JPH0792873B2 - Fire detector - 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 detection device, and more particularly to a fire detection device provided with a microcomputer,
The fire detection level is changed in response to changes in the environmental conditions at the location where the fire detection device is installed, so that a fire can always be detected with a constant fire detection sensitivity.

[0002]

2. Description of the Related Art Environmental conditions at a place where a fire detector is installed vary depending on a time zone, a day of the week, or a season.
Considering this in a room of an office, people enter and leave during the day and dust floats in the room, whereas at night there are no people, so there is almost no dust in the room. It is not floating, and the amount of floating dust is naturally higher during the same day, when people come and go, leave work, and have many people in and out, compared to other times. In addition, while there are many floating dusts in the commuting area during the working hours from Monday to Saturday, the amount of floating dusts is greatly reduced on Sundays because there are few people entering and exiting the resort except in the recreation areas. If a smoke-type fire detector such as an ionization type or a scattered light type that operates at a smoke concentration of 10% is installed in a place of such a commuting area as in the past, the fire detector will not be able to collect floating dust at night or on Sundays. Since there is almost no smoke, it works with smoke with a concentration of about 10%, while there is a large amount of suspended dust during the day from Monday to Saturday, and this amount of suspended dust corresponds to a smoke concentration of several%. The fire detector actually operates with smoke having a concentration of 10% to several%, and the smoke concentration at which the fire detector operates differs between daytime and nighttime.

Considering the room temperature seasonally, in the summer, the room temperature is around 25 ° C. during the daytime operation of the air conditioner, whereas at night, the room temperature rises to around 30 ° C. due to the stop of the air conditioner, and in the winter season. Then, during the daytime, the room temperature is 20 ℃ due to the operation of the heating system.
Before and after, but 0 at night due to the stop of the heating system
It drops to near ℃. If a constant temperature fire detector operating at 70 ° C is installed in such a room, the room temperature should rise by about 40 ° C during the night in summer before the fire detector operates, whereas in the night during winter, A rise of around 70 ° C is required.

As described above, the conventional fire detector having a fixed fire detection sensitivity has a fixed time zone, day of the week,
Due to the environmental conditions that change depending on the season, the relative fire detection sensitivity changes from moment to moment, and it is not possible to detect a fire with a constant sensitivity at all times, resulting in false alarms, late reports or missed reports. Become. The same applies to a fire detector that captures light, gas, etc. generated during a fire other than smoke and heat. Also, some conventional fire detectors have a measurement level of about 2 to 3 and are used by switching, and in this case, a timer device is attached to the receiver and it is scheduled in advance, for example, during the day and at night. In some cases, the sensitivity is automatically switched in response to a command signal from the receiver so that it always has the same sensitivity.
The environment in which the fire detector is installed is various, and even if the sensitivity is set in advance, the sensitivity level is not always the best, and it is necessary to change the purpose of use of the installation place, change the division of the room, or the environment such as the season. When a large change is made, there are many problems such as correction of the sensitivity level setting each time. In consideration of such a point, the present invention changes the fire detection level by calculating with the CPU in response to changes in the environmental conditions of the installation place, and can always detect a fire with a constant fire detection sensitivity. Is what you are trying to get.

[0005]

Therefore, the fire detection device of the present invention has a microcomputer, and the microcomputer can periodically obtain and obtain a physical quantity of a phenomenon similar to a fire phenomenon which is a noise component. The physical quantity signal obtained is stored as cumulative average data, and the current expected environmental noise amount, that is, the average noise component is calculated for each time zone or day of the week based on the past stored data, and this noise component is calculated. The fire detection level is changed according to the time by determining the setting sensitivity commensurate with the average value of, and the fluctuation of the fire detection sensitivity is eliminated.

Specifically, according to the present invention, smoke, heat,
Physical quantity measuring means for detecting one of the physical quantities of fire phenomena such as light and gas, converting the detected physical quantity into an electrical physical quantity signal and outputting it, or by time zone, or
Electrically readable and writable storage means for storing cumulative average data of the detected physical quantity signal in the past for each day of the week and each time zone, and the corresponding time corresponding to the current time zone stored in the storage means Sensitivity setting means for determining the fire discrimination setting sensitivity of the current time zone from the cumulative average data of the zone, a physical quantity signal by the physical quantity measuring means at the current time, and a time zone corresponding to the current time determined by the sensitivity setting means The fire determination means for determining the presence or absence of a fire by comparing and determining the setting sensitivity of, the output means for outputting the result of the comparison determination of the fire determination means, and the time at which the data is aggregated in each of the time zones. One or more physical quantity signals among a plurality of physical quantity signals detected by the physical quantity measuring means in the band, and a time zone corresponding to the time zone of the storage means. Calculating means for calculating new cumulative average data from the cumulative average data, and storage for updating and storing the new cumulative average data calculated by the calculating means as cumulative average data for the corresponding time zone in the corresponding time zone of the storage means There is provided a fire detection device comprising: an updating unit.

[0007]

The storage updating means updates and stores the cumulative average data of the past detected physical quantity signals for each time zone or each day of the week calculated by the calculating means in the corresponding time zone of the storing means to set the sensitivity. The means determines the fire discrimination setting sensitivity of the relevant time zone from the cumulative average data of the relevant time zone stored in the storage means. In this way, the set sensitivity for fire determination determined by the sensitivity setting means is determined from the past detected physical quantity signal for each time zone or each day of the week, so that each time zone is most suitable for the environmental condition. The set sensitivity is set. Thereby, the detection of the fire occurrence is performed by comparing and determining the detected physical quantity signal of the physical quantity measuring means at the present time and the set sensitivity in accordance with the environmental condition in the time zone corresponding to the present time determined by the sensitivity setting means. Since the determination means is used, the fire detection sensitivity is always constant.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be specifically described.

First, FIG. 1 is a block diagram showing the basic construction of a fire detector which is an example of the fire detector according to the present invention. As the fire detector, any commercially available one can be arbitrarily used. Then, the structure is omitted. In FIG. 1, reference numeral 1 denotes a sensor unit which detects a fire phenomenon such as smoke, heat, light, gas or the like or a temperature change or a dust change similar to the fire phenomenon and produces an analog output, and the analog output is an amplifier (not shown). ). Reference numeral 2 is a sample and hold circuit that samples and holds the amplified analog output at predetermined time intervals, for example, every 2 seconds, and 15 is an upper limit setting value (level) and a lower limit setting value (level) of the setting sensitivity illustrated in b of FIG. , And a resistor for giving an initial reference set value (level) which is a fire discrimination level when there is no accumulated data necessary for obtaining the set sensitivity, that is, a temporary reference level at the start, 16 is the sample hold circuit 2 and the resistor 15
A multiplexer 3 connected to the converter 3 converts an analog signal from the multiplexer 16 into a digital signal A-
D converter, 4 is a clock section, and 5 is a CPU which is the heart of the microcomputer. 2 is C in FIG.
The memory map of PU5 is shown. 3 is a main flowchart of the software, FIGS. 4 to 10 are subroutine flowcharts, and FIG. 4 is an example of an initial setting program.
5 is a sensor input reading program example, FIG. 6 is a time reading program example, FIG. 7 is a fire operation program example, FIG. 8 is a fire restoration program example, and FIG. 9 is a setting sensitivity calculation program example.
FIG. 10 shows an example of a past cumulative data rewriting program.
Finally, FIG. 11 shows an example of the passage of the set level with time, a of FIG. 11 shows the conventional sensor, and FIG. 11b shows the case of the embodiment of FIG.

Next, the operation will be described. A fire detection device, such as a fire detector, has a memory RO when the power is turned on.
The operation is started by the control program stored in M1, and first, the set sensitivity as a fire detector is stored in the RAM (FIGS. 3 and 4). That is, since the upper limit setting value, the initial reference setting value, and the lower limit setting value are created by the divided voltage of the resistor 15, the CPU 5 sequentially switches the inputs of the multiplexer 16, and the analog signal is converted into a digital signal by the A / D converter 3. Memory RAM1, RAM
2. Store in RAM3. In more detail,
When the sensor unit 1 is, for example, a scattered light type, the upper limit set value is, for example, smoke of 10% / m in conversion of extinction rate of two kinds of sensitivity defined by Fire Service Act, and extinction rate conversion as noise component. Voltage value corresponding to the output of the sensor unit 1 when detecting 5% / m of dust (15% / m in synthetic extinction ratio) at, for example, 7.5
V) is set by the resistor 15. As the initial reference set value, in addition to smoke of 10% / m in terms of extinction rate, dust of 2% / m in terms of extinction rate (combined extinction rate of 12% / m) was detected as a noise component. Sensor part 1
So that the voltage value (for example, 6V) corresponding to the output of
It is set by the resistor 15. Further, the lower limit setting value is a voltage value (corresponding to the output of the sensor unit 1 when smoke (11% / m in the combined extinction ratio) in which a noise component of 1% / m in the extinction ratio is added is detected ( Resistance 1 so that it becomes 5.5 V)
It is set by 5. In addition, the contents of the memory RAM 8 containing the past accumulated data are all cleared, and the contents of the memory RAM 4, RAM 5, and RAM 6 containing the maximum value, the minimum value, and the average value of the past accumulated data are also cleared (FIG. 4). ).

After the storage and clearing of the data in the memory are completed, the fire detector starts reading the output from the sensor unit 1 at a predetermined interval (FIG. 3). Continuing the description, the output from the sensor unit 1 is amplified by the amplifier and then the output value is held by the sample hold circuit 2. This output is converted from an analog signal to a digital signal by the A / D converter 3 via the multiplexer 16 which switches the set value described above. CP after conversion is completed
A conversion end signal is output to U5. CPU 5 is A-D converter 3
And receives it as data and puts it in the memory RAM 9 for temporary storage. In this case, the CPU 5
One memory RAM1 to RAM9 and one memory ROM1
We shall use and. The CPU 5 reads the current time and day of the week from the clock unit 4 (FIGS. 3 and 6), and reads the cumulative data as data 8 from the address corresponding to the current time and day of the week in the memory RAM 8 for cumulative data. If there is no accumulated data in the data 8, the memory RAM 2 sends the initial reference set value to the digital comparator 12 as a signal. If there is accumulated data as the data 8, the memory RAM1, RA
The upper limit setting value and the lower limit setting value of the operation level are read from M3 as data 1 and data 3, respectively. Also, the memory R
The maximum and minimum values of the noise level of the environment are read as data 4 and data 5 from AM4 and RAM5, respectively. When data 4 = data 5, the initial reference set value is sent from the memory RAM 2 as a signal to the digital comparator 12 as the current or initial setting operation level for fire discrimination. When data 4 ≠ data 5, the maximum value (data 4) and the minimum value (data 5) of the accumulated environmental noise are first calculated.
The ratio of the allowable operating level width determined by the upper limit setting value (data 1) and the lower limit setting value (data 3) of the operation level to the maximum noise width due to

[0012]

## EQU00002 ## Calculated by (data 1-data 3) / (data 4-data 5). The result is set as data 10. Next, the initial reference set value and the average value of the past accumulated data are read as the data 2 and the data 6 from the memories RAM2 and RAM6, respectively.

[0013]

## EQU00003 ## The current set operation level is obtained by the calculation formula of data 2 + .beta..times.data 10.times. (Data 8-data 6). The result is data 11. Note that β is a constant (0 <β ≦ 1). As a result, the current set operation level (set sensitivity) is obtained due to the environmental noise expected from the past accumulated data (FIGS. 3 and 9).

Therefore, the CPU 5 supplies the data 11 to the digital comparator 12 as a signal. On the other hand, the output of the A / D converter 3 is latched and held at a constant value while the CPU 5 is processing it, so that the digital comparator 12 compares the numbers. When the data of the A / D converter 3 is higher than the initial reference setting value or the data 11 which is the calculation output from the CPU 5, that is, the current setting operation level, the output of the digital comparator 12 becomes the level L from the level H. As a result, the latch circuit 13 operates and holds the level L (FIGS. 3 and 7). The latch circuit 13 may be considered as a switching circuit, and the buzzer 14 may be considered as a receiver. Here, the buzzer 14 is sounded to notify the abnormality. Since the output of the digital comparator 12 has changed from the level H to the level L, the CPU 5 determines that the set operation level has been exceeded and does not average the data or process the accumulated data, but reads the data from the sensor unit 1. Continues. When the reset switch RSW is turned on, the latch circuit 13 is reset to release the latch (FIGS. 3 and 8). When the output of the A / D converter 3 becomes equal to or lower than the set sensitivity level, the output of the digital comparator 12 returns to the level H, so that the CPU 5 starts the normal processing in the memory.

When the digital comparator 12 remains at the level H, the CPU 5 judges that the set operation level has not been reached, and the memory RAM containing the current data.
The data of 9 is put into the averaging buffer RAM 7, and the clock unit 4
From the data received from the CPU 5, the CPU 5 determines whether or not it is time to aggregate the time zone data (FIGS. 3 and 10). When it is the total time, a plurality of data collected in the buffer RAM 7 for each 10 minutes, for example, is averaged as data 7, and a memory containing past cumulative data corresponding to the current day and time is stored. The data at a predetermined address in the RAM 8 is read, and from the past accumulated data 8 and the present average data 7, the operating temperature difference is 30 in the case of a constant temperature type fire detector that is particularly susceptible to seasonal factors such as temperature. ℃
In consideration of this, the weighted average of multiplying data 8 by weight 1 and weighting data 7 by weight 2 is performed, and the weighted average result is added to the memory. Only when the lower limit setting value (or the upper limit setting value) stored in the RAM 3 (or the memory RAM 1) is not exceeded, the weighted average result is stored as new accumulated data in the corresponding address of the memory RAM 8, but it is exceeded. Memory RAM3 (or memory RAM if
The data of 1) is stored in the memory RAM 8 as cumulative data (FIG. 10). This means that extremely large weighted average results exceeding the lower limit setting value (or the upper limit setting value) are not used as data. In this way, RAM
8 stores, for each time zone, accumulated data obtained by averaging data collected in the time zone in the past, that is, cumulative average data.

Then, all the data in the memory RAM 8 are checked, and the maximum value and the minimum value are stored in the memory RAM 4 and RAM 5, respectively (FIG. 10). The memory ROM 1 stores a control program, initial setting values, data aggregation time, and the like. In this way, the contents of the past cumulative data will change as time passes, and the maximum and minimum values of environmental noise will fluctuate.Therefore, depending on the environment in which the fire detector is installed, every day of the week and time of day It is possible to change the sensitivity level appropriately.

By the way, when obtaining an average value of a plurality of data in the averaging buffer RAM 7 in the time zone,
As described above, the average value may be obtained from the data excluding the maximum value and the minimum value.

Furthermore, in order to obtain the current set operation level, that is, the set sensitivity, as described above, for example, the smoke density 10
%, A standard value such as a temperature of 50 ° C is set, and the memory ROM1
Alternatively, the standard value may be stored in advance and the data 8 which is the accumulated data in the time zone may be added to obtain the current set operation level.

In order to create new cumulative average data for that time period, a new average value is obtained from the average value of a plurality of data newly detected during that time period and past cumulative data. However, instead of collecting multiple data in that time zone, as described above, read the data only at a specific time in that time zone and obtain the average value of that one data and past cumulative data. You may The second memory 7 stores, as the reference value change time, an even time every two hours, for example. In other words, the sensitivity is switched in even time.
Calculations are made based on the data for 1 o'clock at 2 o'clock, and based on the data for 3 o'clock at 2-4 o'clock.

In this embodiment, the sensor unit 1, the sample and hold circuit 2 and the A / D converter 3 constitute a physical quantity measuring means, the memory RAM 8 constitutes a storing means, and the CP
U5 and the memory RAM7 constitute an arithmetic means, and the CPU5
Constitutes a memory updating means, the CPU 5, the resistor 15 and the memories RAM1 to RAM3 constitute a sensitivity setting means, the digital comparator 12 constitutes a fire discriminating means, and the latch 1
3 (switching circuit) constitutes an output means. Further, in the calculating means, the CPU 5 and the memory RAM 7 constitute the first averaging means, the CPU 5 constitutes the second averaging means, and in the sensitivity setting means, the resistor 15 and the memory RA.
M1 to RAM3 constitute a means for giving an upper limit setting value, a lower limit setting value and a reference setting value, the CPU 5 constitutes a means for obtaining a maximum value, a minimum value and an average value and a means for obtaining a setting sensitivity, and the memory ROM1 is CP as standard value storage means
U5 constitutes a reference value setting means.

In the fire detecting device according to the present invention, past accumulated data of the environmental noise in which the sensor unit is installed is stored, and the present setting sensitivity is determined based on the accumulated data. Therefore, the environmental noise fluctuates with time. In this case, if the noise level is high, the sensitivity becomes dull, and if the noise level is low, the sensitivity is increased and the self-sensitivity is automatically adjusted so that the influence of the season and the ambient temperature can be removed and the appropriate fire detection sensitivity can always be maintained. it can.

[0022]

As described above, according to the present invention, the storage update means updates and stores the accumulated average data of the past detected physical quantity signals for each time zone or each day of the week in the corresponding time zone of the storage means. The fire discrimination setting sensitivity of the relevant time zone is determined from the cumulative average data of the relevant time zone stored in the storage means. In this way, the fire discrimination setting sensitivity is determined by the time zone or the day of the week. Since it is determined by the past detected physical quantity signal for each time zone, the setting sensitivity most suited to the environmental condition is determined for each time zone,
Thereby, the detection of the fire occurrence performed by comparing and discriminating the detected physical quantity signal of the physical quantity measuring means at the present time and the set sensitivity in accordance with the environmental condition in the time zone corresponding to the present time determined by the sensitivity setting means, This has the effect that the fire detection sensitivity can always be kept constant.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a fire detection device according to the present invention.

FIG. 2 is a diagram showing a memory map of a CPU 5 in FIG.

FIG. 3 is a main flow chart showing an example of software for explaining the operation of FIG.

4 is a flowchart showing an example of an initialization program which is a subroutine of FIG.

5 is a flowchart showing an example of a sensor input reading program which is a subroutine of FIG.

6 is a flowchart showing an example of a time reading program which is a subroutine of FIG.

FIG. 7 is a flowchart showing an example of a fire operation program which is a subroutine of FIG.

8 is a flowchart showing an example of a fire recovery program which is a subroutine of FIG.

9 is a flowchart showing an example of a setting sensitivity calculation program which is a subroutine of FIG.

10 is a flowchart showing an example of a past accumulated data rewriting program which is a subroutine of FIG.

11 is a waveform diagram showing an example of a set level over time, where a is an example of a conventional sensor and b is the case of the embodiment of FIG.

[Explanation of reference numerals] 1 sensor unit 2 sample and hold circuit 3 A / D converter 4 clock unit 5 CPU 12 digital comparator 13 latch 15 divided voltage resistor 16 multiplexer RAM1 to RAM9, ROM1 memory

Claims (7)

[Claims] 1. The fire phenomenon of smoke , heat, light, gas, etc.
And detecting a physical quantity of a fire phenomenon of Zureka, it was the detected physical
And a physical quantity measuring means for converting the quantity into an electric physical quantity signal and outputting the electric quantity, and an electric means for storing cumulative average data of the past detected physical quantity signals in each time zone by time zone or by day of the week a storage means freely out read-inclusive can write to, the appropriate time corresponding to the current time zone, which is stored in the storage means
Fire discrimination in the current time zone from cumulative average data of the zone
Sensitivity setting means for determining the setting sensitivity for use, a physical quantity signal at the present time by the physical quantity measuring means, and
The time corresponding to the present time determined by the sensitivity setting means
Determines whether or not a fire has occurred by comparing and determining the setting sensitivity of the belt
Output means for outputting the result of the comparison between the fire discrimination means and the fire discrimination means.
And stage, the data aggregation time of each time zone, a plurality of <br/> including one or more physical quantity signal of the physical quantity signal detected by the physical quantity measuring means during the time period, of the storage means The above
Calculating means for computation of the new cumulative average data from the accumulated average data in the time zone corresponding to that time period, corresponding to said new cumulative average data calculated by said calculation means
Fire sensing device characterized by comprising a storage updating means for the corresponding time zone update stored in the storage means as a cumulative average data time zone. 2. The arithmetic means obtains cumulative average data by a simple average or a weighted average.
Fire detection device as described. 3. The calculating means includes first averaging means for obtaining an average value of a plurality of detected physical quantity signals obtained from the physical quantity measuring means in a current time zone, and current time obtained by the first averaging means. New cumulative average from the average value of the zone and the cumulative average data of the time zone corresponding to the current time zone of the storage means
Fire detection apparatus according to claim 1 or 2, characterized in that it is constituted by a second averaging means for obtaining the data. 4. The maximum average detected physical quantity signal and the minimum detected physical quantity signal among a plurality of detected physical quantity signals
Fire detection apparatus according to claim 3, wherein the average value from the detected physical quantity signals except the signal. 5. The fire detection device according to claim 3, wherein the second averaging means obtains cumulative average data by weighted averaging. 6. The sensitivity setting means for determining the set sensitivity is stored in the storage means, and means for giving an upper limit setting value, a lower limit setting value and a reference setting value between the upper and lower limit values of the setting sensitivity. means for determining the maximum value and the minimum value and average value of a plurality of cumulative average data, the upper limit set value a obtained by the means, the reference set value B, the lower limit set value C, the cumulative average de
From the maximum value D of the data , the average value E of the cumulative average data in all time zones, the minimum value F of the cumulative average data, and the cumulative average data X corresponding to the current time zone stored in the storage means, The fire according to claim 1, further comprising means for calculating B + [{β (A-C)} / (DF)] (X-E) (where β is a constant) to obtain a current sensitivity setting. Sensing device. 7. The sensitivity setting means for determining the set sensitivity is a standard value storage means for storing a change amount of a physical quantity caused only by a fire phenomenon as a standard value of a fire determination level, and the storage means for storing the standard value. 2. The fire detection device according to claim 1, further comprising: a reference value setting means for adding the cumulative average data of the relevant time zone stored in, and determining the setting sensitivity as a reference value for discriminating the fire during the time zone.