JP4359463B2 - Glass breakage detector - Google Patents

Description

  The present invention relates to a glass breakage detection device that detects when a building glass or a showcase glass breaks, and issues an alarm, and particularly uses sound waves and vibration waves generated by the breakage of the glass. The present invention relates to a glass breakage detection apparatus that detects breakage by distinguishing cracks from cracks, and a glass breakage detection apparatus that detects cracks using sound waves and vibration waves generated by breakage of glass.

2. Description of the Related Art Conventionally, there are two known types of devices for detecting glass breakage such as buildings, a type using a contact type sensor and a type using a non-contact type sensor.
As shown in the following Patent Document 1 and the like, the type using the contact type sensor has a high frequency (from 100 kHz) vibration component strength generated when a piezoelectric vibrator is attached to glass and an impact is applied to the glass. Based on the above, it is determined whether the glass is broken.

  On the other hand, the type using a non-contact type sensor detects breakage of glass by installing a microphone in a place away from the glass such as a ceiling or a wall and analyzing an acoustic signal input to the microphone. The glass breakage detection device disclosed in Patent Document 2 below is a representative example of this type. This is based on the fact that a low frequency (50 to 100 Hz) due to the deflection of the glass surface at the moment when the glass was broken and a high frequency (5 kHz to 20 kHz) due to the cracking of the glass occurred at the same time. It is to detect.

  Further, in Patent Document 3 below, sound and vibration are detected to detect breakage (broken or broken) of the window glass of the automobile, and the movement of the detected object in the automobile is detected using microwaves or the like after the detection. The invention of an automobile safety sensor system that detects an intrusion into the automobile by detecting the above is described.

Japanese Patent Publication No.57-57970 JP 7-700438 JP-A-6-258194

  The contact-type sensor as shown in Patent Document 1 requires one sensor to be attached to one piece of glass, and there is a problem of high cost due to an increase in the number of installations in a building that uses a lot of glass. In addition, the contact type sensor has a drawback that it easily falls off the glass surface.

  On the other hand, the non-contact type sensor as shown in Patent Document 2 solves the problem of the contact type sensor and has an advantage that a plurality of glasses can be monitored by one sensor. Although it responds to noise and the glass is not broken, an alarm is issued and there are many false alarms.

  In the automobile safety sensor system disclosed in Patent Document 3, sound and vibration are detected to detect glass breakage. However, in Patent Document 3, since the object is assumed to be in a quiet automobile, if this is applied to a general building with a lot of environmental noise, a false alarm is generated only by vibration or sound caused by mischief or the like. There was a problem.

  In addition, as exemplified in Patent Documents 1 to 3, none of the conventional glass breakage detection devices take into consideration the difference due to the form of breakage of the glass. Actually, the mode of breakage of glass is not uniform, and the physical phenomenon that occurs depends on the mode of breakage. Below, the typical example about the aspect of breakage of glass is demonstrated easily.

  As one mode of breakage of glass, there is one in which “breaking” is caused in a glass by a so-called breaking method in which the glass is blown and broken with a hammer or a bar. In addition, there is a thing that causes a “crack” to the glass by the destructive act of throwing stones to throw the pebbles and destroying the glass.

  According to these breaking methods, the glass surface having a predetermined outer shape is hit, and the first crack is generated in the surface away from the edge defining the outer shape of the glass, and this proceeds in multiple directions. Thus, at least a portion of the crack reaches the edge, and the glass breaks into a plurality of pieces. A feature of “breaking” that occurs in glass when such a breaking method is used is that an opening is formed by a single striking action. Also, when these destruction methods are used, the “cracking” sound is loud.

  On the other hand, as a technique for breaking the glass, insert a flathead screwdriver into the gap between the sash and the glass of the window glass and squeeze it repeatedly to make a `` crack '' in the glass, thereby removing the glass fragments from the sash and opening the opening. There is a method called making a break.

  According to this breaking method, an external force is applied to the edge of the glass having a predetermined outer shape to generate a crack from the edge, and this cracking progresses toward the surface of the glass. According to such breakage, the glass breakage is different from the above-mentioned “cracking” due to the dynamic breaking action, and the glass has one or several “cracks”, and the sound is also “cracked”. Small compared.

  Among the glass breakage detection devices described above, particularly those using a non-contact type sensor are mostly intended for detection of “cracking” due to dynamic destruction such as breaking and throwing stone.

  As described above, the sound generated at the time of “cracking” due to dynamic vandalism contains high-frequency and low-frequency sound waves of a certain level or higher, so that a warning is issued when they are detected. It has become. Therefore, there are many things that cannot prevent false alarms by simply generating loud sounds. Further, since the microphone is located away from the glass, if the sound at the time of breakage is small, it may be buried in noise generated in the living environment.

  If the glass only has “cracks” due to breakage or the like, the intensity of the low frequency is low and the overall strength is also small compared to the “crack” sound at the time of breaking. Therefore, it can be said that it is difficult to detect a “crack” sound caused by dynamic destruction such as breakage and a “crack” sound caused by minute destruction such as breakage with a non-contact sensor.

This invention was made | formed in view of the said actual condition, and makes it the 1st objective to provide the glass breakage detector which can distinguish and detect the breakage of glass reliably according to an aspect like a crack or a crack.
Another object of the present invention is to provide a glass breakage detector that can reliably detect cracks caused by a twist that is difficult to detect with a non-contact sensor because the low-frequency intensity is low and the overall intensity is small.
In addition, these glass breakage detectors are intended to provide a glass breakage detector that can be reliably attached to a windowpane and that can detect breakage of multiple windowspane by placing a sensor in one place. The third purpose is to do.

Glass breakage detection device according to claim 1, crack detection means for detecting that the cracked by the Riga Las the vibration signal obtained from the acoustic signal and an oscillation wave obtained from the sound wave generated by the breakage of glass When, in Ruga Las breakage detection device having a a crack detecting means for detecting that the glass is broken,
The crack detection means includes
Acoustic intensity comparison means for comparing the intensity of the predetermined frequency component of the acoustic signal with an intensity reference value;
A vibration duration comparing means for comparing a vibration duration in which the intensity of a predetermined frequency component of the vibration signal is a predetermined value or more with a vibration duration reference value;
Determination means for determining whether or not the glass is cracked based on a comparison result by the acoustic intensity comparison means and the vibration duration comparison means;
The crack detection means is
When the intensity of the predetermined frequency component of the acoustic signal and the intensity of the predetermined frequency component of the vibration signal are equal to or greater than a predetermined value substantially simultaneously, it is determined that the glass is broken .

The glass breakage detection device according to claim 2 is the glass breakage detection device according to claim 1 ,
The acoustic intensity comparing means compares the intensity of the high frequency component of the acoustic signal with a high frequency intensity reference value, and the intensity of the low frequency component of the acoustic signal is the low frequency intensity. It consists of low-frequency sound intensity comparison means to compare with the reference value,
The determination means is such that the vibration duration is not less than a vibration duration reference value by comparison in the vibration duration comparison means, and the intensity of the high frequency component of the acoustic signal is determined by comparison in the high band acoustic intensity comparison means. When the intensity of the low frequency component of the acoustic signal is equal to or lower than the low frequency intensity reference value by the comparison in the low frequency acoustic intensity comparison means, the glass has cracks. It is characterized by determining that it has entered.

The glass breakage detection device according to claim 3 is the glass breakage detection device according to claim 1, wherein the acoustic intensity comparison means compares the intensity of the high frequency component of the acoustic signal with a high frequency intensity reference value. A high-frequency acoustic intensity comparing means, and a low-frequency acoustic intensity comparing means for comparing the ratio of the intensity of the low-frequency component of the acoustic signal to the intensity of the high-frequency component of the acoustic signal with a predetermined reference value,
The determination means is such that the vibration duration is not less than a vibration duration reference value by comparison in the vibration duration comparison means, and the intensity of the high frequency component of the acoustic signal is determined by comparison in the high band acoustic intensity comparison means. A ratio of the intensity of the low frequency component of the acoustic signal to the intensity of the high frequency component of the acoustic signal is equal to or less than the reference value by the comparison in the low frequency acoustic intensity comparison means, while being above the high frequency intensity reference value. In this case, it is characterized in that it is determined that the glass is cracked.

The glass breakage detection apparatus according to claim 4 , wherein the glass breakage detection apparatus detects a crack in the glass by an acoustic signal obtained from a sound wave generated by a crack generated in the glass and a vibration signal obtained from a vibration wave.
Acoustic intensity comparison means for comparing the intensity of the predetermined frequency component of the acoustic signal with an intensity reference value;
A vibration duration comparing means for comparing a vibration duration in which the intensity of a predetermined frequency component of the vibration signal is a predetermined value or more with a vibration duration reference value;
Determination means for determining whether or not the glass is cracked based on a comparison result by the acoustic intensity comparison means and the vibration duration comparison means;
It is characterized by having.

A glass breakage detection device according to a fifth aspect is the glass breakage detection device according to any one of the first to fourth aspects, wherein a vibration wave when the glass is broken is detected from a structural member that supports the glass.

According to the glass breakage detection device of the present invention, in the glass breakage detection device according to claim 2 , the determination means determines that the intensity of the low frequency component of the acoustic signal is the comparison by the low frequency sound intensity comparison means. Even when the low frequency intensity reference value is exceeded, it can be configured to determine whether or not the glass is cracked.

Furthermore, according to the glass breakage detection device of the present invention, in the glass breakage detection device according to claim 2 , the determination means determines that the intensity of the low frequency component of the acoustic signal is the comparison by the low frequency sound intensity comparison means. When the low frequency intensity reference value is exceeded, it can be configured not to determine whether or not the glass has cracked.

Furthermore, according to the glass breakage detection device of the present invention, in the glass breakage detection device according to claim 1 , the crack detection means includes the intensity of the high frequency component of the acoustic signal and the low frequency component of the vibration signal. It can also be configured to determine that the glass is broken when the strength is equal to or greater than a predetermined value at substantially the same time.

  According to the glass breakage detection device of the present invention, only information on both vibration and sound is used, and a logic that detects a “break” that generates a large breaking sound such as a break and a small breaking sound such as a break is generated. By separately providing logic for detecting “cracks” that do not occur, it is possible to accurately and reliably distinguish and detect glass breakage without false alarms.

  Further, according to the glass breakage detection device of the present invention, since it has a logic for detecting a “crack” that uses only vibration and sound information and generates only a small breaking sound such as tearing, a false alarm Therefore, it is possible to accurately and reliably detect glass breakage due to tearing.

  Furthermore, since the sensor does not need to be directly installed on the glass surface and can be installed on a structural member that supports the glass such as a sash frame, at least two glass surfaces can be monitored by one sensor.

In the following, embodiments of the present invention that the patent applicant thinks best at the time of filing to implement the present invention will be described.
The present invention reliably detects a crack caused by a twist that has been considered difficult to detect, or reliably detects a breakage of glass according to a mode such as a crack or a crack. It has a means to determine that the glass has been cracked with a specific judgment logic using, or in addition to this crack judgment means, the glass has been cracked with a specific judgment logic using the above signal. A means for judging this is used in combination.

  In addition, these glass breakage detectors are particularly characterized in that they can be reliably attached to the window glass, and breakage can be detected for a plurality of window glasses in a single location.

  Therefore, in the first embodiment, a glass breakage detection apparatus using a logic that determines that a crack caused by breakage has occurred in a glass by using signals of sound waves and vibration waves will be described. In the second embodiment, a glass breakage detection apparatus having both a logic for determining a glass breakage using signals by sound waves and vibration waves and a logic for determining a glass breakage will be described.

(1) First Embodiment FIG. 1 is a block diagram showing a configuration of a first embodiment according to the present invention. The first embodiment is a signal that functions in logic for detecting that a “crack” has entered a glass due to a destructive action such as tearing as detailed in the section “Problems to be Solved by the Invention”. A processing unit is provided.

  The vibration pickup 1 as a vibration sensor detects a vibration wave generated when the glass is broken, and converts it into an electrical signal corresponding to the intensity of the vibration wave. A piezoelectric vibrator can be used for the vibration pickup. The microphone 11 as a sound wave sensor detects a sound generated when the glass is broken, and converts it into an electric signal corresponding to the intensity. In this embodiment, an electret condenser microphone can be used.

  The amplifier 2 and the amplifier 12 are for amplifying the signal of the vibration pickup 1 and the signal of the microphone 11 to a predetermined level, respectively.

  The BPF 23 is a bandpass filter that transmits a frequency component near 700 Hz in the output signal of the amplifier 2 and cuts other frequency components. The BPF 13 is a band pass filter that transmits a frequency component near 3.5 kHz in the output signal of the amplifier 12 and cuts other frequency components. The BPF 33 is a band-pass filter that transmits a frequency component near 140 Hz in the output signal of the amplifier 12 and cuts other frequency components.

  Half-wave rectifier circuits 14, 24, and 34 are provided subsequent to the BPFs 13, 23, and 33. Half-wave rectification circuits 14, 24, and 34 half-wave rectify and output the outputs of BPFs 13, 23, and 33, respectively. The smoothing circuits 15, 25, and 35 smooth the outputs of the half-wave rectifier circuits 14, 24, and 34, respectively. Integration circuits 19, 29, and 39 are provided subsequent to the smoothing circuits 15, 25, and 35. The integrating circuits 19, 29, 39 integrate the outputs of the smoothing circuits 15, 25, 35 with an appropriate time constant. The time constant for integration needs to be a time constant for integrating a signal in a section corresponding to, for example, 10 to 100 msec in which the glass breaking sound continues. The outputs of the integrating circuits 19, 29 and 39 are input to the A / D converter of the digital signal processing unit 7. The output of the integrating circuit 29 is also input to the trigger circuit 6.

  The digital signal processing unit 7 is configured by a CPU that performs calculation, an A / D converter that converts an analog output of the integration circuit into a digital signal, a ROM that stores a processing program for determining glass breakage, and a RAM that temporarily stores digital data. The

  The trigger circuit 6 outputs a start pulse to the start terminal of the CPU only when the output value of the integration circuit 29 reaches a predetermined value, and starts the CPU. The predetermined value in the trigger circuit 6 is a value that exceeds the dark vibration level and may cause vibration due to glass breakage. The CPU is activated by the activation pulse from the trigger circuit 6, converts the outputs of the integrating circuits 19, 29, and 39 into digital signals by the A / D converter, stores them in the RAM, and processes to be described later based on the program stored in the ROM. Thus, an external glass breakage detection signal is output to the transmitter 8. The transmission unit 8 transmits a glass breakage detection signal to a reception circuit (not shown) by radio or the like.

  The glass breakage detection device 100 is attached to a sash 50 that is a structural member that supports a glass 51 to be monitored, for example, as shown in FIG. Specifically, as shown in FIG. 2 a, it is screwed to the surface of the sash 50 that holds the glass 51 to be monitored, or disposed inside the sash 50. Thereby, it can prevent falling off.

  Further, when the sash 50 and the sash 60 are locked by locking the crescent lock 52, the glass 61 held by the sash 60 can be monitored. Furthermore, a function of detecting opening / closing of a window by adding a magnet sensor to the glass breakage detection device 100 may be added.

FIG. 2 b is a perspective view of an attachment example of the glass breakage detection device 100.
The vibration pickup 1 needs to be arranged so as to be in direct contact with the sash 50. Although the microphone 11 is illustrated facing the indoor side so that the glasses 51 and 61 can be monitored at the same time, the microphone 11 can be installed in any position in the vicinity of the glasses 51 and 61.

Next, a processing flowchart of the CPU of the glass breakage detection apparatus 100 having the above configuration will be described with reference to FIGS.
In the description of the present embodiment, the input signal from the integration circuit 19 is the “high frequency component of the acoustic signal”, the input signal from the integration circuit 39 is the “low frequency component of the acoustic signal”, and the integration circuit 29. The input signal from is called “vibration signal”.

  First, when the output signal (vibration signal) of the integrating circuit 29 reaches a predetermined value, the trigger circuit 6 is activated and outputs an activation pulse to the activation terminal of the CPU. As a result, the CPU is started, and the output signals of the integrating circuits 29, 19, and 39 are sequentially converted into digital signals (respectively, the vibration signal, the high frequency component of the acoustic signal, and the low frequency component of the acoustic signal).

  When the CPU is activated, the level condition flag is set to FALSE, the vibration continuation flag is set to FALSE, the crack determination flag is set to FALSE, the vibration continuation counter is set to 0, and the vibration pause counter is set to 0 (FIG. 3, step 300).

  Here, the level condition flag is a flag indicating whether or not a condition relating to the intensity level of the signal among the conditions for outputting the glass breakage detection signal is satisfied. If the condition is satisfied, it is set to TRUE. Otherwise, it is set to FALSE.

  The vibration continuation flag is a flag indicating that vibration is continuing. The crack determination flag is a flag that means that the occurrence of a crack is finally detected. The vibration continuation counter is a counter that represents the vibration continuation time. The vibration pause counter is a counter for determining whether vibration is continuing.

Here, the duration counting method will be described with reference to FIG.
First, a time when the vibration signal exceeds a predetermined value TH1 is set as a vibration start time. Next, when the state below TH2 is maintained and below TH2 for a predetermined time ΔT or longer, the first time when TH2 is below TH2 is set as the vibration end time.

  The period from the start time to the end time of vibration is defined as the vibration duration time. Therefore, even if the value once falls below TH2, if it recovers to a value larger than TH2 within the time ΔT, it is considered that the vibration is still continuing.

Next, a crack determination process performed after initialization of the flag and counter will be described (FIG. 3, step 302). Details of the crack determination process will be described with reference to FIG.
In step 310, the value of the vibration continuation counter at the current time is updated. In step 312, the value of the vibration continuation counter is determined. If the value of the vibration continuation counter is 0, it is determined that the vibration has ended before all the crack determination conditions are met, and the crack determination process is terminated. If it is 1 or more, it is determined that vibration is continuing, and the routine proceeds to step 314.

  In step 314, it is determined whether the high frequency component of the acoustic signal is greater than or equal to a predetermined value. This predetermined value is obtained as a value that can reliably detect the high frequency component of the acoustic signal generated when the glass cracks in the experiment. If it is equal to or greater than the predetermined value, it is determined in step 316 whether the low frequency component of the acoustic signal is equal to or lower than the predetermined value. This predetermined value is obtained as a value that can reliably detect the low frequency component of the acoustic signal generated when the glass cracks in the experiment. When the condition of the high frequency component of the acoustic signal and the condition of the low frequency component of the acoustic signal are satisfied at the same time, the level condition flag is set to TRUE (step 318), and the process proceeds to step 320.

  If any of the conditions in steps 314 and 316 is not satisfied, the level condition flag is not changed and the process proceeds to step 320.

  Subsequently, when the value of the vibration continuation counter is equal to or greater than a predetermined value and the level condition flag is TRUE (YES in step 320), the crack determination flag is set to TRUE (step 322), and this crack determination process Exit.

  If the condition of step 320 is not satisfied, the process returns to step 310 and the process is repeated.

  The cycle of this processing is performed in synchronization with the conversion cycle to the digital signal in the A / D converter of the CPU.

  When the crack determination flag is set in the process of step 302 (FIG. 3), in step 304, it is determined whether or not the crack determination flag is TRUE. If TRUE, the process proceeds to step 306, and after outputting the crack signal, The process proceeds to the start pulse waiting state (step 308). On the other hand, if the crack determination flag is FALSE, the process proceeds to the start pulse waiting state (step 308).

Next, the vibration continuation counter update process will be described using the flowchart of FIG.
First, in step 400, it is determined whether or not the vibration continuation flag is already set to TRUE.

  If the vibration has already been continued (when the vibration continuation flag is TRUE), the process proceeds to step 406. If it is not set to TRUE, it is determined whether the vibration signal is equal to or greater than a predetermined value (TH1) (step 402). If it is equal to or greater than the predetermined value (TH1), the vibration continuation flag is set to TRUE (step 404). The process proceeds to step 406.

  If the predetermined value (TH1) is not exceeded, it is determined that vibration has not occurred, and the vibration continuation counter update process is terminated.

  In step 406, it is determined whether the vibration signal is equal to or less than a predetermined value TH2 (<TH1). When the vibration signal becomes equal to or less than the predetermined value TH2, 1 is added to the vibration pause counter (step 408).

  When the vibration pause counter value is equal to or greater than the predetermined value ΔT (step 410), it is determined that the vibration has completely ended, the vibration continuation counter and the vibration pause counter are set to 0, and the vibration continuation flag is set to FALSE. End the vibration duration counter update process.

  On the other hand, if the vibration signal exceeds the predetermined value TH2 in step 406, the vibration pause counter value + 1 is added to the vibration continuation counter (step 414), the vibration pause counter is set to 0 (step 416), and the vibration continuation counter update process is performed. Exit.

  In the present embodiment, the processing related to the level determination, when performing a destructive action such as smashing, the low frequency component of the acoustic signal at the time of the `` crack '' generated thereby is small compared to the breaking, and It is determined that the high frequency component of the acoustic signal at the time of “crack” is large in the same way as the breaking (FIG. 7a).

  The impact sound generated when a soft object such as a ball collides with the glass or knocks is a “crack” sound due to breakage or the like because the high frequency component is small and the low frequency component is large. It is never determined.

  However, in the case shown in FIG. 7b, the glass breakage detection condition that the low frequency component of the acoustic signal is smaller than a predetermined value and the high frequency component of the acoustic signal is larger than a predetermined value even at the time T1. Will be satisfied. This state is not originally intended by the present invention. This is because the low frequency component of the acoustic signal exceeds a predetermined value at time T0. Therefore, as shown in FIG. 7c, even if the condition is changed such that the low frequency component of the acoustic signal never exceeds the predetermined value while the high frequency component of the acoustic signal exceeds the predetermined value. Good.

  A flowchart of such processing is shown in FIG. In the process shown in FIG. 4b, when the low frequency component of the acoustic signal exceeds a predetermined value in step 316, the tear-off determination process is completed, so that the signal as shown in FIG. 7b is not detected. 7c is characterized in that a signal as shown in FIG. 7c is detected, and as a result, a false alarm can be avoided as much as possible.

  On the other hand, in the process shown in FIG. 4a, even when the low frequency component of the acoustic signal exceeds a predetermined value in step 316, the process proceeds to step 320 and the process is continued, as shown in FIGS. 7b and 7c. Since both signals are detected, the detection of cracks due to tearing is more reliable.

  As described above, whether to select the process of FIG. 4a or the process of FIG. 4b can be arbitrarily selected in light of the characteristics of each process according to the object or purpose of installing this apparatus. Further, the difference between these processes may be fixedly set in the apparatus, or may be arbitrarily switched.

  4a and 4b, instead of the condition that the low frequency component of the acoustic signal is equal to or lower than a predetermined value, the low frequency component of the acoustic signal / the high frequency component of the acoustic signal (that is, The condition that the ratio is equal to or less than a predetermined value (for example, “1” or less) does not depart from the intention of the present invention (FIG. 4 c).

  The vibration continuation counter pays attention to the long duration of the “crack” sound generated by the action when a flathead screwdriver or the like is inserted into the gap between the glass and the sash and broken.

  In the case of “cracking” due to breakage or the like, the target glass breaks into a state of being separated into small pieces, and only an instantaneous force is applied to the glass. Therefore, no external force is applied to the broken glass.

  On the other hand, if the glass is “cracked” due to tearing or the like, the shape of the glass remains, so that the force continues to be applied and the vibration continues for a long time.

  On the other hand, when pebbles hit the glass and do not break, the low-frequency sound of the collision sound is small and the high-frequency sound is relatively loud, so the probability of giving a false alarm increases only with the above-mentioned level conditions. However, the time during which a stone or the like is in contact with the glass is an instantaneous phenomenon, and the signal converges relatively quickly, so that the breakage detection performance is improved by adding the duration condition.

  The predetermined values TH1 and TH2 for calculating the vibration continuation counter value should be set based on the dark vibration level of vibration and the vibration level at the time of crack occurrence. Here, the dark vibration level is noise outside the detection target that is constantly generated in the glass as the target. The predetermined value ΔT that serves as a reference for determining the vibration end time is a value that should be set based on the vibration characteristics at the time of crack occurrence, such as when performing a tearing action, and is set to about 200 ms, for example. It is preferable to do this.

  In addition, in order to exclude the sound source which repeats a vibration and a pause intermittently, you may make it exclude the case where the upper limit of a continuous time is set and an upper limit is exceeded.

  The trigger circuit 6 is a circuit that generates a start pulse only when the vibration pickup 1 detects a vibration of a predetermined signal level or higher. As long as the vibration input to the vibration pickup 1 does not reach a predetermined value, the CPU 6 Does not start, the CPU can be driven intermittently and the power consumption can be reduced. On the other hand, if there is a margin in power consumption, there is no problem even if the trigger circuit 6 is not provided and the flowchart of FIG. 3 is always repeated at the cycle of the A / D converter.

  In the above description, the glass breakage is detected based on the integrated value of specific frequency components of sound and vibration. However, the reference value for glass breakage determination is not limited to this. For example, it may be an effective value of power or an average value after rectification. In the configuration shown in FIG. 1, the start pulse is generated by the signal level of the integration circuit 29, but the start pulse may be generated by the signal level of the integration circuit 19 or 39.

  Although the glass breakage detection apparatus 100 of this example is configured using BPFs 13, 23, and 33, a low-pass filter or a high-pass filter is used within a range where vibration and sound caused by glass breakage can be measured. It is good also as a structure.

  Further, half-wave rectifier circuits 14, 24, and 34 are provided in the subsequent stages of the BPFs 13, 23, and 33, respectively, and output signals from the smoothing circuits 15, 25, and 35 are detected after the absolute values are obtained. Instead of the half-wave rectifier circuits 14, 24, 34, a full-wave rectifier circuit may be provided.

  The smoothing circuits 15, 25, and 35 may use smoothing filters using passive elements, and may use half-wave rectifier circuits 14, 24, and 34 and the smoothing circuit 15 using an envelope detection circuit or the like. 25 and 35 may be combined into one.

  In addition, as a means for observing broken glass sound, in this embodiment, a microphone such as an electret condenser microphone is used.However, if the sound caused by broken glass can be detected, the frequency band can be changed. Is possible. In this case, the frequency band of the high frequency component is not limited to the audible sound range, and the ultrasonic band may be detected using an ultrasonic element. Many normal ultrasonic elements have narrow band characteristics, and depending on the element used, the BPF may be omitted.

  In the above embodiment, the glass breakage is determined by the processing of the CPU, but other circuit configurations may be used. For example, it is possible to provide a comparator in place of the CPU to achieve performance equivalent to the configuration shown in FIG. On the contrary, in this example, a function equivalent to that of a hardware BPF, half-end rectifier circuit, smoothing circuit, and integration circuit may be realized by CPU software.

(2) Second Embodiment FIG. 8 is a block diagram showing a configuration of a glass breakage detection device 101 according to a second embodiment of the present invention. In the second embodiment, there are logic for detecting that a “crack” has entered a glass due to a destructive action such as breakage, and logic for detecting a “crack” generated in the glass due to a destructive action such as breaking. A signal processing unit that functions in two types of logic is provided, thereby detecting and accurately detecting breakage of different modes occurring in the glass.

  Vibration breaker 1 of glass breakage detection device 101, microphone 11, amplifiers 2, 12, half-wave rectifier circuits 4, 14, 24, 34, smoothing circuits 5, 15, 25, 35, integrating circuits 9, 19, 29, 39 The configuration is the same as in the first embodiment.

  The BPF 3 transmits only the frequency component near 100 Hz in the output signal of the amplifier 2 and cuts other frequency components. As in the first embodiment, the BPF 23 transmits a frequency component near 700 Hz in the output signal of the amplifier 2 and cuts other frequency components. As in the first embodiment, the BPF 13 transmits a frequency component near 3.5 kHz in the output signal of the amplifier 12 and cuts other frequency components. Similar to the first embodiment, the BPF 33 transmits a frequency component near 140 Hz in the output signal of the amplifier 12 and cuts other frequency components.

  The output of the integrating circuit 29 is also input to the trigger circuit 6. Only when the output value of the integrating circuit 29 reaches a predetermined value, the trigger circuit 6 outputs a starting pulse to the starting terminal of the CPU of the digital signal processing unit 7 to start the CPU. The hardware configuration of the digital signal processing unit 7 is the same as that of the first embodiment, but the control content is different as will be described later.

  The CPU is activated by the activation pulse from the trigger circuit 6, converts the outputs of the integrating circuits 9, 19, 29, and 39 into digital signals by the A / D converter, stores those values in the RAM, and stores them in the ROM. Based on the program, a glass breakage detection signal is output to the outside by processing to be described later. The transmission unit 8 transmits a glass breakage detection signal to a reception circuit (not shown) by radio or the like.

  The installation method of the glass breakage detection device 101 is the same as that in the first embodiment shown in FIG.

  Next, the processing in the CPU of the glass breakage detection apparatus 101 having the above configuration will be described with reference to FIGS. 4 and 6 which are flowcharts in the first embodiment and FIGS.

  In the description of the present embodiment, the input signal from the integration circuit 19 is “high frequency component of the acoustic signal”, the input signal from the integration circuit 39 is “low frequency component of the acoustic signal”, and from the integration circuit 9. The input signal is referred to as “low frequency component of vibration signal”, and the input signal from the integration circuit 29 is referred to as “high frequency component of vibration signal”.

  First, when the output signal (vibration signal) of the integration circuit 29 reaches a predetermined value, the trigger circuit 6 is activated and outputs a start pulse to the start terminal of the CPU (FIG. 9, start). As a result, the CPU is started, and the output signals of the integrating circuits 9, 29, 19, and 39 are sequentially converted into digital signals (respectively low frequency components of vibration signals, high frequency components of vibration signals, acoustic signals, respectively). Is the high frequency component, and the low frequency component of the acoustic signal).

  When the CPU is activated, the level condition flag is set to FALSE, the vibration continuation flag is set to FALSE, the crack determination flag is set to FALSE, the crack determination flag is set to FALSE, the vibration continuation counter is set to 0, and the vibration pause counter is set to 0. (FIG. 9, step 500).

  Note that the level condition flag is a flag indicating whether a condition relating to the intensity level of the signal among the conditions for outputting the glass breakage detection signal is satisfied. The vibration continuation counter and the vibration pause counter are counters related to counting the duration of the signal among the conditions for outputting the glass breakage detection signal. The crack determination flag is a flag that means that a crack has finally occurred. The crack determination flag is a flag that means that a crack is finally detected.

  Step 502 is a step of determining whether or not the input signal is a signal generated due to “break”. Step 504 is a step of determining whether or not the input signal is a signal generated by “crack”.

  If it is determined in one of the above steps that the signal is generated due to glass breakage (steps 506 and 508), after the glass breakage signal is output (step 510), the process returns to the start pulse standby state (step 512).

  If it is not determined in either step that the signal is generated due to glass breakage, the process returns to the start pulse waiting state (step 512).

Next, the processing procedure (step 502) of “break” detection in the CPU of the glass breakage detection apparatus 101 of this example will be described with reference to the flowchart of FIG.
In FIG. 10, when the vibration low-frequency signal is equal to or higher than a predetermined value (step 610, YES) and the high-frequency component of the acoustic signal is equal to or higher than a predetermined value (step 612, YES), crack determination is performed. The flag is set to TRUE (step 614) and the process ends.

  On the other hand, if either of the above conditions cannot be satisfied, the present process is terminated as it is.

  The processing procedure of “crack” detection in the CPU of the glass breakage detection apparatus 101 of the present example is exactly the same as that described in the first embodiment with reference to the flowcharts of FIGS. The detailed description is omitted with reference to the description of the embodiment and the drawings.

  In this embodiment, the vibration signal is divided into two frequency bands centered on 100 Hz and 700 Hz. However, it is more simple to detect cracks and cracks in the same frequency band as one frequency band. It is also possible to configure.

  In addition, the sound pressure level and vibration level of “cracks” due to breakage, etc., and “cracks” due to breakage, etc. vary significantly depending on the actual situation, so detection can be made more reliably by using multiple microphones and pickups with different sensitivities. It becomes possible.

  According to the present embodiment, it is possible to reduce false alarms by determining the detection of “crack” and the detection of “crack” using different logic.

  It should be noted that the crack detection means, crack detection means, sound intensity comparison means, vibration duration comparison means, high frequency sound intensity comparison means, low frequency sound intensity comparison means, etc. of the invention described in the claims of the present application As is apparent from the description of the embodiment of the present invention described above, the function realization means such as comparison / determination / control is provided in the digital signal processing unit 7 including a CPU having an information processing function for sound / vibration signals. Corresponding.

It is the block diagram which showed the structure of 1st embodiment in this invention. It is the schematic which shows the installation state of the glass breakage detection apparatus of 1st embodiment. It is an expansion perspective view which shows the installation state of the glass breakage detection apparatus of 1st embodiment. It is the flowchart (flow diagram) which showed the processing flow of the glass breakage determination in 1st embodiment. It is the flowchart (flow chart) which showed the 1st example of the processing flow of "crack" determination in 1st embodiment. It is the flowchart (flow chart) which showed the 2nd example of the processing flow of "crack" determination in 1st embodiment. It is the flowchart (flow diagram) which showed a part of 2nd example of the processing flow of "crack" determination in 1st embodiment. It is explanatory drawing of the vibration continuation time in 1st embodiment. It is the flowchart (flow diagram) which showed the update process flow of the vibration continuation counter in 1st embodiment. It is the time waveform figure which showed the time transition of the high frequency component of an acoustic signal, and the low frequency component of an acoustic signal. It is the time waveform figure which showed the time transition of the high frequency component of an acoustic signal, and the low frequency component of an acoustic signal. It is the time waveform figure which showed the time transition of the high frequency component of an acoustic signal, and the low frequency component of an acoustic signal. It is the block diagram which showed the structure of 2nd embodiment concerning this invention. It is the flowchart (flow diagram) which showed the processing flow of the glass breakage determination in 2nd embodiment of this invention. It is the flowchart (flow diagram) which showed the processing flow of the "crack" determination in 2nd embodiment.

Explanation of symbols

7: Crack detection means, crack detection means, acoustic intensity comparison means, vibration duration comparison means, high-frequency acoustic intensity comparison means, digital signal processing unit as low-frequency acoustic intensity comparison means 50, 60 ... sash 51 as a structural member 61 ... Glass 100,101 ... Glass breakage detector THc ... Vibration duration reference value THh ... High frequency intensity reference value THL ... Low frequency intensity reference value

Claims (5)

A crack detecting means for detecting that cracked in by Riga Las acoustic signal and an oscillation signal obtained from the vibration wave obtained from the sound wave generated by the breakage of the glass, cracks detecting means for detecting that the glass is broken in Ruga Las breakage detection device having a bets,
The crack detection means includes
Acoustic intensity comparison means for comparing the intensity of the predetermined frequency component of the acoustic signal with an intensity reference value;
A vibration duration comparing means for comparing a vibration duration in which the intensity of a predetermined frequency component of the vibration signal is a predetermined value or more with a vibration duration reference value;
Determination means for determining whether or not the glass is cracked based on a comparison result by the acoustic intensity comparison means and the vibration duration comparison means;
The crack detection means is
A glass breakage detection apparatus, wherein the glass breakage is determined to be broken when the intensity of the predetermined frequency component of the acoustic signal and the intensity of the predetermined frequency component of the vibration signal are substantially equal to or greater than a predetermined value. The sound intensity comparing means includes a high frequency sound intensity comparing means for comparing the intensity of the high frequency component of the acoustic signal with a high frequency intensity reference value, and the intensity of the low frequency component of the acoustic signal as a low frequency intensity. It consists of low-frequency sound intensity comparison means to compare with the reference value,
The determination means is such that the vibration duration is not less than a vibration duration reference value by comparison in the vibration duration comparison means, and the intensity of the high frequency component of the acoustic signal is determined by comparison in the high band acoustic intensity comparison means. When the intensity of the low frequency component of the acoustic signal is equal to or lower than the low frequency intensity reference value by the comparison in the low frequency acoustic intensity comparison means, the glass has cracks. The glass breakage detection device according to claim 1 , wherein the glass breakage detection device is determined to have entered. The sound intensity comparison means includes a high-frequency sound intensity comparison means for comparing the intensity of the high-frequency component of the acoustic signal with a high-frequency intensity reference value, and the acoustic signal relative to the intensity of the high-frequency component of the acoustic signal. It consists of low-frequency sound intensity comparison means that compares the intensity ratio of the low-frequency components with a predetermined reference value,
The determination means is such that the vibration duration is not less than a vibration duration reference value by comparison in the vibration duration comparison means, and the intensity of the high frequency component of the acoustic signal is determined by comparison in the high band acoustic intensity comparison means. A ratio of the intensity of the low frequency component of the acoustic signal to the intensity of the high frequency component of the acoustic signal is equal to or less than the reference value by the comparison in the low frequency acoustic intensity comparison means, while being above the high frequency intensity reference value. If it is, the glass breakage detecting device according to claim 1, wherein determining that that cracked the glass. In a glass breakage detection device that detects a crack in a glass by an acoustic signal obtained from a sound wave generated by a crack generated in the glass and a vibration signal obtained from a vibration wave,
Acoustic intensity comparison means for comparing the intensity of the predetermined frequency component of the acoustic signal with an intensity reference value;
A vibration duration comparing means for comparing a vibration duration in which the intensity of a predetermined frequency component of the vibration signal is a predetermined value or more with a vibration duration reference value;
Determination means for determining whether or not the glass is cracked based on a comparison result by the acoustic intensity comparison means and the vibration duration comparison means;
A glass breakage detection device comprising: Glass breakage detection device according to claim 1 to claim 4, wherein the vibration wave when glass breakage and detecting from the structural member that supports the glass.

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