JP3112057B2 - Fire detection device and fire detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire detecting apparatus and a fire detecting method for detecting a fire by detecting both infrared rays and ultraviolet rays from a flame caused by a fire.

[0002]

2. Description of the Related Art Conventionally, as a fire detecting device for detecting a flame generated at the time of a fire and making a fire judgment, for example, Japanese Patent Publication No.
As disclosed in JP-A-35720, a fire detection device has been proposed which detects both infrared rays and ultraviolet rays from a flame at the time of a fire and prevents malfunctions due to non-fire sources such as sunlight, welding, and a heat source. ing.

That is, in the detection of only infrared rays, sunlight may be reflected on an object (a puddle, a leaf of a tree, or the like), and may be detected as a flicker signal equivalent to a flame under the influence of wind or the like. Further, in the detection of only ultraviolet rays, there is a possibility that welding light at a construction site, a factory or the like is erroneously detected as light from a flame.

[0004] In the above-described fire detection device, since the effects of both of these non-fire sources are extremely unlikely to occur at the same time, both infrared and ultraviolet light are detected using both an infrared sensor and an ultraviolet sensor (UVtron). Detects and calculates the ratio between the infrared detection signal from the infrared sensor and the ultraviolet detection signal from the ultraviolet sensor, compares this ratio with the characteristic range of the fire, and when this ratio is within the characteristic range of the fire, It is intended to detect and reduce the likelihood of false alarms from non-fire sources.

[0005]

As described above, in the above-described conventional fire detecting apparatus, by detecting both infrared rays and ultraviolet rays, false alarms due to non-fire sources are reduced, and the flame generated at the time of fire can be reliably detected. This fire detection device is intended to detect fires with good reliability. However, since this fire detection device makes a fire judgment based solely on the ratio between the infrared detection signal and the ultraviolet detection signal, the fire judgment is more reliable and accurate. There was a limit to doing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fire detection device and a fire detection method capable of making a fire judgment more reliably when making a fire judgment using both an infrared sensor and an ultraviolet sensor. And

[0007]

In order to achieve the above object, according to the present invention, the level of the infrared detection signal from the infrared sensor reaches a certain level. From the point in time, the average peak level and / or peak frequency of the infrared detection signal over a predetermined period is obtained, and in parallel with this, the number of discharge pulses of the ultraviolet sensor over a predetermined period is counted, and the average peak level of the infrared detection signal is obtained. And / or a fire determination is made based on the peak frequency and the number of discharge pulses of the ultraviolet sensor. Thus, when making a fire determination using both the infrared sensor and the ultraviolet sensor, the fire determination can be made more reliably.

In particular, according to the second aspect of the present invention, when calculating the average peak level and / or peak frequency of the infrared detection signal over a predetermined period, the infrared processing means converts the predetermined level of the infrared detection signal over the predetermined period. Since the peak is detected only for the infrared detection signal exceeding the predetermined level, and the average peak level and / or peak frequency is calculated for the peak of the infrared detection signal exceeding a predetermined level, it is possible to make a fire judgment with extremely high reliability. it can.

Further, in the invention according to claim 5, the average peak level and / or peak frequency of the infrared detection signal calculated by the infrared processing means and the count value of the number of ultraviolet discharge pulses counted by the ultraviolet processing means are provided. In addition to determining whether or not there is a fire, the degree of the fire is also determined, and a fire signal corresponding to the degree of the fire is output. This makes it possible to make a more reliable fire determination.

Further, in the invention according to claim 6 or 7, even when the mode of the apparatus is set to the normal processing mode, the infrared detecting means outputs the infrared detecting signal from the infrared sensor every predetermined period. It is checked whether or not the infrared detection signal at this time contains noise. If no noise is included, it is determined that the infrared sensor has failed. Even when is set to the normal processing mode, the number of ultraviolet discharge pulses within a certain period is counted, and when the counted value is equal to or less than a predetermined value, it is determined that the ultraviolet sensor has failed. ing. Thereby, the failure diagnosis of the infrared sensor and the ultraviolet sensor can be automatically performed.

[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 fire detection device according to the present invention. Referring to FIG. 1, the fire detection device includes an infrared sensor 1 for detecting infrared rays emitted from a flame, and an ultraviolet sensor 2 for detecting ultraviolet rays emitted from a flame.

Here, the infrared sensor 1 generally detects 4.3 μ of CO ₂ resonance radiation as infrared radiation radiated from a flame.
m (infrared light in a range of about 4.1 to 4.7 μm) and outputs an infrared detection signal.

On the other hand, for example, a UV TRON is used for the ultraviolet sensor 2, and the ultraviolet sensor 2
When light in a wavelength range of about 00 to 250 nm is detected, the number of ultraviolet discharge pulses corresponding to the intensity (light amount) of the ultraviolet light is output.

The fire detecting device of this embodiment also uses both the infrared sensor 1 and the ultraviolet sensor 2 as in the above-described conventional fire detecting device, but the fire detecting device of this embodiment further includes Mode setting means 3 for setting the mode of the apparatus to the normal processing mode or the fire processing mode; and sampling the infrared detection signal from the infrared sensor 1 at a predetermined time interval Δt when the mode of the apparatus is set to the fire processing mode. average peak level PAV and / or peak power PCN infrared detecting signal over a predetermined period of time T ₁ and
An infrared processing section 4 for calculating the T, when the device mode is set to fire processing mode, the UV treatment unit 5 for counting the number UV ultraviolet discharge pulse from the ultraviolet sensor 2 over a predetermined time period T _2, the fire When the processing mode is set, the average peak level PAV and / or the peak frequency PCNT of the infrared detection signal calculated by the infrared processing means 4 and the count value UV of the number of ultraviolet discharge pulses counted by the ultraviolet processing means 5 A judgment processing means 6 for judging whether or not there is a fire based on the above, and an output means 7 for outputting a fire signal when the judgment processing means 6 judges that a fire has occurred.

FIG. 2 is a diagram showing an example of a temporal change in the intensity level of infrared rays (infrared ray detection signal from the infrared ray sensor 1) emitted from the flame at the time of fire. The infrared sensor 1
Is a signal having both positive voltage and negative voltage levels, but the infrared intensity level in FIG. 2 is obtained by converting the infrared detection signal (AC level) from the infrared sensor 1 into, for example, DC. The DC conversion (rectification) is performed by the converter, and the negative voltage portion of the infrared detection signal is clipped to “0” V. However, in the present invention, for convenience of explanation, the infrared intensity level and the infrared detection signal are treated as synonyms.

Referring to FIG. 2, the intensity level of the infrared rays radiated from the flame at the time of the fire often becomes a predetermined level REF (for example, 0.2 V) or more, and is radiated from the flame at the time of the fire. The intensity level of the infrared ray is, for example, 8 Hz.
It has a degree of temporal fluctuation, that is, a flicker frequency characteristic.

Noting this, in the present embodiment, the mode setting means 3 normally sets the mode of the apparatus to the normal processing mode, but the intensity level of the infrared rays (infrared detection from the infrared sensor 1). When the signal level reaches a predetermined level REF (for example, 0.2 V), it is determined that there is a possibility of a fire, and the mode of the apparatus is switched to the fire processing mode.

Further, when the intensity level of the infrared ray reaches the predetermined level REF and the mode of the apparatus is set to the fire processing mode, the infrared ray processing means 4 changes the intensity level of the infrared ray from this point on to the flame specific to the fire. In order to check the level of the intensity level characteristic and the temporal fluctuation (flicker) characteristic, a predetermined period T
Over _1, (the infrared rays intensity levels over for example, a predetermined time period T _1, the infrared intensity level of the peak exceeds a predetermined level REF) peak of the infrared detection signal (infrared intensity level) detects, for each peak over a predetermined time period T ₁ determined as an average peak level PAV taking the average of the level and the peak of the number of peaks over a predetermined period of time T ₁ degree (i.e., fluctuation of the number) is adapted to determine as PCNT.

[0019] More specifically, as shown in FIG. 2, the infrared intensity level is the infrared intensity level a predetermined time for a predetermined time period T ₁ from the time point exceeds a predetermined level REF interval Δt
And captures (samples) as data, so
In the predetermined period T ₁ , about T ₁ / Δt data is fetched (sampled), and the infrared processing means 4
Of the approximately T ₁ / Δt data (infrared intensity levels) captured in this way, attention is paid only to data exceeding a predetermined level REF, and an increase or decrease in the infrared intensity level exceeding the predetermined level REF is detected. , The peak of the peak, that is, the peak of the intensity level is detected.

[0020] Then, the predetermined time period T _1, to detect the number of peaks of the intensity level, for example, as the m, the level (intensity level) of each peak L _1, L _2, ..., when detecting the L _m, average Peak level PAV, peak frequency PCN
T is determined by the following equation, for example.

[0021]

(Equation 1)

The average peak level PAV obtained in the infrared processing means 4 is used to determine how much the infrared intensity level has the infrared intensity level characteristic peculiar to the flame at the time of fire. Further, since the peak frequency PCNT obtained as described above reflects the fluctuation frequency related to the infrared intensity level, the temporal change in the infrared intensity level causes the temporal fluctuation peculiar to the flame at the time of fire (flickering). ) It is used to judge how much the property has.

The number of ultraviolet discharge pulses generated per unit time output from the ultraviolet sensor 2 depends on the intensity (light amount) of the ultraviolet light incident thereon.
Device mode is based on the number UV ultraviolet discharge pulses counted over a predetermined period of time T ₂ in the UV treatment unit 5 from the time set in the fire processing mode, the flame-specific ultraviolet upon the intensity of ultraviolet (light amount) of the fire It is possible to determine the degree of the intensity (light amount) characteristic.

In the fire processing mode, the average peak level PAV, peak frequency PC
The predetermined period T ₁ used for obtaining NT and the predetermined period T ₂ used for counting the number of ultraviolet discharge pulses in the ultraviolet processing means 5 can be independently set. In this case, the predetermined time period T _1, can be variably set according to the average peak level and / or peak power of example fire processing mode on the calculated the infrared intensity level (infrared detection signal), also, for a predetermined time period T ₂ Can be variably set according to the count value of the number of ultraviolet discharge pulses obtained in the fire treatment mode.

Alternatively, the predetermined periods T ₁ and T ₂ are the same (T ₁
= T ₂ ), where T ₁ and T ₂ are
For example, variably set according to the average peak level and / or peak frequency of the infrared intensity level (infrared detection signal) calculated in the fire processing mode and the count value of the number of ultraviolet discharge pulses obtained in the fire processing mode. it may, alternatively, for a predetermined time period T _1, can also be variably set according to only the average peak level and / or peak power of the infrared intensity level (infrared detection signal) that is calculated for example in a fire processing mode, as for the predetermined time period T _2, it can be variably set according to only count the number of the ultraviolet discharge pulses obtained fire processing mode.

FIG. 3 is a diagram showing an example of a fire judgment process at the time of a high level fire, and FIG. 4 is a diagram showing an example of a fire judgment process at the time of a normal level fire. In addition,
3, in the example of FIG. 4, are set with the predetermined time period T ₁ and T ₂ the same.

First, in the event of a high-level fire, FIG.
As shown in (a), the intensity level of infrared rays emitted from the flame at the time of fire (the level of the infrared detection signal) is large, and
The number of fluctuations is also large, and as shown in FIG. 3 (b), the intensity of ultraviolet rays radiated from the flame at the time of fire
(Light amount), that is, the number of ultraviolet discharge pulses is also large. Accordingly, as shown in FIG. 3C, the predetermined period (T ₁ = T ₂ ) is equal to 4.
Even for a short period of about 5 seconds, this predetermined period (T ₁ =
(T ₂ = 4.5 seconds) alone, the average peak level PAV of the infrared detection signal, the peak frequency PCNT, and the number count value UV of the ultraviolet discharge pulse generally become sufficiently large values. The processing unit 6
The output means 7 determines that the fire is a high-level fire, and outputs a fire signal at an early timing as shown in FIG.
It is possible to output that the level of fire is a high-level fire.

In a normal level fire, FIG.
As shown in (a), the intensity level of infrared rays radiated from the flame at the time of fire (the level of the infrared detection signal) and the number of fluctuations are generally smaller than those at the time of high-level fire.
As shown in FIG. 4 (b), the intensity (light amount) of ultraviolet rays radiated from the flame at the time of fire, that is, the number of ultraviolet discharge pulses is also
Generally less when compared to high-level fires. Therefore, in this case, when the predetermined period (T ₁ = T ₂ ) is as short as about 4.5 seconds, the predetermined period (T ₁ = T ₂ = 4.
(5 seconds), the average peak level PAV of the infrared detection signal, the peak frequency PCNT, and the number count value UV of the ultraviolet discharge pulse are also generally smaller than those at the time of a high-level fire. Judgment cannot be made accurately.

Therefore, the average peak level PAV of the infrared detection signal, the peak frequency PCNT, and the number count value U of the ultraviolet discharge pulse during a predetermined period (T ₁ = T ₂ = 4.5 seconds).
If V is large to some extent but not sufficiently large, the above-mentioned predetermined period (T ₁ = T ₂ ) is set to a longer period, for example, as shown in FIG. As shown in the figure, 2 of the period (4.5 seconds) set as described above
The setting can be changed to the double period, that is, T ₁ = T ₂ = 9 seconds. At this time, as a predetermined period (T ₁ = T ₂ ), an average peak level PAV, a peak frequency PCNT, and a count value UV of the ultraviolet discharge pulse of the infrared detection signal are obtained over a longer period of 9 seconds, and the judgment processing unit 6 is executed.
Can determine whether or not there is a fire based on these. When it is determined that there is a fire, the output means 7 outputs a fire signal at the timing shown in FIG. It is possible to output that the level of fire is a normal level fire.

Specifically, for example, when the following condition is satisfied,
You can judge it as a high level fire. Predetermined period (T ₁ = T ₂ ) 4.5 seconds Infrared intensity level Average peak level PAV ≧ 0.5V Peak frequency PCNT ≧ 28 times (per 4.5 seconds) Number of ultraviolet discharge pulses Count value UV ≧ 50 (4. (Per 5 seconds)

For example, when the following condition is satisfied, it can be determined that the fire is a normal level fire. Predetermined period (T ₁ = T ₂ ) 9.0 seconds Infrared intensity level Average peak level PAV ≧ 0.2 V Peak frequency PCNT ≧ 13 (per 4.5 seconds) Number of ultraviolet discharge pulses Count value UV ≧ 40 (4.5 Per second)

Further, the infrared processing means 4 and the judgment processing means 6 perform the above-mentioned predetermined period T even when the apparatus mode is not set to the fire processing mode (ie, even when the apparatus is set to the normal processing mode). captures the infrared detection signal from the infrared sensor 1 every predetermined period T ₃ which is set longer than _one (e.g., 24 hours), whether there is noise in the infrared detection signal at this time (e.g., white noise) Has a function of determining that the infrared sensor 1 is out of order when noise is not included. When it is determined that the infrared sensor 1 is out of order, for example, a failure signal is output from the output unit 7. It is made to let.

When the mode of the apparatus is not set to the fire processing mode (that is, when the apparatus is set to the normal processing mode), the ultraviolet processing means 5 and the judgment processing means 6 perform the operation for more than the predetermined period T _2. It also has a function of counting the number of ultraviolet discharge pulses within a long set period T ₄ (for example, 24 hours), and judging that the ultraviolet sensor 2 has failed when the counted value is less than a predetermined value. And
When it is determined that the ultraviolet sensor 2 has failed, for example, a failure signal is output from the output means 7.

Specifically, for example, when the following condition is satisfied,
It can be determined that a failure has occurred. Number of ultraviolet discharge pulses 2 or less (per 24 hours) Infrared intensity level (per 4.5 seconds) Vmax−Vmin> 40 mV

Here, Vmax and Vmin represent the maximum level and the minimum level of the received infrared intensity level (infrared ray detection signal), and Vmax−Vmin> 40 m
Whether or not the infrared detection signal includes white noise can be determined based on whether or not the condition of V is satisfied.

FIG. 5 is a diagram showing a specific configuration example of the fire detection device of FIG. Referring to FIG. 5, this fire detection device includes a CPU (central processing unit) 15 such as a microprocessor for controlling the entire device, and amplifies the level of an infrared detection signal from infrared sensor 1 to a predetermined size. A voltage amplifying circuit 11 and a filter circuit 12 that passes only a component in a fluctuation frequency (flame flickering frequency) band of the infrared detection signal level-amplified by the voltage amplifying circuit 11.
A DC level conversion circuit 13 for converting (rectifying) an output (AC level) of the filter circuit 12 to a predetermined DC level;
Comparator 14 for comparing the output voltage (level of infrared detection signal) of C level conversion circuit 13 with reference voltage REF
A high-voltage generating circuit 16 that generates a high-voltage based on a pulse signal (oscillation signal) P0 from the CPU 15; a high-voltage generated by the high-voltage generating circuit 16 is rectified into a DC high-voltage; A rectifier circuit 17 that performs
A differentiating circuit for differentiating a discharge pulse signal output from the ultraviolet sensor when detecting ultraviolet light;
8 converts the output (discharge pulse signal) to a predetermined DC level and outputs the DC level as an ultraviolet discharge pulse, and a fire output circuit 20 outputs a fire signal based on a signal P1 from the CPU 15. And CPU 15
A confirmation output circuit 21 for outputting a failure signal based on the signal P2 from the controller, an operation indicator lamp 22 for displaying the output states of the fire output circuit 20 and the confirmation output circuit 21, and a rectifier circuit 23 for rectifying an external power supply. And a constant voltage power supply 24 for supplying a power supply voltage to each section.

Here, the CPU 15 has a predetermined period T ₁ ,
As T _2, for example, a first timer function for counting a 4.5 seconds, as a period of time T _3, T _4, a second timer for measuring the T _1, longer than T ₂ (e.g., 24 hours) Features and
It is assumed that a third timer function for measuring a data capturing interval in a normal state, for example, 2.5 seconds, is incorporated.

The CPU 15 has an A / D conversion function for converting the infrared intensity level from the DC level conversion circuit 13 into a digital signal. In this A / D conversion function, an infrared intensity level (infrared ray detection signal) is sampled at a predetermined time interval Δt (for example, 10 msec), digitally converted, and taken in.

When the level (amplitude voltage) of the infrared detection signal output from the DC level conversion circuit 13 reaches the reference voltage REF (for example, 0.2 V), the comparator 14 outputs “1” to the interrupt terminal INT 1 of the CPU 15. Is output as an interrupt to the CPU 15 and the CPU 15
Switches the mode of the apparatus from the normal processing mode to the fire processing mode when there is an interrupt input at the terminal INT1. Then, after setting the fire processing mode, the A / D conversion operation of the infrared intensity level (infrared detection signal) by the A / D conversion function is started, and the infrared intensity level is set.
(Infrared detection signal).

That is, in order to detect a fire, the CPU 15 changes the infrared intensity level (infrared detection signal) for a predetermined period T ₁ (for example, 4.5 seconds) for a predetermined time interval (sampling period) Δt (for example, for 10 ms). Of the infrared intensity level data (digital data) captured at every time interval Δt (= 10 msec) over the predetermined period T _1, for example, only for the infrared intensity level exceeding the predetermined level. Is detected, and the average peak level PAV and the peak frequency PCNT are calculated, for example, according to Equation 1. At this time, the peak was extracted by setting the infrared intensity level to 10
When capturing as digital data every ms, it is possible to compare the previous data with the present data, determine whether the data is increasing or decreasing, and extract a point at which the transition from increasing to decreasing occurs as a peak point. When the peak point is extracted, the peak frequency can be obtained by incrementing the peak counter.

The ultraviolet discharge pulse output from the DC level conversion circuit 19 is supplied to the interrupt terminal I of the CPU 15.
NT2 is added as an interrupt, and the level of the infrared detection signal is equal to the reference voltage REF (for example, 0.2 V).
After the CPU 15 sets the mode of the device to the fire processing mode after reaching CPU, the CPU 15
Terminal for a predetermined period of time T ₂ (e.g., 4.5 seconds) INT2
Is counted as the number UV of the ultraviolet discharge pulses.

As described above, the CPU 15 sets the mode of the apparatus to the fire processing mode, and then sets the mode to a predetermined period (T ₁ = T _1).
2 = 4.5 seconds) average peak level PAV of infrared intensity level (infrared detection signal), peak frequency PCN
T and 3 of the count value UV of the number of ultraviolet discharge pulses
One parameter is determined, and the degree of fire is determined based on these three parameters.

More specifically, as described above, the process of determining the degree of fire is such that each of the three parameters obtained during the above-mentioned predetermined period (T ₁ = T ₂ = 4.5 seconds) is at a high level higher than a predetermined level. In some cases, it is determined that a high level fire has occurred, and when the level of each of the three parameters is higher than normal but does not reach the high level, for example, the predetermined periods T ₁ and T ₂ are further extended by 4.5 seconds. (To a total of 9 seconds), the average peak level PAV and the peak frequency PC of the infrared intensity level (infrared detection signal) during the predetermined period (T ₁ = T ₂ = 9 seconds).
It is determined whether or not there is a normal level fire based on NT and the count value UV of the number of ultraviolet discharge pulses.

When the CPU 15 determines that the fire is a high-level fire or a normal-level fire, the CPU 15 outputs a fire signal from the fire output circuit 20 and turns on the operation indicator 22 continuously.

In addition, regardless of whether the mode of the apparatus is set to the normal processing mode or the fire processing mode, the CPU 15 is provided for every predetermined period T ₃ (for example, 24 hours) longer than the predetermined period. In addition, an infrared detection signal is fetched, it is checked whether or not noise (for example, white noise) is included in the infrared detection signal at this time, and a failure diagnosis of the infrared sensor 1 is performed based on the result. In addition, when the CPU 15 is in the normal processing mode (when it is not in the fire processing mode), the CPU 15 performs a predetermined period T ₄ (for example,
Counts the number of ultraviolet discharge pulses input to the interrupt terminal INT2 within (time), and based on the counted result, whether there is self-discharge (discharge due to cosmic rays etc. even when ultraviolet light is not detected with a normal UVtron) Is determined, and a failure diagnosis of the ultraviolet sensor 2 is performed based on the determination result.

When the CPU 15 detects a failure in the infrared sensor 1 or the ultraviolet sensor 2, it outputs a failure signal from the confirmation output circuit 21 and causes the operation indicator lamp 22 to blink, for example.

Further, the CPU 15 determines whether or not the infrared detection signal exceeds the saturation region of the voltage amplification circuit 11, and when the detection signal exceeds the saturation region, the amplification degree of the voltage amplification circuit 11 is 1 / N ( For example, if it is determined that the amplification degree of the voltage amplification circuit 11 needs to be returned, the control can be performed such that the amplification degree is returned to the standard. By doing so, the average peak level and the number of peaks of the infrared intensity level can be detected more accurately.

As can be seen from the above, the mode setting means 3, infrared processing means 4, ultraviolet processing means 5,
The determination processing means 6 is different from the specific configuration example of FIG.
U15, and the output means 7 of FIG.
In FIG. 5, this is realized by a fire output circuit 20, a confirmation output circuit 21, and an operation indicator lamp 22.

Next, the processing operation of the fire detecting device having such a configuration, mainly the processing operation of the CPU 15, will be described with reference to the flowcharts of FIGS. Referring to FIGS. 6 to 8, first, when the power supply 24 of the fire detection device is turned on, the CPU 15 executes an initialization process (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
Clear LG ₁ (set to "0"), also (set to "0") to clear the failure flag FLG _2.

Next, a second timer for measuring, for example, 24 hours is started (step S2). After a while, the terminal IN
It is checked whether an interrupt has been input at T1 (step S3). As a result, when there is an interruption input terminal INT1 is set to "1" in FLG ₁ (step S4), and the process proceeds to step S5, if no interrupt input terminal INT ₁ is directly Proceed to step S5.
In step S5, checks whether FLG ₁ is set to "1", if not set to "1" maintains the mode of the apparatus to the normal processing mode, the processing during normal processing mode (Steps S6 to S13). In contrast, when the FLG ₁ is set to "1" in the step S5, switching the mode of the device to fire the processing mode, the processing of fire processing mode (step S14~
S23).

In the normal processing mode, first, it is checked whether or not the second timer has counted 24 hours (step S6). When the time has counted 24 hours, the failure diagnosis of the infrared sensor 1 is performed. That is, in the normal processing mode, the infrared sensor 1 is set every 2.5 seconds by the third timer that measures 2.5 seconds.
, The maximum and minimum infrared intensity levels are recorded, and the maximum and minimum levels Vmax and Vmi are updated when 24 hours have elapsed.
n (step S7), and the maximum level Vmax,
It is determined whether or not the minimum level Vmin is within a normal range.
(Step S8). For example, Vmax−Vmin> 40 m
It is determined whether or not V is satisfied. As a result, the maximum level Vmax, if the minimum level Vmin within the normal range, while infrared sensor 1 is determined to be normal, to be in the normal range, it is determined that the infrared sensor 1 is a fault, the fault flag FLG ₂ " 1 "is set (step S9), and a failure output is performed (step S10).

When the second timer measures 24 hours in step S6, the CPU 15 performs the fault diagnosis of the ultraviolet sensor 2 in parallel with the fault diagnosis of the infrared sensor 1 as described above. . That is, in step S6, the number of interrupt inputs to the terminal INT2 within a predetermined period of time, for example, 24 hours from the time when the second timer detects the measurement of 24 hours, that is, the number of occurrences of discharge pulses from the ultraviolet sensor 2. Is counted (step S11), and it is determined whether or not the counted value is within a normal range (step S12). As a result, if the counted value is within the normal range, the ultraviolet sensor 2 determines that it is normal, while if not, the ultraviolet sensor 2 determines that there is a failure and sets the failure flag FLG ₂ to “1”. Is set (step S9), and a fault is output (step S1).
0).

As described above, when either the infrared sensor 1 or the ultraviolet sensor 2 is determined to have failed, the failure flag FL
The G ₂ is set to "1", causing the fault output. The failure output is, specifically, the sensor 1 and / or the sensor 2
Is output to the confirmation output circuit 21 to cause the operation indicator lamp 22 to display, for a moment, an indication indicating the failure.

In the normal processing mode, step S6
In the case where the second timer has not timed for 24 hours, check the failure flag FLG ₂ (step S1
3) If failure flag FLG ₂ is set to "1", causing the fault output (step S10). That is, a failure output signal indicating a failure of the sensor 1 and / or the sensor 2 is output to the confirmation output circuit 21 and the operation indicator 2
2 causes the display indicating the failure to be performed for a moment.

[0055] After a fault output in this way is made, the process returns to step S2 again, unless an interrupt input to the INT _1, the normal processing mode is maintained, step S6~S1
Step 3 is repeated. Thereby, the sensor 1
Alternatively, when the sensor 2 is out of order, the operation indicator lamp 22 blinks by this repetitive processing to notify that the sensor 1 or the sensor 2 is out of order.

If it is determined that the sensors 1 and 2 are normal in steps S8 and S12 when 24 hours are counted, the process returns to step S2 without outputting a failure. Further, when the FLG ₂ is determined not "1" in step S13 not elapsed 24 hours, without failure output, the flow returns to step S3.

On the other hand, in step S5, the mode of the apparatus is switched to the fire processing mode, and the fire processing mode setting flag F
When LG ₁ is set to "1", activates the first timer (step S14), and then the first timer monitors whether it has timed the specified time period (e.g., 4.5 seconds) (step S15 ), Until the first timer measures 4.5 seconds.
As described above, the infrared intensity level from the DC level conversion circuit 13 is captured at a predetermined time interval Δt (for example, 10 ms), and at the same time, the discharge pulse is interrupted by the discharge pulse output from the ultraviolet sensor 2. The number is counted (step S16).

When the first timer measures 4.5 seconds, the average peak level PAV and the peak frequency PCNT are obtained based on the infrared intensity level (infrared ray detection signal) captured during 4.5 seconds. Since the count value UV of the number of discharge pulses for .5 seconds is determined, the degree of fire is determined based on these three parameters (step S1).
7). As a result, when it is determined that the level of the fire is a high-level fire, a fire signal is output at this time to the fire output circuit 2.
0 to cause the operation indicator lamp 22 to indicate that a fire has occurred, and that a high-level fire has occurred (step S).
18).

On the other hand, if it is determined in step S17 that the degree of fire is not a high-level fire, the first timer is further timed for the next 4.5 seconds (step S19), Also, the infrared intensity level (infrared ray detection signal) is fetched at a predetermined time interval of 10 ms, and at the same time, the number of discharge pulses is continuously counted (step S21). Then, when the first timer measures the period of the next 4.5 seconds (step S20), at this point, the average peak level PAV, PAV, over the total period of 9 seconds including the period of the previous 4.5 seconds. Peak frequency PC
NT is determined, and the number UV of the discharge pulses for 9 seconds is determined, and it is determined from these three parameters whether or not a fire has occurred (step S22). As a result, when it is determined that a fire (normal level fire) has occurred, a fire signal is output to the fire output circuit 20 and the operation indicator lamp 22 indicates that the fire is occurring, and further indicates that the fire is at the normal fire level. (Step S23).

On the other hand, if it is determined in step S22 that the fire is not a fire, it is determined that the fire is caused by a signal different from the fire, such as a heat source or reflection of sunlight.
The process returns to step S14 without outputting the fire.

As described above, in the processing operation examples of FIGS. 6 to 8, in the normal processing mode, the 24-hour timer and the 2.5-second timer are started, and the infrared detection is performed every 2.5 seconds. The maximum level and the minimum level of the infrared detection signal are constantly updated and recorded by taking in the signal.
At each time, the failure detection of the infrared sensor 1 is performed based on the maximum level and the minimum level of the infrared detection signal, and the failure detection of the ultraviolet sensor is performed based on the discharge pulse count value within 24 hours. When the fire processing mode is exceeded, a 4.5-second timer and a 10-millisecond timer capture an infrared detection signal every 10 milliseconds, and 10 milliseconds within 4.5 seconds (or within 9 seconds) 3. the average peak level and / or peak frequency obtained based on the infrared detection signal taken in every time;
A fire determination is made based on the count value of the ultraviolet discharge pulse within 5 seconds (or within 9 seconds).

As described above, in the present embodiment, when the infrared detection signal (infrared intensity level) from the infrared sensor reaches a predetermined level, it is determined that there is a possibility of a fire, and the mode of the apparatus is set to the fire processing mode. At this point, since the fire determination process is performed using both the infrared sensor and the ultraviolet sensor, the fire determination can be performed with high reliability.

In particular, in this embodiment, not only the determination as to whether or not a fire has occurred, but also the degree of fire,
In other words, judge whether it is a high level fire or a normal level fire,
Since the output means 7 performs output according to the degree of fire,
Fire determination can be performed with higher reliability than a conventional fire detection device. That is, in this embodiment,
The user can recognize whether the fire is a high-level fire or a normal-level fire, and when it is determined that the fire is a high-level fire, the fire output is performed early. Can be recognized early.

In the above-described embodiment, when calculating the average peak level PAV and the peak frequency PCNT of the infrared intensity level (infrared detection signal), the intensity level is set to the predetermined level RE.
Among the points passing F of the infrared intensity level obtained for a predetermined period of time T _1, it focuses only on those exceeds a predetermined level REF, and detects a peak only for infrared intensity level exceeds a predetermined level REF, the average peak The level PAV and the peak frequency PCNT are obtained, thereby preventing a peak due to noise or the like from being detected and making a very reliable fire judgment. infrared intensity levels from the point exceeding the REF obtained over time T _1, the infrared intensity level, including those that do not exceed a predetermined level REF, it detects the peak of the infrared intensity level, the average peak level PAV, peak It is also possible to determine the frequency PCNT and make a fire judgment.

[0065]

As described above, according to the first to fifth and eighth aspects of the present invention, when the level of the infrared detection signal from the infrared sensor reaches a certain level, the infrared detection is started. An average peak level and / or peak frequency over a predetermined period of the signal is determined, and in parallel with this, the number of discharge pulses of the ultraviolet sensor over a predetermined period is counted, and the average peak level and / or peak frequency of the infrared detection signal are calculated. Since the fire determination is performed based on the number of discharge pulses of the ultraviolet sensor and the number of discharge pulses of the ultraviolet sensor, the fire determination can be performed more reliably when the fire determination is performed using both the infrared sensor and the ultraviolet sensor.

In particular, according to the second aspect of the present invention, when calculating the average peak level and / or peak frequency of the infrared detection signal over a predetermined period, the infrared processing means converts the predetermined level of the infrared detection signal over the predetermined period. Since the peak is detected only for the infrared detection signal exceeding the predetermined level, and the average peak level and / or peak frequency is calculated for the peak of the infrared detection signal exceeding a predetermined level, it is possible to make a fire judgment with extremely high reliability. it can.

Further, according to the present invention, the average peak level and / or peak frequency of the infrared detection signal calculated by the infrared processing means and the count value of the number of ultraviolet discharge pulses counted by the ultraviolet processing means. In addition to determining whether or not a fire has occurred, the degree of the fire is also determined, and a fire signal corresponding to the degree of the fire is output, so that the fire determination can be performed with higher reliability.

According to the invention described in claim 6 and claim 7, even when the mode of the apparatus is set to the normal processing mode, the infrared processing means can detect the infrared light from the infrared sensor every predetermined period. The detection signal is taken in, and it is checked whether or not the infrared detection signal at this time contains noise. When the detection signal does not contain noise, it is determined that the infrared sensor is out of order. Even when the mode is set to the normal processing mode, the number of ultraviolet discharge pulses within a certain period is counted, and when the counted value is equal to or less than a predetermined value, it is determined that the ultraviolet sensor has failed. Therefore, the failure diagnosis of the infrared sensor and the ultraviolet sensor can be automatically performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a fire detection device according to the present invention.

FIG. 2 is a diagram illustrating an example of a temporal change in an intensity level of infrared rays emitted from a flame at the time of a fire.

FIG. 3 is a diagram illustrating an example of a fire determination process at the time of a high-level fire.

FIG. 4 is a diagram illustrating an example of a fire determination process at the time of a normal level fire.

FIG. 5 is a diagram showing a specific configuration example of the fire detection device of FIG. 1;

FIG. 6 is a flowchart illustrating an example of a processing operation of the fire detection device in FIG. 1;

FIG. 7 is a flowchart illustrating an example of a processing operation of the fire detection device of FIG. 1;

FIG. 8 is a flowchart illustrating an example of a processing operation of the fire detection device of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 infrared sensor 2 ultraviolet sensor 3 mode setting means 4 infrared processing means 5 ultraviolet processing means 6 judgment processing means 7 output means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-174699 (JP, A) JP-A-51-29098 (JP, A) JP-A-6-131577 (JP, A) 35720 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08B 17/00-17/12 G01J 1/02

Claims (8)

(57) [Claims] 1. An infrared sensor that detects infrared rays emitted from a flame and outputs an infrared detection signal, an ultraviolet sensor that detects ultraviolet rays emitted from the flame and outputs an ultraviolet discharge pulse, and sets a mode of the apparatus to a normal processing mode. A mode setting means for setting a fire processing mode; an infrared processing means for calculating an average peak level and / or a peak frequency of an infrared detection signal over a predetermined period when the mode of the apparatus is set to the fire processing mode; When the mode is set to the fire processing mode, the ultraviolet processing means for counting the number of ultraviolet discharge pulses over a predetermined period, the average peak level and / or peak frequency of the infrared detection signal calculated by the infrared processing means, Judgment of fire or not based on the count value of the number of ultraviolet discharge pulses counted by the ultraviolet processing means And a outputting means for outputting a fire signal when a fire is determined by the determining processing means. The mode setting means normally sets the mode of the apparatus to the normal processing mode. However, when the infrared detection signal reaches a predetermined level, the mode of the apparatus is switched to the fire processing mode and set. 2. The fire detection device according to claim 1, wherein
When calculating the average peak level and / or peak frequency of the infrared detection signal over a predetermined period, the infrared processing means detects a peak only of the infrared detection signal exceeding a predetermined level among the infrared detection signals over a predetermined period, A fire detection device wherein an average peak level and / or a peak frequency is obtained for a peak of an infrared detection signal exceeding a predetermined level. 3. The fire detection device according to claim 1, wherein
The fire detection device according to claim 1, wherein the predetermined period used in the infrared processing means is variably set according to an average peak level and / or a peak frequency of the infrared detection signal. 4. The fire detection device according to claim 1, wherein
The fire detection device according to claim 1, wherein the predetermined period used in said ultraviolet processing means is variably set according to a count value of the number of ultraviolet discharge pulses. 5. The fire detecting device according to claim 1, wherein the determination processing means includes an average peak level and / or a peak frequency of the infrared detection signal calculated by the infrared processing means. And, based on the count value of the number of ultraviolet discharge pulses counted by the ultraviolet processing means, to determine whether or not a fire, so as to determine the degree of fire, and the output means, A fire detection device which outputs a fire signal according to the degree of fire. 6. The fire detection device according to claim 1, wherein
The infrared processing means captures an infrared detection signal from the infrared sensor at regular intervals even when the mode of the apparatus is set to the normal processing mode, and the infrared detection signal at this time contains noise. A fire detection device characterized in that it is determined whether or not the infrared sensor is out of order when noise is not included. 7. The fire detection device according to claim 1, wherein
The ultraviolet processing means counts the number of ultraviolet discharge pulses within a certain period even when the mode of the apparatus is set to the normal processing mode, and when the counted value is equal to or less than a predetermined value, the ultraviolet sensor fails. A fire detection device characterized in that it is determined that a fire has occurred. 8. A fire detection method for detecting a fire by detecting infrared rays and ultraviolet rays emitted from a flame by an infrared sensor and an ultraviolet sensor, respectively, wherein a level of an infrared detection signal from the infrared sensor reaches a certain level. From the time point, the average peak level and / or peak frequency of the infrared detection signal over a predetermined period is obtained, and in parallel with this, the number of discharge pulses of the ultraviolet sensor over a predetermined period is counted, and the average peak of the infrared detection signal is obtained. A fire detection method, wherein a fire is determined based on a level and / or a peak frequency and the number of discharge pulses of an ultraviolet sensor.