) can extract the maximum single noise (Nmax) having the highest decibel (dB) among the plurality of single noises (N1-Nk) constituting the noise (A), and analyze the noise information (W) for the extracted maximum single noise (Nmax) to generate a cancellation waveform of the opposite phase to remove the maximum single noise (Nmax).

Referring to Fig. 3, the cancellation waveform generation unit (24) can generate a cancellation waveform (B) that has the same amplitude as the noise (A) but an opposite phase. Fig. 3 illustrates a cancellation waveform (B) synthesized from a plurality of single cancellation waveforms that have opposite phases for a plurality of single noises (N1-Nk) that constitute the noise (A). For example, referring to Fig. 4, the cancellation waveform generation unit (24) can extract the maximum single noise (Nmax) among the plurality of single noises (N1-Nk) that constitute the noise (A) and analyze the noise information (W) for the extracted maximum single noise (Nmax) to generate a cancellation waveform (C) of the opposite phase to remove the maximum single noise (Nmax).

The offset waveform generation unit (24) can analyze the noise information (W) received from the device communication unit (21) to monitor the degree of noise reduction, and correct the offset waveform (C) so that the degree of noise (A) reduction reaches a predetermined reference value. For example, the noise (A) received from the microphone (23) and the noise information (W) received from the device communication unit (21) can be synthesized to extract the maximum single noise (Nmax) at the point where the mobile communication terminal (1) is located, and the noise information (W) for the extracted maximum single noise (Nmax) can be analyzed to generate an offset waveform (C) of the opposite phase to remove the maximum single noise (Nmax).

The speaker (25) is connected to the rotation module and configured to be rotatable at a predetermined angle. The speaker (25) is rotated under the control of the direction control unit (22) and outputs the offset waveform (C) received from the offset waveform generation unit (24) in the direction in which the mobile communication terminal (1) is located. For example, referring to Fig. 4, when the offset waveform (C) is output, it overlaps with the noise (A), thereby reducing the size of the noise (D). Then, the reduced noise (D) can be heard as a small sound with a small amplitude, thereby reducing the impact on the worker.

Fig. 5 is a drawing illustrating a noise reduction method according to one embodiment.

First, the noise reduction device (2) can receive terminal location information (P) and noise information (W) from the mobile communication terminal (1) in real time or at predetermined intervals (S1). In Fig. 1, an industrial site where multiple single noises (N1-Nk) are generated is illustrated, but the present invention is not limited to industrial sites and can be applied to various places where noise reduction is required. Among the multiple single noises (N1-Nk) illustrated in Fig. 1, the single noise (e.g., N1) that is heard the loudest varies depending on the position of the worker, and when the worker moves, the single noise that is heard the loudest can change (e.g., N1-> N3) depending on the moving position.

Next, the noise reduction device (2) controls the direction of the microphone (23) based on the terminal location information (P) to measure noise (A) in the direction in which the mobile communication terminal (1) is located (S2).

Next, the noise reduction device (2) can analyze the measured noise (A) and generate an opposite phase cancellation waveform (S3) to remove the noise (A). For example, the noise reduction device (2) can extract the maximum single noise (Nmax) having the highest decibel (dB) among the multiple single noises (N1-Nk) that constitute the noise (A), and analyze the noise information (W) for the extracted maximum single noise (Nmax) to generate an opposite phase cancellation waveform to remove the maximum single noise (Nmax).

Referring to FIGS. 1 and 3, the noise reduction device (2) can generate a cancellation waveform (B) having the same amplitude as the noise (A) but an opposite phase. FIG. 3 illustrates a cancellation waveform (B) synthesized from a plurality of single cancellation waveforms having opposite phases for a plurality of single noises (N1-Nk) constituting the noise (A). Referring to FIGS. 1 and 4, the noise reduction device (2) can extract the maximum single noise (Nmax) among the plurality of single noises (N1-Nk) constituting the noise (A) and analyze the noise information (W) for the extracted maximum single noise (Nmax) to generate a cancellation waveform (C) having an opposite phase to remove the maximum single noise (Nmax).

Next, the noise reduction device (2) controls the direction of the speaker (25) based on the terminal location information (P) to output a cancellation waveform (C) in the direction in which the mobile communication terminal (1) is located (S4). For example, referring to Fig. 4, when the cancellation waveform (C) is output, it overlaps with the noise (A), thereby reducing the size of the noise (D). Then, the reduced noise (D) can be heard as a small sound with a small amplitude, thereby reducing the impact on the worker. The noise reduction device (2) can also control the rotation direction of the speaker (25) when controlling the direction of the microphone (23), and the direction control of the speaker (25) is not limited to being performed before outputting the cancellation waveform.

Next, the noise reduction device (2) determines whether terminal location information (P) and noise information (W) are retransmitted from the mobile communication terminal (1) (S5).

If the terminal location information (P) and noise information (W) are not retransmitted within a predetermined time (S5, No), the noise reduction device (2) determines that the worker has left the work site and stops outputting the offset waveform (S6).

If the terminal location information (P) and noise information (W) are retransmitted within a predetermined time (S5, Yes), the noise information (W) received as feedback can be analyzed to monitor the noise reduction degree (S7). Thereafter, the noise reduction device (2) can perform steps S2 to S4 again based on the transmitted terminal location information (P) and noise information (W) to correct the offset waveform (C) so that the noise (A) reduction degree reaches a predetermined reference value.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by a person having ordinary skill in the art to which the present invention pertains also fall within the scope of the present invention.

1: Mobile terminal
11: Terminal communication section
12: Position measurement unit
13: Noise measurement section
2: Noise reduction device
21: Device Communications Unit
22: Direction control unit
23: Mike
24: Offset waveform generator
25: Speaker

Claims (8)

In noise reduction devices,
A device communication unit that receives terminal location information from a mobile communication terminal;
A direction control unit that rotates the microphone and speaker in the direction of the location of the mobile communication terminal based on the terminal location information;
A microphone that rotates under the control of the direction control unit and measures noise in the direction in which the mobile communication terminal is located;
A compensation waveform generation unit that analyzes the measured noise and generates a compensation waveform of the opposite phase to the noise; and
It includes a speaker that rotates under the control of the direction control unit and outputs the offset waveform in the direction in which the mobile communication terminal is located,
The above offset waveform generator,
Extracting the maximum single noise having the maximum amplitude from among the plurality of single noises constituting the measured noise, analyzing the noise information for the maximum single noise, and generating a cancellation waveform having an opposite phase to the maximum single noise,
The above noise reduction device is,
Determine whether the terminal location information and the noise information are retransmitted from the mobile communication terminal,
A noise reduction device that stops outputting the offset waveform if the terminal location information and the noise information are not retransmitted to the noise reduction device within a predetermined time. delete In the first paragraph,
The above offset waveform generator,
A noise reduction device that extracts the single noise with the highest decibel among the plurality of single noises that constitute the above-mentioned measured noise as the maximum single noise. In the third paragraph,
The above offset waveform generator,
A noise reduction device that analyzes noise information transmitted from the mobile communication terminal to monitor the noise reduction level and corrects the output offset waveform when the noise reduction level does not reach a predetermined standard value. In a noise reduction method using a noise reduction device,
A step of receiving terminal location information from a mobile communication terminal;
A step of controlling the rotation direction of a microphone based on the terminal location information to measure noise in the direction in which the mobile communication terminal is located;
A step of analyzing the measured noise to generate a cancellation waveform of the opposite phase to the noise; and
A step of controlling the rotation direction of the speaker based on the terminal location information and outputting the offset waveform in the direction in which the mobile communication terminal is located,
The step of generating the above offset waveform is:
Extracting the maximum single noise having the maximum amplitude from among the plurality of single noises constituting the measured noise, analyzing the noise information for the maximum single noise, and generating a cancellation waveform having an opposite phase to the maximum single noise,
After the step of outputting the above-mentioned offset waveform, the step of determining whether the terminal location information and the noise information are retransmitted from the mobile communication terminal is further included.
A noise reduction method in which, in the step of determining whether the above retransmission is made, if the terminal location information and the above noise information are not retransmitted to the noise reduction device within a predetermined time, the output of the offset waveform is stopped. delete In paragraph 5,
The step of generating the above offset waveform is:
A noise reduction method for extracting a single noise having the highest decibel among a plurality of single noises constituting the measured noise as the maximum single noise. In paragraph 5,
After the step of outputting the above offset waveform,
A noise reduction method further comprising a step of analyzing the noise information transmitted from the mobile communication terminal when terminal location information and noise information are retransmitted from the mobile communication terminal, monitoring the noise reduction degree, and correcting the outputting offset waveform when the noise reduction degree does not reach a predetermined reference value.