KR102559543B1 - Apparatus for measuring raman scattering, and apparatus and method for determining true fire using the apparatus - Google Patents

Abstract

A light source for irradiating light to smoke particles in order to distinguish between fire smoke generated by an actual fire and non-fire smoke generated during daily life or industrial activities; a filter configured to block light incident on smoke particles and pass through the particles and pass Raman scattered light; and a photodetector for detecting Raman scattered light passing through the filter. The present invention also provides a fire determination device and method including a unit for reading Raman shift from the Raman scattered light detected by the photodetector of the Raman scattered light measuring device, estimating a smoke component from the read Raman shift, and determining whether fire/non-fire is present from the estimated smoke component.

Description

Raman scattering light measuring device and fire determination device and method using the same

The present invention relates to a technology for measuring components of smoke based on optical spectrum analysis and a technology for distinguishing between fire smoke generated from an actual fire and non-fire smoke generated from daily life or industrial activities using the same.

A fire detector is a fire monitoring device that detects a fire early by recognizing the heat or smoke generated in the event of a fire. Fire detectors include heat detectors, smoke detectors, composite detectors, and flame detectors.

Thermal detectors are divided into differential type that detects fire when the temperature rises rapidly, constant temperature type that detects fire when the temperature rises above a certain temperature, and compensation type that combines both differential and constant temperature (spot type and distribution type depending on the sensing range). Smoke detectors operate when detecting smoke generated in a fire. There are ionization type using the change of ion current when smoke enters the detection unit, and photoelectric type using the change in incident light amount of the photoelectric element when smoke enters the detection unit. The hot smoke complex detector detects both heat and smoke at the same time with a compensating heat detection function and a photoelectric smoke detection function. In addition, the flame detector operates when the change in flame exceeds a certain amount in case of fire, and operates when the light receiving amount of the light receiving element changes due to a flame in one place. There are ultraviolet type, infrared type, ultraviolet/infrared combined type, and composite type flame detectors.

In order to detect a fire in a house or building, such a fire detector is mainly installed by attaching a base to a ceiling or wall, and assembling a sensing unit composed of circuit elements to the base. In the event of a fire, the fire detector detects flame, smoke, temperature, etc., and transmits a signal to the outside to issue an alarm.

However, since conventional smoke-sensing fire detectors generate an alarm by determining the presence or absence of particles based on the size of smoke particles, vapor, cigarette smoke, food cooking smoke, fine dust, and by-products generated in daily life or industrial activities, even when particles similar to fire smoke are generated, there is a problem in that non-fire alarms in which the fire detector operates by determining that it is not a fire as a fire often occur.

As described above, the present invention has been devised to solve the problem that non-fire alarms that determine non-fire as fire are frequently issued due to heat generated in everyday environments and smoke caused by living or industrial activities such as cigarette smoke, food cooking smoke, fine dust, and by-products. Accordingly, an object of the present invention is to reduce non-fire alarms by distinguishing between fire smoke generated by an actual fire and non-fire smoke generated by daily life or industrial activities.

According to one aspect of the present invention to achieve the above object, a light source for irradiating light to the smoke particles; a filter configured to block light incident on smoke particles and pass through the particles and pass Raman scattered light; and a photodetector for detecting the Raman scattered light passing through the filter.

According to another aspect of the present invention to achieve the above object, a light source for irradiating light to the smoke; a filter that blocks light transmitted through smoke particles from irradiated light and passes Raman scattered light; a photodetector for detecting light passing through the filter; and a unit configured to read a Raman shift from the detected light, estimate a smoke component from the read Raman shift, and determine fire/non-fire from the estimated smoke component.

According to another aspect of the present invention to achieve the above object, irradiating light to the smoke; Filtering is performed to block light transmitted through the smoke particles and pass Raman scattered light; detect the filtered light; reading a Raman shift from the detected light; estimating a smoke component from the read Raman shift; A fire determination method is provided which includes determining fire/non-fire from estimated smoke components.

The configuration and operation of the present invention will become more clear through specific embodiments described later in conjunction with the drawings.

According to the present invention, it is possible to distinguish whether the smoke is fire smoke or non-fire smoke by measuring the Raman scattering light of the smoke particles generated for some reason, analyzing the Raman shift, and finding out the components of the smoke.

1 is a conceptual diagram showing a schematic description of Raman scattering.
Figure 2 is an exemplary view showing that the Raman shift is different depending on the material.
3 is a block diagram of an embodiment of an apparatus for measuring Raman scattered light of smoke particles to be used for smoke component analysis according to the present invention.
FIG. 4 is a wavelength-intensity relationship diagram for explaining the filtering action of the optical filter 20 and the nanoimprint filter 30 used in the Raman scattered light measuring device of FIG. 3 .
5 is a block diagram of a method and apparatus according to the present invention for determining fire/non-fire by analyzing smoke components from data obtained by measuring Raman scattering light for smoke particles.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of preferred embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described below and may be implemented in various other forms. The examples are only provided to completely disclose the present invention and to completely inform those skilled in the art of the scope of the invention to which the present invention belongs, and the present invention is defined by the description of the claims.

In addition, terms used in this specification are for describing embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless otherwise specified. In addition, the terms 'comprise (comprise, comprising, etc.)' used in the specification do not exclude the presence or addition of one or more other elements, steps, operations, and / or elements other than the mentioned elements, steps, operations, and / or elements.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the embodiments, if a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

1 is a conceptual diagram for schematic explanation of Raman scattering. When strong light (3) of a single wavelength from a light source (1) (laser, etc.) is irradiated to a gas, liquid, or solid substance (2), in addition to light with the same wavelength as the incident light included in the scattered light scattered from the material particles, Stokes Scattering (4), Anti-Stokes Scattering (5), and Rayleigh Scattering (6) with a shorter wavelength are observed. This phenomenon is called Raman scattering. When a material receives light energy, some of the energy is used as energy for vibration of atoms or rotation of molecules that make up the material, and when the remaining energy is scattered as light, light with a long wavelength is mixed with the scattered light, resulting in Stokes Scattering. Conversely, when the energy of a material is applied to the light energy, the wavelength of the scattered light is shortened, resulting in Anti-Stokes Scattering.

By measuring the spectrum displayed by Raman scattering, molecular structure and qualitative/quantitative analysis of materials are possible. A pattern in which the spectrum of scattered light appearing in the Raman scattering process is shifted with respect to Rayleigh scattering is called a Raman shift. Raman shift appears differently depending on the material. Figure 2 illustrates that the Raman shift (cm ^-1 ) shows a different aspect for each material. In FIG. 2, (a) is a Raman shift for acetonitrile, (b) is a Raman shift for ethanol, (c) is benzene, and (d) is a Raman shift for toluene.

In this way, by using the fact that the Raman shift generated by Raman scattering varies depending on the material, the Raman shift is found from the Raman scattering light measured for the smoke particle material and the identity of the smoke is analyzed to determine whether it is fire smoke caused by a fire or non-fire smoke generated during daily life or industrial activity. However, it is not easy to observe the Raman scattered light because the scattered light generated by the Raman scattering effect is insignificant compared to the intensity of the laser light irradiated on the smoke particle material. Accordingly, the present invention proposes a Raman scattered light measuring device configured as follows.

3 is a block diagram of an embodiment of an apparatus for measuring Raman scattered light of smoke particles for fire/non-fire determination.

The apparatus for measuring Raman scattered light illustrated in FIG. 3 includes a light source 10 , an optical filter 20 , a nanoimprint filter 30 , and a photodetector 40 . This device can be employed in fire detectors installed inside and outside buildings.

The light source 10 that irradiates, for example, laser light to the smoke generated inside and outside the building may emit light of a single wavelength, but a plurality of light sources to emit one or more wavelengths or a single light source emitting multiple wavelengths may be used. For example, as multiple wavelengths, wavelengths of about 532 ± 10% (≒ 478 to 586) nm, 785 ± 10% (≒ 706 to 864) nm, 830 ± 10% (≒ 747 to 913) nm, and 1064 ± 10% (≒ 957 to 1171) nm can be used. However, depending on the type of smoke particle material to be measured, a light source of a wavelength band other than the above-mentioned may be used. For example, the type of smoke particle material will vary depending on whether the place where the fire detector in which the present device is employed is installed is a place where ethanol is mainly handled, a place where benzene is mainly handled, or a general household. Accordingly, the emission wavelength of the light source 10 can be applied differently.

The optical filter 20 blocks the wavelength range of the light 3′ that is incident on the smoke particles 2 and passes through the particles, and transmits only the wavelength range of the Raman scattered light, that is, the Stokes scattering (4) or/and Anti-Stokes scattering (5) shown in FIG. The optical filter 20 can be designed as one of a low-pass, high-pass, and band-pass filter, and the wavelength filtering parameter in each case can be designed to correspond to the type of smoke particle material that will vary depending on the place where the fire detector in which the present device is employed, such as the light source 10, will be installed. This will be explained in detail below.

The nanoimprint filter 30 limits the wavelength range of the Raman scattered light to correspond to the detection characteristics of the photodetector 40 so that the photodetector 40 can detect the Raman scattered light filtered by the optical filter 20 with maximum efficiency and passes the Raman scattered light. That is, it serves to narrow the allowable wavelength range of the detection sensor constituting the photodetector 40 and increase the sensitivity. The nanoimprint filter has a plurality of nanostructures formed using a semiconductor nanoprocess of 100 nm or less, and has a characteristic of passing or blocking light of a specific wavelength through a combination of wavelengths of light sources passing through each nanostructure. The nanoimprint filter 30 may be configured in a form included in the photodetector 40, but is not limited thereto.

Here, the filtering by the optical filter 20 functions to filter the Raman scattered light in a wide range so as to roughly correspond to the type of smoke particle material that will vary depending on the place, and the filtering by the nanoimprint filter 30 narrows the allowable wavelength range and increases the sensitivity of the wide range of Raman scattered light primarily filtered by the optical filter 20 according to the characteristics of the photodetector 40. You can call it filtering.

Now, various embodiments of the wavelength of the light source and the filtering wavelength of the apparatus for measuring Raman scattered light of smoke particles, configured as shown in FIG. 3 , will be illustrated. In the following description, it will be described with reference to FIG. 4 . 4 is a wavelength vs. intensity relationship diagram (response characteristics in the frequency domain) for explaining the filtering function by the optical filter 20 and the nanoimprint filter 30. (a) shows response characteristics in the frequency domain of the light 3 irradiated from the laser light source 10. (b) shows response characteristics in the frequency domain of the irradiated light transmitted through the smoke particles (3′) and the Raman scattered light scattered from the smoke particles, that is, Stokes scattering (4) and Anti-Stokes scattering (5). (c1), (c2), and (c3) indicate response characteristics in the frequency domain of the light filtered by the optical filter 20, and detailed descriptions will be given below.

First, in the case of an embodiment in which the Raman scattering light measuring device installed in the fire detector is set so that the laser light source 10 emits light of a single wavelength of about 785 nm and the photodetector 40 detects a wavelength of about 800 to 100 nm, the optical filter 20 blocks the occupied band of 785 nm, which is the wavelength of the light source (eg, 780 to 790 nm) and lower bands, and passes the excess band to transmit smoke It may be composed of a high-pass filter that removes light 3' and Anti-Stokes scattering 5 (see (c1) in FIG. 4). In this case, the photodetector 40 may detect Stokes Scattering of approximately 20 to 2700 (cm ^-1 ).

In addition, in the case of an embodiment in which the laser light source 10 irradiates the same wavelength as the Raman scattering light measuring device and the photodetector 40 is set to detect wavelengths in the range of about 650 to 770 nm, the optical filter 20 may be composed of a low-pass filter that blocks the occupied band of 785 nm, which is the wavelength of the light source, and higher bands, and passes the lower band to remove the light 3' passing through the smoke and the Stokes scattering 4. (See Fig. 4 (c2)). In this case, the photodetector 40 can measure Anti-Stokes Scattering of approximately 20 to 2700 (cm ^-1 ).

In addition, in the case of an embodiment in which the laser light source 10 irradiates the Raman scattered light measuring device with the same wavelength as described above and the photodetector 40 is set to detect wavelengths in the range of about 650 to 770 nm and about 800 to 100 nm, the optical filter 20 blocks the occupied band of 785 nm, which is the wavelength of the light source, and passes other wavelengths (e.g., wavelengths less than 780 nm and wavelengths greater than 790 nm), It may be composed of a band-stop filter that removes only the light 3' that has passed through the smoke (see (c3) in FIG. 4). In this case, the photodetector 40 can measure both Stokes Scattering and Anti-Stokes Scattering of approximately 20 to 2700 (cm ^-1 ).

In the above embodiments, the laser light source 10, the optical filter 20, the photodetector 40, and the nanoimprint filter 20 are set to operate in a wavelength band corresponding to the particulate matter constituting the smoke to be generated. It is to help understand the Raman scattered light measuring device of various specifications. That is, the emission wavelength of the laser light source 10, the wavelength of the pass and cut-off band of the optical filter 30, and the detection wavelength of the photodetector 40 including/without the nanoimprint filter 20 may be changed and set according to the installation location of the fire detector in which the Raman scattered light measuring device of the present invention is employed or according to the user's intention.

5 is a configuration diagram of a method and apparatus according to the present invention for determining fire/non-fire by analyzing smoke components from data obtained by measuring Raman scattered light of smoke particles with the above-described Raman scattered light measuring device. Descriptions of overlapping contents with those described above are omitted.

First, when the above-described Raman scattered light measuring device emits light, the emitted light is irradiated to smoke particles (110).

Scattered light (Raman effect) is generated in smoke particles by the irradiated light (120).

The Raman scattered light is first filtered, that is, optically filtered (130). As described above, the optical filter used at this time is designed to block light penetrating smoke particles and transmit only Raman scattered light in a set wavelength band.

The light passing through the optical filter is detected by a photodetector (150). Nanoimprint filtering 140 may be performed prior to photodetection. The nanoimprint filtering 140 serves to narrow the allowable wavelength range of the detection sensor constituting the photodetector by limiting the wavelength range when the photodetector detects Raman scattered light and to increase sensitivity.

A Raman shift is read from the detected light (Raman scattered light measurement data) (160). Raman shift was explained through FIG. 2 .

Smoke components are estimated from the read Raman shift (170). Since Raman shift is a characteristic of a material, Raman shift data for various materials have been accumulated. This data can be used to infer the substances that make up the smoke.

From the estimated smoke components, it is determined whether the currently generated smoke is fire smoke or smoke caused by living or industrial activities to determine whether it is fire/non-fire (180).

Here, reading the Raman shift from the Raman scattered light measurement data, estimating the smoke component from the read Raman shift, and determining fire/non-fire from the estimated smoke component is a digital signal processor (DSP), processor, controller, ASIC (application-specific IC), programmable logic device (FPGA, etc.), at least one of other electronic devices, and combinations thereof. In addition, it can be combined with hardware elements or executed as independent software, which can be stored in a recording medium and executed or moved.

Although the present invention has been described in detail through preferred embodiments of the present invention, those skilled in the art to which the present invention pertains may understand that the present invention may be embodied in a specific form different from that disclosed herein without changing the technical spirit or essential features. It should be understood that the embodiments described above are illustrative in all respects and not restrictive. In addition, the scope of protection of the present invention is determined by the claims described below rather than the detailed description above, and all changes or modifications derived from the scope of the claims and equivalent concepts thereof should be construed as being included in the technical scope of the present invention.

Claims (16)

delete delete delete delete delete a light source that irradiates light of a preset wavelength to the smoke particles;
a filter for blocking light passing through smoke particles from the irradiated light and passing Raman scattered light;
a photodetector for detecting Raman scattered light passing through the filter; and
A fire determination device including a unit for reading a Raman shift corresponding to a substance of the smoke particle from detected Raman scattered light, estimating a component of the smoke particle by referring to the stored Raman shift for a plurality of substances, and determining whether the smoke particle is caused by a fire or a non-fire from the estimated components of the smoke particle. The fire detection device according to claim 6, wherein the light source is a laser light source. The fire detection device according to claim 6, wherein the preset wavelength is set differently according to the type of the smoke particle substance. The method of claim 6, wherein the filter
A filter that removes Stokes scattering included in Raman scattered light, a filter that removes Anti-Stokes scattering included in Raman scattered light, and a filter that passes both Anti-Stokes scattering and Stokes scattering included in Raman scattered light. Fire determination device, characterized in that one of the following. [7] The fire detection device according to claim 6, further comprising a nanoimprint filter that secondarily filters the Raman scattered light passing through the filter and sends the Raman scattered light to the photodetector. irradiating the smoke particles with light of a preset wavelength;
performing filtering of the irradiated light to block light passing through smoke particles and pass Raman scattered light;
detecting the filtered Raman scattered light;
reading a Raman shift corresponding to the substance of the smoke particle from the detected Raman scattered light;
estimating components of the smoke particles by referring to stored Raman shifts for a plurality of materials;
A fire determination method comprising determining whether the smoke particles are caused by fire or non-fire from the composition of the estimated smoke particles. The fire determination method according to claim 11, wherein the irradiated light is a laser light. The fire determination method according to claim 11, wherein the predetermined wavelength is set differently according to the type of the smoke particle substance. 12. The method of claim 11, wherein the filtering
Filtering to remove Stokes scattering included in Raman scattered light, filtering to remove Anti-Stokes scattering included in Raman scattered light, and filtering to pass both Anti-Stokes scattering and Stokes scattering included in Raman scattered light Fire determination method, characterized in that one of. The fire determination method according to claim 11, further comprising secondarily filtering the filtered Raman scattered light before detecting the filtered Raman scattered light. 16. The method of claim 15, wherein the secondary filtering is performed by a nanoimprint filter.

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