Flame detection method and flame detector for infrared sensor

Abstract

The present invention provides a flame detection method for an infrared sensor and a flame detector, wherein the flame detection method comprises: S11: respectively collecting output signals of infrared sensors of a 4.5um detection channel, a 5.3um detection channel, a 3.8um detection channel and a 0.3-10.6um wide spectrum detection channel; S12: determining whether the output signal meets a preset condition; S13: when it is determined that the output signal meets the preset condition, determining the ratio of the energy sum of the 4.5um detection channel in a preset time window to the energy sum of the 5.3um detection channel or the 3.8um detection channel; and S14: determining whether a flame exists based on the relationship between the ratio and a threshold value. Compared with the prior art, the technical solution of the present invention has a simpler algorithm, reduces the requirements for the processing unit, and takes into account the accuracy of the detection result, which can reduce the production cost and extend the service life of the flame detector.

Description

Technical Field

[0001] The present invention generally relates to the field of fire protection, and in particular to a flame detection method for an infrared sensor and a flame detector. Background Art

[0002] At present, flame detection in the field of fire protection is mostly carried out by infrared, ultraviolet or infrared and ultraviolet composite methods. Among them, infrared detection is usually based on two-band, three-band or four-band detection. In order to reduce the false alarm rate and obtain more accurate detection results, most of them use more complex algorithms (such as Fourier transform, etc.), which have high requirements for processing units. Ultraviolet detectors are more expensive because they mostly use imported ultraviolet tubes. In addition, the detection distance of ultraviolet detectors is shorter than that of infrared detectors, and their service life is also shorter. Therefore, there is an urgent need for a flame detection method and flame detector with simple algorithm, low cost, long service life, accurate detection results and long detection distance.

[0003] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0004] In view of one or more of the problems in the prior art, the present invention provides a flame detection method for an infrared sensor, which has a simple algorithm, low cost, accurate detection results, and a long detection distance. The flame detection method comprises:

[0005] S11: Collect the output signals of the infrared sensors of the 4.5um detection channel, the 5.3um detection channel, the 3.8um detection channel and the 0.3-10.6um wide spectrum detection channel respectively;

[0006] S12: Determine whether the output signal meets a preset condition;

[0007] S13: when it is determined that the output signal satisfies a preset condition, determining a ratio of the energy sum of the 4.5um detection channel to the energy sum of the 5.3um detection channel or the 3.8um detection channel in a preset time window; and

[0008] S14: Determine whether there is a flame based on the magnitude relationship between the ratio and the threshold.

[0009] According to one aspect of the present invention, the step S12 comprises: respectively determining the energy sum of the output signals of the 4.5um detection channel, the 3.8um detection channel and the 5.3um detection channel; wherein the energy sum Where AD is the AD sampling value of the corresponding detection channel, m is the starting point of sampling, and n is the ending point.

[0010] According to one aspect of the present invention, the step S12 further comprises: respectively determining the maximum values ​​of output signals of the 4.5um detection channel, the 3.8um detection channel, the 5.3um detection channel and the 0.3-10.6um wide spectrum detection channel.

[0011] According to one aspect of the present invention, step S12 includes: determining whether the output signal meets a first preset condition; wherein the first preset condition includes: a sampling length greater than 15, a sampling period of 1 ms, and a waveform frequency of the output signal less than 33 Hz.

[0012] According to one aspect of the present invention, the first preset condition further includes: the energy sum of the output signal of the 4.5um detection channel is greater than the energy sum of the output signal of the 3.8um detection channel, and greater than the energy sum of the output signal of the 5.3um detection channel.

[0013] According to one aspect of the present invention, the first preset condition further includes:

[0014] The maximum value of the output signal of the 4.5um detection channel is greater than the maximum values ​​of the output signals of the 3.8um and 5.3um detection channels, and is not greater than the maximum value of the output signal of the 0.3-10.6um wide spectrum channel;

[0015] The maximum value of the output signal of the 5.3um detection channel is not greater than twice the maximum value of the output signal of the 3.8um detection channel; and

[0016] The maximum value of the output signal of the 3.8um detection channel is not greater than 10 times the maximum value of the output signal of the 5.3um detection channel.

[0017] According to one aspect of the present invention, the step S12 further comprises: determining whether the output signal satisfies a second preset condition;

[0018] The step of determining whether the output signal satisfies the second preset condition includes: determining a first ratio of the energy sum of the output signal of the 4.5um detection channel to the energy sum of the output signal of the 3.8um detection channel, and determining a second ratio of the energy sum of the output signal of the 4.5um detection channel to the energy sum of the output signal of the 5.3um detection channel.

[0019] According to one aspect of the present invention, the second preset condition includes:

[0020] One of the first ratio and the second ratio is greater than 20; or

[0021] One of the first ratio and the second ratio is greater than 15 and the other is greater than 2.

[0022] According to one aspect of the present invention, the second preset condition further includes: the number of voltage waveforms of the output signal is greater than or equal to 2.

[0023] According to one aspect of the present invention, the method further includes: when the output signal does not meet the second preset condition, determining whether the output signal meets a third preset condition to perform a saturation judgment.

[0024] According to one aspect of the present invention, when it is determined that the output signal satisfies the third preset condition, it is determined that the output signal is saturated; wherein the third preset condition includes:

[0025] The difference between the energy sum of the output signal of the 4.5um detection channel, the energy sum of the output signal of the 3.8um detection channel, and the energy sum of the output signal of the 5.3um detection channel is greater than 200;

[0026] The maximum value of the output signal of the 4.5um detection channel is greater than 180; and

[0027] The number of voltage waveforms of the output signal is greater than or equal to 5.

[0028] According to one aspect of the present invention, step S13 comprises:

[0029] Determine a third ratio of the energy sum of the 4.5um detection channel to the energy sum of the 3.8um detection channel in a 10 second time window; or

[0030] A fourth ratio of the energy sum of the 4.5 um detection channel to the energy sum of the 5.3 um detection channel in a 10 second time window is determined.

[0031] According to one aspect of the present invention, step S14 comprises:

[0032] When the output signal satisfies the second preset condition, if the third ratio or the fourth ratio is greater than or equal to a first threshold, it is determined that a flame exists;

[0033] When the output signal does not satisfy the second preset condition but satisfies the third preset condition, if the third ratio or the fourth ratio is greater than or equal to a second threshold, it is determined that flame exists.

[0034] The present invention also relates to a flame detector, comprising:

[0035] A collection unit configured to collect output signals of each detection channel;

[0036] a storage unit, coupled to the acquisition unit and configured to store the output signal acquired by the acquisition unit; and

[0037] The processing unit is coupled to the acquisition unit and the storage unit, and is configured to execute the flame detection method as described above.

[0038] According to one aspect of the present invention, the acquisition unit comprises a pyroelectric infrared sensor.

[0039] By using the flame detection method and flame detector of the present invention, when it is determined that the output signal of each channel meets the preset conditions, whether there is a flame is determined by the ratio of the energy sum of the 4.5um detection channel in the preset time window to the energy sum of the 5.3um detection channel or the 3.8um detection channel and the size relationship of the threshold. Compared with the prior art, the same stable detection effect can be achieved, and the algorithm is simple, the calculation amount is small, the processing burden of the processing unit can be effectively reduced, the cost can be effectively reduced, and the service life of the flame detector can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 A flow chart of a flame detection method for an infrared sensor according to an embodiment of the present invention is shown;

[0042] Figure 2 shows the flame radiation spectrum diagram when carbon-containing fuel is burning;

[0043] Figure 3 A flow chart of a flame detection method for an infrared sensor according to a preferred embodiment of the present invention is shown;

[0044] Figure 4 A waveform diagram showing an output signal satisfying a first preset condition and a second preset condition according to a preferred embodiment of the present invention is shown;

[0045] Figure 5 A waveform diagram showing an output signal satisfying a first preset condition and a third preset condition according to a preferred embodiment of the present invention; and

[0046] Figure 6 A schematic diagram of a flame detector according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0047] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0052] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0053] The present invention provides a flame detection method for an infrared sensor. Compared with the prior art, it can not only achieve the same stable detection effect, but also has a simple algorithm and a small amount of calculation, which can effectively reduce the processing burden of the processing unit and can effectively reduce the cost. Before the flame detection method of the present invention is specifically introduced, the basic principle of the flame detection method of the present invention is first introduced.

[0054] Figure 2 The flame radiation spectrum of carbon-containing fuel combustion is shown in FIG. Figure 2 As shown, the flame radiation intensity has a peak value near 4.3um, which is the resonance radiation luminescence spectrum emitted by the combustion product CO2 when heated. Based on this principle, the present invention selects a 4.5um infrared sensor as a flame feature detection, and uses 5.3um, 3.8um and 0.3-10.6um wide-spectrum sensors as auxiliary references to collect the output signal of the infrared sensor, calculate the energy sum of the output signal of each channel through an integration algorithm, and accurately judge the flame through the relative relationship between the flame feature and the reference channel. The flame detection method of the present invention is introduced in detail below.

[0055] Figure 1 FIG. 1 shows a flow chart of a flame detection method 10 for an infrared sensor according to an embodiment of the present invention. Figure 1 As shown, the flame detection method 10 includes steps S11 to S14. The following specifically introduces each step of the flame detection method 10.

[0056] In step S11, output signals of infrared sensors of a 4.5um detection channel, a 5.3um detection channel, a 3.8um detection channel, and a 0.3-10.6um wide spectrum detection channel are collected respectively.

[0057] According to a preferred embodiment of the present invention, an 8-bit AD can be used to collect the output signals of the infrared sensors of the 4.5um detection channel, the 5.3um detection channel, the 3.8um detection channel, and the 0.3-10.6um wide spectrum detection channel. It should be understood that in addition to using an 8-bit AD to collect the output signals of the infrared sensors, a 12-bit, 16-bit, or 24-bit AD can also be used for collection, which can be determined according to actual conditions and is not limited by the present invention.

[0058] In some preferred embodiments, when designing the application circuit, the output signal of the infrared sensor before entering the AD can be processed, and only the value of the positive half axis is retained, thereby increasing the response range of the infrared sensor and reducing the signal saturation distortion when the infrared sensor is close to a fire. Therefore, the starting point can be selected as the moment when the measured value of the flame detection channel changes from 0 to non-0, and the end point is just the opposite, that is, the moment when the measured value of the flame detection channel changes from non-0 to 0. In addition, the starting point and end point of the flame detection channel can also be used when determining the energy and of the detection channel later. In this way, multiple signal waveforms are obtained, and the starting point of each signal waveform is the moment when the measured value changes from 0 to non-0, and the end point is the moment when the measured value of the flame detection channel changes from non-0 to 0.

[0059] In step S12, it is determined whether the output signal meets a preset condition. For example, for each signal waveform obtained in step S11, it is determined whether it meets a preset condition.

[0060] Before determining whether the output signal meets the preset condition, the output signal needs to be preprocessed. In some preferred embodiments, the energy sum of the output signals of the 4.5um detection channel, the 3.8um detection channel, and the 5.3um detection channel can be determined respectively, and are recorded as E(4.5um), E(3.8um), and E(5.3um), respectively, where the energy sum E can be calculated using the following formula:

[0061]

[0062] Where AD is the AD sampling value of the output signal of the corresponding detection channel, m is the starting point of the sampling, and n is the ending point. The present invention accumulates the AD sampling value of each sampling point between the starting point and the ending point instead of accumulating the square of the AD sampling value of each sampling point, thereby effectively reducing the operation and reducing the time for the processing unit (such as MCU) to execute the code, which helps to improve the sampling speed, and the sampling speed can reach 1000 times per second.

[0063] In addition, it is also necessary to determine the maximum values ​​of the output signals of the 4.5um detection channel, 3.8um detection channel, 5.3um detection channel and 0.3-10.6um wide spectrum detection channel between the starting point and the end point, which are respectively recorded as Rmax(4.5um), Rmax(3.8um), Rmax(5.3um) and Rmax(0.3-10.6um).

[0064] It should be noted that, in addition to determining the energy sum of the output signals of the 4.5um detection channel, the 3.8um detection channel and the 5.3um detection channel, and determining the maximum value of the output signals of the 4.5um detection channel, the 3.8um detection channel, the 5.3um detection channel and the 0.3-10.6um wide spectrum detection channel, other preprocessing methods can also be adopted on this basis, and the present invention is not limited thereto.

[0065] According to a preferred embodiment of the present invention, after preprocessing the output signals of each detection channel, it can be determined whether the output signals meet the first preset condition (i.e., sub-step S121 of step S12, refer to Figure 3 ), the first preset condition is, for example, a condition that the output signal must satisfy first.

[0066] In some preferred embodiments, the first preset condition includes: the sampling length L is greater than 15, the sampling period is 1ms, and the flickering frequency of the flame is generally 0.5-20Hz. Since a half-wave is used, the waveform frequency of each data recording is actually required to be less than 33Hz, wherein the sampling length L = (nm), where m is the starting point of the sampling and n is the ending point.

[0067] In some preferred embodiments, the first preset condition further includes: the energy sum of the output signal of the 4.5um detection channel is greater than the energy sum of the output signal of the 3.8um detection channel, and greater than the energy sum of the output signal of the 5.3um detection channel, that is, it satisfies:

[0068]

[0069] In some preferred embodiments, the first preset condition also includes: the maximum value of the output signal of the 4.5um detection channel is greater than the maximum values ​​of the output signals of the 3.8um and 5.3um detection channels, and is not greater than the maximum value of the output signal of the 0.3-10.6um wide spectrum channel, so as to reduce the interference of the ambient light and help improve the accuracy of the detection result, that is, satisfying:

[0070]

[0071] In some preferred embodiments, the first preset condition also includes: the maximum value of the output signal of the 5.3um detection channel is not greater than twice the maximum value of the output signal of the 3.8um detection channel, that is, it satisfies: Rmax(5.3um)≤2*Rmax(3.8um), which is used to eliminate false alarms caused by low-temperature objects shaking in front of the infrared sensor, and helps to improve the accuracy of the detection results.

[0072] In some preferred embodiments, the first preset condition also includes: the maximum value of the output signal of the 3.8um detection channel is not greater than 10 times the maximum value of the output signal of the 5.3um detection channel, that is, it satisfies: Rmax(3.8um)≤10*Rmax(5.3um), which is used to eliminate false alarms caused by high-temperature objects shaking in front of the infrared sensor, and helps to improve the accuracy of the detection results.

[0073] The first preset conditions among the preset conditions that the output signals of each detection channel need to satisfy are introduced above. These first preset conditions are the conditions that the output signals need to satisfy first. Figure 3 FIG. 2 shows a flow chart of a flame detection method 20 for an infrared sensor according to a preferred embodiment of the present invention. Figure 3 As shown, when the output signal does not meet the first preset condition, it is necessary to return to step S11 and continue to collect the output signals of each detection channel until the first preset condition is met; when the output signal meets the first preset condition, it is necessary to further determine whether the output signal meets the second preset condition (i.e., sub-step S122 of step S12, refer to Figure 3 ), which will be described below.

[0074] In some preferred embodiments, the step of determining whether the output signals of each detection channel meet the second preset condition includes: determining a first ratio R1 of the energy sum of the output signal of the 4.5um detection channel to the energy sum of the output signal of the 3.8um detection channel, and determining a second ratio R2 of the energy sum of the output signal of the 4.5um detection channel to the energy sum of the output signal of the 5.3um detection channel, wherein R1 = E(4.5um) / E(3.8um), R2 = E(4.5um) / E(5.3um). In specific operations, the energy sum of the 10-second time window closest to the current signal acquisition time can be determined. It should be understood that this embodiment is only for illustration and does not constitute a limitation of the present invention.

[0075] In some preferred embodiments, the second preset condition includes: the number of voltage waveforms of the output signal that currently meets the first preset condition is greater than or equal to 2 (for example, the output signals of the infrared sensors of the 4.5um detection channel, the 5.3um detection channel, the 3.8um detection channel, and the 0.3-10.6um wide spectrum detection channel are two respectively), and at the same time, one of the first ratio R1 and the second ratio R2 is greater than 20, that is, R1>20 or R2>20.

[0076] Alternatively, the second preset condition includes: the number of voltage waveforms of the output signal is greater than or equal to 2, and one of the first ratio R1 and the second ratio R2 is greater than 15 and the other is greater than 2, that is: R1>15 and R2>2; or R2>15 and R1>2.

[0077] The above introduces the second preset condition that the output signal needs to meet. Figure 4 The waveform diagram of the output signal satisfying the first preset condition and the second preset condition according to a preferred embodiment of the present invention is exemplarily shown. It should be noted that the output signal satisfying the first preset condition and the second preset condition is actually an unsaturated signal. When it is determined that the output signal satisfies the second preset condition, steps S13 and S14 can be executed to determine whether there is a fire (to be described later). On the contrary, when it is determined that the output signal does not satisfy the second preset condition, it is necessary to further determine whether the output signal satisfies the third preset condition (i.e., sub-step S123 of step S12, refer to Figure 3 ) to make a saturation judgment, which is described in detail below.

[0078] In some preferred embodiments, when it is determined that the output signal satisfies a third preset condition, the output signal is determined to be saturated, wherein the third preset condition includes: the number of voltage waveforms of the output signal is greater than or equal to 5, and the difference between the energy and E(4.5um) of the output signal of the 4.5um detection channel and the energy and E(3.8um) of the output signal of the 3.8um detection channel and the energy and E(5.3um) of the output signal of the 5.3um detection channel is greater than 200, and the maximum value Rmax(4.5um) of the output signal of the 4.5um detection channel is greater than 180, that is:

[0079]

[0080] The above introduces the third preset condition that the output signal needs to meet. Figure 5The waveform diagram of the output signal satisfying the first preset condition and the third preset condition according to a preferred embodiment of the present invention is shown. When it is determined that the output signal satisfies the third preset condition, steps S13 and S14 may be executed to determine whether there is a fire, and when it is determined that the output signal does not satisfy the third preset condition, the process returns to step S11, and the output signals of each detection channel are continuously collected, and then the judgment of whether the first preset condition and the second preset condition or the third preset condition are satisfied is performed in sequence, until the second preset condition or the third preset condition is satisfied, and steps S13 and S14 may be executed to determine whether there is a flame.

[0081] In step S13, when it is determined that the output signal meets the preset condition, the ratio of the energy sum of the 4.5um detection channel to the energy sum of the 5.3um detection channel or the 3.8um detection channel in the preset time window is determined. In step S14, whether there is a flame is determined based on the relationship between the ratio and the threshold.

[0082] In some preferred embodiments, a third ratio R3 of the energy sum of the 4.5um detection channel in a preset time window to the energy sum of the 3.8um detection channel can be determined; or a fourth ratio R4 of the energy sum of the 4.5um detection channel in a preset time window to the energy sum of the 5.3um detection channel can be determined. When the output signal satisfies the second preset condition, if the third ratio R3 or the fourth ratio R4 is greater than or equal to the first threshold value S1, it is determined that a flame exists; when the output signal does not satisfy the second preset condition but satisfies the third preset condition, if the third ratio R3 or the fourth ratio is greater than or equal to the second threshold value S2, it is determined that a flame exists.

[0083] In some specific embodiments, when it is determined that the output signal satisfies the first preset condition and the second preset condition, a third ratio R3 of the energy sum E(4.5um) of the output signal of the 4.5um detection channel in a 10-second time window and the energy sum E(3.8um) of the output signal of the 3.8um detection channel can be determined, that is, R3=E(4.5um) / E(3.8um). If the third ratio R3 is greater than or equal to the first threshold S1 (for example, 4), that is, R3≥S1, it is determined that there is a flame; conversely, if the third ratio R3 is less than the first threshold S1 (for example, 4), that is, R3<S1, it is determined that there is no flame. Alternatively, a fourth ratio R4 of the energy sum E(4.5um) of the output signal of the 4.5um detection channel in a 10-second time window to the energy sum E(5.3um) of the output signal of the 5.3um detection channel can be determined, that is, R4=E(4.5um) / E(5.3um). If the fourth ratio R4 is greater than or equal to the first threshold value S1 (for example, 4), that is, R4≥S1, it is determined that there is a flame; conversely, if the fourth ratio R4 is less than the first threshold value S1 (for example, 4), that is, R4<S1, it is determined that there is no flame.

[0084] In addition, in some specific embodiments, when it is determined that the output signal does not satisfy the second preset condition but satisfies the first preset condition and the third preset condition, a third ratio R3 of the energy sum E(4.5um) of the output signal of the 4.5um detection channel in the 10-second time window and the energy sum E(3.8um) of the output signal of the 3.8um detection channel can be determined, that is, R3=E(4.5um) / E(3.8um). If the third ratio R3 is greater than or equal to the second threshold value S2 (for example, 1), that is, R3≥S2, it is determined that there is a flame; conversely, if the third ratio R3 is less than the second threshold value S2 (for example, 1), that is, R3<S2, it is determined that there is no flame. Alternatively, a fourth ratio R4 of the energy sum E(4.5um) of the output signal of the 4.5um detection channel in a 10-second time window to the energy sum E(5.3um) of the output signal of the 5.3um detection channel can be determined, that is, R4=E(4.5um) / E(5.3um). If the fourth ratio R4 is greater than or equal to the second threshold value S2 (for example, 1), that is, R4≥S2, it is determined that there is a flame; conversely, if the fourth ratio R4 is less than the second threshold value S2 (for example, 1), that is, R4<S2, it is determined that there is no flame.

[0085] The flame detection method 10 / 20 of the present invention is described in detail above. In addition, the present invention also relates to a flame detector 300, such as Figure 6 As shown, the flame detector 300 includes a collection unit 310, a storage unit 320 and a processing unit 330, wherein the collection unit 310 is configured to collect output signals of each detection channel, wherein the collection unit includes an infrared sensor, and the infrared sensor includes but is not limited to a pyroelectric infrared sensor. Compared with the ultraviolet detector, the infrared flame detector used in the present invention can detect a farther distance; the storage unit 320 is coupled to the collection unit 310, and is configured to store the output signal collected by the collection unit 310; the processing unit 330 is coupled to the collection unit 310 and the storage unit 320, and is configured to execute the flame detection method 10 / 20 as described above.

[0086] The present invention further provides a computer-readable storage medium, comprising computer-executable instructions stored thereon, and when the executable instructions are executed by a processor, the flame detection method 10 / 20 as described above is implemented.

[0087] In some preferred embodiments, the computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it. The computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable storage medium can be, for example, but not limited to, the form or device of electricity, magnetism, light, or semiconductor, and more specific examples (non-exhaustive list) include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a non-volatile random access memory (NVRAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. It should be understood that the storage medium can be either a separate module or a built-in processing unit.

[0088] The processing unit can be a central processing unit (CPU), a microcontroller unit (MCU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The present invention does not limit this and it depends on the specific circumstances.

[0089] In summary, the technical solution of the present invention has been introduced in detail. The present invention is based on a four-band infrared sensor for detection. Compared with the prior art, the algorithm is simpler, which reduces the requirements for the processing unit, while taking into account the accuracy of the detection results and the longer detection distance, which can reduce production costs and extend the service life of the detector.

[0090] It should be noted that this specification provides method operation steps as described in the embodiments or schematic diagrams, but more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual system or device product is executed, it can be executed in the order or in parallel according to the method shown in the embodiments or flowcharts.

[0091] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A flame detection method for an infrared sensor, include: S11: respectively collecting output signals of infrared sensors of a 4.5um detection channel, a 5.3um detection channel, a 3.8um detection channel, and a 0.3-10.6um wide spectrum detection channel; S12: Determine whether the output signal meets a preset condition; S13: when it is determined that the output signal satisfies a preset condition, determining a ratio of the energy sum of the 4.5um detection channel to the energy sum of the 5.3um detection channel or the 3.8um detection channel in a preset time window; and S14: Determine whether there is a flame based on the relationship between the ratio and the threshold value; The step S12 includes: determining whether the output signal satisfies a first preset condition; the first preset condition includes: The maximum value of the output signal of the 4.5um detection channel is greater than the maximum values ​​of the output signals of the 3.8um and 5.3um detection channels, and is not greater than the maximum value of the output signal of the 0.3-10.6um wide spectrum channel; The maximum value of the output signal of the 5.3um detection channel is not greater than twice the maximum value of the output signal of the 3.8um detection channel; and The maximum value of the output signal of the 3.8um detection channel is not greater than 10 times the maximum value of the output signal of the 5.3um detection channel.

2. The flame detection method according to claim 1, wherein the step S12 include: Determine the energy sum of the output signals of the 4.5um detection channel, the 3.8um detection channel and the 5.3um detection channel respectively; wherein the energy sum , where AD is the AD sampling value of the corresponding detection channel, m is the starting point of sampling, and n is the ending point.

3. The flame detection method according to claim 1, wherein the step S12 further comprises: include: The maximum values ​​of the output signals of the 4.5um detection channel, the 3.8um detection channel, the 5.3um detection channel and the 0.3-10.6um wide-spectrum detection channel are determined respectively.

4. The flame detection method according to any one of claims 1 to 3, wherein the first preset condition include: The sampling length is greater than 15, the sampling period is 1 ms, and the waveform frequency of the output signal is less than 33 Hz.

5. The flame detection method according to claim 4, wherein the first preset condition further include: The energy sum of the output signals of the 4.5um detection channel is greater than the energy sum of the output signals of the 3.8um detection channel, and greater than the energy sum of the output signals of the 5.3um detection channel.

6. The flame detection method according to any one of claims 1 to 3, wherein the step S12 further comprises: include: Determining whether the output signal satisfies a second preset condition; The step of determining whether the output signal satisfies the second preset condition includes: determining a first ratio of the energy sum of the output signal of the 4.5um detection channel to the energy sum of the output signal of the 3.8um detection channel, and determining a second ratio of the energy sum of the output signal of the 4.5um detection channel to the energy sum of the output signal of the 5.3um detection channel.

7. The flame detection method according to claim 6, wherein the second preset condition include: One of the first ratio and the second ratio is greater than 20; or One of the first ratio and the second ratio is greater than 15 and the other is greater than 2.

8. The flame detection method according to claim 7, wherein the second preset condition further comprises: include: The number of voltage waveforms of the output signal is greater than or equal to 2.

9. The flame detection method according to claim 6, further comprising: include: When the output signal does not meet the second preset condition, it is determined whether the output signal meets a third preset condition to perform a saturation judgment.

10. The flame detection method according to claim 9, when it is determined that the output signal satisfies the third preset condition, the output signal is determined to be saturated; wherein the third preset condition include: The difference between the energy sum of the output signal of the 4.5um detection channel, the energy sum of the output signal of the 3.8um detection channel, and the energy sum of the output signal of the 5.3um detection channel is greater than 200; The maximum value of the output signal of the 4.5um detection channel is greater than 180; and The number of voltage waveforms of the output signal is greater than or equal to 5.

11. The flame detection method according to claim 9 or 10, wherein the step S13 include: Determine a third ratio of the energy sum of the 4.5um detection channel to the energy sum of the 3.8um detection channel in a 10 second time window; or A fourth ratio of the energy sum of the 4.5 um detection channel to the energy sum of the 5.3 um detection channel in a 10 second time window is determined.

12. The flame detection method according to claim 11, wherein the step S14 include: When the output signal satisfies the second preset condition, if the third ratio or the fourth ratio is greater than or equal to a first threshold, it is determined that a flame exists; When the output signal does not satisfy the second preset condition but satisfies the third preset condition, if the third ratio or the fourth ratio is greater than or equal to a second threshold, it is determined that flame exists.

13. A flame detector, include: A collection unit configured to collect output signals of each detection channel; a storage unit, coupled to the acquisition unit and configured to store the output signal acquired by the acquisition unit; and A processing unit is coupled to the acquisition unit and the storage unit, and is configured to execute the flame detection method according to any one of claims 1 to 12.

14. The flame detector according to claim 13, wherein the acquisition unit comprises a pyroelectric infrared sensor.

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