Acoustic monitoring system

Abstract

To provide an acoustic monitoring system comprising a function for identifying a person position in a monitoring target area on the basis of acoustic signals collected by a plurality of microphones.SOLUTION: The acoustic monitoring system comprises: a plurality of microphones which are installed in a monitoring target area and collect sounds generated in the monitoring target area as acoustic signals; a level calculation section which calculates a frequency level and a sound pressure level regarding each of the acoustic signals; and a position identification section which identifies a person position in the monitoring target area on the basis of the frequency level and the sound pressure level. In a case where two or more acoustic signals at frequency levels in an allowable frequency difference range are present, the position identification section determines that audio signals of the same person are included in the two or more acoustic signals, and identifies a position of the same person in the monitoring target area as the person position based on sound pressure levels of the two or more acoustic signals and fixture positions of microphones that collect the two or more acoustic signals.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an acoustic monitoring system that identifies the position of a person in a monitored area based on acoustic information generated in the monitored area.

Background Art

[0002] There is a fire alarm device that determines whether there is a person who has been left behind by determining whether a signal indicating a human voice is included in a sound signal collected by a sound collection means when a fire occurrence is detected, and displays the determination result (see, for example, Patent Document 1).

[0003] According to the fire alarm device according to Patent Document 1, the status information of each fire detector and the sound signal of each sound collection means can be collected on the same signal line, and it can be displayed on the fire receiver that there is a person who has been left behind during a fire.

[0004] Furthermore, according to the fire alarm device according to Patent Document 1, a sound signal can be output to an acoustic output means corresponding to the sound collection means determined to have a person who has been left behind, enabling a call between the person who has been left behind during a fire and the fire receiver.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Patent Document 1 determines whether there is a person who has been left behind by determining whether a signal indicating a human voice is included in a sound signal. However, in Patent Document 1, the position of the person is not specified.

[0007] Furthermore, acoustic information is expected to be effectively utilized not only for determining whether people are trapped during a fire, but also for identifying the location of individuals within the monitored area in the event of abnormal situations such as falls in elderly care facilities or hospitals, or in the event of an earthquake.

[0008] This disclosure is made to solve the above-mentioned problems and aims to provide an acoustic monitoring system that has the function of identifying the location of a person within a monitored area based on acoustic signals picked up by multiple microphones. [Means for solving the problem]

[0009] The acoustic monitoring system described herein comprises: multiple microphones, each installed at predetermined fixed positions within the monitoring area to capture sounds generated in the monitoring area as acoustic signals; a level calculation unit that calculates the frequency level and sound pressure level for each acoustic signal captured by the multiple microphones; and a position identification unit that identifies the location of a person within the monitoring area based on the frequency level and sound pressure level calculated by the level calculation unit for each of the multiple microphones. The position identification unit determines that if there are two or more acoustic signals with frequency levels within a predetermined permissible frequency difference range, the two or more acoustic signals contain the voice signals of the same person. Includes audio signals from the same person Based on the sound pressure levels of two or more acoustic signals, and the fixed positions of each microphone that captured the two or more acoustic signals, For each microphone, the distance from the fixed position to the source of the sound signal is estimated from the magnitude of the sound pressure level. The source of the sound signal from the same person is assumed to exist on the circumference of a circle with the fixed position of the microphone as the center and the estimated distance as the radius. The intersection of the circumferences corresponding to each microphone is then determined. Location of the same person within the monitored area Equivalent to This identifies the location of a person. [Effects of the Invention]

[0010] According to this disclosure, an acoustic surveillance system can be obtained that has the function of identifying the location of a person within a monitored area based on acoustic signals picked up by multiple microphones. [Brief explanation of the drawing]

[0011] [Figure 1]This is a functional block diagram of the acoustic monitoring system according to Embodiment 1 of the present disclosure. [Figure 2] This is an explanatory diagram illustrating how the location identification unit according to Embodiment 1 of the present disclosure identifies the location of the same person from the sound signal acquisition results at two locations. [Figure 3] This is an explanatory diagram illustrating how the location of the same person can be identified by the location identification unit according to Embodiment 1 of the present disclosure, based on the sound pickup results of acoustic signals at three locations. [Figure 4] This is a functional block diagram of the acoustic monitoring system according to Embodiment 2 of the present disclosure. [Figure 5] This is an overall configuration diagram of an automatic fire alarm system incorporating the acoustic monitoring system according to Embodiment 3 of this disclosure. [Modes for carrying out the invention]

[0012] Hereinafter, preferred embodiments of the acoustic monitoring system of this disclosure will be described with reference to the drawings. The acoustic monitoring system described herein is technically characterized by its ability to identify the same person based on a comparison of frequency levels of acoustic signals picked up by multiple microphones, and to identify the location of the same person based on the position of each microphone and the sound pressure level of each microphone that picked up the acoustic signal of the same person.

[0013] Embodiment 1. Figure 1 is a functional block diagram of an acoustic monitoring system according to Embodiment 1 of the present disclosure. The acoustic monitoring system according to Embodiment 1 comprises a plurality of microphones 100(1) to 100(N) and a controller 200.

[0014] Multiple microphones 100(1) to 100(N) are each installed at predetermined fixed positions within the monitoring area. Here, the monitoring area is not limited to areas where the location of a person needs to be identified in the event of a fire, but also includes areas where the location of a person needs to be identified in the event of an emergency such as a fall in a nursing home or hospital, or in the event of an earthquake.

[0015] Each of the plurality of microphones 100(1) to 100(N) picks up the sound generated at the installation position within the monitoring target area as an acoustic signal. The controller 200 has a function of specifying the position of a person within the monitoring target area based on each of the acoustic signals picked up by the plurality of microphones 100(1) to 100(N).

[0016] Specifically, the controller 200 includes a level calculation unit 201 and a position specification unit 202, and realizes the function of specifying the person position. The level calculation unit 201 performs level calculations regarding the frequency level and the sound pressure level for each of the acoustic signals picked up by the plurality of microphones 100(1) to 100(N).

[0017] Further, the position specification unit 202 specifies the position of a person within the monitoring target area based on the frequency level and the sound pressure level calculated for each of the plurality of microphones 100(1) to 100(N) by the level calculation unit 201.

[0018] Specifically, the position specification unit 202 executes a frequency level check to determine whether there are two or more acoustic signals having a frequency level within a predetermined allowable frequency difference range. And when, as a result of executing the frequency level check, there are two or more acoustic signals having a frequency level within the allowable frequency difference range, the position specification unit 202 determines that the voice signals of the same person are included in the two or more acoustic signals.

[0019] For example, when ±5 Hz is set as the allowable frequency difference range, the position specification unit 202 calculates the frequency level corresponding to the acoustic signal acquired by the microphone 100(1), and checks whether an acoustic signal having a frequency level of ±5 Hz from that value is picked up by the other microphones 100(2) to 100(N), thereby determining whether there are two or more acoustic signals having a frequency level within the allowable frequency difference range.

[0020] If, as a result of performing the frequency level check, there are two or more acoustic signals with frequency levels within the allowable frequency difference range, the location specific unit 202 determines that the two or more acoustic signals include voice signals of the same person.

[0021] Furthermore, the location specific unit 202 specifies the location of the same person within the monitored area as the person location based on the sound pressure level of each of the two or more acoustic signals having a frequency level within the allowable frequency difference range, and the fixed position of each microphone that picked up the two or more acoustic signals.

[0022] FIG. 2 is an explanatory diagram of the case where the location specific unit 202 according to Embodiment 1 of the present disclosure specifies the location of the same person from the sound collection results of acoustic signals at two locations. In FIG. 2, within the monitored area, a microphone 100(1) is installed at a fixed position P1, a microphone 100(2) is installed at a fixed position P2, and a location specifying method in the case where two acoustic signals having frequency levels within the allowable frequency difference range are picked up by each of these two microphones 100(1) and 100(2) is illustrated.

[0023] In this case, the location specific unit 202 can estimate the distance between the sound source of the acoustic signal and P1 as r1 from the magnitude of the sound pressure level of the acoustic signal picked up by the microphone 100(1), and can estimate that the sound source of the acoustic signal is on the circumference with a radius r1 centered on P1.

[0024] Similarly, the location specific unit 202 can estimate the distance between the sound source of the acoustic signal and P2 as r2 from the magnitude of the sound pressure level of the acoustic signal picked up by the microphone 100(2), and can estimate that the sound source of the acoustic signal is on the circumference with a radius r2 centered on P2.

[0025] Therefore, the location specific unit 202 can specify X1 or X2, which is the intersection of the circumference with a radius r1 and the circumference with a radius r2, as the location of the same person having a frequency level within the allowable frequency difference range. In the case of FIG. 2, although location specification as a single point is not possible, it can be specified that the person is at a position closer to P1 than P2.

[0026] Therefore, the results obtained in this way to pinpoint the location of individuals can be effectively used when conducting search and rescue operations, or when making appropriate announcements from the nearest speaker.

[0027] Figure 3 is an explanatory diagram illustrating how the location of the same person can be identified by the location identification unit 202 according to Embodiment 1 of this disclosure, based on the sound pickup results of acoustic signals at three locations. Figure 3 illustrates a method for identifying a location when three acoustic signals with frequency levels within an allowable frequency difference range are picked up by microphones 100(1), 100(2), and 100(3), each installed at three fixed locations P1, P2, and P3 within the monitoring area.

[0028] In this case, the positioning unit 202 can further estimate the distance between the source of the acoustic signal and P3 as r3 from the magnitude of the sound pressure level of the acoustic signal picked up by the microphone 100(3), and can estimate that the source of the acoustic signal lies on the circumference of a circle with radius r3 centered on P3.

[0029] Therefore, the position identification unit 202 can identify X2, which is the intersection point of the circumferences of radius r1, radius r2, and radius r3, as the position of the same person whose frequency level is within the allowable frequency difference range. In other words, in the case of Figure 3, it becomes possible to identify the position as a single point.

[0030] Therefore, the results obtained in this way to pinpoint the location of individuals can be effectively used when conducting search and rescue operations, or when making appropriate announcements from the nearest speaker.

[0031] In the acoustic monitoring system according to this embodiment 1, the level calculation unit 201 calculates the frequencies contained in the acoustic signal. Therefore, the location identification unit 202 can refer to the frequency calculation result and estimate further attribute information, such as whether the person at the identified location is female, male, or a baby, based on the magnitude of the frequency.

[0032] Therefore, when the location identification unit 202 outputs the result of identifying the location of a person, it is also possible to output attribute information such as gender and whether or not the person is a baby, which are estimated from the frequency level.

[0033] As described above, according to Embodiment 1, it is possible to realize an acoustic system that identifies the same person based on the comparison of frequency levels of the acoustic signals picked up by multiple microphones, and identifies the location of the same person from the position of each microphone and the sound pressure level of each microphone that picked up the acoustic signal of the same person.

[0034] Furthermore, based on the frequency level calculation results, it is possible to estimate attribute information such as whether the identified person is male, female, or a baby.

[0035] As a result, the results of identifying people's locations and estimating their attribute information can be effectively utilized, for example, in rescue operations and evacuation guidance during a fire. Specifically, the results of identifying people's locations can be used to guide evacuations using more appropriate routes, or to prioritize the evacuation of people closer to the source of the fire. In addition, the results of estimating attribute information can be used to prioritize rescue operations for babies and women.

[0036] Furthermore, in elderly care facilities and hospitals, the results of identifying the location of individuals based on acoustic signals can be used to quickly detect intruders at night, as well as wandering individuals in the facility or among patients.

[0037] Embodiment 2. This second embodiment describes an acoustic monitoring system that has a function to actively identify the location of a person by prompting them to make a sound when they are within the monitored area.

[0038] Figure 4 is a functional block diagram of an acoustic monitoring system according to Embodiment 2 of this disclosure. The acoustic monitoring system according to Embodiment 2 comprises a plurality of microphones 100(1) to 100(N), broadcasting equipment 110, and a controller 200.

[0039] Compared to the configuration shown in Figure 1 of the previous embodiment 1, the configuration shown in Figure 4 of this embodiment 2 differs in that it further includes broadcasting equipment 110. Therefore, the functions of the acoustic monitoring system according to this embodiment 2 will be explained, focusing on the broadcasting equipment 110, which is the main difference.

[0040] The broadcasting equipment 110 has the function of prompting people within the monitored area to speak upon receiving a person identification command, and is composed of an announcement control unit 111 and multiple speakers 112(1) to 112(M).

[0041] In Figure 4, the microphone 100 is configured as N units, while the speaker 112 is configured as M units. N and M may be the same positive number or different positive numbers.

[0042] The acoustic monitoring system according to this second embodiment is equipped with a function that facilitates the collection of acoustic signals by multiple microphones 100(1) to 100(N) by outputting a person confirmation command from the position identification unit 202 when a situation arises in which it is necessary to identify the location of a person within the monitored area.

[0043] For example, if fire monitoring is being performed in a monitored area and a situation arises where it is necessary to identify the location of a person who is trapped or unable to escape, the location identification unit 202 outputs a person identification command to the announcement control unit 111 to make an announcement saying, "If you are trapped, please shout."

[0044] Upon receiving such a person identification command, the announcement control unit 111 broadcasts an audio announcement from multiple speakers 112(1) to 112(M) stating, "If you are unable to escape, please shout." By broadcasting such an audio announcement, it is possible to encourage people within the monitored area to make sounds asking for help.

[0045] Furthermore, when making voice announcements, the announcement control unit 111 can simultaneously make voice announcements from multiple speakers 112(1) to 112(M), or it can make voice announcements sequentially in a predetermined order.

[0046] Furthermore, if the announcement control unit 111 can obtain information regarding the location of the fire source, it can also make voice announcements in order from the speaker closest to the fire source.

[0047] People within the monitored area, upon hearing such voice announcements, will recognize that they can signal their location by voice and will be able to proactively make voice calls to request help.

[0048] In this way, instead of waiting for an acoustic signal, the controller 200 can output a person identification command itself, thereby quickly obtaining an acoustic signal as a response, and enabling the identification of the person's location at the desired timing.

[0049] As described above, according to Embodiment 2, by providing broadcasting equipment that makes announcements based on a person identification command, in addition to the effects of Embodiment 1, it becomes possible to quickly acquire an acoustic signal at a desired timing and identify the person's location.

[0050] Embodiment 3. In this third embodiment, we will describe a case in which the acoustic monitoring system described in the previous second embodiment is incorporated into an automatic fire alarm system, instead of being installed as a standalone device.

[0051] First, let me explain the overall picture of the automatic fire alarm system. Figure 5 is an overall configuration diagram of an automatic fire alarm system incorporating the acoustic monitoring system according to Embodiment 3 of this disclosure. The fire alarm receiver 10 is connected via signal line SG1 to an addressable transmitter 20, fire detectors 31 and 32, a detector repeater 40, and a smoke control repeater 50.

[0052] Multiple fire detectors are connected to the detector relay 40. Figure 1 shows two fire detectors 41 and 42 as an example. In addition, a fire door 51, a smoke exhaust fan 52, a shutter 53, and a curtain wall 54 are connected to the smoke control relay 50.

[0053] Furthermore, the fire alarm receiver 10 is connected to the sound devices 61 and 62 and the sound device repeater 70 via the signal line SG2. In addition, multiple sound devices are connected to the sound device repeater 70. Figure 1 shows two sound devices 71 and 72 as examples.

[0054] Furthermore, the fire alarm receiver 10 is also connected to the emergency broadcast panel 80. Multiple speakers are connected to the emergency broadcast panel 80. Figure 1 shows two speakers, 81 and 82, as an example.

[0055] Here, fire detectors 31, 32 and fire detectors 41, 42 correspond to multiple fire detectors that detect the occurrence of a fire in their respective pre-configured fire monitoring areas. A group of multiple fire detectors constitutes a detector group.

[0056] Furthermore, the fire door 51, smoke exhaust fan 52, shutter 53, and hanging wall 54 operate in conjunction with the detection results of multiple fire detectors and constitute multiple terminal equipment that functions to prevent the spread of fire, smoke, etc. A group of terminal equipment is formed by multiple terminal equipment.

[0057] Furthermore, sound devices 61, 62, and sound devices 71, 72 correspond to multiple district sound devices that notify the occurrence of a fire in each pre-defined district. A group of sound equipment is formed by multiple district sound devices.

[0058] Furthermore, speakers 81 and 82 correspond to multiple broadcasting equipment that outputs messages such as fire alarms and evacuation guidance in pre-configured areas. A group of broadcasting equipment is composed of multiple broadcasting equipment.

[0059] Each of the multiple fire detectors is pre-assigned address information to identify it. When each of the multiple fire detectors detects a fire, it can transmit a fire signal to the fire receiver 10, including the address information assigned to it. The fire receiver 10, on the other hand, can transmit necessary information to the desired fire detector by adding the address information during information transmission.

[0060] Furthermore, each of the multiple terminal devices is pre-assigned address information to identify the individual terminal device. Therefore, the fire alarm receiver 10 can transmit a start command to activate the desired terminal device by adding the address information during information transmission.

[0061] Furthermore, each of the multiple sound devices is pre-assigned address information to identify the individual sound device. Therefore, the fire alarm receiver 10 can transmit an activation command to sound the desired sound device by adding the address information during information transmission.

[0062] Furthermore, each of the multiple broadcasting equipment is pre-assigned address information to identify the individual broadcasting equipment. Therefore, the fire alarm receiver 10 can transmit an activation command via the emergency broadcasting panel 80 to output a desired voice message from the desired broadcasting equipment by adding the address information during information transmission.

[0063] With this configuration, the fire alarm receiver 10 collects fire signals from multiple fire detectors and addressable transmitters 20 installed in various predetermined fire monitoring areas. Based on the collected fire signals, the fire alarm receiver 10 can identify the location of the fire source, issue a fire alarm, and activate the terminal equipment.

[0064] Furthermore, the fire alarm receiver 10 can sound the bells of sound devices installed in areas where an alarm is needed, based on the fire signals it has collected, and can output desired voice messages from broadcasting equipment installed in areas where evacuation guidance via voice messages is needed. It should be noted that the operation of each of the multiple sound devices and each of the multiple broadcasting equipment is predetermined to be linked to the detection results of each fire detector.

[0065] Although not shown in the diagram, the fire alarm receiver 10 can also output a transmission signal based on the collected fire signal, activate the fire extinguishing equipment to start firefighting operations, or transmit the fire signal to a higher-level device via the network.

[0066] To incorporate an acoustic monitoring system, which includes multiple microphones 100(1) to 100(N), broadcasting equipment 110, and a controller 200, as shown in Figure 4, into an automatic fire alarm system with the configuration shown in Figure 5, the following system configuration can be considered.

[0067] First, while multiple microphones 100(1) to 100(N) can be installed as standalone devices, they can also be built into fire detectors 31, 32, 41, 42, etc., as shown in Figure 5.

[0068] The broadcasting equipment 110 can be configured as a group of broadcasting equipment equipped with the emergency broadcasting panel 80 shown in Figure 5 and multiple speakers 81 and 82.

[0069] The functions of the controller 200 can be performed by the fire alarm receiver 10 shown in Figure 5. In this case, the controller 200 can effectively utilize the fire source location information that can be identified by the original function of the fire alarm receiver 10.

[0070] As described above, according to Embodiment 3, the acoustic monitoring system according to this disclosure can be easily incorporated into existing equipment, and the function of identifying the location of a person within the monitoring area based on acoustic signals picked up by multiple microphones can be easily realized. [Explanation of symbols]

[0071] 10 Fire alarm receiver, 31, 32, 41, 42 Fire detectors, 80 Emergency broadcast panel, 81, 82 Speakers, 100 Microphone, 110 Broadcasting equipment, 111 Announcement control unit, 112 Speaker, 200 Controller, 201 Level calculation unit, 202 Location identification unit.

Claims

1. Multiple microphones are installed at predetermined fixed positions within the monitored area to capture sounds generated in the monitored area as acoustic signals, A level calculation unit calculates the frequency level and sound pressure level for each of the acoustic signals picked up by the plurality of microphones, Based on the frequency level and sound pressure level calculated by the level calculation unit for each of the plurality of microphones, a position identification unit identifies the location of a person within the monitored area. Equipped with, The aforementioned position identification unit is If there are two or more acoustic signals with frequency levels within a predetermined permissible frequency difference range, it is determined that the two or more acoustic signals contain the voice signals of the same person. Based on the sound pressure levels of the two or more acoustic signals, including the voice signal of the same person, and the fixed positions of the microphones that picked up the two or more acoustic signals, the distance from the fixed position to the source of the acoustic signal is estimated from the magnitude of the sound pressure level for each microphone. It is then estimated that the source of the acoustic signal from the same person lies on a circle with the fixed position of the microphone as the center and the estimated distance as the radius. The intersection of the circles corresponding to each microphone is identified as the location of the person, which corresponds to the location of the same person within the monitored area. Acoustic monitoring system.

2. Broadcasting equipment that, upon receiving a person identification command, makes an announcement prompting people within the monitored area to speak. Furthermore, The aforementioned position identification unit is When a situation arises within the monitored area where it is necessary to identify a person's location, the system outputs the person identification command and facilitates the acquisition of the acoustic signal by the multiple microphones. The acoustic monitoring system according to claim 1.

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