A method and system for detecting fire smoke

Abstract

This application provides a method and system for detecting smoke in fires, relating to the field of emergency fire protection technology. The smoke detection system includes a dual-spectrum transmitter and a multispectral receiver. The method includes: the dual-spectrum transmitter transmitting a first beam of a first band and a second beam of a second band to the area to be detected according to a preset transmission cycle. The multispectral receiver receives and determines a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam. Based on the first spectral response signal and a pre-calculated first reference spectral response signal, the multispectral receiver determines a first attenuation rate corresponding to the first beam, and based on the second spectral response signal and a pre-calculated second reference spectral response signal, determines a second attenuation rate corresponding to the second beam. The multispectral receiver outputs a smoke alarm signal based on each attenuation rate and an attenuation rate threshold. Using this application can avoid false smoke alarms caused by false alarm sources such as dust and water vapor.

Description

Technical Field

[0001] This application relates to the field of emergency fire protection technology, and in particular to a method and system for detecting fire smoke. Background Technology

[0002] Currently, linear beam smoke detectors are the mainstream products in the field of emergency fire protection. Linear beam smoke detectors are usually composed of a pair of infrared transmitters and infrared receivers. Their working principle is to use smoke to reduce the amount of light emitted by the infrared transmitter to the infrared receiver in order to determine the fire.

[0003] However, linear beam smoke detectors cannot distinguish whether the reduced beam intensity is due to smoke from a fire or interference from dust or vapor in the air. Furthermore, aligning linear beam smoke detectors is extremely difficult, and even after alignment, beam deviation caused by building structural deformation and vibration will lead to detector malfunction. Therefore, a new method for detecting fire smoke is urgently needed. Summary of the Invention

[0004] Therefore, it is necessary to provide a fire smoke detection method and system to address the aforementioned technical problems.

[0005] In a first aspect, a method for detecting fire smoke is provided, the method being applied to a fire smoke detection system, the detection system comprising a dual-spectrum emitter and a multi-spectrum receiver, the method comprising:

[0006] According to a preset emission cycle, the dual-spectrum emitter emits a first beam of the first band and a second beam of the second band toward the region to be detected.

[0007] The multispectral receiver receives the first beam and the second beam, and determines the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam.

[0008] The multispectral receiver determines the first attenuation rate corresponding to the first beam based on the first spectral response signal and the pre-calculated first reference spectral response signal, and determines the second attenuation rate corresponding to the second beam based on the second spectral response signal and the pre-calculated second reference spectral response signal.

[0009] If the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold, then the multispectral receiver outputs a smoke alarm signal.

[0010] As an optional implementation, the multispectral receiver receives the first beam and the second beam, and determines a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam, including:

[0011] The multispectral receiver receives the first beam and the second beam, and converts them into a first electrical signal corresponding to the first beam and a second electrical signal corresponding to the second beam.

[0012] The multispectral receiver determines the ratio of the first electrical signal to the pre-calculated reference electrical signal of the corresponding band as the first spectral response signal corresponding to the first beam, and determines the ratio of the second electrical signal to the pre-calculated reference electrical signal of the corresponding band as the second spectral response signal corresponding to the second beam.

[0013] As an optional implementation, the multispectral receiver determines the first attenuation rate corresponding to the first beam based on the first spectral response signal and a pre-calculated first reference spectral response signal using the following formula:

[0014]

[0015] Where m is the first attenuation rate, U w (λ1) is the first reference spectral response signal, and U(λ1,t1) is the first spectral response signal of the multispectral receiver at time t1;

[0016] The formula for determining the second attenuation rate corresponding to the second beam based on the second spectral response signal and the pre-calculated second reference spectral response signal is as follows:

[0017]

[0018] Where n is the second decay rate, U w (λ2) is the second reference spectral response signal, and U(λ2,t2) is the second spectral response signal of the multispectral receiver at time t2.

[0019] As an optional implementation, the method further includes:

[0020] In the absence of smoke in the area to be detected, the dual-spectrum emitter emits the first beam and the second beam toward the area to be detected for each emission cycle;

[0021] The multispectral receiver receives the first beam and the second beam, and determines the first weighted average spectral response signal of the first beam in each emission cycle and the second weighted average spectral response signal of the second beam in each emission cycle;

[0022] The multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle, and determines the second reference spectral response signal based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle.

[0023] As an optional implementation, the multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle using the following formula:

[0024]

[0025]

[0026] Where n is the number of launch cycles, Ti is the launch cycle, i=1 is the current launch cycle, i=2 is the previous launch cycle, i=3 is the launch cycle before the previous launch cycle, and so on. U w (λ1) is the first reference spectral response signal, U(λ1,Ti) is the first weighted average spectral response signal corresponding to the emission period Ti, and C i1 The first weighting coefficient corresponding to the launch period Ti;

[0027] The formula for determining the second reference spectral response signal by the multispectral receiver based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle is as follows:

[0028]

[0029]

[0030] Where n is the number of launch cycles, Ti is the launch cycle, i=1 is the current launch cycle, i=2 is the previous launch cycle, i=3 is the launch cycle before the previous launch cycle, and so on. U w (λ2) represents the second reference spectral response signal, U(λ2,T) i C represents the second weighted average spectral response signal corresponding to the emission period Ti. i2 This is the second weighting coefficient corresponding to the emission period Ti.

[0031] Secondly, a fire smoke detection system is provided, the detection system comprising a dual-spectrum emitter and a multi-spectrum receiver; wherein...

[0032] The dual-spectral emitter is used to emit a first beam of the first band and a second beam of the second band toward the area to be detected according to a preset emission period.

[0033] The multispectral receiver is used to receive the first beam and the second beam, and to determine the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam.

[0034] The multispectral receiver is further configured to determine a first attenuation rate corresponding to the first spectral response signal based on the first spectral response signal and a pre-calculated first reference spectral response signal, and to determine a second attenuation rate corresponding to the second spectral response signal based on the second spectral response signal and a pre-calculated second reference spectral response signal.

[0035] The multispectral receiver is further configured to output a smoke alarm signal if the first attenuation rate is greater than a preset first attenuation rate threshold, the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold.

[0036] As an optional implementation, the dual-spectrum emitter includes a first emission source in a first band, a second emission source in a second band, and an emission control circuit; wherein,

[0037] The first emitting light source is used to emit the first beam of light into the area to be detected;

[0038] The second emitting light source is used to emit the second beam of light toward the area to be detected;

[0039] The emission control circuit is used to turn on the first emission light source according to the emission cycle and the preset first turn-on duration, so that the first emission light source continuously emits the first beam into the area to be detected within the first turn-on duration;

[0040] The emission control circuit is further configured to activate the second emission light source according to the emission cycle and a preset second activation duration, so that the second emission light source continuously emits the second beam toward the area to be detected within the second activation duration.

[0041] As an optional implementation, the multispectral receiver includes an optical window, an optical sensor, a signal processing circuit, and an alarm output circuit; wherein,

[0042] The optical window is used to filter light beams in bands other than the first and second bands;

[0043] The optical sensor is used to receive the first beam and the second beam, and convert them into a first electrical signal corresponding to the first beam and a second electrical signal corresponding to the second beam.

[0044] The signal processing circuit is used to determine the ratio of the first electrical signal corresponding to the first beam to the pre-calculated reference electrical signal of the corresponding band as the first spectral response signal corresponding to the first beam, and to determine the ratio of the second electrical signal corresponding to the second beam to the pre-calculated reference electrical signal of the corresponding band as the second spectral response signal corresponding to the second beam.

[0045] The signal processing circuit is further configured to determine a first attenuation rate corresponding to the first spectral response signal based on the first spectral response signal and a pre-calculated first reference spectral response signal, and to determine a second attenuation rate corresponding to the second spectral response signal based on the second spectral response signal and a pre-calculated second reference spectral response signal.

[0046] The alarm output circuit is further configured to output a smoke alarm signal if the first attenuation rate is greater than a preset first attenuation rate threshold, the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold.

[0047] As an optional implementation, when both the bispectral emitter and the multispectral receiver are located on one side of the area to be detected, the detection system further includes a reflector; wherein,

[0048] The dual-spectral emitter is used to emit a first beam and a second beam from one side of the region to be detected to the other side according to the emission period;

[0049] The reflector is disposed on the other side of the area to be detected, and is used to reflect the first beam and the second beam emitted by the dual-spectral emitter onto the multispectral receiver.

[0050] As an alternative implementation, the optical sensor is a solar panel.

[0051] This application provides a fire smoke detection method and system. The technical solution provided by the embodiments of this application brings at least the following beneficial effects: The fire smoke detection system includes a dual-spectrum emitter and a multi-spectrum receiver. The method includes: the dual-spectrum emitter emits a first beam of a first band and a second beam of a second band to a detection area according to a preset emission cycle; the multi-spectrum receiver receives the first beam and the second beam, and determines a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam; the multi-spectrum receiver determines a first attenuation rate corresponding to the first beam based on the first spectral response signal and a pre-calculated first reference spectral response signal, and determines a second attenuation rate corresponding to the second beam based on the second spectral response signal and a pre-calculated second reference spectral response signal; if the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold, then the multi-spectral receiver outputs a smoke alarm signal. The dual-spectrum transmitter emits a first and second beam of light in different wavelengths. This design addresses the issue that smoke attenuates different wavelengths differently, while dust and water vapor attenuate at nearly the same rate across different wavelengths, thus eliminating false alarms in smoke alarm systems. Furthermore, the dual-spectrum transmitter and multispectral receiver do not require precise alignment; simply adjusting their angles allows for the acquisition of the maximum signal dynamic range.

[0052] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the structure of a fire smoke detection system provided in an embodiment of this application;

[0055] Figure 2 A flowchart of a fire smoke detection method provided in this application embodiment;

[0056] Figure 3 A flowchart of another fire smoke detection method provided in the embodiments of this application;

[0057] Figure 4A flowchart illustrating yet another fire smoke detection method provided in this application embodiment;

[0058] Figure 5 This is a schematic diagram of another fire smoke detection system provided in an embodiment of this application;

[0059] Figure 6 A flowchart illustrating another example of a fire smoke detection method provided in an embodiment of this application. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0061] The fire smoke detection method provided in this application embodiment can be applied to a fire smoke detection system. Figure 1 This is a schematic diagram of the structure of a fire smoke detection system provided in an embodiment of this application, as shown below. Figure 1 As shown, the fire smoke detection system includes a dual-spectrum emitter 110 and a multispectral receiver 120. The dual-spectrum emitter 110 and the multispectral receiver 120 are respectively located on both sides of the area to be detected.

[0062] The following will describe in detail a fire smoke detection method provided in this application embodiment, with reference to specific implementation methods. Figure 2 A flowchart of a fire smoke detection method provided in this application embodiment is shown below. Figure 2 As shown, the specific steps are as follows:

[0063] Step 201: According to the preset emission cycle, the dual-spectrum emitter emits a first beam of the first band and a second beam of the second band toward the area to be detected.

[0064] In practice, the dual-spectrum emitter transmits a first beam in the first band and a second beam in the second band to the area to be detected according to a preset emission cycle. Within the response range of the multispectral receiver, the greater the interval between the first and second bands selected for smoke detection, the more accurate the smoke detection. However, the selection of the first and second bands cannot exceed the response range of the multispectral receiver. For example, if the multispectral receiver uses a gallium arsenide solar panel, the first band λ1 can be 450nm and the second band λ2 can be 850nm. If the multispectral receiver uses a polycrystalline silicon solar panel, the first band λ1 can be 405nm and the second band λ2 can be 620nm.

[0065] Step 202: The multispectral receiver receives the first beam and the second beam, and determines the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam.

[0066] In practice, the multispectral receiver receives the first beam and the second beam, and determines the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam based on the optical signals of the first beam and the second beam.

[0067] As an alternative implementation method, Figure 3 A flowchart of another fire smoke detection method provided in the embodiments of this application is shown below. Figure 3 As shown, the specific steps in step 202 for the multispectral receiver to receive the first beam and the second beam, and to determine the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam are as follows:

[0068] Step 301: The multispectral receiver receives the first beam and the second beam, and converts them into a first electrical signal corresponding to the first beam and a second electrical signal corresponding to the second beam.

[0069] In practice, when the first beam of light in the first band and the second beam of light in the second band illuminate the multispectral receiver, each photon in the beam generates a number of charge carriers. That is, the multispectral receiver converts the light energy of the first beam of light in the first band and the second beam of light in the second band into electrical energy. Because the multispectral receiver has different absorption capabilities for different wavelengths of light, the first electrical signal (e.g., voltage) corresponding to the first beam and the second electrical signal corresponding to the second beam converted by the multispectral receiver are also different.

[0070] Step 302: The multispectral receiver determines the ratio of the first electrical signal to the pre-calculated reference electrical signal of the corresponding band as the first spectral response signal corresponding to the first beam, and determines the ratio of the second electrical signal to the pre-calculated reference electrical signal of the corresponding band as the second spectral response signal corresponding to the second beam.

[0071] In practice, each wavelength is incident on the multispectral receiver with a certain amount of radiation energy. The multispectral receiver determines the first spectral response signal based on the ratio of the generated first electrical signal to the pre-calculated reference electrical signal of the corresponding band. Similarly, the multispectral receiver determines the second spectral response signal based on the ratio of the generated second electrical signal (short-circuit current) to the pre-calculated reference electrical signal of the corresponding band.

[0072] Step 203: The multispectral receiver determines the first attenuation rate corresponding to the first beam based on the first spectral response signal and the pre-calculated first reference spectral response signal, and determines the second attenuation rate corresponding to the second beam based on the second spectral response signal and the pre-calculated second reference spectral response signal.

[0073] In practice, if aerosol media such as smoke, dust, or water vapor are present in the area to be detected, the light beam passing through the aerosol will attenuate due to the scattering and absorption of light by aerosol particles. The multispectral receiver can determine the attenuation rate of the light beam based on the current spectral response signal and a pre-calculated reference spectral response signal. The reference spectral response signal is calculated and stored in real-time by the detection system when there are no aerosol media such as smoke, dust, or water vapor in the area to be detected. Therefore, the multispectral receiver determines the first attenuation rate corresponding to the first light beam based on the first spectral response signal and the pre-calculated first reference spectral response signal, and determines the second attenuation rate corresponding to the second light beam based on the second spectral response signal and the pre-calculated second reference spectral response signal.

[0074] As an optional implementation, in step 203, the multispectral receiver determines the first attenuation rate corresponding to the first beam based on the first spectral response signal and the pre-calculated first reference spectral response signal using the following formula:

[0075]

[0076] Where m is the first attenuation rate, U w (λ1) is the first reference spectral response signal, and U(λ1,t1) is the first spectral response signal of the multispectral receiver at time t1;

[0077] The formula for determining the second attenuation rate corresponding to the second beam based on the second spectral response signal and the pre-calculated second reference spectral response signal by the multispectral receiver is as follows:

[0078]

[0079] Where n is the second decay rate, U w (λ2) is the second reference spectral response signal, and U(λ2,t2) is the second spectral response signal of the multispectral receiver at time t2.

[0080] Step 204: If the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold, then the multispectral receiver outputs a smoke alarm signal.

[0081] In practice, since the attenuation rate of different aerosol particles to the same wavelength of light is only related to the properties of the aerosol particles themselves (average particle diameter and refractive index), it is difficult to distinguish the types of aerosol particles using only one wavelength of light. Therefore, the multispectral receiver determines whether smoke is generated based on the first attenuation rate of the first beam, the second attenuation rate of the second beam, and the relative attenuation rates of the first and second beams. The determination of smoke generation is based on the following logic: if the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first and second attenuation rates is greater than a preset third attenuation rate threshold, then the multispectral receiver outputs a smoke alarm signal. If the difference between the first and second attenuation rates is less than or equal to the preset third attenuation rate threshold, it indicates that the first and second attenuation rates are similar, suggesting the presence of interference sources such as water vapor or dust in the detection area, thus avoiding false alarms related to fire smoke.

[0082] As an alternative implementation method, Figure 4 A flowchart of another fire smoke detection method provided in the embodiments of this application is shown below. Figure 4 As shown, the specific steps for the multispectral receiver to determine the first reference spectral response signal and the second reference spectral response signal are as follows:

[0083] Step 401: In the absence of smoke in the area to be detected, for each emission cycle, the dual-spectrum emitter emits a first beam and a second beam toward the area to be detected.

[0084] In practice, when there is no smoke in the area to be detected, the dual-spectrum emitter emits a first beam and a second beam toward the area to be detected for each emission cycle.

[0085] Step 402: The multispectral receiver receives the first beam and the second beam, and determines the first weighted average spectral response signal of the first beam in each emission cycle and the second weighted average spectral response signal of the second beam in each emission cycle.

[0086] In implementation, a multispectral receiver receives a first beam and a second beam, and determines the first weighted average spectral response signal of the first beam in each transmission cycle and the second weighted average spectral response signal of the second beam in each transmission cycle. Specifically, for the first band λ1, the preset transmission cycle is T, the current time is t, and the cycle is marked as T. The multispectral receiver determines the first spectral response signal of the first beam in one transmission cycle T as U(λ1, t1), U(λ1, t2), U(λ1, t3)...U(λ1, t4)...U(λ1, t5)...U(λ1, t6)...U(λ1, t7)...U(λ1, t8)...U(λ1, t9)...U(λ1, t1)...U(λ1, t1)...U(λ1, t1)...U(λ1, t2 ...2)...U(λ1, t2)...U(λ1, t2)...U(λ1, t2)...U(λ1, t2)...U nThe first weighted average spectral response signal can be calculated by averaging the n first spectral response signals, or by calculating the moving average of the n first spectral response signals. Calculating the moving average can remove the influence of external optical noise. The second beam is calculated similarly.

[0087] Step 403: The multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle, and determines the second reference spectral response signal based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle.

[0088] In practice, the multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle, and determines the second reference spectral response signal based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle.

[0089] As an optional implementation, in step 403, the multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle using the following formula:

[0090]

[0091]

[0092] Where n is the number of launch cycles, Ti is the launch cycle, i=1 is the current launch cycle, i=2 is the previous launch cycle, i=3 is the launch cycle before the previous launch cycle, and so on. U w (λ1) is the first reference spectral response signal, U(λ1,Ti) is the first weighted average spectral response signal corresponding to the emission period Ti, and C i1 This is the first weighting coefficient corresponding to the emission period Ti.

[0093] The formula for determining the second reference spectral response signal by the multispectral receiver based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle is as follows:

[0094]

[0095]

[0096] Where n is the number of launch cycles, Ti is the launch cycle, i=1 is the current launch cycle, i=2 is the previous launch cycle, i=3 is the launch cycle before the previous launch cycle, and so on. U w (λ2) represents the second reference spectral response signal, U(λ2,T)i C represents the second weighted average spectral response signal corresponding to the emission period Ti. i2 This is the second weighting coefficient corresponding to the emission period Ti.

[0097] Alternatively, for detection areas with low levels of dust and moisture, a detection system equipped with a single-spectrum emitter can be used. This system only obtains the spectral response attenuation rate for a single band. When the attenuation rate exceeds a set threshold, an alarm is triggered. Typically, the attenuation rate is converted into a signal strength value, calculated using the following formula:

[0098] DR = 10log 10 1 / m;

[0099] Where DR is the signal strength value in dB, and m is the attenuation rate.

[0100] The signal strength threshold of the detection system can be set to 1.0 dB or 2.0 dB, which are equivalent to attenuation rates of 20% and 36.5%, respectively.

[0101] Optionally, Figure 6 A flowchart illustrating another example of a fire smoke detection method provided in this application embodiment is shown below. Figure 6 As shown, after the detection system is installed and powered on, it first performs a self-test. If the self-test is normal, the transmission control circuit begins to control the first and second transmitting light sources to turn on and off according to the preset transmission cycle and on-time duration. During this process, the detection system begins to adjust the angles of the dual-spectrum transmitter and multi-spectrum receiver. The detection system acquires the voltage or current signals output by the optical sensor in real time and, depending on the type of the dual-spectrum transmitter, separates the spectral response signals of the single-band or dual-band light source from the overall carrier signal. The detection system determines whether the spectral response signal meets the required dynamic range for analysis. If not, it adjusts the angles of the dual-spectrum transmitter and multi-spectral receiver to obtain the maximum signal dynamic range. Once the adjustment is complete, the detection system enters the formal operation state. The detection system acquires the spectral response signals of the first beam λ1 and the second beam λ2 in real time and calculates the first and second reference spectral response signals, as well as the attenuation rates and relative attenuation rates of the first beam λ1 and the second beam λ2. The detection system further performs attenuation rate threshold judgment. Typically, the sensitivity level of the detection system can be set to 3 to 5 levels. When the attenuation rate and relative attenuation rate of the beam response in different bands are both greater than the corresponding sensitivity level threshold, the system will determine that it is a fire smoke alarm.

[0102] This application provides a method for detecting smoke in a fire. The technical solution provided by the embodiments of this application brings at least the following beneficial effects: The fire smoke detection system includes a dual-spectrum transmitter and a multi-spectrum receiver. The method includes: the dual-spectrum transmitter transmitting a first beam of a first band and a second beam of a second band to the area to be detected according to a preset transmission cycle. The multi-spectrum receiver receives the first beam and the second beam, and determines a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam. The multi-spectrum receiver determines a first attenuation rate corresponding to the first beam based on the first spectral response signal and a pre-calculated first reference spectral response signal, and determines a second attenuation rate corresponding to the second beam based on the second spectral response signal and a pre-calculated second reference spectral response signal. If the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold, then the multi-spectrum receiver outputs a smoke alarm signal. The dual-spectrum transmitter transmits first and second beams of different bands. Taking into account the characteristic that smoke has different attenuation rates for beams of different bands, while dust and water vapor have nearly the same attenuation rate for different bands, this eliminates false alarm sources in the smoke alarm process. In addition, the dual-spectrum transmitter does not need to be precisely aligned with the multispectral receiver; simply adjusting the angles of the dual-spectrum transmitter and the multispectral receiver is sufficient to obtain the maximum signal dynamic range.

[0103] It should be understood that, although Figures 2 to 4 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figures 2 to 4 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0104] It is understood that the same / similar parts between the various embodiments of the methods described above in this specification can be referred to each other. Each embodiment focuses on the differences from other embodiments, and relevant parts can be referred to the description of other method embodiments.

[0105] This application also provides a fire smoke detection system, such as... Figure 1 As shown, the device includes a detection system comprising a dual-spectral emitter 110 and a multispectral receiver 120; wherein,

[0106] The dual-spectral emitter 110 is used to emit a first beam of the first band and a second beam of the second band toward the area to be detected according to a preset emission cycle.

[0107] A multispectral receiver 120 is used to receive a first beam and a second beam, and to determine a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam.

[0108] The multispectral receiver 120 is also configured to determine a first attenuation rate corresponding to the first spectral response signal based on the first spectral response signal and a pre-calculated first reference spectral response signal, and to determine a second attenuation rate corresponding to the second spectral response signal based on the second spectral response signal and a pre-calculated second reference spectral response signal.

[0109] The multispectral receiver 120 is also configured to output a smoke alarm signal if a first attenuation rate is greater than a preset first attenuation rate threshold, a second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold.

[0110] As an alternative implementation method, such as Figure 1 As shown, the dual-spectrum emitter 110 includes a first emission light source 1101 in a first band, a second emission light source 1102 in a second band, and an emission control circuit 1103; wherein,

[0111] The first emitting light source 1101 is used to emit a first beam of light toward the area to be detected;

[0112] The second light source 1102 is used to emit a second beam of light toward the area to be detected;

[0113] In practice, the first emitting light source 1101 can be a light-emitting diode of the first band, and the second emitting light source 1102 can be a light-emitting diode of the second band.

[0114] The emission control circuit 1103 is used to turn on the first emission light source 1101 according to the emission cycle and the preset first turn-on duration, so that the first emission light source 1101 continuously emits a first beam of light toward the area to be detected during the first turn-on duration.

[0115] The emission control circuit 1103 is also used to turn on the second emission light source 1102 according to the emission cycle and the preset second turn-on duration, so that the second emission light source 1102 continuously emits a second beam towards the area to be detected during the second turn-on duration.

[0116] In implementation, to avoid interference, the dual-spectrum emitter 110 emits a first beam and a second beam using periodic pulses. The emission control circuit 1103 controls the first emission source 1101 and the second emission source 1102 to activate the first emission source 1101 for a first activation duration within the emission period T, so that the first emission source 1101 continuously emits the first beam towards the area to be detected during the first activation duration. The second emission source 1102 is activated for a preset second activation duration, so that the second emission source 1102 continuously emits the second beam towards the area to be detected during the second activation duration.

[0117] As an alternative implementation method, such as Figure 1 As shown, the multispectral receiver 120 includes an optical window 1201, an optical sensor 1202, a signal processing circuit 1203, and an alarm output circuit 1204; wherein,

[0118] Optical window 1201 is used to filter light beams in bands other than the first and second bands.

[0119] In practice, an optical window that transmits a preset spectrum is installed in front of the optical sensor 1202. The transmitted spectrum is the selected detection spectrum band, namely the first band and the second band, thereby avoiding beam interference from other bands.

[0120] The optical sensor 1202 is used to receive the first beam and the second beam, and convert them into a first electrical signal corresponding to the first beam and a second electrical signal corresponding to the second beam.

[0121] As an alternative implementation, the optical sensor is a solar panel.

[0122] In implementation, the optical sensor 1202 can be made of single-crystal silicon, polycrystalline silicon, amorphous silicon, gallium arsenide or other materials. Different materials of solar panels respond differently to the spectrum. Therefore, the selection of the first beam and the second beam band must refer to the material type of the optical sensor 1202 and the first and second beam bands must be determined according to the spectral response range of the optical sensor 1202.

[0123] The signal processing circuit 1203 is used to determine the ratio of the first electrical signal corresponding to the first beam to the pre-calculated reference electrical signal of the corresponding band as the first spectral response signal corresponding to the first beam, and to determine the ratio of the second electrical signal corresponding to the second beam to the pre-calculated reference electrical signal of the corresponding band as the second spectral response signal corresponding to the second beam.

[0124] The signal processing circuit 1203 is also used to determine the first attenuation rate corresponding to the first spectral response signal based on the first spectral response signal and the pre-calculated first reference spectral response signal, and to determine the second attenuation rate corresponding to the second spectral response signal based on the second spectral response signal and the pre-calculated second reference spectral response signal.

[0125] In implementation, the signal processing circuit 1203 processes the electrical signal output by the optical sensor 1202 as follows: extracts the beam response signal, performs signal filtering, sorting, AD sampling, and calculation and analysis.

[0126] The alarm output circuit 1204 is also used to output a smoke alarm signal if the first attenuation rate is greater than a preset first attenuation rate threshold, the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold.

[0127] As an alternative implementation method, Figure 5 This is a schematic diagram of another fire smoke detection system provided in an embodiment of this application, as shown below. Figure 5 As shown, when both the dual-spectral emitter 510 and the multispectral receiver 520 are located on one side of the area to be detected, the detection system also includes a reflector 530; wherein,

[0128] The dual-spectral emitter 510 is used to emit a first beam and a second beam from one side of the area to be detected to the other side according to the emission cycle;

[0129] A reflector 530 is disposed on the other side of the area to be detected, and is used to reflect the first beam and the second beam emitted by the dual-spectral emitter 510 onto the multispectral receiver 520.

[0130] Optionally, the fire smoke detection system provided in this application also includes a status display module 1205. The status display module 1205 can use several LED lights, mainly including equipment operation status indicator lights, warning indicator lights, fire alarm indicator lights, fault indicator lights, and beam alignment strength indicator lights. Among them, the beam alignment strength indicator lights are used to indicate the strength of the light source signal during the installation of the detection system, so as to indicate the degree of beam alignment.

[0131] This application provides a fire smoke detection system. The technical solution provided by this application has at least the following beneficial effects: The device includes a detection system comprising a dual-spectrum transmitter 110 and a multispectral receiver 120; wherein, the dual-spectrum transmitter 110 is used to emit a first beam of a first band and a second beam of a second band to the area to be detected according to a preset emission cycle. The multispectral receiver 120 is used to receive the first beam and the second beam, and determine a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam. The multispectral receiver 120 is also used to determine a first attenuation rate corresponding to the first spectral response signal based on the first spectral response signal and a pre-calculated first reference spectral response signal, and to determine a second attenuation rate corresponding to the second spectral response signal based on the second spectral response signal and a pre-calculated second reference spectral response signal. The multispectral receiver 120 is also used to output a smoke alarm signal if the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold. The dual-spectrum transmitter 110 emits a first beam and a second beam of different wavelengths. This eliminates false alarms during smoke alarms because smoke attenuates beams of different wavelengths differently, while dust and water vapor attenuate beams at nearly the same rate. Furthermore, the dual-spectrum transmitter 110 does not require strict alignment with the multispectral receiver 120; simply adjusting the angles of the two transmitters is sufficient to achieve the maximum signal dynamic range.

[0132] Specific limitations regarding fire smoke detection systems can be found in the limitations of fire smoke detection methods described above, and will not be repeated here. Each module in the aforementioned fire smoke detection system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0133] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0134] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0135] It should also be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data used for analysis, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0136] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0137] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for detecting smoke in a fire, characterized in that, The method is applied to a fire smoke detection system, the detection system including a dual-spectrum emitter and a multi-spectrum receiver, and the method includes: According to a preset emission cycle, the dual-spectrum emitter emits a first beam of the first band and a second beam of the second band toward the region to be detected. The multispectral receiver receives the first beam and the second beam, and determines the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam. The multispectral receiver determines the first attenuation rate corresponding to the first beam based on the first spectral response signal and the pre-calculated first reference spectral response signal, and determines the second attenuation rate corresponding to the second beam based on the second spectral response signal and the pre-calculated second reference spectral response signal. If the first attenuation rate is greater than a preset first attenuation rate threshold, and the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold, then the multispectral receiver outputs a smoke alarm signal. The multispectral receiver receives the first beam and the second beam, and determines the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam, including: The multispectral receiver receives the first beam and the second beam, and converts them into a first electrical signal corresponding to the first beam and a second electrical signal corresponding to the second beam. The multispectral receiver determines the ratio of the first electrical signal to the pre-calculated reference electrical signal of the corresponding band as the first spectral response signal corresponding to the first beam, and determines the ratio of the second electrical signal to the pre-calculated reference electrical signal of the corresponding band as the second spectral response signal corresponding to the second beam.

2. The method according to claim 1, characterized in that, The multispectral receiver determines the first attenuation rate corresponding to the first beam based on the first spectral response signal and the pre-calculated first reference spectral response signal using the following formula: ； Where m is the first attenuation rate, U w (λ1) is the first reference spectral response signal, and U(λ1,t1) is the first spectral response signal of the multispectral receiver at time t1; The formula for determining the second attenuation rate corresponding to the second beam based on the second spectral response signal and the pre-calculated second reference spectral response signal is as follows: ； Where n is the second decay rate, U w (λ2) is the second reference spectral response signal, and U(λ2,t2) is the second spectral response signal of the multispectral receiver at time t2.

3. The method according to claim 1, characterized in that, The method further includes: In the absence of smoke in the area to be detected, the dual-spectrum emitter emits the first beam and the second beam toward the area to be detected for each emission cycle; The multispectral receiver receives the first beam and the second beam, and determines the first weighted average spectral response signal of the first beam in each emission cycle and the second weighted average spectral response signal of the second beam in each emission cycle; The multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle, and determines the second reference spectral response signal based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle.

4. The method according to claim 3, characterized in that The multispectral receiver determines the first reference spectral response signal based on the first weighted average spectral response signal and the first weighting coefficient corresponding to each transmission cycle using the following formula: ； ； Where n is the number of launch cycles, Ti is the launch cycle, and U w (λ1) is the first reference spectral response signal, U(λ1,Ti) is the first weighted average spectral response signal corresponding to the emission period Ti, and C i1 The first weighting coefficient corresponding to the launch period Ti; The formula for determining the second reference spectral response signal by the multispectral receiver based on the second weighted average spectral response signal and the second weighting coefficient corresponding to each transmission cycle is as follows: ； ； Where n is the number of launch cycles, Ti is the launch cycle, and U w (λ2) represents the second reference spectral response signal, U(λ2,T) i C represents the second weighted average spectral response signal corresponding to the emission period Ti. i2 This is the second weighting coefficient corresponding to the emission period Ti.

5. A fire smoke detection system, characterized in that, The detection system includes a dual-spectral emitter and a multi-spectral receiver; wherein... The dual-spectral emitter is used to emit a first beam of the first band and a second beam of the second band toward the area to be detected according to a preset emission period. The multispectral receiver is used to receive the first beam and the second beam, and to determine the first spectral response signal corresponding to the first beam and the second spectral response signal corresponding to the second beam. The multispectral receiver includes an optical window, an optical sensor, a signal processing circuit, and an alarm output circuit; wherein, The optical window is used to filter light beams in bands other than the first and second bands; The optical sensor is used to receive the first beam and the second beam, and convert them into a first electrical signal corresponding to the first beam and a second electrical signal corresponding to the second beam. The signal processing circuit is used to determine the ratio of the first electrical signal corresponding to the first beam to the pre-calculated reference electrical signal of the corresponding band as the first spectral response signal corresponding to the first beam, and to determine the ratio of the second electrical signal corresponding to the second beam to the pre-calculated reference electrical signal of the corresponding band as the second spectral response signal corresponding to the second beam. The signal processing circuit is further configured to determine a first attenuation rate corresponding to the first spectral response signal based on the first spectral response signal and a pre-calculated first reference spectral response signal, and to determine a second attenuation rate corresponding to the second spectral response signal based on the second spectral response signal and a pre-calculated second reference spectral response signal. The alarm output circuit is configured to output a smoke alarm signal if the first attenuation rate is greater than a preset first attenuation rate threshold, the second attenuation rate is greater than a preset second attenuation rate threshold, and the difference between the first attenuation rate and the second attenuation rate is greater than a preset third attenuation rate threshold.

6. The system according to claim 5, characterized in that, The dual-spectral emitter includes a first emission source in a first band, a second emission source in a second band, and an emission control circuit; wherein... The first emitting light source is used to emit the first beam of light into the area to be detected; The second emitting light source is used to emit the second beam of light toward the area to be detected; The emission control circuit is used to turn on the first emission light source according to the emission cycle and the preset first turn-on duration, so that the first emission light source continuously emits the first beam into the area to be detected within the first turn-on duration; The emission control circuit is further configured to activate the second emission light source according to the emission cycle and a preset second activation duration, so that the second emission light source continuously emits the second beam toward the area to be detected within the second activation duration.

7. The system according to claim 5, characterized in that, When both the bispectral emitter and the multispectral receiver are located on one side of the area to be detected, the detection system further includes a reflector; wherein, The dual-spectral emitter is used to emit a first beam and a second beam from one side of the region to be detected to the other side according to the emission period; The reflector is disposed on the other side of the area to be detected, and is used to reflect the first beam and the second beam emitted by the dual-spectral emitter onto the multispectral receiver.

8. The system according to claim 5, characterized in that, The optical sensor is a solar panel.

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