Apparatus and method for space monitoring using a three-dimensional acoustic web

Abstract

The present invention relates to a space monitoring device and method using a 3D acoustic web, and proposes a method for emitting multiple acoustic signals to form a 3D acoustic web in a monitored space through interference between sound waves, and then analyzing changes in the received acoustic signals to grasp the situation in the monitored space.

Description

[Technical Field]

[0001] The present invention relates to a space monitoring device and method using a 3D acoustic web, which emits multiple acoustic signals to form a 3D acoustic web in a monitored space through interference between sound waves, and analyzes changes in the received acoustic signals to grasp the situation in the monitored space. [Background technology]

[0002] Various detection sensors and devices are used to detect intrusion of outsiders into indoor spaces, fire outbreaks, gas leaks, etc. These various detection technologies generally include CCTV, IR cameras, vibration detection sensors, gas detection sensors, etc. In the conventional technology, a separate sensing device is required for each situation, such as intrusion, fire, gas, etc., so that in order to monitor various indoor space situations, a corresponding number of sensing devices are required, which results in problems such as high costs for building the equipment and considerable power consumption.

[0003] To solve these problems, a technology has been proposed that emits an acoustic signal and detects the indoor space situation based on changes in the received acoustic signal. Such an acoustic signal-based sensing technology emits acoustic signals having multiple frequencies in the indoor space, receives the signals, and measures changes in sound pressure or phase of the received signals at each frequency. For convenience, an example of measuring changes in sound pressure at each frequency will be described below.

[0004] The frequency-specific sound pressure of the received sound varies depending on the physical characteristics of the room. Fluctuations in the received frequency-specific sound pressure indicate that the physical characteristics of the room have also changed. Therefore, by analyzing the change pattern of the received frequency-specific sound pressure, it is possible to infer how the physical characteristics of the room have changed.

[0005] In the conventional detection technology using acoustic signals, a single acoustic emitter is generally used to emit acoustic signals of multiple frequencies, and changes in sound pressure of the received acoustic signals are detected according to the frequencies. When a single acoustic emitter is used, for example, the amount of change in sound pressure of the received sound due to the presence or absence of an intruder or the movement of the intruder's position is relatively small, resulting in a problem of reduced detection capability.

[0006] Technologies using multiple acoustic emitters have also been proposed, but these technologies are based on the idea that interference between sound waves has an adverse effect on spatial situation perception, and are therefore directed toward eliminating or reducing interference between sound waves. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been devised to solve the problems of the prior art described above, and aims to solve the problem of decreased detection capability due to insufficient change in the sound pressure (or phase) of the received sound at each frequency, even when the physical conditions of the monitored space change.

[0008] The objects of the present invention are not limited to those described above, and other objects and advantages of the present invention not described above can be understood from the following description. [Means for solving the problem]

[0009] One embodiment of a space monitoring device using a three-dimensional acoustic web according to an embodiment of the present invention may include an acoustic emission unit that emits multiple acoustic signals into a monitored space, an acoustic control unit that controls the emission of the acoustic signals from the acoustic generation unit so that a three-dimensional acoustic web is formed in the monitored space through interference between multiple sound waves, an acoustic receiving unit that receives the acoustic signals in the monitored space, and a situation determination unit that grasps the situation of the monitored space based on the received acoustic signals.

[0010] Preferably, the situation assessment unit measures the frequency response of the monitored space using the received acoustic signal, and assesses the situation of the monitored space based on the measured frequency response, or assesses a change in the situation of the monitored space based on a change pattern of the measured frequency response.

[0011] For example, the audio control unit may control the audio signals to emit a complex sound consisting of multiple frequencies whose frequency does not change over time, a simple sound of a single frequency whose frequency changes over time, or a complex sound consisting of multiple frequencies whose frequency changes over time.

[0012] Preferably, the acoustic control unit can adjust at least one of the acoustic signal emission duration, emission time interval, emission direction, number and frequency values ​​of simultaneously emitted frequencies, rate of change of emitted frequencies, phase of emitted frequencies, and separation distance between multiple acoustic emitters based on spatial elements for the monitored space or sensing elements for the sensing object.

[0013] Furthermore, one embodiment of a space monitoring method using a three-dimensional acoustic web according to the present invention includes an acoustic emission step of emitting a plurality of acoustic signals into a monitored space, an acoustic web formation step of forming a three-dimensional acoustic web in the monitored space through interference between a plurality of sound waves, an acoustic reception step of receiving acoustic signals in the monitored space, and a space situation determination step of determining the situation of the monitored space based on the received acoustic signals.

[0014] Preferably, the spatial situation determination step measures the frequency response of the monitored space using the received acoustic signal and determines the situation of the monitored space based on the measured frequency response, or determines a change in the situation of the monitored space based on a change pattern of the measured frequency response.

[0015] For example, the sound emitting step may emit a complex sound consisting of multiple frequencies whose frequency does not change over time, a simple sound of a single frequency whose frequency changes over time, or a complex sound whose frequency changes over time.

[0016] As another example, the acoustic emission step may emit a plurality of acoustic signals into the monitored space by adjusting at least one of the emission duration, emission time interval, emission direction, number and frequency values ​​of simultaneously emitted frequencies, rate of change of emitted frequencies, phase of emitted frequencies, and separation distance between a plurality of acoustic emitters based on spatial elements for the monitored space or sensing elements for the sensing object. [Effects of the Invention]

[0017] According to the present invention, a three-dimensional acoustic web can be formed through interference between acoustic signals by emitting a plurality of acoustic signals adjusted according to the situation and purpose, taking into consideration various spatial elements of the monitored space, such as the shape, size, and pattern, and various detection elements, such as an intruder, a fire outbreak, a gas leak, and a temperature change. By forming a three-dimensional acoustic web in an appropriate shape, it is possible to amplify the amount of change in the received acoustic signal when various situation changes occur in the monitored space.

[0018] Therefore, the present invention can solve the problem of poor detection performance when using only a single acoustic emitter, and can also optimize detection efficiency for each situation by adjusting the acoustic signal taking into account various factors.

[0019] However, in the case of the conventional technology using multiple acoustic emitters, interference between the multiple acoustic emitters is minimized, so the problem of slight changes in the received acoustic signal when a situation occurs in the monitored space is the same as when only a single acoustic emitter is used. However, in contrast to the existing technology, the present invention solves this problem by actively causing interference between multiple acoustic emitters.

[0020] The effects of the present invention are not limited to those described above, and other effects not described above will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a configuration diagram showing an embodiment of a space monitoring device using a three-dimensional acoustic web according to the present invention. [Figure 2] 1 is a block diagram of an embodiment of a sound emitting means of a space monitoring device according to the present invention; [Figure 3] 1 is a diagram showing an embodiment for adjusting the arrangement of multiple acoustic emitters in a space monitoring device according to the present invention; [Figure 4] 1 is a block diagram of an embodiment of a situation determination means of a space monitoring device according to the present invention; [Figure 5] FIG. 1 illustrates an enhanced object sensing concept via acoustic interference according to the present invention. [Figure 6] FIG. 1 illustrates one embodiment of forming a three-dimensional acoustic web over a monitored volume using acoustic interference in accordance with the present invention. [Figure 7] 10A and 10B are diagrams showing simulation results of changes in acoustic signals due to adjustment of the separation distance between two acoustic emitters in the present invention. [Figure 8] 10A and 10B are diagrams showing simulation results of acoustic signal changes due to wavelength adjustment of acoustic signals emitted from two acoustic emitters in the present invention. [Figure 9] 10A and 10B are diagrams showing simulation results of acoustic signal changes depending on the number of acoustic emitters in the present invention. [Figure 10] 1 is a flowchart of one embodiment of a method for space monitoring using a three-dimensional acoustic web in accordance with the present invention. [Figure 11] 4 is a flowchart of one embodiment of adjusting an emitted acoustic signal in a space monitoring method according to the present invention. [Figure 12]3 is a flowchart of an embodiment of determining a space situation in a space monitoring method according to the present invention. [Figure 13] 1 is a diagram illustrating an embodiment of detecting an intruder in a monitored space according to the present invention. [Figure 14] FIG. 1 illustrates one embodiment of detecting a fire condition in a monitored space according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] In the present invention, multiple acoustic signals are emitted into a monitored space, and interference between the multiple acoustic waves forms a three-dimensional acoustic web in the space. As a result, when the conditions in the space change, the amount of change in the received acoustic signal is maximized, thereby improving the sensing performance of the space monitoring device. This principle of the present invention can be equally applied to both cases where the frequency response of the space or reflected waves is used to monitor the conditions of the space.

[0023] FIG. 1 is a diagram showing the configuration of an embodiment of a space monitoring device using a three-dimensional acoustic web according to the present invention.

[0024] The space monitoring device 100 according to the present invention can generally include an acoustic emission means 200 and a situation determination means 300 .

[0025] Here, the sound emitting means 200 and the situation determination means 300 may be included in one space monitoring device 100, or the sound emitting means 200 and the situation determination means 300 may be separately arranged at separate locations to form the space monitoring device 100.

[0026] The integration or separation of these components can be selected depending on the acoustic signal to be applied, or can be appropriately selected depending on spatial elements such as the shape, size, and pattern of the monitored space, sensing elements such as intruders, fire outbreaks, gas leaks, and temperature changes, and other situations and purposes.

[0027] The sound emitting means 200 may include a sound control unit 210 and a sound emitting unit 230 .

[0028] The acoustic control unit 210 adjusts the acoustic signal to be emitted into the monitored space. The acoustic control unit 210 can adjust the emission duration, emission time interval, emission direction, number and frequency values ​​of simultaneously emitted frequencies, rate of change of emitted frequencies, and phase of emitted frequencies of the acoustic signal to form an appropriate 3D acoustic web in the monitored space through interference between multiple sound waves, and can emit the acoustic signal through the acoustic emission unit 230.

[0029] For example, to measure the frequency response of a monitored space, an acoustic signal having multiple frequencies must be emitted, and the acoustic control unit 210 can control the emission of a complex sound consisting of multiple frequencies, or can control the emission of an acoustic signal such as a sine sweep that consists of a single frequency at a specific time but changes frequency over time, and can even control the emitted frequency to change linearly or stepwise over time. In addition, various acoustic synthesis and emission methods can be used in combination.

[0030] The sound emitting unit 230 can emit a plurality of sound signals into the monitored space. To this end, the sound emitting unit 230 can include a plurality of sound emitters 231 and 232. Here, the sound emitters 231 and 232 can include speakers or the like that emit sound signals.

[0031] In addition, the sound emitter 230 can adjust the spacing and angle of the sound emitters 231 and 232 through the control of the sound controller 210 so that an appropriate three-dimensional acoustic web can be formed in the monitored space.

[0032] The sound control unit 210 can control the sound emission unit 230 through machine learning of artificial intelligence, and can change and adjust various conditions in a variety of ways, for example, by adjusting the emission duration, emission time interval, emission direction, emission frequency value, emission frequency change rate, emission frequency phase, etc. of the sound signal emitted according to the situation and purpose, taking into account spatial elements such as the shape, size, and pattern of the monitored space, and detection elements such as intruders, fire outbreaks, gas leaks, and temperature changes, or by adjusting the component frequency values ​​of multiple frequencies or the number of component frequencies.

[0033] The situation determination means 300 may include a situation determination unit 310 and an acoustic receiving unit 330 .

[0034] The acoustic receiver 330 can receive acoustic signals from the monitored space. To this end, the acoustic receiver 330 can include a microphone for receiving the acoustic signals. Furthermore, the acoustic receiver 330 can include multiple microphones arranged at multiple positions in the monitored space depending on the situation.

[0035] The situation determination unit 310 can determine the spatial situation in the monitored space based on the acoustic signal or a change pattern of the acoustic signal received by the acoustic receiving unit 330. When various changes occur in the monitored space, such as object movement, temperature change, and air movement, changes in the acoustic signal occur, but the change in the acoustic signal occurs to an even greater extent due to the influence of the 3D acoustic web formed in the monitored space. The situation determination unit 310 can grasp such changes in the acoustic signal and determine what situation is occurring in the monitored space based on the change pattern of the acoustic signal.

[0036] Preferably, the situation determination unit 310 can learn change patterns of various situations-based acoustic signals occurring in the monitored space through machine learning of artificial intelligence, and determine the situation in the monitored space based on the learned change patterns.

[0037] [Mode for carrying out the invention]

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but the present invention is not limited or restricted by these embodiments.

[0039] DETAILED DESCRIPTION OF THE INVENTION For the purposes of explaining the invention, its operating advantages, and objects attained by its practice, the following description will be given with reference to an example of a preferred embodiment of the invention.

[0040] First, the terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention, and singular expressions can include plural expressions unless the context clearly indicates a different meaning. Furthermore, in this application, terms such as "include" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0041] In describing the present invention, if it is determined that a detailed description of related publicly known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0042] Acoustic sensors use sound to detect the physical shape or characteristics of a space, and a representative example is SONAR (Sound Navigation, Vision, and Ranging). SONAR generates a pulse of sound and measures the sound that is reflected back from the target object (reflected sound or reflected wave) to calculate the direction and distance of the object. Representative applications of SONAR include diving boxes, fish finders, and ultrasound devices for observing the shape of organs such as fetuses and livers.

[0043] There is a frequency response sensor, which is an acoustic sensor that senses spatial conditions using a completely different principle from SONAR. The present invention can be applied to cases where reflected waves are used for spatial monitoring, as with SONAR, or cases where spatial frequency response is used.

[0044] The spatial frequency response can be explained as follows: If the monitored space is considered a type of closed circuit, and an acoustic signal is emitted as an input signal and then received as an output signal, the frequency-specific sound pressure or phase difference of the received acoustic signal is called the spatial frequency response. When the spatial frequency response is expressed on a graph, the horizontal axis is frequency and the vertical axis is sound pressure or phase difference. When measuring the spatial frequency response as described above, some previous literature uses the expression "measuring a sound field," and in this case, measuring a sound field can be considered an example of frequency response measurement.

[0045] Since the frequency response of a space varies depending on the physical characteristics of the space, the physical situation of the space can be inferred using the frequency response of the space, and further, the change in the physical characteristics of the space can be grasped using the pattern in which the frequency response of the space changes. In this case, the greater the difference in the frequency response of the space due to the difference in the physical characteristics of the space, or the greater the change in the frequency response of the space caused by the change in the physical characteristics of the space, the more accurately the physical situation of the space can be sensed using the frequency response of the space.

[0046] Each component of the space monitoring device using a three-dimensional acoustic web according to the present invention will be described in more detail below through an embodiment.

[0047] FIG. 2 is a block diagram showing an embodiment of the sound emitting means of the space monitoring device according to the present invention.

[0048] The sound control unit 210 of the sound emitting means 200 generates and adjusts the sound signal to be emitted. The sound control unit 210 can generate an appropriate sound signal depending on the situation and purpose, taking into consideration sensing elements according to the sensing target, such as object movement, temperature change, air movement, etc., and spatial elements, such as the shape, size, and pattern of the monitored space.

[0049] The sound control unit 210 may generate different sound signals or the same sound signal corresponding to the multiple sound emitters 231, 232 of the sound emitting unit 230. In addition, the sound control unit 210 may adjust the sound emitters 231, 232 so that a specific sound emitter selected from the multiple sound emitters 231, 232 outputs a sound signal, or adjust all the sound emitters so that they output a sound signal simultaneously.

[0050] The sound control unit 210 can generate a complex sound consisting of multiple frequencies or a simple sound whose frequency changes over time. The sound control unit 210 can adjust the number of frequencies, frequency value, phase, frequency change rate, sound signal emission duration, emission time interval, etc.

[0051] In addition, the sound control unit 210 can control the sound emitting unit 230 to adjust the distance between the sound emitters and the direction of sound signal emission.

[0052] At this time, the sound control unit 210 can adjust and provide the sound signal based on the sensing element according to the sensing object, the space element according to the monitored space, and the artificial intelligence learning result for other situations and purposes.

[0053] The sound emitting unit 230 of the sound emitting means 200 may include a plurality of sound emitters 231 and 232, a position adjuster 235, and the like.

[0054] Preferably, the sound emitting unit 230 may include an even number of sound emitters 231, 232. For example, the sound emitting unit 230 may include two sound emitters spaced apart from each other and arranged parallel or perpendicular to the ground of the monitored space, or may include four sound emitters spaced apart from each other and arranged in a cross shape.

[0055] To this end, the arrangement adjuster 235 can adjust the positions of the plurality of sound emitters 231, 232. The arrangement adjuster 235 can adjust the separation distance between the plurality of sound emitters 231, 232 or the sound emission angle to adjust interference caused by overlapping of sound waves.

[0056] FIG. 3 shows an embodiment for adjusting the arrangement of a plurality of acoustic emitters in a space monitoring device according to the present invention.

[0057] When the sound emitting unit includes two sound emitters as shown in FIG. 3, the arrangement adjuster 235 can adjust the distance between the sound emitters 231a, 232a, 231b, and 232b as shown in FIG. 3(a).

[0058] For example, the position adjuster 235 may move the sound emitters 231b and 232b so that the separation distance H1 between the sound emitters 231a and 232a becomes the separation distance H2. To this end, the position adjuster 235 may include a guide rail (not shown) and a driving means (not shown) for moving the sound emitters.

[0059] 3(b), the position adjuster 245 can adjust the sound emission angles of the sound emitters 231c, 232c, 231d, and 232d. For example, the position adjuster 235 can adjust the angles so that the sound emitters face the same direction or so that they face different directions. To this end, the position adjuster 235 can include a tilt function (not shown) for adjusting the sound emission angles of the sound emitters.

[0060] FIG. 4 is a block diagram showing an embodiment of the situation determination means of the space monitoring device according to the present invention.

[0061] The situation determination unit 310 may include an acoustic signal change determination unit 311, a space situation determination unit 315, and the like.

[0062] The acoustic signal change determination unit 311 may detect a change by comparing acoustic signals received at different times by the acoustic receiving unit 330 or by comparing the received acoustic signal with a reference acoustic signal. Alternatively, the acoustic signal change determination unit 311 may detect a change by measuring a spatial frequency response based on the received acoustic signal and comparing the spatial frequency responses measured at different times or by comparing the measured spatial frequency response with a reference frequency response. When measuring the spatial frequency response based on the received acoustic signal, a Fourier Transform algorithm or a Fast Fourier Transform algorithm may be used.

[0063] The space situation determination unit 315 can determine the situation of the monitored space using the received acoustic signal. Preferably, the space situation determination unit 315 can interpret the frequency response of the space or a change pattern of the frequency response of the space and determine the corresponding situation of the monitored space.

[0064] Here, the space situation determination unit 315 may determine the situation of the monitored space according to the spatial frequency response or the change pattern of the spatial frequency response based on the learning results of the artificial intelligence. To this end, machine learning is performed in advance on the spatial situation for each spatial frequency response or the change pattern of the spatial frequency response, and the space situation determination unit 315 may determine the situation of the monitored space corresponding to the spatial frequency response or the change pattern of the spatial frequency response based on the learning results of the artificial intelligence. Furthermore, by continuously acquiring and learning data on the spatial frequency response or the change pattern of the spatial frequency response for each situation in a specific monitored space, a situation determination optimized for the monitored space may be performed.

[0065] The acoustic receiving unit 330 may include an acoustic receiver 331, a position adjuster 335, and the like.

[0066] The acoustic receiver 331 is disposed in the monitored space and may include one microphone corresponding to the acoustic emitting unit 230, or may include multiple microphones spaced apart from one another.

[0067] The placement adjuster 335 can adjust the placement position and placement angle of the acoustic receiver 331 so that the acoustic receiver 331 can be positioned at an optimal position corresponding to the acoustic emitter 230. If the acoustic receiver 331 includes multiple microphones, the placement adjuster 335 can adjust the distance between the multiple microphones or the direction in which they face.

[0068] Next, the operating principle of the space monitoring device according to the present invention will be described with reference to FIGS.

[0069] FIG. 5 is a diagram illustrating the concept of enhanced object sensing by acoustic interference according to the present invention.

[0070] A change in the relative position of an object in a specific space can be sensed by outputting an acoustic signal into the specific space using a single acoustic emitter and measuring the change in the received acoustic signal, or by outputting acoustic signals of multiple frequencies from an acoustic emitter, receiving the signals, measuring the frequency response of the space, and then using the change in the frequency response to sense the change in the relative position of an object in the specific space.

[0071] However, the relative position change of an object can be detected more precisely when it is detected using acoustic signals emitted from two acoustic emitters, rather than when it is detected using an acoustic signal generated from one acoustic emitter.

[0072] 5(a) shows a situation in which a space monitoring device is placed in a specific space, including two sound emitters 10a and 10b that emit sound signals and one sound receiver 30. In this case, the sound emitters 10a and 10b may include speakers, and the sound receiver 30 may include a microphone.

[0073] Interference occurs between the acoustic signals output from the acoustic emitters 10a and 10b, but assuming that destructive interference occurs between the acoustic signals at positions A and C and constructive interference occurs between the acoustic signals at position B, when an object M1 moves from position A to position B to position C in a specific space, the amount of change in the acoustic signal measured by the acoustic receiver 30 can be maximized due to destructive interference and constructive interference caused by the superposition of sound waves.

[0074] If there is only one acoustic emitter, the object M1 is detected using only one acoustic signal emitted from the acoustic emitter, and the change in the acoustic signal measured by the acoustic receiver may be minimal. If the acoustic signal emission power is increased, the absolute magnitude of the received acoustic signal increases, but the rate of change in the received acoustic signal in response to the movement of the object does not increase. In other words, the absolute magnitude of the signal can be increased, but the signal-to-noise ratio does not increase.

[0075] When two or more acoustic emitters are used in this manner, constructive and destructive interference occurs between the acoustic signals emitted from the multiple acoustic emitters. Therefore, when an object M1 moves in a specific space, the change pattern of the acoustic signal measured by the acoustic receiver 30 shows a distinct appearance, making it possible to sensitively detect changes in the relative position of the object M1.

[0076] In particular, when the acoustic signals emitted from the two acoustic emitters have multiple frequency components, the change pattern of the acoustic signals appears differently for each frequency, so that the relative position change of the object M1 can be measured more precisely.

[0077] In this way, destructive interference and constructive interference of signals, which act as noise in conventional signal processing technology, act as important factors in the present invention that can improve detection performance for various spatial situations such as intrusion, fire, and gas leak.

[0078] On the other hand, mutual interference between acoustic signals generated by two acoustic emitters is an extreme example, but it often occurs when acoustic emitters 10a and 10b are arranged so that they emit acoustic signals in the same direction, as shown in Figure 5(a).

[0079] If the acoustic signals emitted from the two acoustic emitters 20a and 20b are arranged in a direction that reduces or prevents mutual interference between them, as shown in Figure 5(b), destructive and constructive interference between the acoustic signals does not occur or is weak, so the amount of change in the acoustic signal due to a change in the situation is small, and the detection performance is reduced.

[0080] In addition, by appropriately adjusting the number of sound emitters, the amount of change in sound signal can be further maximized, thereby improving the detection performance for various situations.

[0081] For example, if four acoustic emitters are arranged in a cross shape, it is possible to more precisely observe the change pattern of the acoustic signal through the alternating destructive and constructive interference that occurs between the acoustic signals emitted from the four acoustic emitters, regardless of the direction of the intruder's movement.

[0082] FIG. 6 is a diagram illustrating one embodiment of the present invention for forming a three-dimensional acoustic web over a monitored volume using acoustic interference.

[0083] For example, assuming that two sound emitters emit the same sound, if the difference in distance from a specific location to the two sound emitters, i.e., the difference in path length, is an integer multiple of the wavelength of the emitted sound, the sounds emitted from the two sound emitters will cause mutual constructive interference at that location. On the other hand, if the difference in distance from a specific location to the two sound emitters, i.e., the difference in path length, is an odd multiple of half the wavelength, the sounds emitted from the two sound emitters will cause destructive interference at that location. Therefore, when an object moves in space, it passes through positions where destructive interference occurs and positions where constructive interference occurs. This maximizes the amount of change in the received sound signal.

[0084] Although a planar acoustic web is shown in Figure 6, in reality, acoustic signals emitted from the acoustic emitters 231 and 232 spread in three-dimensional space. Therefore, for example, when points where the path difference is an integer multiple of the wavelength or points where the path difference is an odd multiple of half the wavelength are connected to each other, a region where constructive or destructive interference occurs is formed in a planar, net-like shape in three-dimensional space. In the present invention, this is called an acoustic web. The shape of the three-dimensional acoustic web can become more complex depending on the number and arrangement of the acoustic emitters.

[0085] Next, conditions for increasing the detection efficiency for a spatial situation through interference between acoustic signals in the present invention will be described with reference to an embodiment.

[0086] Figure 7 shows the simulation results of the change in acoustic signal due to the adjustment of the separation distance between two acoustic emitters in the present invention. The acoustic signals with a frequency of 4 kHz and a wavelength of 8.5 cm were emitted from the two acoustic emitters, and the change in the acoustic signal was simulated while an object was moved within a range of 2.5 m to the left and right at a distance of 5 m from the acoustic emitters.

[0087] 7(a) to 7(d) show interference images between acoustic signals and graphs of sound pressure depending on object position when the separation distance between the two acoustic emitters is adjusted to 0.5, 1, 2, and 4 times the wavelength.

[0088] Referring to (c) of FIG. 7, the interval between the peaks of the acoustic signal depending on the position is approximately 2.6 m, and referring to (d) of FIG. 7, the interval between the peaks of the acoustic signal is approximately 1.3 m. Let's assume that a person moves 1.3 m in the situation shown in FIG. 7. In (a) of FIG. 7, even if the person moves 1.3 m, the change in the acoustic signal before and after the person does not become significant, and in (b) of FIG. 7, the change in the acoustic signal before and after the person moves is also not significant. However, in (c), it can be seen that the difference between the acoustic signals before and after the person moves 1.3 m is maximized. On the other hand, in (d), it can be seen that the difference in the acoustic signal after the person moves 1.3 m is not very large. Therefore, for example, in the situation shown in FIG. 7, if it is important to detect a person moving 1 meter at a distance of 5 m within a secure space, it is preferable to set the separation distance between the acoustic emitters to approximately twice the wavelength.

[0089] If the separation distance between the acoustic emitters in Figure 7 is increased to 10 or 20 times the wavelength, the interval between peaks of the acoustic signal will decrease by several tens of centimeters. In this case, the acoustic signals reflected by each part of the body of a person standing still in the monitored space will exhibit constructive interference in some parts and destructive interference in others. The acoustic signal reflected and received from a stationary person will be the sum of the signals from each part of the body, and will ultimately be close to the average value. Therefore, in this case, even if a person moves within the secure space, the difference in the acoustic signal will be small. On the other hand, if you want to efficiently detect the movement of a small animal like a hamster, it is actually preferable for the interval between peaks of the acoustic signal to be several tens of centimeters.

[0090] The spacing between constructive interference or destructive interference in a 3D acoustic web, i.e., the mesh spacing, is typically about 3 to 10 times the size of the target being monitored. Therefore, the appropriate separation distance for the acoustic emitters varies depending on how the target is set within the monitored space and the frequency being used. If one were to monitor the movements of a person in a situation like Figure 7, the appropriate separation distance for the acoustic emitters would be about 1 to 2 times the wavelength. If one were to monitor the movements of a cat, the appropriate separation distance would be about 2 to 4 times the wavelength.

[0091] That is, the distance between the acoustic emitters can be appropriately adjusted in consideration of the spatial factors of the monitored space and the sensing factors of the sensing type.

[0092] From these simulation results, it can be seen that when interference between acoustic signals occurs using multiple acoustic emitters, a clearer change in the acoustic signal appears than when a single acoustic emitter is used.

[0093] Figure 8 shows the results of a simulation of changes in acoustic signals due to wavelength adjustments of the acoustic signals emitted from two acoustic emitters according to the present invention. With the separation distance between the two acoustic emitters fixed at 20 cm, the acoustic signals were emitted with different frequencies, and the sound pressure was measured while an object was moved 2.5 m to the left and right at a distance of 5 m.

[0094] 8(a) to 8(d) show interference images between acoustic signals and graphs of sound pressure depending on object position when the frequency of the acoustic signal is changed to 4 kHz, 8 kHz, 12 kHz, and 16 kHz. In FIG. 8(a) to 8(d), the ratio of the separation distance between the acoustic emitters to the frequency is approximately 2.5 times, 4.5 times, 7 times, and 9.5 times.

[0095] 9 shows the results of a simulation of the change in acoustic signal depending on the number of acoustic emitters in the present invention. The number of acoustic emitters was changed while the separation distance between multiple acoustic emitters emitting 16 kHz acoustic signals was fixed at six times the wavelength of the acoustic signal, and interference between the acoustic signals was investigated.

[0096] 9(a) to 9(d) show interference images between acoustic signals when the number of acoustic emitters is 2, 4, 6, and 8. Experimental results for varying the number of acoustic emitters show that increasing the number of acoustic emitters can improve the resolution for minute changes in the sensing target space.

[0097] However, when detecting changes above a certain level in the monitored space, such as the movement of an intruder, two to four acoustic emitters are sufficient for detection. That is, improving the resolution for minute spatial position changes makes it possible to detect the minute movements of small objects, but conversely, it may not be appropriate for detecting the movements of large objects. Therefore, the number of acoustic emitters can be appropriately adjusted taking into account the spatial factors of the monitored space and the factors of the object to be detected.

[0098] Depending on the results of the simulation described above, the wavelength of the acoustic signal, the separation distance between multiple acoustic emitters, the number of acoustic emitters, etc. can be adjusted taking into account spatial elements such as the shape, size, and pattern of the monitored space, and sensing elements such as intruders, fire outbreaks, gas leaks, and temperature changes.

[0099] Furthermore, the present invention provides a space monitoring method using a three-dimensional acoustic web. Below, the space monitoring method using a three-dimensional acoustic web according to the present invention will be discussed with reference to one embodiment of the space monitoring device according to the present invention described above.

[0100] 10 is a flowchart showing an embodiment of a method for monitoring a space using a three-dimensional acoustic web according to the present invention. To monitor a monitored space, an acoustic emitting means 200 emits (S100) a plurality of acoustic signals into the monitored space via a plurality of acoustic emitters 231, 232.

[0101] At this time, taking into consideration spatial elements such as the shape, size, and pattern of the monitored space and detection elements such as an intruder, a fire outbreak, a gas leak, and a temperature change, the acoustic emission means 200 emits an acoustic signal by adjusting the wavelength of the acoustic signal, the distance between the multiple acoustic emitters, the number of acoustic emitters, etc., depending on the situation and purpose.

[0102] One embodiment of a process for adjusting the emission of an acoustic signal is described with reference to FIG.

[0103] Taking into consideration the spatial elements of the monitored space and the sensing elements of the sensing object, the audio control unit 210 adjusts the audio signal based on, for example, the learning results of artificial intelligence.

[0104] First, the sound control unit 210 selects the frequency of the sound signal to be emitted in consideration of the spatial element and the sensing element (S110), and selects the number of sound emitters that output the sound signal (S120).

[0105] The sound control unit 210 determines the separation distance between the sound emitters in consideration of various factors such as spatial elements, sensing elements, frequency of the sound signal, and number of sound emitters (S130), and adjusts the separation distance between the sound emitters in consideration of various factors such as spatial elements, sensing elements, frequency of the sound signal, and number of sound emitters (S140).The sound control unit 210 may also determine the sound signal emission angle of the sound emitter in consideration of spatial elements, sensing elements, frequency of the sound signal, and number of sound emitters, and adjust the angle of the sound emitter.

[0106] Through machine learning using artificial intelligence, acoustic signal conditions for optimal sensing performance for various situations can be set, and based on this, the frequency of the acoustic signal, the number of acoustic emitters, the separation distance between the acoustic emitters, etc. can be adjusted.

[0107] Furthermore, the acoustic control unit 210 can adjust the acoustic signal emission duration, emission time interval, emission frequency value, emission frequency change rate, emission frequency phase, etc., taking into account spatial factors and sensing factors, and can also adjust the number of frequency components, frequency values, etc. Once the acoustic signal settings are made, the acoustic control unit 210 controls the acoustic emission unit 230 to emit a plurality of acoustic signals into the monitored space (S150).

[0108] Returning to Figure 10, the following process will be described. As multiple acoustic signals are emitted, a three-dimensional acoustic web is formed in the monitored space due to interference between the multiple acoustic signals (S200).

[0109] When a 3D acoustic web is formed in the monitored space, various situational changes such as intruder movement, fire outbreak, gas leak, temperature change, etc. occur, and the 3D acoustic web is affected by the changes, generating acoustic signal changes according to each spatial situation (S300).

[0110] The situation determination means 300 receives acoustic signals in the monitored space (S400), and determines the spatial situation by detecting changes in the received acoustic signals (S500).

[0111] Meanwhile, based on the results of AI data learning, it is possible to analyze the change patterns in the frequency response of the measured space and determine what situation has occurred in the monitored space.

[0112] One embodiment of the process for determining the spatial context will be described with reference to FIG.

[0113] When an acoustic signal in the monitored space is received via the acoustic receiver 331 and the frequency response of the monitored space is measured, the acoustic signal change determination unit 311 compares the frequency responses of the space measured at different times or compares the frequency response of the measured space with a reference frequency response to determine the frequency response change (S510).

[0114] Then, the space situation determination unit 315 determines the situation of the monitored space based on the change pattern of the frequency response of the space (S550). For example, based on the learning result of the artificial intelligence on the change pattern of the frequency response of the space by situation, the space situation determination unit 315 can grasp what situation will occur in the monitored space.

[0115] An embodiment of determining the status of a monitored space using a three-dimensional acoustic web will be described with reference to FIGS.

[0116] 13 shows an embodiment of a method for detecting an intruder in a monitored space according to the present invention. A plurality of acoustic signals are emitted from a plurality of acoustic emitters 231 and 232 of an acoustic emitting unit 230 in a monitored space 50 to form a three-dimensional acoustic web W. When an intruder M3 enters and moves in the monitored space 50 with the three-dimensional acoustic web W formed in the monitored space 50, a larger change in the acoustic signal occurs than if there were no acoustic web. The acoustic signal in the monitored space 50 is received through an acoustic receiver 331 of an acoustic receiving unit 330, and the change pattern of the frequency response of the space is identified, and the occurrence of the intruder M3 can be detected based on this.

[0117] 14 shows an embodiment of detecting a fire condition in a monitored space according to the present invention. If a fire M4 breaks out in a monitored space 50 with a three-dimensional acoustic web W formed therein, a larger change in the acoustic signal occurs due to the influence of the three-dimensional acoustic web W. The acoustic signal in the monitored space 50 is received through the acoustic receiver 331 of the acoustic receiving unit 330, and the change pattern of the frequency response of the space is grasped, and the occurrence of the fire M4 can be detected based on this.

[0118] In this way, the present invention adjusts acoustic signals in consideration of various spatial elements such as the shape, size, and pattern of the monitored space, as well as various detection elements such as an intruder, a fire, a gas leak, and a temperature change, and emits multiple acoustic signals to form a 3D acoustic web through interference between the acoustic signals. In this way, by actively and appropriately forming a 3D acoustic web, the present invention can increase the amount of acoustic signal variation due to various situations occurring in the monitored space, ultimately improving the ability to sense spatial situations.

[0119] The above description merely exemplifies the technical concept of the present invention, and various modifications and variations are possible by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are for illustrative purposes only, and are not intended to limit the technical concept of the present invention. The scope of protection of the present invention should be interpreted by the following claims, and all technical concepts within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims

1. an acoustic emission unit that emits a plurality of acoustic signals of the same frequency into a monitored space; an acoustic control unit that controls emission of acoustic signals from the acoustic emission unit so that a three-dimensional acoustic web is formed in the monitored space through interference between a plurality of sound waves; an acoustic receiving unit that receives an acoustic signal in the monitored space; a situation determination unit that determines a situation of the monitored space based on the received acoustic signal, A spatial monitoring device using a three-dimensional acoustic web, characterized in that the three-dimensional acoustic web includes a plurality of constructive interference nodes and a plurality of destructive interference nodes, and each destructive interference node of the plurality of destructive interference nodes and each constructive interference node of the plurality of constructive interference nodes are arranged alternately.

2. The situation determination unit 2. A space monitoring device using a three-dimensional acoustic web as described in claim 1, characterized in that the frequency response of the monitored space is measured using the received acoustic signal, and the situation of the monitored space is determined based on the measured frequency response, or the change in the situation of the monitored space is determined based on the change pattern of the measured frequency response.

3. The acoustic control unit 2. The spatial monitoring device using a three-dimensional acoustic web according to claim 1, characterized in that the device controls a plurality of acoustic signals to emit a complex sound consisting of a plurality of frequencies whose frequency does not change over time, a simple sound of a single frequency whose frequency changes over time, or a complex sound consisting of a plurality of frequencies whose frequency changes over time.

4. The acoustic control unit 2. The three-dimensional acoustic system according to claim 1, wherein at least one of the acoustic signal emission duration, emission time interval, emission direction, number and frequency values ​​of simultaneously emitted frequencies, rate of change of emitted frequencies, phase of emitted frequencies, and separation distance between a plurality of acoustic emitters is adjusted based on the spatial element of the monitored space or the sensing element of the sensing object. A space monitoring device using the Google Web.

5. An acoustic emission step of emitting a plurality of acoustic signals of the same frequency into a monitored space; an acoustic web forming step of forming a three-dimensional acoustic web in the monitored space through interference between a plurality of sound waves; an acoustic receiving step of receiving an acoustic signal in the monitored space; a space situation determination step of determining a situation of the monitored space based on the received acoustic signal, A spatial monitoring method using a three-dimensional acoustic web, characterized in that the three-dimensional acoustic web includes a plurality of constructive interference nodes and a plurality of destructive interference nodes, and each destructive interference node of the plurality of destructive interference nodes and each constructive interference node of the plurality of constructive interference nodes are arranged alternately.

6. The spatial situation determination step includes:

6. A method for space monitoring using a three-dimensional acoustic web as described in claim 5, characterized in that the frequency response of the monitored space is measured using the received acoustic signal, and the status of the monitored space is determined based on the measured frequency response, or the change in the status of the monitored space is determined based on a change pattern of the measured frequency response.

7. The acoustic emission step includes:

6. The method for space monitoring using a three-dimensional acoustic web according to claim 5, characterized in that a complex sound consisting of a plurality of frequencies whose frequency does not change with time, a simple sound of a single frequency whose frequency changes with time, or a complex sound whose frequency changes with time is emitted by controlling a plurality of acoustic signals to emit into the monitored space.

8. The acoustic emission step includes:

6. The method for space monitoring using a three-dimensional acoustic web according to claim 5, wherein a plurality of acoustic signals are emitted into the space to be monitored by adjusting at least one of the emission duration, emission time interval, emission direction, number and frequency values ​​of simultaneously emitted frequencies, rate of change of emitted frequencies, phase of emitted frequencies, and separation distance between a plurality of acoustic emitters, based on spatial elements for the space to be monitored or sensing elements for the sensing object.

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