KR20220077549A - Fire sensing system using a wideband spectrometer - Google Patents

Abstract

The present invention is a fire detection system using a broadband spectrometer that can easily detect smoke and flames in a fire by analyzing a wide range of spectrum, so that an initial response to a fire is possible, and that fire can be detected over a wide area. is about
According to the present invention, there is provided a fire detection system installed to monitor a monitoring area (M) of a predetermined space in anticipation of a fire; a wide-angle lens 20 capable of receiving light on the monitoring area M; A spectrometer including a body 31 to which the wide-angle lens 20 is mounted, and a diffraction grating 33 provided in the body 31 to transmit or reflect light by the wide-angle lens 20 to form a spectrum (30) and; a detector 40 connected to the spectrometer 30 to detect a spectrum; A fire detection system using a broadband spectrometer is provided, which is connected to the detector 40 and includes a processor 50 configured to analyze a spectrum.

Description

Fire sensing system using a wideband spectrometer

The present invention relates to a fire detection system using a broadband spectrometer, and more particularly, it is possible to easily detect smoke and flame in a fire by analyzing a wide range of spectrum, so that an initial response to a fire is possible, as well as a wide range. It relates to a fire detection system using a broadband spectrometer that enables the detection of fires throughout.

In general, a fire detector detects a fire by combustion products such as heat, smoke, or flame. Usually, a mechanical detector that is turned on/off by mechanical operation depending on the operation method or detection type, or temperature, smoke or flame, etc. is individually controlled. It is classified into a single sensor that detects temperature and smoke, or a hot-rolled composite sensor that detects temperature and smoke at the same time.

However, in general, combustion products are not only generated in a complex manner depending on the type of fire, but also are generated even in non-fire situations. ) or a false negative error in which an alarm sounds in a non-fire situation frequently occurs, which may reduce operational reliability.

Such a conventional fire detector is a fire detection technology of the same concept as a conventional point sensor that detects air particles, temperature, or smoke in a local space during a fire, which generally has low sensitivity and a long response time. Not only that, but the stability is also reduced. The reliability of the smoke sensor may decrease indoors due to the diffusion of air, and the heat sensor detects after a fire has progressed to some extent due to the detection principle that operates when the ambient temperature of the detector is already high. There is a disadvantage that early detection is difficult due to the high temperature control system, and in the case of a flame detector, there is a risk of false detection as it can respond to LED lights used indoors.

On the other hand, in some cases, in order to improve the problems described above, the image-based fire detector is a technology that analyzes and extracts the flame or smoke in the video coming from the CCTV through an algorithm and detects it, which can detect the fire early. In addition, although it is possible to determine the authenticity of a fire by monitoring, in the case of smoke detection, it requires a lot of data information because it is calculated using a probabilistic model, and has disadvantages in that the processing speed is slow and the price is high.

In addition, the method using a color image has a disadvantage in that erroneous detection occurs depending on an index lighting environment similar to a fire. It is detected as a fire, and there is a risk of false detection due to changes in lighting or environment because it is determined only with brightness information.

Korean Patent Publication No. 10-1165821 (2012. 07. 09)

The present invention is intended to solve the above problems, and the present invention can easily detect smoke and flames in a fire by analyzing a wide range of spectrum, so that not only can it be equipped with rapidity to enable an initial response to a fire, but also smoke It is to provide a fire detection system using a broadband spectrometer that has a wide-area detection function capable of detecting fires over a wide area and accuracy of the fire situation by simultaneously detecting fires and flames.

According to a feature of the present invention, there is provided a fire detection system that is installed to monitor a monitoring area (M) of a predetermined space in anticipation of a fire;

a wide-angle lens 20 capable of receiving light on the monitoring area M;

A spectrometer including a body 31 to which the wide-angle lens 20 is mounted, and a diffraction grating 33 provided in the body 31 to transmit or reflect light by the wide-angle lens 20 to form a spectrum (30) and;

a detector 40 connected to the spectrometer 30 to detect a spectrum;

There is provided a fire detection system using a broadband spectrometer, which is connected to the detector 40 and includes a processor 50 configured to analyze the spectrum.

According to another feature of the present invention, the diffraction grating 33 is composed of a first diffraction grating 34 and a second diffraction grating 35 arranged side by side up and down or left and right to diffract different wavelengths. A fire detection system using a broadband spectrometer is provided.

According to another feature of the present invention, there is provided a fire detection system using a broadband spectrometer, characterized in that the detector 40 is composed of a first detector 41 and a second detector 42 configured to detect different wavelengths. do.

According to another feature of the present invention, the spectrometer 30 is disposed at the front end of the diffraction grating 33 to focus the light received from the wide-angle lens 20 to be incident on the diffraction grating 33 side. There is provided a fire detection system using a broadband spectrometer, characterized in that the cylinder lens (60) is further provided.

As described above, according to the present invention, as the spectrum of the light entering through the wide-angle lens 20 is analyzed by a spectrometer and a processor, a wide monitoring area can be secured by the wide-angle lens 20 as well as a conventional image The analysis and processing speed is faster in determining the authenticity of a fire than the method of detecting a fire only by using image information, and the present invention uses image information as in the conventional method using infrared images. Since it is not a method of detecting only a fire, there is an advantage in that erroneous detection that may occur due to a change in the lighting environment of the monitoring area M can be reduced.

In addition, as a plurality of the diffraction grating 33 or the detector 40 of the present invention is arranged to diffract or detect different wavelengths, it is possible to detect and analyze by separating broadband wavelengths, and thereby, it is diffracted by the diffraction grating 33 There is an advantage in that it can resolve errors or inaccuracies in analysis due to overlapping of the spectra of the different wavelengths.

In addition, according to the present invention, as the cylinder lens 60 is provided to be incident on the diffraction grating 33 side, the incident light is focused on the cylinder lens 60 and made to enter the diffraction grating 33 to stand by like a normal absorption spectrometer. In addition to being able to optically extract information on chemical components in a fire, there is an advantage in that it is possible to detect a fire at an early stage by analyzing the gas component generated in the combustion process when a fire occurs.

1 is a block diagram showing an embodiment of the present invention;
2 is a reference diagram for explaining the present invention;
3 is another reference diagram for explaining the present invention;
4 is another reference diagram for explaining the present invention;
5 is a block diagram showing another embodiment of the present invention;
6 is a block diagram showing another embodiment of the present invention;
7 is a block diagram showing another embodiment of the present invention;

The objects, features and advantages of the present invention described above will become more apparent through the following detailed description. Hereinafter, it will be described based on the accompanying drawings.

1 to 7 show various embodiments of the present invention. As shown in Fig. 1, the fire detection system 10 of the present invention is installed to monitor the monitoring area M of a certain space where a fire is expected, and for this purpose, the monitoring area M to be monitored is secured as wide as possible. A spectrometer 30 is provided to focus natural light using a wide-angle lens 20 to form a spectrum by the light by the wide-angle lens 20, and the spectrometer 30 is a wide-angle lens 20 ) is mounted, a slit 32 through which the light received by the wide-angle lens 20 passes is formed on the body 31, and the slit is formed inside the body 31 The diffraction grating 33 is built-in to form a spectrum by transmitting or reflecting the light passing through 32, and by this spectrometer 30, various spectral data can be obtained by the refractive index and frequency that varies depending on the light component. there will be

In addition, a detector 40 for detecting a spectrum generated by the diffraction grating 33 and a processor 50 for analyzing the spectrum connected to the detector 40 are provided on the spectrometer 30, the detector ( 40) converts the spectral data by the spectrometer 30 into an electrical signal through a camera or a sensor for each wavelength and transmits it to the processor 50, and the processor 50 uses a PC or the like to perform an algorithm for fire detection This built-in analyzes the spectrum data transmitted by the detector 40 to provide information on the authenticity of the fire or the occurrence situation.

The present invention does not judge only with a simple image as in the prior art, but converts the spectrum separated into each wavelength through the diffraction grating 33 of light of several wavelengths included in the input light into data, and detects fire using this spectrum data. However, prior to the description of the detailed configuration, the relationship between the temperature and the wavelength at the time of fire will be schematically described with reference to the accompanying drawings.

FIG. 2(a) is a diagram showing the relationship between the maximum temperature and the maximum wavelength emitted from a blackbody. According to this, in the case of a general fire, it does not completely coincide with the case of a blackbody, but as the temperature increases, the spectrum is located on the shorter wavelength side. It can be seen, and since the temperature has reached the region including the peak in the visible region wavelength range of 380 ~ 750 nm, if a wavelength in the visible ray region is detected in the analysis stage, it can be determined that the fire has progressed considerably. will be.

In addition, (b) of FIG. 2 is a diagram showing the relationship between the maximum wavelength emitted at approximately 200 to 2000 ° C. As in the general Wien law, it can be seen that the higher the temperature, the shorter the wavelength emitted is, and the Since heat transfer is converted into electromagnetic waves and transferred from a high-temperature object to a low-temperature object without passing through the medium, it is very efficient to detect the temperature by radiation in order to detect the temperature near the source of the fire from a long distance. The analysis of heat transfer by radiation can analyze the equations according to Wien's law indicating the relationship between temperature and wavelength.

On the other hand, FIG. 3 shows the spectrum of the light component for each region, and the infrared wavelength band is subdivided into 3 zones. Here, the wavelength at which the long wave IR wavelength band and the medium wave infrared band are separated is 4 μm, which is approximately 850° F. (454° C.) when converted into temperature.

Usually, the temperature that occurs in the early stage of a fire can be thought of as a temperature close to the wick of a candle (400~900℃), and since the wavelength of this temperature corresponds to the infrared band as described above, a general camera used in the normal visible light band It is a wavelength band in which detection is impossible.

As described above, in order to accurately grasp the initial stage of the fire and its progress, it should be possible to detect a wavelength in a wide range from visible light to a wavelength in the infrared band. In the present invention, a broadband wavelength can be detected by the spectrometer 30 equipped with the wide-angle lens 20 as described above. In particular, the diffraction grating 33 built into the spectrometer 30 is a wavelength component of the light source It is a representative optical element used for spatially dispersing the .

As shown in FIG. 4 , the incident light arrives at the diffraction grating 33 without being divided by wavelength, and after the incident light passes through the diffraction grating 33 , it is dispersed at a diffraction angle according to the wavelength, usually diffracted The basic principle of the grating 33 is to use the interference effect of light reflected from the grooves 36 created on the grating surface, and the following diffraction grating equation can be used to calculate the diffraction angle.

식(1)

Formula (1)

Here, d means the number of grooves 36 included per 1 mm of the surface of the diffraction grating, α is the incident angle to the diffraction grating 33, β is the diffraction angle with respect to the incident wavelength, and m is the diffraction order (m = ± 1, ±2, ±3, ...), λ represents the incident wavelength.

For example, if the number of grooves in the diffraction grating 33 is d=1800 [lines/mm] and the incident angle of the light source is 49°, the diffraction angle of each wavelength diffracted in the +1st order is determined by Equation (1). , when the diffraction angles are calculated for 800nm and 900nm wavelengths, 62° and 43° can be obtained, respectively, and the dispersion angle is calculated as the difference between the two angles, 19°.

The most important factor to consider in determining such a diffraction grating 33 is the d value, and the diffraction angle varies according to this value, and as a result, it becomes a factor determining the overall dispersion angle. If the d value is large, the dispersion angle increases and , if the d value is small, the diffraction efficiency is small, and since the d value may be changed in consideration of the imaging conditions of the optical system, it is natural that the conditions can be modified in the optimization process, and this dispersion angle is the diffraction grating (33) After passing through, it is used for sensor arrangement or positioning to be formed in an optimal state on a linear optical sensor, etc.

)이 나오는데, 식(1)에서 m은 정수로 크기가 1보다 높은 경우를 고차 회절각이라고 한다. 광대역 파장의 빛이 격자를 통과할 때, 차수가 인접한 스펙트럼에 대해 부분적으로 겹칠 수 있다. 이때에, 겹치지 않는 입력 최대 입사광의 파장대역을 '자유스펙트럼 범위'라고 하는데, 이는 다음과 같은 식(2) 방정식이 충족되면 λ1~λ2 범위의 파장을 가진 m차 빛을 겹치지 않고 사용할 수 있다. On the other hand, if the calculated dispersion angle is wide as in the present invention, since the applied wavelength region becomes wider, a phenomenon in which the second diffracted spectrum of high wavelength and the diffracted spectrum region of low wavelength overlap may occur, which is After the light source passes through the diffraction grating 33, several diffraction angle values (

), where m is an integer in Equation (1). When broadband wavelengths of light pass through the grating, the orders may partially overlap for adjacent spectra. At this time, the wavelength band of the non-overlapping input maximum incident light is called the 'free spectrum range', which can be used without overlapping the m-th light having a wavelength in the range of λ1 to λ2 if the following equation (2) is satisfied.

식(2)

Equation (2)

For example, when primary light having a wavelength in the range of 400 nm to 1600 nm is used, the secondary diffracted light in the wavelength band of 400 nm to 800 nm overlaps the first diffracted light in the 800 nm to 1600 nm range. We try to solve this by the configuration as follows.

As shown in FIG. 5 , a first diffraction grating 34 and a second diffraction grating are vertically disposed at the same distance from the slit 32 with the diffraction grating 33 embedded on the body 31 of the spectrometer 30 . (35) is provided so that the free spectrum region can be fundamentally secured. The first diffraction grating 34 and the second diffraction grating 35 are manufactured to have a different number of grooves d, so that the It is provided to diffract the wavelength, For example, the first diffraction grating 34 is manufactured for 400 nm to 800 nm, and the second diffraction grating 35 is manufactured for 800 nm to 1600 nm and vertically disposed vertically to separate the broadband wavelengths at the same time. It becomes possible to independently resolve wavelength components in the infrared band, which are sensitive to radiation and heat.

In addition, as another method for securing the free spectrum region, as shown in FIG. 6 , the detector 40 is composed of a first detector 41 and a second detector 42 to detect wavelengths of different bands. Arranged side by side, for example, when the second diffracted light of 400 nm, which is long wave infrared, overlaps with the first diffracted light of 800 nm of short wave infrared, the first detector 41 and the second detector 42 as described above are the same. It is arranged in a position to detect different wavelengths.

The present invention extracts features of images that occur in case of fire from the spectrum of the visible ray band, extracts information about the temperature from the spectrum of the infrared band and integrates it, and analyzes the integrated data through a treadmill technique, etc. It becomes possible to provide a system for generating an effective fire alarm.

On the other hand, as shown in Figure 7, on the spectrometer 30 of the present invention, between the slit 32 and the diffraction grating 33, a cylinder lens 60 may be further built in, such a cylinder lens 60 is a slit The incident light entering through 32 is focused on an axis parallel to the diffraction grating 33 and is incident on the diffraction grating 33, whereby information on the chemical composition in the atmosphere can be obtained as in a conventional absorption spectrometer. can be optically extracted.

This method has the ability to accurately detect changes in gas and light emitted as combustible materials are burned at the initial stage of a fire by analyzing the spectral data by the spectrometer 30 and the processor 50 to accurately detect the early stage of a fire. Not only that, but by using the spectral data input to the optical system, it is possible to detect a fire even in a large space, and thereby, it is also possible to find the initial fire alarm and the root cause of the fire.

The present invention described above is not limited by the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes can be made within the scope without departing from the technical spirit of the present invention. It will be clear to those who have the knowledge of

10: fire detection system 20: wide-angle lens
30: spectrograph 31: body
32: slit 33: diffraction grating
34: first diffraction grating 35: second diffraction grating
36: home 40: detector
41: first detector 42: second detector
50: processor 60: cylinder lens

Claims (4)

A fire detection system installed to monitor a monitoring area (M) of a certain space in anticipation of a fire;
a wide-angle lens 20 capable of receiving light on the monitoring area M;
A spectrometer including a body 31 to which the wide-angle lens 20 is mounted, and a diffraction grating 33 provided in the body 31 to transmit or reflect light by the wide-angle lens 20 to form a spectrum (30) and;
a detector 40 connected to the spectrometer 30 to detect a spectrum;
and a processor (50) connected to the detector (40) to analyze the spectrum.
2. The diffraction grating according to claim 1, wherein the grating (33) comprises a first diffraction grating (34) and a second diffraction grating (35) arranged side by side up and down or left and right to diffract different wavelengths. A fire detection system using a broadband spectrometer.
The fire detection system according to claim 1 or 2, wherein the detector (40) is composed of a first detector (41) and a second detector (42) configured to detect different wavelengths.
The method according to claim 1 or 2, wherein the spectrometer (30) is disposed at the front end of the diffraction grating (33) to focus the light received from the wide-angle lens (20) to make it incident toward the diffraction grating (33). A fire detection system using a broadband spectrometer, characterized in that the cylinder lens (60) is further provided.

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