JP2582847B2 - Fire alarm - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fire alarm device for judging a fire abnormality based on a physical quantity such as heat, smoke or gas, and more particularly to a fire alarm device which is activated when a sign of the abnormality is detected. Alternatively, the present invention relates to a fire alarm device that starts a fire determination routine for fire determination, such as arithmetic processing such as integration, differentiation, or difference, or pattern determination, by applying a trigger.

[Prior art and problems] It is possible to perform a fire determination by processing, for example, a digitized analog quantity signal output by a fire phenomenon detection means by arithmetic processing such as integration, differentiation or difference, or pattern determination. It is considered.

If you always run such a fire detection routine,
There are problems such as an increase in current consumption, an increase in time required for determination processing, and a delay in other processing.

For this reason, the fire discrimination routine is normally set to a halt state, and when the analog amount signal exceeds a predetermined level, that is, when the analog level signal exceeds a fixed level, the fire discrimination routine is triggered to execute fire discrimination such as arithmetic processing. It is possible.

However, in this case, fluctuations in environmental noise components such as temperature, humidity, dust, light, or a volatile liquid (a gas component is emitted with paint, etc.) The difference between the level of the analog quantity signal and the fixed level is not constant but constantly fluctuates due to contamination or deterioration of the detecting element such as the light receiving element. For this reason, when the difference is large, for example, at nighttime when the environmental noise component is small, the level of the analog amount signal does not easily reach the fixed level, and the trigger of the fire determination routine is greatly delayed. When the difference is small or 0,
For example, in the daytime when the environment noise component is large, the fire discrimination routine is immediately triggered or remains in the triggered state, and therefore, there is a problem that an error is caused in the result of the fire judgment and a correct fire judgment cannot be performed. Would.

[Means for Solving the Problems] The present invention seeks to detect a state in which the environment goes from normal to abnormal, that is, a state showing signs of abnormality, from the temporal gradient of the physical quantity, that is, the analog quantity signal level.
It is an object of the present invention to provide a fire alarm device which is not affected by environmental noise, contamination or deterioration of elements by triggering or starting a fire determination routine when the inclination exceeds a predetermined inclination. .

Therefore, according to a specific embodiment of the present invention, a change rate determining means for determining a change rate of a physical quantity of a fire phenomenon detected by a fire phenomenon detecting means based on a plurality of latest samples, and a change rate determining means Holding means for holding any physical quantity of the plurality of samples as a reference physical quantity when the rate of change determined by the control means exceeds a predetermined value; and holding the reference physical quantity by the holding means. A fire discriminating means for starting an operation for discriminating a fire based on the reference physical quantity and the physical quantity detected by the fire phenomenon detecting means from the time when the fire is detected. Is provided.

[Operation] The rate-of-change determining means determines the temporal gradient or rate of change of the analog quantity signal level based on the latest plurality of samples of the physical quantity, that is, the analog quantity signal level, for example, using the least square method, the average vector method, It is determined by a method for obtaining the inclination.

Further, since the holding unit holds any of the plurality of samples as a reference physical quantity, the reference physical quantity thus held is, for example, the first data of data determined to exceed a predetermined slope, that is, the level change. Can be used as the data at the time when it starts appearing, whereby the fire discrimination means can perform a stable fire discrimination process without malfunction.

Example An example of the present invention will be described below.

FIG. 1 shows an embodiment in which the present invention is applied to an optical smoke detector. In the drawing, RE is a receiver, DE is a plurality of sensors connected to the receiver RE, FIG. 1 shows only one of them. L _{1 to} L _n are, for example, a pair of power / signal lines to which a plurality of detectors DE are connected.

In the sensor DE, the MPU is a microprocessor, the ROM 1 is a storage area for a program, an example of which is shown in the flowchart of FIG. 2, and the RAM 1 is a work area, a part of which is shown in FIG. A storage area for the analog level signal level, that is, the output level is provided.

FS is a fire phenomenon detection means, and shows an optical smoke detection unit as an example.

LED is a light-emitting element such as a light-emitting diode, DR is a light-emitting circuit that causes the light-emitting diode LED to emit light at predetermined time intervals, for example, and SB is, for example, a solar light that receives light scattered by smoke of light emitted from the light-emitting diode LED. Light receiving elements such as batteries, AM is an amplifier, and SH is an amplifier AM synchronized with light emission of a light emitting diode LED.
AD is an analog-to-digital converter for converting an analog signal into an analog quantity signal of a digital signal, TRX is a fire signal transmitting unit, and IF1 and IF2 are interfaces.

The operation of FIG. 1 will be described with reference to the flowchart of FIG.

To read the sensor output level SLV, light emitting circuit DR
Is driven at predetermined time intervals, for example, every two seconds to cause the light emitting element LED to emit light. When the scattered light emitted from the light emitting element LED and scattered by the smoke is received by the solar cell SB, the solar cell SB generates an electric signal corresponding to the received light and samples it through the amplifier AM.・ Hold circuit
SH, where it is held at predetermined time intervals. The signal held in the sampling and holding circuit SH is converted into a digital analog signal by the analog-to-digital converter AD, and is output to the interface IF1 as a detection output level in the fire phenomenon detection means FS, that is, a sensor output level SLV.

In this way, when the sensor output level SLV is read into the microprocessor MPU side at predetermined time intervals from the fire event detecting means FS via the interface IF1 (step 201), the read sensor output level is processed. Is stored in the storage area RAM1 (step 202). At that time, the oldest data is discarded.

A sensor output level storage area for storing the sensor output level in the work area RAM1 is shown in FIG. 3, and this area includes N pieces of data, that is, storage locations of the sensor output level. The latest data, i.e., the sensor output level, is stored at the top of the storage area, the data stored up to that point is sequentially shifted down one by one, and at the very end, i.e., at the bottom. Data is discarded. In this way, the latest N data are always stored.

Here, the case where a new sensor output level is given to the sensor output level storage area at predetermined time intervals and updated is shown, but the update of the sensor output level in the storage area is updated at predetermined time intervals. Instead, it may be a long time interval, for example, every 30 samples, that is, every other minute.

When the latest sensor output level SLV is stored in the uppermost position of the sensor output level storage area in the work area RAM1, the N sensor output levels stored next in the sensor output level storage area are stored. On the basis of the sensor output level, a rising tendency of the sensor output level, that is, a gradient m of the sensor output level with respect to time is obtained by the least square method (step 20).
3). The sensor output level of N data is set to SLVn (n = 1).
ＮN), assuming that the time between data, that is, the sampling interval is 1, the slope m of the N pieces of data is determined by the least square method. Can be obtained by The inclination obtained in this way is conceptually shown in FIG.

Here, the method of obtaining the gradient m is shown by the method of least squares, but various methods are conceivable for obtaining this gradient. For example, the mean vector method,
A simple inclination (for example, a ratio between two points or a difference between two points divided by a time interval therebetween) may be used.

When a slope m based on N data is obtained, the slope m
Is compared with a reference value A of a slope to be triggered, which is exemplarily shown in FIG. 4 (step 204). If the slope m is smaller than the slope reference value A (N in step 204),
For example, if the inclination is as shown as the inclination B in FIG. 4, the next new sensor output level is read in step 201, and the same operation from step 202 is performed.

If the slope m is equal to or larger than the reference value A (Y in step 204), a fire determination routine is performed to monitor and monitor the sensor output level to determine whether or not a fire is abnormal (step 205). ). Examples of the fire determination routine that can be adopted here include, for example,
There is one described in the specification of a patent application entitled Fire Alarm Applied on March 1, 2013. In order to avoid false alarms, this patent application specification describes that when a trigger is applied, that is, when the slope m exceeds a reference value A of the slope, a rising function is generated, and after the trigger, the sensor output level is higher than the rising function by C. Only when the value exceeds a large value, a fire is determined. Further, as another example, the sensor output level is integrated from the time when the output slope m exceeds the slope reference value A at the trigger point level, and the integrated value reaches a predetermined reference integrated value. A routine that sometimes determines that a fire has occurred may be used, and various other types of so-called fire determination routines may be employed here.

Here, the fire determination routine of step 205 described in the specification of the patent application will be described in more detail. That is, when m inclination as shown in FIG. 2A exceeds the reference value A of the slope (Y in step 204) to hold the sensor output level V ₁ of the at that time as a level V _T of the trigger point (step 211), generating a rising function V _T + aT = V ₃ based on the value of the trigger point level V _T (step 213). Here, T is the number of times of sampling of the sensor output level after the trigger point, and a is a constant determined by environmental conditions. If if the sensor output level V ₁ to trigger after is less than the value V ₃ of the rise function, but the trigger (N in step 214) is released, if the value V ₁ of the trigger after the sensor output level in the opposite rising function V If the difference is equal to or greater than the difference C from the value of ₃ (Y in step 206), it is determined that a fire has occurred. Since the one described in this patent application monitors a certain width from a rising function that rises as a function of time after triggering in this way, it can be used under environmental conditions such as a sudden rise in temperature. Significantly reduce the possibility of misinformation.

After the fire determination routine in step 205, if it is not determined that a fire has occurred (N in step 206), step 2
Returning to step 01, the next sensor output level is read and stored at the top of the sensor output level storage area in FIG.
203), the slope m is similarly obtained by the least squares method based on the new N sensor output levels.

If it is determined that a fire has occurred (Y in step 206), a so-called fire operation of transmitting a fire signal to the receiver RE by operating the fire signal transmission unit TRX via the interface IF2 is performed (step 207). At this time, the fire signal transmitting unit TRX may transmit its own address together with the fire signal.

A fire signal from the fire detector is received by the receiver RE, the receiver RE is judged whether it has received the fire signal from any of the line L ₁ Ln, and displays the generated fire alarm district fire . If the fire detector also sends out its own address, the location of the fire or the fire detector that has operated is also determined from the received address signal and displayed together.

In the above embodiment, the case where the present invention is applied to a fire alarm device in which a fire detector performs a fire determination and transmits a fire signal and / or an address signal to a receiver has been described. Is an analog fire alarm that sends a physical quantity signal of the detected fire phenomenon, and performs a fire discrimination based on the physical quantity signal sent from the analog fire sensor with a receiver or a relay device, so-called analog fire alarm The present invention can be applied to an apparatus.

In the case where the present invention is applied to a fire alarm device in which a fire is determined by a receiver or a repeater as described above, the fire detector DE is an analog fire detector (fire sensor) in FIG. ROM1 and RAM1 are receiver RE
Relocated to. The receiver RE is provided with a microprocessor, and the RAM 1 in the receiver RE is provided with sensor output level storage areas shown in FIG. 4 for the number of connected sensors. Then, a program for executing the flowchart of FIG. 2 is added to the ROM 1 in the receiver RE by polling the connected sensor to collect an analog amount signal and collecting the analog amount signal every time the sensor is collected.

On the other hand, the sensor DE determines whether or not a call has been received from the receiver RE by polling, and sends a detected analog amount signal of the fire phenomenon detection means FS to the receiver RE through the transceiver TRX when the call is received. And a working RAM are provided.

[Effects of the Invention] As described above, according to the present invention, the temporal gradient of the analog amount signal level, that is, the sensor output level is obtained, and when the gradient exceeds a predetermined gradient, that is, the reference gradient, the fire determination routine is triggered. With such a configuration, there is an effect that the influence of environmental noise, contamination of the element, deterioration, and the like is not exerted when the fire is determined.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a fire alarm device according to one embodiment of the present invention, FIGS. 2 and 2A are flowcharts for explaining the operation of FIG. 1, and FIG. 3 is a work area.
FIG. 4 is a graph showing a sensor output level storage area in the RAM 1, and FIG. 4 is a graph conceptually showing a gradient of the sensor output level obtained by the least square method. In the figure, RE is a receiver, DE is a sensor, MPU is a microprocessor, ROM1 is a program storage area, RAM1 is a work area, and FS is fire phenomenon detection means.

Claims (1)

(57) [Claims] 1. A change rate determining means for obtaining a change rate of a physical quantity of a fire phenomenon detected by a fire phenomenon detecting means based on a plurality of latest samples, and a change rate determined by the change rate determining means. However, when the predetermined physical value exceeds a predetermined value, holding means for holding any physical quantity of the plurality of samples as a reference physical quantity, from the time when the reference physical quantity is held by the holding means,
A fire alarm device comprising: a fire discriminating means for starting an operation for fire discrimination based on the reference physical quantity and the physical quantity detected by the fire phenomenon detecting means.