KR20140124317A - Monitoring system and monitoring method - Google Patents

Abstract

The present invention relates to a security monitoring system and a security monitoring method for monitoring fire and invasion situation separately, based on sound field sensing. The security monitoring system includes: a sound generation device which outputs a multi-tone sound wave comprising linear sum of sine waves of a number of frequency components by applying a constant voltage in a fixed space; a sound receiving device which receives the sound wave within the fixed space, and obtains a sound field from the received sound wave; and a sound field signal processing device which calculates and stores reference sound field information using a sound field pattern per frequency of the sound generation device in a preparation mode, and senses occurrence of security situation by comparing the reference sound field information with the current sound field information, after calculating current sound field information per frequency in a monitoring mode. The sound field signal processing device classifies fire outbreak or invasion occurrence in the security monitoring space by comparing a pattern of the reference sound field information per frequency with a pattern of the sound field information per frequency collected during a fixed period when a security situation occurs. Thus the system classifies fire and invasion situation by analyzing the characteristics of the sound field pattern per frequency according to time variation, and classifying the condition of temperature distribution variation in the security space individually or synthetically.

Description

[0001] Monitoring system and monitoring method [0002]

The present invention relates to security surveillance, and more particularly, to a security surveillance system and method capable of separately detecting fire and intrusion based on a sound field change.

Security sensors used to detect fire or intrusion have been studied for a long time.

The sensor for detecting a fire can use one of a temperature sensing method, a smoke sensing method, a gas sensing method and a flame sensing method. Meanwhile, the sensor for detecting an intrusion may use one of a passive infrared detection (PIR) method, an ultrasonic method, a sound sensing method, a vibration sensing method, and a microwave sensing method.

In recent years, video surveillance systems using camera image information such as CCTV, IP cameras, and automobile black boxes have been widely used in the field of security surveillance.

As an example of the prior art, an intrusion detector for detecting a change in sound pressure to detect an intrusion is known. After detecting the number of differences between the detected sound pressure and the reference sound pressure for each frequency exceeding a predetermined value, and when the number is greater than or equal to a predetermined reference number, the intrusion detector generates an output to judge that it is intrusion. Such an intrusion detector has the advantage of detecting a silent intrusion. However, such an intrusion detector has a disadvantage that it must be determined in accordance with the space or environment conditions when determining the criteria of the intrusion determination, and further, there is a problem that the intrusion and the fire can not be distinguished from each other.

As another prior art, there is a hybrid fire detector that detects smoke, flame, and heat. Combined smoke detectors detect smoke, flame, and heat using a single, integrated fire detector. The hybrid type fire detector has both a smoke detection function for preparing for spontaneous ignition and a flame detection function for preparing for arcing.

Such a hybrid fire detector has the advantage of detecting the initial fire when installed at a location where the false rate is low and the flame or smoke is directly detected for various fire situations. However, such a composite type fire detector can not detect the fire generated at the position where the sensor is installed or the initial fire situation where the smoke density is not high, and when the fire is obstructed by the object or a fire occurs in a cornered blind spot There is a problem that it is difficult to detect a fire early because it is difficult to detect a flame.

As another conventional art, a fire monitoring method and system based on sound field change detection can detect a fire early by detecting a sound field change in a fire monitoring space. Here, the change of the sound field is caused by the change of the air density and the speed of the sound wave depending on the temperature change of the ambient air caused by the fire, which affects the transmission of the sound wave. However, the fire detection method based on the sound field change can detect the occurrence of fire based on the change of the sound field due to the fire, but it is difficult to detect the temperature distribution change in detail and quantitatively. There is a problem that can not be distinguished strictly.

As another conventional art, there is a security method through analysis of a sound field change pattern. This security method detects the change of the sound field but detects the deviation and the average of the sound pressure and detects the intrusion based on the sound pressure change value (SNR) relative to the reference deviation. Also, it detects the pattern of the sound field change according to the time change or the wavelength change of the sound source, thereby increasing the security detection reliability.

However, since this security method is also difficult to detect the temperature distribution change in detail and quantitatively, it is still difficult to strictly distinguish the fire and the intrusion situation, which are the main factors of the sound field change.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a security monitoring method and system capable of separately detecting security situations of fire and intrusion.

Another object of the present invention is to provide a security monitoring method and system based on sound field change detection that can detect and distinguish fire and intrusion situations and provide comprehensive security monitoring.

According to an aspect of the present invention, there is provided a security monitoring system comprising:

An acoustic generator for outputting a multi-tone sound wave having a linear sum of sine waves having a plurality of frequency components within a set security monitoring space;

A sound receiving device for obtaining sound field information representative of sound pressure and phase from sound waves received in the security monitoring space for each frequency; And

A sound field signal processing for storing frequency-specific sound field information obtained from the sound receiving apparatus in the preparation mode as reference sound field information and for comparing the sound field information with the current frequency outputted from the sound receiving apparatus in the monitoring mode, Wherein the sound field signal processing apparatus compares a pattern of the reference sound field information for each frequency with a pattern of the sound field information for each frequency collected during a predetermined period when a security situation occurs, And whether or not it occurs.

In the embodiment of the present invention, the sound field signal processing apparatus may be configured such that, when a pattern of frequency-specific sound field information is compared, whether the pattern of the frequency-dependent sound field information has continuously moved in a high- By analyzing the change, it is possible to distinguish between the fire and the invasion situation.

In the embodiment of the present invention, the sound field signal processing apparatus performs a function shift of the pattern of the sound field information for each frequency in a predetermined period in a high frequency or low frequency direction, compares the pattern with the pattern of the reference sound field information, analyzes the degree of frequency shift, By detecting the rate of change of the continuous temperature rise, it is possible to judge whether or not the fire has occurred, and to detect the state of the infiltration by detecting the occurrence of the temperature change or irregularity.

In the embodiment of the present invention, the sound field signal processing apparatus performs a function shift of a pattern of frequency-specific sound field information of a certain period in a high-frequency or low-frequency direction when a security situation occurs, and calculates an index After the value is derived, the direction and speed of the temperature change can be analyzed by using it, so that it is possible to judge the fire, the temperature change by the heating and cooling, and the invasion situation separately.

In the embodiment of the present invention, the sound field signal processing apparatus analyzes whether the change value of the sound field information continuously or irregularly changes according to the deviation of the reference sound field information in a predetermined period when a security situation occurs, Can be distinguished from each other.

According to another conceptual embodiment of the present invention for solving the above-mentioned technical problems,

A sound wave output step of outputting a multi-tone sound wave having a linear sum of sine waves having a plurality of frequency components into a set security monitoring space;

A sound wave receiving step of obtaining a sound field from a sound wave received in the security monitoring space;

Storing the frequency-based reference sound field information through the sound field obtained in the preparation mode;

Calculating the current sound field information of the current frequency in the monitoring mode, and comparing the current sound field information with the reference sound field information of each frequency to determine whether a security situation occurs; And

And comparing the frequency-based reference sound field information with the frequency-dependent sound field information collected for a predetermined period to generate a fire or an intrusion state when a security situation occurs.

According to another exemplary embodiment of the present invention, there is provided a security monitoring system comprising:

An acoustic generator for outputting sound waves;

An acoustic receiver for acquiring sound field information from sound waves received in the security monitoring space for each set frequency;

A sound field signal processing device for storing frequency-based reference sound field information by using sound field information output through the sound receiving device, and comparing the reference sound field information for each frequency with sound field information for current frequency outputted from the sound receiving device to determine whether a security situation occurs; And

And an image acquisition unit for acquiring an image of the security monitoring space when the security situation occurs,

The sound field signal processing apparatus compares patterns of the frequency-based reference sound field information and patterns of frequency-dependent sound field information collected during a predetermined period to generate a fire and an intrusion, It is classified.

According to another exemplary embodiment of the present invention, there is provided a black box system comprising:

A sound generating and receiving device for outputting and receiving sound waves;

Frequency reference sound field information is prepared using the sound field information obtained from the sound waves received and the sound field information of the current frequency and the reference sound field information of each frequency obtained in the monitoring mode in the security monitoring space are compared with each other to determine whether a security situation occurs A sound field signal processing device; And

And a black box for acquiring an image of the security monitoring space when the security situation occurs,

The sound field signal processing apparatus discriminates whether the occurrence event is fire or intrusion by comparing and analyzing patterns of the reference sound field information for each frequency and patterns of sound field information for each frequency collected during a predetermined period when a security situation occurs.

The surveillance system according to the present invention provides a surveillance system that distinguishes between fire and intrusion based on the sound field change detection, so that the surveillance system according to the present invention can appropriately cope with fire and intrusion according to the situation in the early stage.

In addition, by providing a security monitoring system based on sound field change detection, which is complementary to existing fire detection sensors and intrusion detection sensors, it is possible to provide a highly reliable and comprehensive security monitoring system by reducing malfunctions and malfunctions have.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a change of a sound wave wavelength according to a temperature change. Fig.
FIG. 2 is a view for explaining the principle of sound field change according to a temperature change; FIG.
Fig. 3 is a diagram showing the frequency shift of the sound pressure level according to the temperature change; Fig.
4 is a block diagram of a security monitoring apparatus according to a conceptual embodiment of the present invention.
FIG. 5 is a graph showing a change in sound pressure level of each frequency according to temperature change in the security space according to FIG. 4; FIG.
FIG. 6 is a view showing a time-frequency mobility diagram according to FIG. 5; FIG.
Figure 7 is a comparative view of the normalized frequency mobility diagram according to Figure 6;
8 is a graph showing a change in sound pressure level according to the moving distance of an object in the security space according to FIG.
9 is a view showing a frequency mobility according to a moving distance according to FIG. 8. FIG.
FIG. 10 is a comparative view of the normalized frequency mobility diagram according to FIG. 9; FIG.
11 is a view showing the frequency shift indexes according to Figs. 7 and 10. Fig.
12 is a graph showing a relatively negative pressure change rate (SNR) according to FIG. 11. FIG.
FIG. 13 is a view showing surface maps by multi-tone frequency-dependent sound pressure levels in a fire and intrusion situation according to FIG. 11; FIG.
14 is a flowchart of a security monitoring flow according to an embodiment of the present invention.
15 is a diagram showing an application example of the present invention applied to a security service system;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted in order to avoid obscuring the gist of the present invention.

The process of changing the sound field as the speed of the sound wave changes in the security monitoring space can be explained theoretically through FIG. 1 and FIG.

FIG. 1 is a diagram showing a change in the wavelength of a sound wave according to a temperature change. FIG.

When a fire occurs, the speed of the sound wave increases due to the temperature rise inside the security monitoring space (SA). As a result, the wavelength of a sound wave emitted from the sound generator or the like at the same frequency is increased. In FIG. 1, a circle formed by a solid line represents the wavelength of a sound wave output at a low temperature, and a circle formed by a dot line represents a wavelength of a sound wave output at a high temperature.

Therefore, the sound receiving apparatus installed inside the security monitoring space (SA) differently senses the sound field of the sound wave according to the temperature state. Such a sound field change phenomenon can be more easily generated in an acoustic space in which the resonance of a sound wave occurs well. Thus, when a sound field change is detected, a fire in a blind spot in which a flame or smoke is not observed can be detected.

는 아래 수학식 2와 3에 의해서 공기의 온도 T 에 비례하여 증가하는 성질을 가진다. 파장이 달라지면 같은 크기의 보안 공간 내부에서 공기의 음압 분포는 달라지며 이를 분석하기 위한 이론적인 해석 조건은 다음과 같다.In general, the velocity v of a sound wave can be expressed by the following Equation 1 and is proportional to the temperature T of the air. Therefore, even if the frequency f of the sound wave is the same,

Has the property of increasing in proportion to the temperature T of the air by the following equations (2) and (3). When the wavelength is changed, the sound pressure distribution of the air changes in the security space of the same size, and the theoretical analysis conditions for analyzing it are as follows.

1, when the temperature rises, the speed of a sound wave is increased, so that a sound wave of the same frequency becomes longer as the temperature goes higher.

FIG. 2 is a diagram for explaining the principle of sound field change according to a temperature change. FIG.

The process of changing the sound field with the change in the speed of the sound wave when there is a rise in temperature in the overall area (for example, 18 ° C -> 30 ° C) due to fire in a security monitoring space with a hard acoustic wall (Acoustic Hard Wall) Lt; / RTI >

In Figs. 2 (a) and 2 (b), the size of the acoustic wall existing in the security monitoring space is 3 m x 3 m. Fig. 2 (a) shows the sound pressure level at room temperature (18 캜) before the fire occurred, and Fig. 2 (b) shows the sound pressure level at the time when the internal air temperature rose to 30 캜 overall due to fire. In this case, the sound generating device 210 was described as generating a sound wave of 1 kHz at an acceleration of 10 m / s ² . When sound waves generated in the sound generating device 210 propagate into the security monitoring space, the sound waves are analyzed by a two-dimensional finite element analysis method to map the sound pressure level within the security monitoring space in two dimensions, 2 (a) and 2 (b) are obtained.

As the temperature rises, the phenomenon that the sound field change occurs as shown in FIG. 2 (b) occurs in all the audio frequency bands or ultrasonic bands. The change of the sound field according to the temperature change can be detected by using the sound receiving device 220 that can be installed inside the security monitoring space. In a hard acoustic wall, sound waves do not disperse and disappear, but are reflected and superimposed inside the security monitoring space. Therefore, in such a case, the effect of the temperature rise by the fire can cause a much larger sound field change, so that the fire occurrence can be detected more easily.

3 is a diagram showing the frequency shift of the sound pressure level according to the temperature change.

In contrast to FIG. 3 (a) of FIG. 3, the sound pressure level of each frequency is shifted by a certain amount in the high frequency direction by a temperature rise (for example, 18 ° C-> 30 ° C) ) Can be confirmed.

In FIG. 3, the horizontal axis represents the frequency in Hertz and the vertical axis represents the sound pressure level (SPL) in decibels.

3 is a spectral curve of the sound pressure level of each frequency measured using the sound receiving device 220 installed in the security monitoring space and shows that the sound pressure level shifts in the high frequency direction due to the internal temperature rise .

According to FIG. 1 and FIG. 2, as the temperature of the internal air increases, the speed of the sound wave increases, and the wavelength increases proportionally at the same frequency.

Since the size of the inside of the security space is fixed, when the temperature is increased, the wavelength of the sound wave must be constant in order for the acoustic receiving elements at the same position to have the same sound pressure. As a result, the sound pressure level pattern moves in the high frequency direction without changing its shape.

At this time, the change value? F of the moving frequency can be simply expressed as shown in Equation (4). Since the velocity change? V of the sound wave is proportional to the temperature change? T in Equation 1, the change value? F of the frequency is expressed by Equation And the result is proportional to the temperature change.

The change in frequency when the temperature rises from room temperature (18 ℃) to 19 ℃ corresponds to about 1.75Hz at 1kHz acoustic frequency, 3.5Hz at 2kHz and 7Hz at 4kHz.

As shown in FIG. 3, when the temperature rises from room temperature (18 ° C) to 30 ° C, it can be seen that the frequency shifts from an acoustic frequency of 1 kHz to a high frequency of about 21 Hz. Of course, the temperature change of the air due to the actual fire is difficult to simplify due to the increase of the total temperature, and the local temperature change around the fire and the overall temperature change are complicated. However, in general, the degree of movement of the sound pressure level pattern to high frequency by the rise in temperature is proportional to the change in temperature, so that it is possible to monitor the change in the internal air temperature in general. For example, when the center frequency of the multitone frequency is 4 kHz and the frequency gap is 4 Hz, the temperature change amount? T is expressed by Equation (6) below, which corresponds to 0.57 占 폚 at room temperature (T = 18 占 폚).

4 is a block diagram of a security monitoring apparatus according to a conceptual embodiment of the present invention.

Referring to FIG. 4, the security monitoring apparatus includes a sound generating device 410, a sound receiving device 420, and a sound field signal processing device 430.

The sound generating device 410 outputs a sound wave according to the input voltage in the security monitoring space SA. Here, the sound wave output from the sound generator 410 may be a multi-tone sound file consisting of a linear sum of sine waves having a plurality of frequency components in an audible frequency range of 20 to 20 kHz and an ultrasonic range of 20 kHz or more. Where the multi-tone sound waves may be in the form of a continuous wave or a pulsed wave.

The sound pressure of the sound generator 410 is preferably set to an optimum size that can be sensed by a sound field driven by the occurrence of a security situation while operating at a rated power of the apparatus.

The acoustic receiver 420 receives the sound waves in the security monitoring space, and obtains the sound pressure from the received sound waves. Here, the acoustic receiver 420 may include a frequency conversion filter for converting the received sound wave into the frequency domain.

The sound field signal processing device 430 may be implemented by a processor such as a PC or a DSP as an apparatus for determining an intrusion or a fire situation using a sound field change in a security monitoring space. Sound field values can be represented by sound pressure and phase, and sound pressure and phase can be used individually or in combination. However, in this embodiment, the sound pressure is shown as an example, and the sound pressure level, which is the magnitude of the sound pressure, is used as the object of signal processing. Here, the sound pressure level is generally expressed by a logarithmic function, and the value obtained by measuring the sound pressure within the security monitoring space SA by the sound receiving apparatus 420 becomes the sound pressure level. Here, the sound pressure within the security monitoring space SA is a sound pressure generated by the sound pressure output from the sound generating device 410 spreading in the security monitoring space SA.

Accordingly, the sound field signal processing apparatus 430 can calculate the reference sound pressure information (the magnitude of the reference sound pressure Amp = 20 logP) or the phase of the reference sound pressure Ph = ang (P) using the sound pressure P of the sound in the preparation mode, . In this case, in order to prevent the sound pressure P from changing due to environmental changes such as gradual changes in temperature and humidity of the air, the sound field signal processing device 430 calculates an average and a deviation of the frequency-dependent sound pressure information, . The sound field signal processing device 430 analyzes the measured sound field change patterns by time and sets an initialization time period and a security situation determination reference value.

The sound field signal processing device 430 uses the sound transfer function P 'in the monitoring mode to calculate the current sound pressure information (the current sound pressure level Amp = 20 log (P')) or the current sound pressure phase Ph = ang (P ')), and then compares the reference sound pressure information with the current sound pressure information to determine whether a fire or intrusion has occurred.

More specifically, the sound field signal processing apparatus 430 compares the average value of the reference deviation (Noise) with the signal value (Signal) (hereinafter referred to as the 'reference deviation to sound pressure change rate SNR'), , It is judged that a security situation has occurred. Here, the reference deviation may be a maximum value of the deviation of the reference sound pressure information by frequency, and the signal value may be a difference between the average of the reference sound pressure information by frequency and the average of the current sound pressure information by frequency, ') -20 log (P)).

In this case, the sound field signal processing device 430 can reset the initialization time period and the determination reference value to prevent the sound pressure P from changing due to a change in the temperature and humidity of the atmospheric air gradually. Such a reset can be performed by calculating the mean and variance of the frequency-specific sound pressure information at the initialization time period intervals in the monitoring mode.

On the other hand, since the sound field can be changed not only by a fire but also by an intrusion, it is difficult to accurately distinguish a fire or an intrusion situation by measuring a sound field change only. To this end, the sound field signal processor 430 detects a sound field change pattern by frequency. The sound field signal processing device 430 can discriminate whether the sound field change is caused by a fire or an intrusion by comparing the detected sound field change pattern for each frequency with a previously stored sound field change pattern for each reference frequency.

Thus, the distinction between fire and intrusion in the security monitoring space is performed based on the sound field variation. Detection of the sound field change is performed using a multi-tone sound source composed of a linear sum of sine waves. Here, the change of the sound field with time and the frequency shift characteristic of the sound pressure pattern determine the fire situation or the intrusion situation.

FIG. 5 is a graph showing a change in sound pressure level of each frequency according to temperature change in the security space according to FIG.

In FIG. 5, the horizontal axis represents frequency in Hertz and the vertical axis represents sound pressure level (SPL) in decibels.

In order to simulate the fire situation, a heater is operated inside the security monitoring space (SA). It can be seen that the sound pressure levels by frequency in accordance with the variation of the heating time by the operation of the electric heater are individually measured as shown in the graphs of FIG. That is, as shown in FIG. 5, it can be seen that as the internal air temperature is increased, the sound pressure level is continuously shifted in the high-frequency direction without changing the shape of the pattern. Here, 17 multi-tone sound sources having a center frequency of 4 kHz and an equal interval of 4 Hz were used to obtain the result of FIG.

FIG. 6 is a view showing frequency mobility according to time in FIG.

In Fig. 6, the horizontal axis indicates the frequency shift, and the vertical axis indicates the difference index. Here, the minimum unit of the frequency shift i of the horizontal axis is 4 Hz. The frequency shift i has a value of -4? I? 4.

When there is a temperature change, the sound pressure pattern is shifted in the high frequency or low frequency direction by an integer multiple (i) of the multi-tone frequency gap, and the absolute value of the difference in sound pressure level value for each frequency of the multi-tone is added. Expressing the summed absolute value as a function of frequency shift can be compared to what extent the frequency shift has occurred.

Here, since the sound pressure level data of the multi-tone maximum frequency before movement and the multi-tone minimum frequency after movement can not be obtained, a circularly shifting method may be used in which the last value is shifted to the first value for convenience. When the frequency shift (i) is equal to or greater than 3 (3 × 4 = 12 Hz), the result of calculation of the difference index becomes larger. If the sound pressure level pattern is similar but the frequency is shifted, as shown in FIG. 6, the absolute value of the difference in the sound pressure level value for each frequency becomes the lowest for any frequency shift.

In general, this value can be defined as the Discrepancy Index of two sound field patterns according to the frequency shift. The inverse transform or the similarity index is obtained by subtracting this value from the maximum difference index value. .

There are many ways to define the similarity index, but these values are commonly used to show how similar the two sound pressure level patterns are.

In the initial stage, the difference index value is the minimum value because the sound pressure level pattern is the same. However, as the frequency is shifted in the high frequency or low frequency direction, the difference index value becomes larger and the shape of the left and right symmetry is as shown in FIG. 6 (a).

Since the sound pressure level pattern is moved in the high frequency direction when the internal temperature of the security monitoring space rises, a minimum value is formed when the sound pressure level pattern moves by 4 Hz, which is one step (i = 1) of the gap of the multi- Can be seen.

6 (c), when the internal temperature is further increased with time, the lowest value is formed in the case of 8 Hz movement in two steps (i = 2).

In addition, when the internal temperature is maximized with time, it can be seen that the minimum value is formed in the case of 12 Hz movement in three steps (i = 3) as shown in FIG. 6 (d).

FIG. 7 is a graph showing the normalized frequency mobility according to FIG. 6 in a comparative manner.

In Fig. 7, the horizontal axis indicates the frequency shift, and the vertical axis indicates the similarity index. Here, the frequency shift i of the horizontal axis is a value of -4? I? 4, and the minimum unit of i is 4 Hz. The similarity index is obtained by taking the inverse of the difference index (D-index). It is preferable to have a certain value to use the similarity index as a coefficient for calculating an index indicating the degree of movement of the frequency. Thus, similarity indices for frequencies of multi-tones can be summed together. As a result, it is possible to set the exponent for the frequency shift to coincide with the frequency shift in the real spectrum, and add the similarity indexes corresponding to the respective multi-tone frequencies so that the exponent can be constant as shown in Equation (7) below.

FIG. 8 is a graph showing a change in sound pressure level according to an object moving distance in the security space according to FIG.

In FIG. 8, the horizontal axis represents frequency in hertz and the vertical axis represents sound pressure level (SPL) in decibels.

The mannequin is slowly moved inside the security monitoring space to simulate the intrusion situation. In other words, a mannequin moving device is installed in the security monitoring space to distinguish between the fire situation and the intrusion situation. The sound pressure level pattern when the mannequins moved 2.75, 5.5, 8.25 cm, respectively, are shown in the graphs of FIG. The sound pressure level pattern is slightly similar when moving at 2.75 cm, but it is confirmed that the shape of the pattern changes greatly when moving at 5.5 and 8.25 cm. Generally, in case of intrusion, unlike the fire, the reflection and diffraction patterns of the sound wave change according to the location of the intruder. Therefore, even if the intruder moves a little, the sound pressure level pattern changes not only in a similar manner but also in a very irregular manner.

FIG. 9 is a view showing a frequency mobility according to the movement distance according to FIG. FIG. 10 is a graph showing the normalized frequency mobility according to FIG. 9 in a comparative manner.

As a result, the discrepancy index according to the moving distance of the mannequin is expressed as a function of the frequency shift (-4? I? 4), and the pattern of the difference index is confirmed through FIG. In addition, when the similarity index (S-index) obtained by taking the reciprocal of the D-index is expressed as a function of the frequency shift (-4? I? 4), the result graph as shown in FIG. 10 is obtained.

In Figures 9 and 10, the calculated difference index and calculated similarity index in the intrusion situation are shown in contrast to the case of fire situation. It is very different from the fire situation in the intrusion situation. That is, the frequency shift does not occur continuously, but the frequency shift rarely occurs or the frequency shift occurs irregularly.

Fig. 11 is a diagram showing the frequency shifts according to Figs. 7 and 10. Fig.

In the case of FIG. 11, the S-index values obtained in FIGS. 7 and 10 are used as a coefficient for deriving an index value representing the degree of frequency shift. The frequency shifts according to heating time and moving distance are shown in Fig.

11 (a) shows the degree of frequency shift according to the heating time of the electric heater in a fire situation, and Fig. 11 (b) shows the frequency shift due to the movement of the mannequin in the intrusion situation.

11 (a) showing the fire situation is a result obtained by measuring 50 sound fields at intervals of 7 seconds for 5 minutes and 50 seconds. Also, Fig. 11 (b) showing the state of intrusion shows the results obtained by measuring the sound field 90 times by moving the mannequin by 5.5 mm at intervals of 3 seconds for 4 minutes and 30 seconds. Here, the mannequin is finally moved to 49.5 cm.

There are various methods for defining the frequency shift index. In one embodiment, a method of multiplying the frequency shift value by a similarity index and summing the results can be used. That is, a frequency shift index (Shift_index) can be defined as Equation (8) below.

As shown in FIG. 11 (a), the index may gradually increase in a fire situation. Considering such a gradual rise in temperature, it is possible to distinguish whether the temperature is increased or decreased by the heating and cooling of the air in the security space, or whether a sudden and continuous temperature rise occurs due to a fire.

As shown in Fig. 11 (b), it is observed that the frequency shift occurs infrequently or irregularly in the intrusion situation. Analysis of this frequency shift pattern can distinguish between fire situation and intrusion security situation.

FIG. 12 is a graph showing a relatively negative pressure change rate (SNR) according to FIG.

12 (a) shows the sound pressure change rate (SNR) relative to the reference deviation when the security space is heated using the electric heater.

12 (b) shows the sound pressure change rate (SNR) with respect to the reference deviation when the mannequin is moved.

In contrast to FIGS. 12 (a) and 12 (b), it can be seen that the patterns of the sound pressure change rate (SNR) versus the initial reference deviation are different in the fire situation and the intrusion situation. That is, the SNR is continuously increased in a fire situation, but the SNR fluctuates irregularly in an intrusion situation.

In order to quantitatively analyze this aspect more clearly, it is necessary to derive an index (Shift_index) indicating the degree of frequency shift and a rate of change of SNR with time. Fire and intrusion can be easily distinguished by graphing derived results or comparing quantitatively the mean value of change rate over a period of time. As a method for deriving an index representing the degree of frequency shift, various expressions indicating correlation of frequency-specific sound field patterns other than the above-mentioned method may be used. In this patent, the method is not particularly limited.

A surface map of the sound pressure level pattern is shown in FIG. 13 in order to more clearly show the change of the sound pressure level pattern with time.

FIG. 13 is a diagram showing surface maps according to sound pressure levels of multi-tone frequencies in a fire and intrusion situation according to FIG.

13, the horizontal axis represents angular frequency components of multi-tones, and the vertical axis represents the number of times of measurement according to the change of time. The color of the pixel at each coordinate represents the magnitude of the sound pressure level (SPL). As shown in FIG. 13 (a), in the case of fire, since the temperature of the air increases as the heating time of the electric heater increases, the sound pressure level pattern is constant, but has a shape moving constantly in the high frequency direction. On the other hand, in the case of the intrusion as shown in FIG. 13 (b), the sound pressure level pattern changes irregularly and complicatedly with the movement of the mannequin. By analyzing these changes, fire or intrusion can easily be distinguished in real security space.

Sound field changes due to temperature changes due to air conditioners or sudden temperature fluctuations due to atmospheric sudden diurnal variations or sunshine are generally very slow compared to fires or intrusions, making them distinct from security situations. However, there may be a special case in which the sound field changes abruptly or the sound field changes abruptly due to a sudden diurnal difference in temperature or a difference in temperature due to the amount of sunshine. In such a case, if the reference SNR is exceeded within a predetermined time period, it may be mistaken for a security situation even if it is not a fire or an intrusion situation.

When the temperature drops as in the operation of the cooler, it can be easily distinguished from the intrusion or fire situation by confirming the pattern of the sound pressure pattern moving in the low frequency direction by analyzing the sound field change pattern according to the frequency. The situation caused by the sudden rise of the atmospheric temperature is difficult to distinguish from fire but it is easy to distinguish from intrusion.

In the practical application of the security system, not only the intrusion and fire situations but also the cooling conditions can be separately set to transmit security information. On the other hand, in the case of fire, it is necessary to consider that there may be a malfunction due to temperature rise due to daylight or sunshine.

In the fire, the sound field changes continuously due to the temperature rise, and the sound pressure pattern continuously moves in the high frequency direction. However, the temperature rise due to sunshine or sunshine is generally slow compared to fire, and the temperature rises and stagnates and falls repeatedly. Therefore, if the sound field pattern change is monitored for a predetermined period of time, it is possible to distinguish whether it is fire or temperature rise due to temperature change.

4, the security monitoring system 400 according to the embodiment of the present invention acquires image information on a fire or an intrusion in the case where the sound field signal processing device 430 separately judges a fire or an intrusion situation And a camera module 440 for storing or transmitting to a destination.

In addition, the sound field signal processing device 430 may receive a photographed image related to a fire or an intrusion transmitted from the camera module 440 and transmit the captured image through the communication interface 450. Since the communication interface 450 can be connected to a wired / wireless communication network, photographed images can be displayed on various smart devices such as a mobile phone, a smart phone, or a tablet PC. The communication interface 450 may be connected to a fire department server or a police server under the control of the sound field signal processor 430 to transmit the captured image and the unique ID of the security monitoring system 400.

As described above, the security monitoring system based on the sound field change detection according to the present invention can distinguish security risks in an early stage of a fire situation or an intrusion situation, and can alert an alarm according to a fire or an intrusion situation. Also, in case of interworking with a camera module such as CCTV, the security monitoring system can save photographed images related to a fire or intrusion situation or transmit them to a set destination. Here, the destination may be a smart phone such as a mobile phone remote device of a certain person, a mobile phone, a guard room server, a security company server, a fire department server, or a police server. According to the security monitoring system based on the sound field change detection, there is an advantage that a rapid and effective security monitoring service is realized.

14 is a flowchart of a security monitoring process according to an embodiment of the present invention.

FIG. 14 can be implemented by the operation of the sound field signal processing device 430 of FIG. 4, and detects fire and intrusion based on the sound field change detection.

Referring to FIG. 14, the security monitoring method according to the embodiment of the present invention is largely divided into a preparation mode and a monitoring mode.

The preparation mode may include an initialization step S710, a sound field change pattern measurement step S720, a sound field change pattern analysis step S730, and a security monitoring condition setting step S740.

The monitoring mode includes a sound field change measurement step S750, a security situation occurrence determination step S760, a fire / intrusion classification step S770 through sound field change pattern analysis, an image acquisition step S780, S790).

In the initial setting step S710, the sound generating device 410 is operated to output a sound wave into the security monitoring space according to a constant input voltage. Also, the acoustic receiver 420 is operated to receive sound waves in the security monitoring space. The sound field signal processor 430 calculates an average and a deviation of the reference sound field (sound pressure and phase) information for each frequency provided from the sound receiver 420. The calculated information is stored in an internal DRAM or a flash memory.

In step S720, the sound field signal processing device 430 calculates an average and a deviation of the sound pressure information according to a time-dependent change in frequency in order to measure a sound field change pattern in time, And the average and deviation of the sound pressure information by frequency are respectively compared.

In the analysis step S730, the sound field signal processing device 430 analyzes the measured sound field change pattern by time and then stores a sound pressure change rate (SNR) relative to a reference deviation, which is a time field change index value.

In the security monitoring condition setting step S740, the sound field signal processing device 430 sets the initialization time period and the security situation occurrence criterion value with reference to the sound field variation index (SNR) according to the stored time.

In the sound field change measurement step S750 under the security monitoring mode, the sound field signal processing device 430 calculates an average and a deviation of the current sound pressure information by frequency. In this case, the sound field signal processing device 430 can reset the initialization time period and the security situation occurrence determination reference value at the initialization time period intervals.

The sound field signal processing device 430 compares the mean and the deviation of the current sound pressure information by frequency with the mean and the deviation of the frequency-dependent reference sound pressure information, respectively, to determine whether or not a security situation occurs (step S760) . Specifically, the sound field signal processing device 430 determines that a security situation of fire or intrusion occurs when the average value of the sound pressure change rate (SNR) with respect to the reference deviation is equal to or greater than the security situation occurrence determination reference value.

In the fire / intrusion classification step S770 of detecting the sound field change pattern, when it is determined that the security situation has occurred, the sound field signal processing device 430 analyzes the sound field change pattern for a certain period when the reference time and the security situation occur. Here, the degree of the frequency shift of the sound pressure level pattern and the change of the sound pressure information change rate (SNR) with respect to the reference deviation are analyzed to determine whether the cause of the security situation is fire or security situation due to intrusion.

In the image acquiring step S780, when it is confirmed that a fire or an intrusion has occurred, the camera module is operated under the control of the sound field signal processing device 430 to perform image capturing and image information storage in order to accurately verify the fire or intrusion.

In the alarm announcement and information transmission step S790, the sound field signal processing device 430 may issue a fire or an intrusion alarm sound or may transmit an alarm to the automobile wireless remote device. In addition, images photographed through the camera module can be transmitted to a server such as a mobile phone, a smart device, a security room, a security company, and a police station through a wired / wireless communication network. In the case of a general automobile without a network function, a wireless remote device such as a remote control may be used to activate or deactivate the alarm function.

It is needless to say that the steps of FIG. 14 may be omitted if necessary or may be operated by adding other processes.

15 is a diagram showing an application example of the present invention applied to a security service system.

Referring to FIG. 15, the function of detecting fire and intrusion occurring within the security monitoring space (SA) based on the sound field change is classified into a car black box, a security camera connected to a wired / wireless network, Smart home appliances including smart phones, smart cars, and the like. In the event of an intrusion or fire security situation, a text or video message may be provided in Fig. 15 to the user's mobile phone or smart device via the Internet or wired or wireless communication.

That is, FIG. 15 shows a concept of a security service system that utilizes a security monitoring system that detects fire and intrusion based on a sound field change. The security service system basically includes the security monitoring system 400, and the security camera 440 and the security information destination 460 can be further connected.

The security information destination 460 may be an automobile wireless remote device, a smart phone, a smart device, or a server.

The security monitoring system 400 may be installed in the security monitoring space SA.

The security monitoring system 400 detects an intruder situation without a blind spot when an intruder intrudes through a boundary area, an entrance, a window, a ceiling, a floor, or a wall of the security monitoring space. Meanwhile, when applied to the interior of a car, the security monitoring system 400 can detect the intrusion of a vehicle without a blind spot when an intruder penetrates through a car door or breaks a glass window.

The security monitoring system 400 may include a security monitoring space SA in case of a fire occurring due to various reasons such as overheating and ignition of the electric heater, electric leakage and short circuit, overheating of the kitchen appliance, overheating of the appliance, gas leakage, By detecting changes in the internal temperature distribution, the fire situation can be detected early.

The security service system of FIG. 15 may be integrated into a security camera such as a CCTV or a car black box. In addition, the security monitoring system 400 may be manufactured externally and connected to the security camera through wired / wireless.

As a variety of applications, the security monitoring system 400 may be connected to an internet telephone and may be used as an integral type or an external type. The security monitoring system 400 may be embedded or enclosed in a smart appliance including various types of smart devices, such as a smart phone, a smart TV, a smart car, or an interphone.

Thus, the security monitoring system that detects fire and intrusion based on the sound field change separately does not require the hardware change of the existing Internet telephone or smart device. That is, if only the related algorithm is embedded in the internal processor, interlocking use becomes possible.

According to an exemplary embodiment of the present invention, the detected security information may be transmitted to various smart devices connected to a network as multimedia information such as text and images. Furthermore, when a user of a smart phone or a smart device accesses the related security system in the form of an app (App), it is possible to provide various security related services.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the equivalents of the claims of the present invention as well as the claims of the following.

410: Acoustic generator 420: Acoustic receiver
430: Sound field signal processing device

Claims (26)

An acoustic generator for outputting a multi-tone sound wave having a linear sum of sine waves having a plurality of frequency components within a set security monitoring space;
A sound receiving device for obtaining sound field information representative of sound pressure and phase from sound waves received in the security monitoring space for each frequency; And
A sound field signal processing for storing frequency-specific sound field information obtained from the sound receiving apparatus in the preparation mode as reference sound field information and for comparing the sound field information with the current frequency outputted from the sound receiving apparatus in the monitoring mode, Wherein the sound field signal processing apparatus compares a pattern of the reference sound field information for each frequency with a pattern of the sound field information for each frequency collected during a predetermined period when a security situation occurs, A security surveillance system that distinguishes between occurrences.
The sound field signal processing apparatus according to claim 1, wherein, when the pattern of the sound field information according to the frequency is compared, the pattern of the sound field information according to the frequency is continuously changed in the high frequency direction, The security monitoring system distinguishes between fire and intrusion.
The apparatus as claimed in claim 1, wherein the sound field signal processing device performs a function shift of a pattern of the sound field information of each frequency in a predetermined period in a high frequency or low frequency direction and compares the pattern with a pattern of the reference sound field information to analyze a degree of frequency shift, The security surveillance system judges the occurrence of fire by detecting the rate of change of temperature rise, and judges the state of intrusion by detecting the occurrence of irregular or no temperature change.
The apparatus of claim 1, wherein the sound field signal processing apparatus performs a function shift of a pattern of frequency-specific sound field information in a high frequency or low frequency direction for a predetermined period when a security situation occurs, and calculates an exponent value And then analyze the direction and speed of the temperature change by using it to judge the fire, the temperature change due to the heating and cooling, and the intrusion situation separately.
The sound field signal processing apparatus according to claim 1, wherein the sound field signal processing apparatus analyzes whether a change value of the sound field information continuously or irregularly changes according to a deviation of reference sound field information in a predetermined period when a security situation occurs, Separate security surveillance system.
The security surveillance system according to claim 1, wherein the multi-tone sound wave is generated as a continuous wave or a pulse wave in the audible frequency of 20 to 20 kHz and the ultrasonic wave of 20 kHz or more.
The security monitoring system according to claim 1,
A temperature sensor, a smoke sensor, a gas sensor, and a flame detection type fire sensor, such as a passive infrared sensor (PIR), an ultrasonic sensor, a sound detection sensor, a vibration detection sensor, a microwave sensor, A security surveillance system that interlocks to detect fire and intrusion.
The security surveillance system according to claim 1, further comprising a camera module for storing image information in the event of a fire or an intrusion situation and performing image shooting to verify the situation.
The security monitoring system according to claim 1,
A security surveillance system that is integrated or external to be integrated with smart home appliances, including car black box, security camera with network function, internet phone, smart TV, smart car, or interphone.
The security monitoring system according to claim 9, wherein when the security monitoring system is interlocked, the security monitoring system is implemented by installing only software without adding hardware of the interlocking device.
10. The security surveillance system according to claim 9, wherein the security surveillance system provides remote control or acquired security information when a program in the form of an app related to a user's smart phone or a smart device is executed.
The security surveillance system according to claim 9, wherein the security surveillance system provides security information to a user's smart phone or a smart device or provides security information to a government office when a security situation occurs.
A sound wave output step of outputting a multi-tone sound wave having a linear sum of sine waves having a plurality of frequency components into a set security monitoring space;
A sound wave receiving step of obtaining a sound field from a sound wave received in the security monitoring space;
Storing the frequency-based reference sound field information through the sound field obtained in the preparation mode;
Calculating the current sound field information of the current frequency in the monitoring mode, and comparing the current sound field information with the reference sound field information of each frequency to determine whether a security situation occurs; And
And comparing the frequency-based reference sound field information with the frequency-dependent sound field information collected for a predetermined period to generate a fire or an intrusion state when a security situation occurs.
[14] The method of claim 13, wherein the fire or intrusion state is classified by analyzing whether the pattern of the frequency-specific sound field information has continuously moved in a high frequency state without changing its shape, Monitoring method.
14. The method according to claim 13, wherein the fire or intrusion state is classified by analyzing a pattern of the sound field information of a frequency for a predetermined period in a high frequency or low frequency direction, comparing the pattern with the pattern of the reference sound field information, And detecting the rate of change of the continuous temperature rise.
[14] The method of claim 13, wherein the fire or the intrusion state is classified into an exponent value representing a degree of frequency shift by functionally moving a pattern of the sound field information for each frequency in a predetermined period in a high frequency or low frequency direction, And analyzing the direction and speed of the temperature change using the detected temperature.
14. The security monitoring method according to claim 13, further comprising analyzing whether the change value of the sound field information with respect to the deviation of the reference sound field information during a predetermined period of time is continuously increased or irregularly changed, .
14. The security monitoring method according to claim 13, wherein the multi-tone sound waves are generated as continuous waves or pulsed waves in an audible frequency of 20 to 20 kHz or an ultrasonic range of 20 kHz or more.
[14] The method of claim 13, wherein the fire and the intrusion are classified into an intrusion detection sensor, a temperature sensor, a smoke sensor, a gas sensor, and an infrared sensor, such as a passive infrared ray sensor (PIR), an ultrasonic sensor, And a flame detection type fire detection sensor.
The security monitoring method according to claim 13, further comprising the step of performing image capturing to store image information and verify the situation when a fire or an intrusion situation occurs.
The security monitoring method according to claim 13, wherein the security monitoring method is interlocked with a smart home appliance including a car black box, a security camera having a network function, an Internet phone, a smart TV, a smart car, or an interphone.
22. The security monitoring method according to claim 21, wherein the interlocking device is implemented by software installation without adding hardware.
The security monitoring method according to claim 21, wherein, when a program in the form of an app related to a user's smartphone or smart device is executed, the security monitoring method transmits security information executed or obtained by remote control.
The security monitoring method according to claim 21, further comprising providing security information to a user's smartphone or smart device or providing security information to a government office when the security situation occurs.
An acoustic generator for outputting sound waves;
An acoustic receiver for acquiring sound field information from sound waves received in the security monitoring space for each set frequency;
A sound field signal processing device for storing frequency-based reference sound field information by using sound field information output through the sound receiving device, and comparing the reference sound field information for each frequency with sound field information for current frequency outputted from the sound receiving device to determine whether a security situation occurs; And
And an image acquisition unit for acquiring an image of the security monitoring space when the security situation occurs,
The sound field signal processing apparatus compares patterns of the frequency-based reference sound field information and patterns of frequency-dependent sound field information collected during a predetermined period to generate a fire and an intrusion, Separate security surveillance system.
A sound generating and receiving device for outputting and receiving sound waves;
Frequency reference sound field information is prepared using the sound field information obtained from the sound waves received and the sound field information of the current frequency and the reference sound field information of each frequency obtained in the monitoring mode in the security monitoring space are compared with each other to determine whether a security situation occurs A sound field signal processing device; And
And a black box for acquiring an image of the security monitoring space when the security situation occurs,
The sound field signal processing apparatus compares patterns of the frequency-based reference sound field information and patterns of frequency-dependent sound field information collected during a predetermined period in a security situation to discriminate whether the generated event is a fire or an intrusion, Box system.

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