JPH0962963A - Device and method for sensing flame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly and surely judge whether flame is generated or not by judging the existence of flame by considering the randomness of a feature amount characteristic of flame, which is extracted from the detected signal of radiation emitted by the flame. SOLUTION: An infrared detection means 11 is used for a radiated light detection means 1. A flame judging means 2 judges that there is the possibility of flame when the intensity level of the infrared ray reaches a prescribed threshold alue based on an infrared detection signal detected by the infrared detection means 11. Then the means 2 detects the peak of the level of the infrared detection signal for a prescribed period from the point of this time to obtain the number of the peaks as the number of a peak frequency (the frequency of fluctuations) and prepares a histogram concerning each peak level. Though frequency distribution made by frame at the time of a fire is nearly equal in each section (being random), that made by a low temp. heat source is concentrated on a specified section (nonrandom).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detector and a flame detecting method for use in a fire detector or the like for detecting a flame generated during a fire or the like.

[0002]

2. Description of the Related Art Conventionally, as a flame detector for making a flame judgment (fire judgment) by detecting radiant light emitted from a flame, 1) a single wavelength type ultraviolet ray for detecting an ultraviolet ray of a predetermined wavelength emitted from a flame Type flame detector, 2) Single wavelength type flame detector that detects infrared rays of a predetermined wavelength emitted from the flame, 3) Dual wavelength type or three wavelength type that detects infrared rays of multiple wavelength ranges emitted from the flame 4) A flame detector of 2 wavelength type or 3 wavelength type that detects ultraviolet rays of a predetermined wavelength and infrared rays of a predetermined wavelength emitted from a flame is known.

[0003]

However, in various conventional flame detectors as described above, the determination as to whether or not there is a flame may be subtle (fuzzy), and the determination as to whether or not it is a flame is ambiguous. If it becomes a problem, there is a problem that it is not possible to correctly judge whether or not it is a flame. For example,
A first wavelength of about 4.3 to 4.4 μm and the vicinity of the first wavelength
In a two-wavelength flame detector that detects two wavelength signals with a second wavelength (for example, 3.9 μm) to judge the flame, gas flame, wood, paper burning flame, initial fire When detecting the radiated light from the flame of the above, the level of the first wavelength signal is considerably higher than the level of the second wavelength signal, and it can be determined that it is a flame, but it is caused by the combustion of gasoline, etc. When detecting radiant light from a flame with a lot of oil smoke or a low temperature object below 100 ° C, the ratio between the level of the first wavelength signal and the level of the second wavelength signal is "1".
However, there is a problem that it is not possible to accurately and surely determine whether or not a flame is present because the determination as to whether or not it is a flame becomes ambiguous.

In general, a flame detector senses a feature of infrared light emitted by a flame to make a fire judgment, but the flame detector is required to have high sensitivity like a general fire detector. Also, malfunction cannot be tolerated. In particular, an infrared flame detector that uses a pyroelectric element as a sensor uses an amplifier with a high amplification degree to detect flicker of a flame, and thus is susceptible to various noises. In particular, popcorn noise is generated when electronic parts such as operational amplifiers (operational amplifiers), capacitors, and pyroelectric sensors are subject to sudden temperature changes and mechanical stress. Popcorn noise generated by the element has the greatest effect.

According to the present invention, it is possible to accurately and surely determine whether or not a flame is present even if the determination as to whether or not the flame is vague in the conventional flame determination process. The aim is to provide a possible flame detector and a flame detection method.

Another object of the present invention is to provide a flame detector capable of avoiding malfunction due to popcorn noise with a relatively simple method.

[0007]

In order to achieve the above object, the invention according to claims 1 to 6 detects radiation light emitted from a flame as a radiation light detection signal, and the radiation light detection signal is detected. When extracting flame-specific feature values from a flame judgment and making a flame judgment based on the flame-specific feature values, if the flame judgment is ambiguous, consider the randomness of the extracted flame-specific feature values. It is characterized by making a flame judgment. This makes it possible to correctly and reliably determine whether or not a flame is present, even when the determination as to whether or not the flame is a vague source in the conventional flame determination process.

Particularly, in the invention according to claim 2, an infrared detecting means for detecting light having an infrared wavelength peculiar to a flame as an infrared detecting signal is used as the emitted light detecting means, and the flame determining means is an infrared detecting means. Even if the judgment of the flame based on the infrared detection signal detected by the method becomes ambiguous, if the level of each peak of the infrared detection signal is randomly dispersed, it will be judged as a flame. It is characterized by being. As a result, the flame determination can be performed with extremely high reliability while maintaining the advantages of the one-wavelength type that is small and low cost.

Further, in the inventions according to claims 3 to 5, in the two-wavelength type flame judgment processing, the flame judgment can be made more reliably.

Further, the invention according to claims 7 to 10 is a flame sensor provided with a plurality of infrared detecting means, wherein each infrared detecting means has a structure equivalent to noise. In each infrared detection signal from the infrared detection means, an asynchronous signal is detected as noise. As a result, it is possible to suppress the influence of noise in flame judgment, especially the influence of popcorn noise.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a flame detector according to the present invention. Referring to FIG. 1, this flame detector detects a radiant light detecting means 1 for detecting a radiant light emitted from a flame, and a feature amount peculiar to the flame from a radiant light detecting signal detected by the radiant light detecting means 1. And a flame determining means 2 for performing flame determination based on the characteristic amount of the flame extracted.
Is designed to judge the flame in consideration of the randomness of the extracted characteristic features of the flame.

FIG. 2 is a diagram showing a structural example of the flame detector of FIG. Referring to FIG. 2, in this flame detector, an infrared detecting means 11 for detecting light having an infrared wavelength peculiar to a flame as an infrared detecting signal is used as the radiant light detecting means 1, and the flame determining means 2 is an infrared detecting means. Even if the judgment of the flame based on the infrared detection signal detected in 11 becomes ambiguous, if the level of each peak of the infrared detection signal is randomly dispersed, it will be judged as a flame. There is.

FIG. 3 shows the spectrum intensity of a general flame such as a gas flame with a relatively small amount of oil smoke, a combustion flame of wood or paper, or a flame at the time of an initial fire, as can be seen from FIG. In addition, the flame generated in the event of a fire is 4.3 to 4.4.
It has the largest spectral intensity due to CO ₂ resonance radiation at an infrared wavelength of about μm (a clear peak spectrum appears). Although FIG. 3 shows the spectrum intensity of a flame with a relatively small amount of oil smoke, even in the case of a flame with a large amount of oil smoke such as gasoline, the largest spectrum is obtained at an infrared wavelength of about 4.3 to 4.4 μm. Has strength. Therefore, the infrared detecting means 11 has an infrared wavelength peculiar to the flame to be detected, that is, a main feature of the flame, for example, 4.3 to 4.4 μm.
An infrared sensor that detects infrared light having a wavelength of about m can be used.

FIG. 4 shows an example of temporal changes in the level of infrared rays radiated from a flame during a fire (the intensity level of the infrared detection signal output from the infrared sensor when the infrared sensor is used as the infrared detecting means 11). FIG. Referring to FIG. 4, the intensity level of infrared rays radiated from the flame at the time of a fire often becomes equal to or higher than a predetermined threshold level V _th (for example, 0.2 V), and is also radiated from the flame at the time of a fire. The infrared intensity level has a temporal fluctuation of, for example, about 8 Hz, that is, a flicker frequency characteristic.

With this in mind, in the flame judging means 2, the infrared intensity level (the level of the infrared detection signal from the infrared detecting means 11) is a predetermined threshold level V _th (eg 0.2).
When it reaches V), it is judged that there is a possibility of flame, and from this point, the level of the infrared detection signal is taken in at a predetermined sampling interval.

The flame determination means 2 determines that the infrared detection signal from the time when the level of the infrared detection signal reaches a predetermined threshold level V _th has characteristics peculiar to the flame (intensity level characteristic peculiar to the flame, temporal fluctuation (flicker). ) Characteristic), a peak of the level of the infrared detection signal (for example, of the levels of the infrared detection signal over the predetermined period T from the time when the predetermined threshold level V _th is reached to the predetermined period T , A peak of the infrared detection signal level _exceeding a predetermined threshold level V _th ) is detected, and the average of the levels of the respective peaks over a predetermined period T is averaged to obtain an average peak level M.
_Avg is obtained, and the number of peaks over a predetermined period T is obtained as peak frequency (that is, the number of fluctuations) PCNT.

More specifically, as shown in FIG. 4, the infrared detection signal is fetched as data at a predetermined time interval Δt for a predetermined period T from the time when the level of the infrared detection signal exceeds a predetermined threshold level V _th. (Sampled),
Therefore, in the predetermined period T, about T / Δt pieces of data are fetched (sampled), and the flame determination means 2 receives, for example, about T / Δt pieces of data thus fetched.
Of (infrared detection signal level), a predetermined threshold level V
_th focusing only on those beyond, by detecting the increase or decrease in the level of the infrared detection signal exceeds a predetermined threshold level V _th, it adapted to sense a part of the mountain as a peak level. That is, when the level of the infrared detection signal is captured as digital data at predetermined time intervals Δt, for example, in the level data (digital data) of the captured infrared detection signal, infrared detection exceeding a predetermined threshold level V _th Regarding the signal level, it is possible to compare the previous data and the current data, determine whether the tendency is an increasing tendency or a decreasing tendency, and extract the point at which the increase changes to the decreasing point as a peak point.

Then, when the number of level peaks is detected as, for example, m in the predetermined period T and the level of each peak is detected as M ₁ , M ₂ , ..., M _m , the average peak level _Mavg , peak The frequency PCNT is calculated, for example, by the following equation.

[0019]

[Equation 1]

In the infrared detecting means 11, the average peak level _Mavg thus obtained can be used to judge to what extent the level of the infrared detection signal has the infrared intensity level characteristic peculiar to the flame at the time of fire. Since the peak frequency PCNT used as described above reflects the fluctuation frequency related to the infrared intensity level, the temporal change in the level of the infrared detection signal is the time peculiar to the flame during a fire. It is used to judge how much the characteristic (flicker) characteristic is.

In such a flame determination process, the average peak level _Mavg is a good reflection of how much the infrared detection signal has the main characteristics peculiar to the flame at the time of fire, and Since the peak frequency PCNT reflects the fluctuation frequency relating to the infrared intensity level, the flame determination means 2 basically determines the average peak level _Mavg and / or the peak frequency PCNT, The judgment as to whether or not it is a flame can be made far better than the conventional flame judgment.

Further, even if such flame judgment processing makes it difficult to judge whether or not it is a flame, a predetermined time T is set until the flame can be judged to some extent with reliability. You can change it and make a flame judgment. As a result, the basic flame judgment can be made more reliably.

In the flame determination process as described above, for example, in the case of a gas flame with a relatively small amount of oil smoke, a burning flame of wood, paper, or a flame at the time of an initial fire, the average peak level M obtained as described above is used. _{Since avg} has a sufficiently large level and the peak frequency PCNT also has a large level, it can be easily determined that the flame is present.

However, even when such an excellent and reliable basic flame judgment is made, when the amount of oil smoke is extremely large (for example, gasoline, heavy oil, petrochemical,
Combustion of rubber products tends to result in combustion with a lot of oil smoke.
In particular, in the case of a fire with a large combustion scale and a lack of oxygen, the amount of carbon monoxide CO increases and becomes a flame with a lot of oil smoke), or when noise from other heat sources is mixed in, for example, as described above _Obtained average peak level _Mavg
Is a delicate level to judge whether it is a flame, that is,
The level may be ambiguous, and at this time, it may not be possible to reliably determine whether or not the flame is present.

The inventor of the present application investigated the characteristics of combustion of a flame so that the flame can be correctly and surely determined even in the case of a flame containing a lot of oil smoke. As a result, in the case of a combustion flame, fluctuations of several to ten and several Hz occur in the radiated light because it is affected by the air flow (oxygen supply) from the surroundings. When this radiated light is detected using a pyroelectric sensor with characteristics, fluctuations in the radiated light detection signal from the pyroelectric sensor have strong and weak fluctuations, and the peak level (peak voltage value) of the radiated light detection signal is Upon examination, it was found that the level of each peak had randomness (it was found to be randomly dispersed (scattered)).

Therefore, if a histogram is taken for each peak level of the synchrotron radiation detection signal within a predetermined time,
It was found that the frequencies were not concentrated in a specific rank (section), but the frequencies were distributed over multiple sections.

The histogram for each peak level of the emitted light detection signal within a predetermined time is, for example,
It can be created as follows.

That is, the level of the emitted light detection signal is divided into a plurality of sections, and the number of sections at that time is N (for example, "7"). In addition, the number of data within the predetermined time T
Let (the number of peaks) be m (for example, "35"), and m
Among the data (peak level) of (35), the maximum value is M
_{When max} and the minimum value are M _min , the width W of each section of the histogram is determined by the following equation.

[0029]

(2) W = (M _max −M _min ) / N

After setting the number N of sections (for example, "7") and the width W of each section in this way, m pieces (35 pieces) are set.
Can be applied to the corresponding predetermined section of the N sections to create the frequency distribution of each section.

FIG. 5 shows an example of the level change of the infrared detection signal obtained by detecting the infrared rays from the flame at the time of the fire with the infrared sensor (pyroelectric type sensor), and FIG. 6 shows the low temperature heat source.
An example of a level change of an infrared detection signal obtained by detecting infrared rays (100 ° C. or lower) with an infrared sensor (pyroelectric sensor) is shown. Further, FIG. 7 shows the infrared detection signal of FIG.
An example of creating a frequency distribution (histogram) of peak levels in each case (a signal due to a flame during a fire) and the infrared detection signal (a signal due to a low temperature heat source) in FIG. 6 is shown.

In the examples of FIGS. 5 and 6, the number m of peak levels within the predetermined time T is “50”, and the maximum peak level of the 50 peak levels is “2450”.
Since the minimum peak level is “0 mV”, the histogram of FIG. 7 divides the peak level into seven sections and sets the width W of each section to “350 mV” to obtain 50 peaks. It is created as a frequency distribution when the level is assigned to each of the seven sections.

As can be seen from FIG. 7, the frequency distribution due to the flame at the time of fire is almost equal (random) in each section, whereas the frequency distribution due to the low temperature heat source is concentrated in a specific section. You can see (not random).

Therefore, in the basic flame determination process as described above, even when the average peak level _Mavg and / or the peak frequency PCNT is ambiguous in determining whether or not a flame is present, By creating a histogram as shown in FIG. 7 and detecting whether or not each peak level has randomness, it is possible to reliably determine whether or not it is a flame. In the above example, each peak level of the infrared detection signal due to the flame at the time of fire has sufficient randomness, so it can be reliably determined as a flame, and the infrared detection signal from the low temperature heat source has a random peak level. Since it does not have, it can be definitely judged that it is not a flame.

More specifically, when the number of data m within a predetermined time is "35" and the number of sections N is "7", the frequency of each section is ranked as shown in the following table (see the table below). In the example,
It can be classified into _four ranks R ₁ , R ₂ , R ₃ , and R ₄ ).

[0036]

[Table 1]

In Table 1, the average frequency is the total number of data / the number of sections, which is "5" in the above example. When the frequency of each section is divided into ranks in this way, the degree of flame (index indicating the probability of being a flame) can be obtained by the number of sections belonging to each rank, for example, as shown in the following table.

[0038]

[Table 2]

Although Table 2 shows the number U ₁ of sections belonging to the rank R ₁ , for example, (U ₂ ≦
1, U ₃ = 0, U ₄ = 0), U ₁ is, for example, “6”
And when (U ₂ ≦ 2, U ₃ = 0, U ₄ = 0), U ₁
Is, for example, "5".

As can be seen from Table 2, (U ₂ ≤1, U ₃ =
0, U ₄ = 0), U ₁ is the largest, and therefore the peak level frequencies are almost evenly distributed (randomly distributed) in each section. At this time, from Table 2, the probability of being a flame is high. That is, the flame degree can be calculated as "1".

In the flame detector having such a structure, for example,
When the average peak level M _avg and peak frequency (number of peaks) PCNT is sufficiently large (for example, the average peak level M _avg is sufficiently larger than 0.2V, also,
Only when the peak frequency (the number of peaks) PCNT is 30 or more), it is possible to judge that there is a fire and output that fact.

On the other hand, when the average peak level _Mavg or the peak frequency (number of peaks) PCNT or both of them is not sufficiently large, and it is difficult (subtle) to judge whether or not there is a fire only by this. (For example, when the average peak level _Mavg is slightly higher than 0.2V, or the peak frequency (number of peaks) PCNT is 1).
In the case of about 0 to 20 pieces), for example, Table 1,
As shown in Table 2, the flame level based on the randomness of the peak level is used, and when the flame level is "1" (that is, when the randomness is sufficiently large), it is judged as a flame, and the flame level is " When it is 0 ", it can be determined that it is not a flame.

As described above, according to the present invention, even if the determination as to whether the flame is a conventional flame determination process is ambiguous, the determination as to whether or not the flame is correct is made correctly. And it becomes possible to perform reliably.

In the example shown in FIG. 2, the radiated light detecting means 1 shown in FIG. 1 is composed of only the infrared detecting means 11.
The radiated light detection means 1 may have any configuration as long as it can detect infrared rays. For example, a two-wavelength type or three-wavelength type flame detector can be used.

FIG. 8 is a diagram showing another configuration example of the flame detector of FIG. Referring to FIG. 8, this flame detector is configured as a two-wavelength flame detector, and the radiant light detecting means 1 detects the infrared ray having a wavelength peculiar to the flame as a first wavelength signal. Means 15 and second wavelength detecting means 16 for detecting light having a wavelength different from the infrared wavelength detected by the first wavelength detecting means 15 as a second wavelength signal are provided, and the flame judging means 2 is Even when the flame is determined based on the first wavelength signal from the one-wavelength detecting means 15 and the second wavelength signal from the second-wavelength detecting means 16 and the determination of the flame becomes ambiguous, When the levels of the peaks of the first wavelength signal are randomly dispersed, it is determined that the flame is present.

Specifically, the first wavelength detecting means 15 includes, for example, 4.3 to 4.
An infrared sensor (for example, a pyroelectric sensor) that detects infrared rays having a wavelength of about 4 μm can be used.

Further, the second wavelength detecting means 16 uses infrared rays having a wavelength near the infrared wavelength peculiar to the flame, for example, infrared rays having a wavelength different from the infrared wavelength peculiar to the flame (about 4.3 to 4.4 μm). An infrared sensor (for example, a pyroelectric sensor) that detects infrared rays having a wavelength of about 3.9 μm or 5.1 μm can be used. That is, at a wavelength of about 3.9 μm or about 5.1 μm, as can be seen from FIG. 3, the spectrum intensity of the flame is small (minimum value). Therefore, in this case, the second wavelength detecting means 16 is 3.9 μm. Infrared levels at wavelengths of the order of magnitude or 5.1 μm can be detected as ancillary features of the flame.

Alternatively, the second wavelength detecting means 16 detects, for example, ultraviolet rays in a wavelength range of about 200 to 260 nm as light having a wavelength different from the infrared wavelength (about 4.3 to 4.4 μm) peculiar to the flame. UV sensor (eg UV Tron)
Can also be used.

When the second wavelength detecting means 16 is one that detects infrared rays having a wavelength in the vicinity of the infrared wavelength detected by the first wavelength detecting means 11, the flame determining means 2 is shown in FIG. Thus, at the peak of the level of the first wavelength signal detected by the first wavelength detecting means 11, the levels S ₁ , S ₂ , ..., Of the second wavelength signal detected by the second wavelength detecting means 16 are detected.
S _m is taken in, and the average value S _avg of the levels S ₁ , S ₂ , ..., S _m of the second wavelength signal from the second wavelength detecting means 16 taken in this way over the predetermined period T is obtained as an average auxiliary level, For example, the ratio of the average peak level _Mavg of the first wavelength signal from the first wavelength means 15 to the average auxiliary level _Savg of the second wavelength signal from the second wavelength detecting means ( _Mavg /
_Savg ) and the peak frequency (number of peaks) PCNT (= m) of the first wavelength signal over a predetermined period T, and a basic flame determination is performed.

When the second wavelength detecting means 16 detects ultraviolet rays, for example, the second wavelength detecting means 16 is used.
When an ultraviolet sensor is used in the above, the number of occurrences of the ultraviolet discharge pulse output from the ultraviolet sensor per unit time depends on the intensity (light amount) of the ultraviolet light incident on the ultraviolet discharge pulse. Is, as shown in FIG.
The second wavelength detecting means 16 continues for a predetermined period T from the time when the level of the infrared detection signal exceeds the predetermined threshold level V _th.
Counting the number of UV discharge pulses UV from
Average peak level _Mavg and peak frequency PCNT obtained from the first wavelength signal from the first wavelength detecting means 15
Then, based on the second wavelength signal (the number UV of UV discharge pulses) from the second wavelength detecting means 16, the disaster is judged. That is, the basic flame determination is performed by taking into consideration how much the intensity (light intensity) of the ultraviolet light has the ultraviolet intensity (light intensity) characteristic peculiar to the flame.

Also, as in the configuration example of FIG. 2, in the configuration example of FIG. 8 as well, the predetermined period T can be variably set according to the basic flame determination result.

[0052] For example, in the configuration example of FIG. 8, the ratio M of the second case wavelength detection means 16 is for detecting infrared rays, average peak levels were obtained over a predetermined time period T M _avg and average the auxiliary level S _avg the ratio of the time it is difficult to perform based flame decision in _avg / S _avg sets change for a predetermined time T, for thus setting changed predetermined time T, the average peak level M _avg and average the auxiliary level S _avg Basically, the setting of the predetermined time T is changed until the flame determination can be performed with a certain degree of reliability, for example, by recalculating M _avg / S _avg and again determining the flame based on this. It is possible to judge the flame.

Further, in the configuration example of FIG. 8, when the second wavelength detecting means 16 detects ultraviolet rays, the number of ultraviolet ray discharge pulses generated over a predetermined time T has occurred.
(Count number) When it is difficult to judge the flame based on UV, the setting of the predetermined time T is changed, and the number UV of the ultraviolet discharge pulses is again obtained within the predetermined time T thus changed, The basic flame determination can be performed by changing the setting of the predetermined time T until the flame determination can be performed with a certain degree of reliability, such as performing the flame determination again.

FIG. 11 is a diagram showing an example of the first wavelength signal and the second wavelength signal at the time of fire, and FIG. 12 shows the first wavelength signal and the second wavelength signal at the time of non-fire (for example, when a halogen lamp, heat source noise, etc. are added). It is a figure which shows an example of a 1 wavelength signal and a 2nd wavelength signal. In the example of FIGS. 11 and 12, an infrared sensor (pyroelectric sensor) that detects infrared rays having a wavelength different from the infrared rays detected by the first wavelength detecting means 15 is used as the second wavelength detecting means 16. It is supposed to be.

First, at the time of fire, the intensity level of infrared rays (level of the first wavelength signal) peculiar to the flame at the time of fire is shown in FIG.
While it becomes large as shown in (a), the level of the second wavelength signal does not become so large as shown in FIG. 11 (b). Therefore, the ratio M _avg / S _avg of the average peak level M _avg obtained over a predetermined period T (e.g., 4.5 sec) and the average assist level S _avg is sufficiently large. This allows
In this case, as shown in FIGS. 11C and 11D, the predetermined period T (= 4.
Only 5 seconds), it is possible to judge that the flame is present and output the result as a flame detection signal.

Even when a halogen lamp, heat source noise, etc. occur during a non-fire, the intensity level of the infrared wavelength (first wavelength signal level) peculiar to the flame during a fire is as shown in FIG.
It becomes large as shown in 2 (a).
Intensity level of wavelength signal becomes large as shown in FIG. 12 (b), therefore, the average assist level and the average peak level M _avg obtained over a predetermined period T (e.g., 4.5 seconds) S _avg
The ratio _Mavg / _Savg becomes smaller and it is difficult to judge the flame based on this. As a result, in this case, as shown in FIG. 12C, the setting of the predetermined time T is changed until the flame can be determined with a certain degree of reliability, and the basic flame determination is performed. Predetermined period T
To extend further. In the example of FIG. 12 (c), it is further extended by 9 seconds, the setting is changed to T = 13.5 seconds in total, and the flame is judged again. In the example of FIG. 12, the predetermined period T is 13.5.
When it is judged in seconds whether or not it is a flame, it is judged that it is not a flame. Therefore, in this case, the flame detection signal is not output as shown in FIG. 12 (d).

As described above, when the reliability is considered to be low even in the basic flame judgment processing, the averaging time is lengthened to make it possible to judge the flame with higher reliability due to the integral effect, and to give a false alarm. Can reduce the risk of.

However, even if such a reliable and excellent basic flame judgment is made, as described above, when the amount of oil smoke is very large, or noise from other heat sources is generated. when mixed in, for example, the ratio M _avg / S _avg determined as described above, subtle levels to determine whether the flame, i.e., so may obscure level, at this time, or flame It may not be possible to determine for sure.

FIG. 13 shows low oil smoke (normal-heptane).
First wavelength signal (4.3-4.4μ) when a flame is generated
m) and the measurement result (temporal change) of the level of the second wavelength signal (for example, 3.9 μm) are shown, and FIG. 14 shows the first wavelength when a high oil smoke (gasoline) flame is generated. signal
(About 4.3 to 4.4 μm) and the second wavelength signal (for example, 3.
9 μm) level measurement result (temporal change) is shown, and in FIG. 15, the first wavelength signal (about 4.3 to 4.4 μm) when a low temperature object (100 ° C. or less) is choppered by hand. ) And the measurement result of the level of the second wavelength signal (for example, 3.9 μm)
(Time change) is shown.

In the case of low oil smoke (normal-heptane) flame, as can be seen from FIG. 13, the level of the first wavelength signal is sufficiently higher than the level of the second wavelength signal, and therefore,
Only this can be judged to be a flame. On the other hand, in the case of high-energy smoke (gasoline) flame or thermal radiation from a low temperature object,
As can be seen from FIG. 15, the level of the first wavelength signal is the second level.
Since it is larger than the level of the wavelength signal but not sufficiently large, there is ambiguity in flame judgment based on this.

Therefore, when there is ambiguity in flame determination as shown in FIGS. 14 and 15, the flame determining means 2 further randomly distributes the levels of the respective peaks of the first wavelength signal in the same manner as described above. It is determined whether or not it is, and when the level of each peak is randomly dispersed, it is judged as a flame.

As described above, even when the flame detector is of the two-wavelength type as shown in FIG. 8 or of the three-wavelength type, the flame judgment becomes ambiguous. In this case, the flame determination means 2 further checks whether or not the levels of the respective peaks of the first wavelength signal are randomly dispersed, and finally determines whether or not there is a flame.

FIG. 16 is a diagram showing a specific example of a flame detector when an infrared sensor for detecting infrared rays is used for the first wavelength detecting means 15 and the second wavelength detecting means 16. In addition, in the example of FIG. 16, the flame detector is configured as a fire detector.

Referring to FIG. 16, the first of the flame detectors
The wavelength detecting means 15 first emits infrared rays peculiar to the flame (generally, infrared rays of about 4.3 μm to 4.4 μm of CO ₂ resonance radiation).
An infrared sensor 21 that detects a wavelength signal, a voltage amplifier circuit 22 that amplifies a first wavelength signal (voltage) from the infrared sensor 21, and a component of a predetermined frequency band in the first wavelength signal from the infrared sensor 21. And a DC level conversion circuit 2 that performs DC level conversion on the first wavelength signal that has passed through the filter circuit 23.
4.

The second wavelength detecting means 1 of this flame detector
6 is a wavelength different from the infrared wavelength peculiar to the flame (for example,
An infrared sensor 25 for detecting an infrared ray having a wavelength of 3.9 μm or 5.1 μm as a second wavelength signal, a voltage amplifier circuit 26 for amplifying a second wavelength signal (voltage) from the infrared sensor 25, and a second wavelength The signal is composed of a filter circuit 27 that passes only a component of a predetermined frequency band, and a DC level conversion circuit 28 that performs DC level conversion on the second wavelength signal that has passed through the filter circuit 27.

The flame judging means 2 of the flame detector is a CPU such as a microprocessor for controlling the entire apparatus.
(Central processing unit) 30, a comparator 29 that compares the output voltage (the level of the first wavelength signal) of the DC level conversion circuit 24 with the threshold voltage V _th, and outputs a fire signal based on the signal P1 from the CPU 30. Fire output circuit 31 and CPU
A confirmation output circuit 32 that outputs a failure signal based on the signal P2 from 30, a fire output circuit 31, and a confirmation output circuit 32
It is composed of an operation indicator lamp 33 for displaying the output state of the above, a rectifier circuit 34 for rectifying the power source from the outside, and a constant voltage power source 35 for supplying a power source voltage to each part.

Here, as the infrared sensors 21 and 25, pyroelectric type sensors (pyroelectric type elements) widely used as crime prevention sensors can be used. In this case, the pyroelectric sensor generates a differential charge output with respect to the incident light, and therefore outputs a signal proportional to the change (fluctuation) in the thermal energy from the flame. In connection with this, the filter circuits 23 and 27 are designed to pass only the component of the fluctuation frequency (flicker frequency of flame) band as the component of the predetermined frequency band (configured as a bandpass filter. ing).

That is, the fluctuation of the flame detected by the infrared sensors 21 and 25 is about several Hz to several tens of Hz, and in order to obtain the first wavelength signal and the second wavelength signal peculiar to the flame, in the example of FIG. The first wavelength signal and the second wavelength signal from the infrared sensors 21 and 25 are passed through the filter circuits 23 and 27 having transmission characteristics in this frequency band, and only the flame fluctuation component of the first wavelength signal and the second wavelength signal is passed. In the preserved form (that is, the fluctuation signal of the flame captured at about 4.3 to 4.4 μm,
The signal of fluctuation of the flame captured at about 3.9 μm or 5.1 μm is used) and is taken in by the CPU 30.

Further, the CPU 30 has a first timer function for measuring a predetermined period T of, for example, 4.5 seconds, and a predetermined timer T ₃ for measuring a period longer than T (for example, 24 hours). It is assumed that the second timer function and the third timer function for measuring the data capturing interval at the normal time, for example, 2.5 seconds are incorporated. The CPU 30 has a DC level conversion circuit 24 and a DC level conversion circuit 28.
It has an A / D conversion function for converting the level (intensity level) of the first wavelength signal and the second wavelength signal from the digital signal into a digital signal. The A / D conversion function is performed by the first wavelength signal,
The second wavelength signal is sampled at a predetermined time interval Δt (for example, 5 msec), digitally converted, and fetched.

Further, when the level (amplitude voltage) of the infrared detection signal output from the DC level conversion circuit 24 reaches the threshold voltage V _th (eg 0.2 V), the comparator 29
The output signal of “1” is added to the interrupt terminal INT1 of the CPU 30 as an interrupt to the CPU 30, and the CPU 30
When there is an interrupt input at the terminal INT1, the mode of the device is switched from the normal processing mode to the fire processing mode. And after setting the fire treatment mode,
The A / D conversion operation for the levels of the first wavelength signal and the second wavelength signal by the A / D conversion function is started, and arithmetic processing is performed on the first wavelength signal and the second wavelength signal.

That is, the CPU 30 performs the first operation for a predetermined period T (for example, 4.5 seconds) in order to detect a fire.
The wavelength signal level is set to a predetermined time interval (sampling period)
Captured as digital data at Δt (for example, a time interval of 5 msec) and timed at a time interval Δt (= 5 msec) for a predetermined period T.
Of the level data (digital data) of the first wavelength signal captured for each, for example, a peak is detected only for the level of the first wavelength signal that exceeds a predetermined threshold level V _th , and the average peak level _Mavg and the peak. The frequency PCNT and the frequency PCNT are calculated in accordance with, for example, Equation 1.

Further, as described above, the first wavelength detecting means 15
When detecting the peak of the first wavelength signal from the DC level conversion circuit 24, the CPU 30 determines the DC at the time of extraction.
The average auxiliary level S _avg is calculated by taking in the level of the second wavelength signal from the level conversion circuit 28 and averaging the levels of the second wavelength signal taken in over the predetermined period T. Then, the CPU 30 _causes the ratio _Mavg between the average peak level _Mavg and the average auxiliary level _Savg.
/ S _avg is _calculated .

In this way, the CPU 30 sets the mode of the apparatus to the fire treatment mode, and then the predetermined period (T =
4.5 seconds), the average peak level _Mavg of the infrared detection signal, the peak frequency PCNT, and the ratio _Mavg / S
The three parameters of _avg are obtained, and the flame is judged (for example, the degree of fire is judged) based on these three parameters.

Specifically, the flame (degree of fire) determination processing is as follows:
As described above, when each of the three parameters obtained in the above-mentioned predetermined period (T = 4.5 seconds) is at a high level above a predetermined level, it is judged as an abnormal level fire or a high level fire I, When the level of each of the three parameters does not reach the high level fire I, for example, the predetermined period T is further extended by 4.5 seconds (total of 9 seconds),
Average peak level _Mavg and peak frequency P of the infrared intensity level (infrared detection signal) in this predetermined period (T = 9 seconds)
Based on CNT and the ratio _Mavg / _Savg , it is judged whether or not the high level fire II is reached. As a result, when the high level fire II is not reached, the predetermined period T is further extended by 4.5 seconds.
In the same manner (for a total of 13.5 seconds), three parameters are obtained and it is determined whether or not the fire is a normal level fire.

The CPU 30 is, for example, an abnormal level fire,
When it is possible to clearly determine a fire as in the case of high level fire I, a fire signal is output from the fire output circuit 31 and the operation indicator light 33 is continuously lit, for example. Even if the process is performed while extending the predetermined time T, if the above-mentioned judgment process alone cannot clearly determine the fire (ambiguous), based on the randomness of the peak level of the first wavelength signal, the final decision is made as to whether or not there is a fire. It is decided to judge it. When it is determined that there is a fire, a fire signal is output from the fire output circuit 31 and the operation indicator lamp 33 is continuously lit, for example.

Further, the CPU 30 has a fixed period T ₃ (for example, 24 hours) set to be longer than the predetermined period T regardless of whether the apparatus mode is set to the normal processing mode or the fire processing mode. Each time, the first wavelength signal and the second wavelength signal are taken in, and it is checked whether or not the first wavelength signal and the second wavelength signal at this time include, for example, noise (for example, white noise), and based on this result, infrared rays are detected. Sensor 2
1, The failure diagnosis of the infrared sensor 25 is performed.

When the CPU 30 detects a failure in the infrared sensor 21 or the infrared sensor 25, the CPU 30 causes the confirmation output circuit 32 to output a failure signal and the operation indicator lamp 33.
Is displayed, for example, in a blinking manner.

Further, the CPU 30 further determines whether or not the first wavelength signal and the second wavelength signal exceed the saturation region of the voltage amplifying circuits 22 and 26. If the first wavelength signal and the second wavelength signal exceed the saturation region, voltage amplification is performed. When the amplification of the circuits 22 and 26 is set to 1 / N (for example, 1/2), and when it is determined that the amplification of the voltage amplification circuits 22 and 26 needs to be returned, the amplification is returned to the standard. Such a control function can be provided. With such a control function, the average peak level _Mavg , the peak frequency, and the average auxiliary level _Savg can be detected more accurately.

Next, the processing operation of the flame detector having such a configuration, mainly the processing operation of the CPU 30, will be described with reference to FIGS.
This will be described using the flowchart of FIG. 17 to 1
Referring to FIG. 9, first, when the power supply 35 of the flame detector is turned on, the CPU 30 executes initialization processing (step S1). At this time, the mode of the apparatus is initialized to the normal processing mode. That is, the fire processing mode setting flag F
LG ₁ is cleared (set to “0”), and the failure flag FLG ₂ is cleared (set to “0”).

Then, a second timer for counting, for example, 24 hours is started (step S2). After that, the terminal IN
It is checked whether there is an interrupt input at T1 (step S3). As a result, if there is an interrupt input at the terminal INT1, FLG ₁ is set to "1" (step S4), and the process proceeds to step S5, while if there is no interrupt input at the terminal INT ₁ , directly. Go to step S5.
In step S5, it is checked whether or not FLG ₁ is set to "1", and if it is not set to "1", the mode of the apparatus is maintained in the normal processing mode and the processing in the normal processing mode is performed. Perform (steps S6 to S10). On the other hand, when FLG ₁ is set to "1" in step S5, the mode of the device is switched to the fire treatment mode and the fire treatment mode is processed (steps S11 to S11).
S19).

In the normal processing mode, first, it is checked whether or not the second timer has clocked 24 hours (step S6). When 24 hours have been clocked, the failure diagnosis of the infrared sensor 21 and the infrared sensor 25 is performed. That is, in the normal processing mode, the first timer from the infrared sensor 21 and the infrared sensor 25 is activated every 2.5 seconds by the third timer that counts 2.5 seconds.
The respective levels of the wavelength signal and the second wavelength signal are captured, and it is determined whether or not the infrared sensor 21 and the infrared sensor 25 are normal based on the captured levels (step S
7). For example, when the level of the first wavelength signal or the second wavelength signal from the infrared sensor 21 or the infrared sensor 25 is very small and does not include a noise component, the infrared sensor 21 or the infrared sensor 25. Can be judged as a failure. In this way,
When it is determined that either the infrared sensor 21 or the infrared sensor 25 has a failure, the failure flag FLG ₂ is set to "1" (step S8) and the failure output is performed (step S9). Specifically, the failure output is performed by outputting a failure output signal indicating a failure of the sensor 21 and / or the sensor 25 to the confirmation output circuit 32 and causing the operation indicator lamp 33 to display the failure for a moment, for example. It

In the normal processing mode, step S6
In the case where the second timer does not count 24 hours, the failure flag FLG ₂ is checked (step S1
0), if the failure flag FLG ₂ is set to "1", failure output is performed (step S9). That is,
A failure output signal indicating a failure of the sensor 21 and / or the sensor 25 is output to the confirmation output circuit 32, and the operation indicator lamp 3
Display the failure in 3 for a moment.

After the failure output is made in this way, the process returns to step S2 again, and the normal processing mode is maintained unless an interrupt input is made to INT ₁ , and steps S6 to S1 are performed.
The process of 0 is repeated. Thereby, the sensor 2
1 or the sensor 25 is out of order, the operation indicator lamp 33 blinks by this repeated processing, and the sensor 2
1 or sensor 25 can be informed that it has failed.

If it is determined in step S7 that the sensors 21 and 25 are normal when the time is measured for 24 hours, no failure output is performed and step S7 is performed.
Return to 2. If 24 hours have not passed, step S
When it is determined in 10 that FLG ₂ is not "1", the failure output is not performed and the process returns to step S3.

On the other hand, in step S5, the mode of the device is switched to the fire treatment mode, and the fire treatment mode setting flag F is set.
When LG ₁ is set to "1", the first timer is started (step S11), and then it is monitored whether or not the first timer clocks a predetermined period (for example, 4.5 seconds) (step S12). ), Until the first timer clocks 4.5 seconds,
As described above, the level of the first wavelength signal from the DC level conversion circuit 24 is set to the sampling period Δt (for example, 5 msec).
Each time, capture the peak as described above,
While obtaining the number of peaks (peak frequency) PCNT,
Retain the level of each peak. In parallel with this, C
PU30 takes in the level of the 2nd wavelength signal at this time, when the peak of the level of the 1st wavelength signal is detected, and holds this (step S13).

When the first timer measures 4.5 seconds by repeating such fetching processing, the level of each peak of the first wavelength signal and the level of the second wavelength signal that have been fetched and held for 4.5 seconds. take the respective average of the average peak level M _avg, respectively calculated as an average aid level S _avg, obtains these ratios M _avg / S _avg (step S14), and for example, the average peak level M _avg and the ratio M
Flame determination and fire determination are performed based on _avg / _Savg and the peak frequency PCNT.

Specifically, for example, the voltage amplifier circuits 22 and 2
Assuming that the voltage amplification level in 6 is a high amplification level, the fire condition is, for example, the average peak level M.
_avg is 0.5 V or more, and the ratio M _avg / S _avg is, for example, 4
As described above, it is also checked whether the peak frequency PCNT satisfies the condition of 2 times / second or more (step S15). As a result, when all the above conditions are satisfied, it can be clearly determined that it is a flame (fire) (for example, it can be determined that it is an abnormal level fire or high level fire I), and at this time, a fire signal is output. Output to fire output circuit 31 and operation indicator lamp 3
3 is displayed to indicate that it is a fire and further that it is an abnormal level fire or a high level fire I (step S
16).

On the other hand, when at least one of all the conditions is not satisfied in the determination in step S15, for example, when it is determined that the ratio M _avg / S _avg is not 4 or more (when it is 4 or less). Determines whether the first timer has counted the time (for example, 13.5 seconds) until a certain degree of reliability is obtained (step S17). Step S1
In 7, when the first timer does not measure the time until a certain degree of reliability is obtained, the process returns to step S12 again, and the first timer measures the next 4.5 second period (step S12), also in this period
Similarly, the process of capturing the levels of the first wavelength signal and the second wavelength signal is performed (step S13). Then, when the first timer measures the next 4.5 seconds (step S
12), at this point, the average peak level M determined over a total of 9 seconds including the previous 4.5 seconds.
_{Based on the avg} , the peak frequency PCNT, and the ratio _Mavg / _Savg , the same flame determination and fire determination are performed (step S1).
4, S15). As a result, for example, when all the fire conditions are met, it can be clearly determined that it is a flame (fire).
(For example, it can be judged that it is abnormal level fire or high level fire I). Thus, in the determination of step S15, when the fire condition is not satisfied, the flame determination and the fire determination are performed while extending the predetermined period T until a certain degree of reliability is obtained (step S15) and the predetermined period. T
Is a period in which some reliability is obtained (for example, 13.5 seconds)
When it becomes (step S17), the final flame determination and fire determination are performed (step S18). As a result, for example, when the ratio M _avg / S _{avg of} the fire condition is 2 or less, it is clearly determined that it is not a flame (fire), the fire output is not performed, and the process returns to step S11. On the other hand, at this point, for example, when the ratio of the fire conditions M _avg / S _avg is 4 or less and 2 or more, it is not possible to clearly determine whether or not it is a flame (fire) only by this (that is, the determination is delicate). (It will be ambiguous).

Therefore, in step S18, when it is not possible to clearly determine whether or not a flame (fire) has occurred, in order to further investigate the randomness of the peak level of the first wavelength signal,
A histogram (frequency distribution) as described above is created, and based on this, it is determined whether or not the peak level of the first wavelength signal has randomness (step S19).

As a result, when the peak level of the first wavelength signal has sufficient randomness (fire degree is, for example, "1.
To is the time) 0 ", clearly determined to be flame (fire). In this case, the average peak level M _avg, peak power PCNT, based on the ratio M _avg / S _avg, the degree of fire, For example, it is determined as a high level fire II or a normal level fire.When it is determined that there is a fire in this way, a fire signal is output to the fire output circuit 31 and the operation indicator lamp 33 indicates that there is a fire. Displays a high level fire II or a normal level fire (step S16).

On the other hand, in step S19, when the peak level of the first wavelength signal has no randomness (when the fire level is, for example, "0.0"), it is clearly determined that it is not a flame (fire). To do. Then, in this case, it is assumed that the signal is different from the fire such as the heat source and the reflection of sunlight, and the fire output is not performed, and the step S
Return to 11.

The following table shows specific examples of the determination of the degree of fire. In addition, in the example of the following table, the degree of fire is divided into four stages according to the predetermined period T and the parameter. Further, M _avg / S _avg is actually obtained as a ratio of integrated values before being averaged, that is, (peak voltage integrated value of first wavelength signal) / (corresponding voltage integrated value of second wavelength signal) Has been.

[0093]

[Table 3]

For example, in the above-mentioned chopped low temperature object (100 ° C. or less), the average peak level _Mavg is 0.5 V or more, and the peak frequency PCNT is 2 times / second or more, but the ratio M _{If avg} / S _avg is 4 or less and is 2 or more, it is not possible to judge whether or not there is a fire only from these conditions (it becomes ambiguous). However, in a chopped low temperature object (100 ° C. or lower), since the peak level of the first wavelength signal has no randomness, it can be clearly determined that it is not a fire.

In a high oil and smoke fire, the average peak level _Mavg is 0.5 V or higher, and the peak frequency PCN
T is 2 times / second or more, but the ratio _Mavg / _Savg is 4 or less and is 2 or more, and it is not possible to judge whether or not there is a fire only from these conditions (it becomes ambiguous). However, in a high oil and smoke fire, the peak level of the first wavelength signal has randomness, and thus it can be clearly determined that the fire is a fire.

As described above, in the present invention, the flame detector is shown in FIG.
In addition to the one-wavelength type shown in Fig. 8, the two-wavelength type (infrared-infrared composite type, infrared-type
Basic flame judgment (fire judgment) regardless of whether it is (UV combined type) or even 3 wavelength type
When the ambiguity occurs, it is possible to make a reliable and reliable flame judgment (fire judgment) by examining the randomness of the peak level of the signal from the infrared detection means (first wavelength detection means). Become. However, when the present invention is applied to a one-wavelength type flame detector as shown in FIG. 2, it is possible to provide a flame detector of small size, low cost and high reliability. Also, FIG.
When the present invention is applied to a two-wavelength type flame detector or a three-wavelength type flame detector as shown in (1), a highly reliable flame detector can be provided.

In the embodiment shown in FIG. 8, a second light (infrared ray or ultraviolet ray) having a wavelength different from the infrared ray having a wavelength peculiar to the flame to be detected by the infrared ray detecting means 11 is detected.
Instead of the wavelength detecting means 16, any other object, for example, a smoke / heat detecting means for detecting smoke or heat may be used.

When smoke / heat detecting means for detecting smoke or heat is used instead of the second wavelength detecting means 16,
It is possible to add the smoke density or temperature detected by the smoke / heat detecting means to one of the parameters to make a flame judgment or a fire judgment.

In each of the embodiments shown in FIGS. 2 and 8, the average peak level and the peak frequency of the infrared detection signal are used as the feature quantity (feature quantity peculiar to the flame) when judging the flame.
At this time, of the levels of the infrared detection signal obtained over the predetermined period T from the time when the level of the infrared detection signal exceeds the predetermined threshold level V _th , the predetermined threshold level V
_th focusing only on those beyond, to detect the peak only infrared detection signal exceeds a predetermined threshold level V _th,
The average peak level and peak frequency are calculated, and this prevents peaks due to noise from being detected,
Although it is possible to make a very reliable judgment of a fire, as the basic characteristic amount when making a judgment of a flame, an arbitrary one can be used depending on the case. For example, only the average peak level of the infrared detection signal can be used as the characteristic amount of the flame, or only the peak frequency of the infrared detection signal can be used as the characteristic amount of the flame, or the infrared detection signal. for from the time when the level of the exceeds a predetermined threshold level V _th infrared detection signal obtained over time T, the level, including those that do not exceed a predetermined threshold level V _th, to detect the peak levels Alternatively, the average peak level PAV and / or the peak frequency may be obtained and used as a characteristic amount peculiar to the flame. Alternatively, not only the average peak level and the peak frequency, but also the feature amount of the flame can be used as long as the feature of the flame is extracted.

In any case, according to the present invention, the radiant light detecting means for detecting the radiant light emitted from the flame, and the feature quantity peculiar to the flame are extracted from the radiant light detecting signal detected by the radiant light detecting means, And a flame judging means for making a basic flame judgment based on a characteristic quantity peculiar to the flame, wherein the flame judging means is a random characteristic quantity peculiar to the flame when ambiguity occurs in the basic flame judgment. It is sufficient if the flame judgment is made in consideration of.

Further, in the above-described embodiment, it is determined whether or not there is a flame in the flame detector and outputs the determination result as to whether or not the flame is present. The present invention is not limited to the above configuration and can be applied to any flame monitoring system. That is, the present invention detects the radiated light emitted from the flame, extracts the characteristic amount of the flame from the detected radiant light detection signal, when performing the flame judgment based on the characteristic amount of the flame,
Since the flame judgment is made in consideration of the randomness of the extracted characteristic features of the flame, its application is not limited to a single flame detector, but any flame monitoring system.
(On / off type monitoring system, analog type monitoring system)
It is also possible to make the flame judgment on the receiver side, for example, when applied to the analog type monitoring system.

FIG. 20 is a diagram showing another structural example of the flame detector according to the present invention. Referring to FIG. 20, the flame detector includes a plurality of infrared detecting means 11-1 to 11-n (n ≧ 2).
And a flame judging means 5 for judging a flame based on each infrared detection signal detected by each of the plurality of infrared detecting means 11-1 to 11-n.

Here, each of the infrared detecting means 11-1 to 11-1.
11-n has an equivalent structure with respect to noise superimposed on each infrared detection signal, and the judging means 5 determines the infrared detection signal from each infrared detection means 11-1 to 11-n. , The asynchronous signal component is detected as noise, and the flame is judged only based on the synchronized signal component.

A specific example of the flame detector having such a structure is n
2 is the same as that shown in FIGS. 8 and 16, and in FIGS. 8 and 16, the first wavelength detecting means 15 and the second wavelength detecting means 16 have an equivalent structure, Further, the CPU 30 has a function of the flame determining means 5, that is, an asynchronous signal component in each infrared detection signal (first wavelength signal, second wavelength signal) from the first wavelength detecting means 15 and the second wavelength detecting means 16. Is detected as noise, and the flame can be judged based on only the synchronized signal component.

More specifically, the flame detector of FIG.
6, the infrared sensor 21 of the first wavelength detecting means 15 and the infrared sensor 25 of the second wavelength detecting means 16 use pyroelectric elements having the same structure, and the voltage amplifying circuit 22 and the filter of the first wavelength detecting means 15 are used. Circuit 23, DC level conversion circuit 24
And the voltage amplifying circuit 26, the filter circuit 27, and the DC level converting circuit 28 of the second wavelength detecting means 16 may be embodied by using circuits having equivalently designed circuit structures.

Generally, popcorn noise is caused by a sudden temperature change or by a component (for example, infrared sensor).
Occurs when mechanical stress is applied to the popcorn, even if multiple parts (for example, multiple infrared sensors) are placed close to each other in the same environment, popcorn The probability of noise occurring at the same time is extremely low. On the other hand, when a plurality of infrared detecting means having equivalent structures are placed close to each other in the same environment, the fire signal and non-fire signal detected by these infrared detecting means have signal synchronism. is there.

Therefore, in the flame detector as shown in FIG. 16, when the first wavelength detecting means 15 and the second wavelength detecting means 16 have an equivalent structure, the first wavelength detecting means 15 and the second wavelength detecting means are provided. If the signals respectively detected by 16 are synchronized with each other, it can be determined that this signal is a fire signal or a non-fire signal and is not noise, and
When the signals detected by the first wavelength detecting means 15 and the second wavelength detecting means 16 are asynchronous signals, it can be determined that the signals are noise.

Specifically, a high temperature object and a low temperature object (100 ° C.
For the infrared rays emitted from the low oil smoke flame and the high oil smoke flame, the level of the first wavelength signal detected by the first wavelength detection means 15 and the second wavelength detected by the second wavelength detection means 16 will be described.
The level of the wavelength signal is synchronized with each other, although there is a difference in magnitude.

FIG. 21 is a diagram showing the results of detecting infrared rays radiated from a low oil smoke flame by the first wavelength detecting means 15 and the second wavelength detecting means 16 having mutually equivalent structures. FIG. 22 is a low temperature object chopped by hand.
It is a figure which shows the result which each detected the infrared rays radiated from (100 degrees C or less) by the 1st wavelength detection means 15 and the 2nd wavelength detection means 16 of a mutually equivalent structure.

As can be seen from these results, when the signal is not noise, it is detected by the first wavelength detecting means 15 regardless of whether it is due to fire or non-fire. The level of the one-wavelength signal and the level of the second wavelength signal detected by the second wavelength detecting means 16 are synchronized with each other. On the other hand, for example, when popcorn noise occurs in the first wavelength detecting means 15, even if the level of the first wavelength signal from the first wavelength detecting means 15 increases, the second wavelength detecting means 16 causes The level of the second wavelength signal of is generally sufficiently small (for example, approximately 0 V), and the level of the first wavelength signal detected by the first wavelength detecting means 15 and the second wavelength detecting means 16 It is not synchronized with the level of the second wavelength signal detected in.

FIG. 23 and FIG. 24 are diagrams respectively showing the first wavelength signal and the second wavelength signal when popcorn noise is generated in the first wavelength detecting means. It should be noted that FIG. 24 is an enlarged view of FIG. 23 in the time axis direction and shows the capture of the level of the second wavelength signal when the peak of the level of the first wavelength signal is detected. As can be seen from FIGS. 23 and 24, even if the signal level of one of the detection means becomes large due to popcorn noise, the signal level of the other detection means is very small, and these signals are generally asynchronous with each other. .

Utilizing this feature, in the flame judging means 5 of the flame detector of FIG. 20, each infrared detecting means 11-1 to 11-1 is used.
The level of each infrared detection signal from 1-n is compared at each time point, and as a result of this comparison, the asynchronous signal component is detected as noise, and the flame is judged based only on the synchronized signal component. Can be done.

If popcorn noise occurs in the first wavelength detecting means 15 at the same time, the second wavelength detecting means 1
For example, even if white noise is superimposed on 6 and the level of the first wavelength signal and the level of the second wavelength signal are accidentally synchronized at this time, for example, the first wavelength signal is maintained for a predetermined period T. When the level of the second wavelength signal with respect to the peak of the level is checked, if popcorn noise is generated, each peak of the level of the first wavelength signal, for example, the second wavelength signal for each of the m peaks It can be determined that popcorn noise is generated when the level becomes equal to or lower than the predetermined threshold level a plurality of times, for example. Then, in this case, each signal obtained over the predetermined period T can be rejected and not used for flame determination or fire determination.

That is, the plurality of infrared detecting means 11
When the level of the infrared detection signal from one of the infrared detection means of -1 to 11-n reaches a peak, the level of the infrared detection signal from the other infrared detection means is checked, and the infrared light of the one infrared ray is detected for a predetermined period. When the level of the infrared detection signal from the other infrared detection means with respect to each peak of the level of the infrared detection signal from the detection means is a predetermined number of times or more, below a predetermined threshold level, it is determined that noise is mixed,
It is possible not to use the infrared detection signal for the predetermined period for the flame judgment.

In the above description, in FIG.
Is "2" and the flame detector is of the dual wavelength type as shown in FIGS. 8 and 16, but in FIG. 20, when n is "3", that is, 3 Even in the case of the wavelength type, popcorn noise is generated by setting each infrared detection means to have an equivalent structure and checking the synchronization or asynchronism of each infrared detection signal detected by each infrared detection means. Can be detected. Furthermore, not only popcorn noise but also white noise, electric noise, radio wave noise, vibration noise, etc. can be detected, and flame judgment and fire judgment can be performed with or without the influence of these. In other words, flame judgment and fire judgment can be performed by suppressing or eliminating the influence of internal noise (popcorn noise, white noise) and external noise (electricity, radio wave, vibration noise).

The flame judging means 5 in FIG. 20 may have the function of the flame judging means 2 in FIGS. 1, 8 and 16 or may not have the function of the flame judging means 2. good. That is, the flame determination means 5 may be a flame determination processing function that takes randomness into consideration and a noise detection function as described above, or a conventional flame determination processing function that has the above-described noise detection function. It may have a noise detection function. However, when the flame determination processing function considering randomness is provided with the noise detection function as described above, it is possible to perform flame determination with extremely high performance.

Further, in the configuration example of FIG. 20, the flame detector itself is provided with the flame judging means 5 so that the flame judgment and the fire judgment can be made within this flame detector (that is, ON / OFF).
Although it is configured as an off-type sensor), when the flame sensor is configured as an analog-type sensor, noise can be similarly detected and the influence of noise can be removed. FIG. 25 is a diagram showing an example of a case where the flame detector is configured as an analog type sensor which is address polled from the receiver. In this case, in the signal processing means of the flame detector, as described above, The noise can be detected, the noise can be removed from the signal, and the signal can be returned to the receiver.

In other words, according to the present invention, in a flame sensor provided with a plurality of infrared detecting means, each infrared detecting means has an equivalent structure with respect to noise, and each infrared detecting means has a structure equivalent to that of the infrared detecting means. It suffices if an asynchronous signal in the infrared detection signal is detected as noise, and there is no limitation to whether the flame detector is an on / off type or an analog type.

[0119]

As described above, according to the first to sixth aspects of the present invention, the radiant light emitted from the flame is detected as the radiant light detection signal, and the radiant light detection signal is used to identify the flame. When making a flame judgment based on the feature quantity peculiar to the flame when the flame judgment becomes ambiguous, the flame judgment is performed considering the randomness of the extracted flame peculiar feature quantity. Since it is designed to be performed, even if the judgment as to whether or not it is a flame is an ambiguous source in the conventional flame judgment processing, the judgment as to whether or not it is a flame is made correctly and reliably. be able to.

In particular, in the invention according to claim 2, an infrared detecting means for detecting light having an infrared wavelength peculiar to a flame as an infrared detecting signal is used as the emitted light detecting means, and the flame determining means is an infrared detecting means. Even if the judgment of the flame based on the infrared detection signal detected by the method becomes ambiguous, if the level of each peak of the infrared detection signal is randomly dispersed, it will be judged as a flame. Therefore, the flame judgment can be performed with extremely high reliability, while maintaining the advantages of the one-wavelength type, small size, and low cost.

Further, in the inventions according to claims 3 to 5, in the two-wavelength type flame judgment processing, the flame judgment can be made more reliably.

According to the invention described in claims 7 to 10, in the flame sensor provided with a plurality of infrared detecting means, each infrared detecting means has a structure equivalent to noise. Since the asynchronous signal is detected as noise in each infrared detection signal from each infrared detection means, the influence of noise in flame judgment,
Especially, the influence of popcorn noise can be suppressed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a flame detector according to the present invention.

FIG. 2 is a diagram showing a configuration example of a flame detector of FIG.

FIG. 3 is a diagram showing a spectrum intensity of a general flame.

FIG. 4 is a diagram showing an example of temporal changes in the intensity level of infrared rays emitted from a flame during a fire.

FIG. 5 is a diagram showing an example of a level change of an infrared detection signal obtained by detecting infrared rays from a flame during a fire with an infrared sensor (pyroelectric sensor).

FIG. 6 is a diagram showing an example of a level change of an infrared detection signal obtained by detecting infrared rays from a low temperature heat source (100 ° C. or lower) with an infrared sensor (pyroelectric sensor).

FIG. 7: Infrared detection signal of FIG. 5 (signal due to flame at the time of fire)
FIG. 7 is a diagram showing an example of creating a frequency distribution (histogram) of peak levels in each case of the infrared detection signal (signal from the low temperature heat source) of FIG.

FIG. 8 is a diagram showing another configuration example of the flame detector of FIG. 1.

FIG. 9 is a diagram showing the second wavelength signal when the flame detector of FIG. 8 uses an infrared ray having a wavelength in the vicinity of the infrared ray wavelength detected by the first wavelength detecting means as the second wavelength detecting means. It is a figure for demonstrating loading of a level.

FIG. 10 is a diagram for explaining the capture of the level of the second wavelength signal when the second wavelength detecting means detects ultraviolet rays in the flame sensor of FIG.

FIG. 11 is a diagram showing an example of a first wavelength signal and a second wavelength signal at the time of fire.

FIG. 12 is a diagram showing an example of a first wavelength signal and a second wavelength signal at the time of non-fire (for example, when a halogen lamp, heat source noise, etc. are added).

FIG. 13: Measurement results of the level of the first wavelength signal (about 4.3 to 4.4 μm) and the second wavelength signal (for example, 3.9 μm) when a low oil smoke (normal-heptane) flame is generated (time FIG.

FIG. 14: First when high-energy smoke (gasoline) flame is generated
It is a figure which shows the measurement result (temporal change) of the level of a wavelength signal (about 4.3-4.4 micrometers) and a 2nd wavelength signal (for example, 3.9 micrometers).

FIG. 15 is a result of measuring the levels of the first wavelength signal (about 4.3 to 4.4 μm) and the second wavelength signal (for example, 3.9 μm) when the low temperature object (100 ° C. or less) is choppered by hand (time. FIG.

16 is a diagram showing a specific example of the flame sensor in the case where an infrared sensor for detecting infrared rays is used for the first wavelength detecting means and the second wavelength detecting means in the flame sensor of FIG.

FIG. 17 is a flowchart showing an example of processing operation of the fire detection device of FIG.

FIG. 18 is a flowchart showing an example of the processing operation of the fire detection device of FIG.

FIG. 19 is a flowchart showing an example of processing operation of the fire detection device of FIG. 16.

FIG. 20 is a diagram showing another configuration example of the flame detector according to the present invention.

FIG. 21 is a diagram showing a result of detecting infrared rays emitted from a low oil smoke flame by a first wavelength detecting means and a second wavelength detecting means having structures which are equivalent to each other.

FIG. 22: A low temperature object chopped by hand (100 ° C.
It is a figure which shows the result of having respectively detected the infrared rays radiated from (below) with the 1st wavelength detection means and the 2nd wavelength detection means of mutually equivalent structure.

FIG. 23 is a diagram showing a first wavelength signal and a second wavelength signal when popcorn noise is generated in the first wavelength detecting means.

FIG. 24 is a diagram showing a first wavelength signal and a second wavelength signal when popcorn noise is generated in the first wavelength detecting means.

FIG. 25 is a diagram showing an example of a case where the flame sensor is configured as an analog sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Synchrotron radiation detecting means 2,5 Flame judging means 11 Infrared ray detecting means 15 First wavelength detecting means 16 Second wavelength detecting means

Claims (10)

[Claims] 1. A radiant light detecting means for detecting radiant light emitted from a flame, and a feature quantity peculiar to a flame is extracted from a radiant light detection signal detected by the radiant light detecting means to obtain a feature quantity peculiar to the flame. And a flame determining means for performing flame determination based on the randomness of the extracted characteristic features of the flame. . 2. The flame detector according to claim 1, wherein the emitted light detecting means is an infrared detecting means for detecting light having an infrared wavelength peculiar to the flame as an infrared detecting signal, and the flame determining means is Even if the judgment of the flame based on the infrared detection signal detected by the infrared detection means becomes ambiguous, if the level of each peak of the infrared detection signal is randomly dispersed, it should be judged as a flame. Flame detector characterized by becoming. 3. The flame detector according to claim 1, wherein the emitted light detecting means includes first wavelength detecting means for detecting infrared rays having a wavelength peculiar to flame as a first wavelength signal, and the first wavelength detecting means. Second wavelength detecting means for detecting an infrared ray having a wavelength near the infrared wavelength detected by the second wavelength signal as the second wavelength signal, and the judging means uses the first wavelength signal detected by the first wavelength detecting means. , And the level of the second wavelength signal detected by the second wavelength detecting means, even when the determination of the flame becomes ambiguous, the first wavelength signal of A flame detector characterized in that it is judged as a flame when the level of each peak is randomly dispersed. 4. The flame detector according to claim 1, wherein the emitted light detecting means includes a first wavelength detecting means for detecting an infrared ray having a wavelength peculiar to the flame as a first wavelength signal, and an ultraviolet ray having a predetermined wavelength. A second wavelength detecting means for detecting as a two-wavelength signal is used, and the judging means uses a first wavelength signal from the first wavelength detecting means and a second wavelength signal from the second wavelength detecting means.
When making a flame determination based on the wavelength signal, even if the flame determination is ambiguous, it is determined that a flame is present when the peak levels of the first wavelength signal are randomly dispersed. Flame detector characterized in that 5. The flame detector according to claim 1, wherein the radiation detecting means detects infrared rays having a wavelength peculiar to a flame as an infrared detection signal, and smoke or heat smoke concentration signal or temperature. Smoke / heat detecting means for detecting as a signal is used, and the judging means uses a flame based on an infrared detection signal from the infrared detecting means and a smoke concentration signal or a temperature signal from the smoke / heat detecting means. When making the above determination, even if the determination of the flame becomes ambiguous, it is determined that the flame is determined when the peak levels of the infrared detection signal are randomly dispersed. And a flame detector. 6. A radiant light emitted from a flame is detected as a radiant light detection signal, a feature amount peculiar to the flame is extracted from the radiant light detection signal, and flame judgment is performed based on the feature amount peculiar to the flame.
A flame detection method characterized in that, when the flame judgment is ambiguous, the flame judgment is performed in consideration of the randomness of the extracted characteristic features of the flame. 7. A flame sensor provided with a plurality of infrared detecting means, each infrared detecting means having an equivalent structure with respect to noise, and each infrared detecting signal from each infrared detecting means is asynchronous. A flame detector characterized by detecting a signal as noise. 8. A plurality of infrared detecting means, and a judging means for judging a flame based on the infrared detecting signals respectively detected by the plurality of infrared detecting means, wherein each infrared detecting means detects each infrared ray. The determination means has an equivalent structure with respect to noise superimposed on a signal,
In each infrared detection signal from each infrared detection means, a non-synchronous signal component is detected as noise, and the flame is judged based on only the synchronized signal component. . 9. The flame detector according to claim 7 or 8, wherein at least one infrared detecting means of the plurality of infrared detecting means includes a pyroelectric element as an infrared sensor. A flame detector characterized by being present. 10. The flame detector according to claim 7, wherein when the level of an infrared detection signal from one of the plurality of infrared detecting means reaches a peak, another infrared ray is detected. The level of the infrared detection signal from the detection means is checked, and the level of the infrared detection signal from the other infrared detection means with respect to each peak of the level of the infrared detection signal from one infrared detection means is predetermined times or more over a predetermined period. The flame detector is characterized in that it is determined that noise is mixed when the threshold level is lower than, and the infrared detection signal over the predetermined period is not used for flame determination.