JPS60134999A - Fire alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fire alarm system that determines a fire by predicting and calculating the degree of danger based on analog detection data such as temperature, gas concentration such as CO, and smoke concentration. .

Conventional fire alarm systems generally turn on the fire detector,
Since the off signal is received by the receiver to notify fire, and fire detection is dependent on the fire detector, false alarms are likely to occur due to causes other than fire, and fire detectors are required to prevent false alarms. There was a problem in that reducing the detection sensitivity of fire caused a time delay in fire detection.

For this reason, in recent years, progress has been made in the development of so-called analog fire alarm devices in which analog detection data from a fire detector is sent to a receiver, and the receiver makes a fire judgment. A fire alarm system has been proposed in Japanese Patent Application No. 58-29976. - In this device, the degree of danger is defined as the time required for the environmental condition to reach a dangerous state for humans in the near future due to the progression of physical changes in the surrounding environment due to the occurrence of a fire, and the degree of danger to the mouth was sampled this time. A prediction calculation of the degree of danger using the so-called difference method based on the difference between detected data and the previous detection data, or a prediction calculation of the degree of danger using the so-called function approximation method that approximates the physical change due to a fire using a predetermined polynomial. is executed, and when the calculated danger level is below a certain time, it is determined that there is a fire.

However, when determining fires using such predictive calculations, regardless of the detected data, predictive calculations are performed using the difference method or function approximation method every time detected data is sampled at a predetermined period to determine the presence or absence of a fire. Therefore, when detection data from multiple analog detectors was sampled sequentially, it took time to process each sampled data, resulting in a large time delay for fire alarms. Ta.

The present invention was made in view of these problems, and
To provide a fire alarm device which prevents a delay in issuing a fire alarm by shortening the time required for a fire alarm in a state of low danger.

To achieve this objective, the present invention provides a fire alarm system that detects changes in physical phenomena in the surrounding environment due to the occurrence of a fire in an analog manner, samples this detected data at predetermined intervals, and determines whether or not there is a fire. A fire is determined by calculating the danger to humans of physical changes in the surrounding environment caused by a fire from the detected data, and prohibits calculation of the danger until the detected data reaches a predetermined level, and when the danger exceeds a predetermined level. The system is designed to issue a command to start calculation of the danger level only when the

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

First, to explain the configuration, Ia, Ib, ... 1n are analog detectors that detect changes in physical phenomena in the surrounding environment due to the occurrence of fire, and detect temperature, gas concentration, smoke degree, etc. It has a built-in detection unit 2 and a transmission circuit 3 that transmits lζ detection data detected by the detection unit 2. Reference numeral 4 denotes a receiver connected to the analog detectors 1a to In@signal line 5, which performs arithmetic processing based on the detection data from the analog detectors 18 to 1n, and this calculation is performed by, for example, program control by a microcomputer. executed.

In the receiver 4, 6 is a receiving circuit, which sequentially samples the detection data of the analog detectors 18 to 1n at regular intervals, and extracts, for example, three consecutive detection data of one detector with one sampling. do. 7 is the receiving circuit 6
8 is an average value calculation circuit that calculates the average value of the three digital detection data obtained at each sampling.

The calculated data of the average value calculation circuit 8 is given to a memory circuit 9, which has a memory address for each analog detector 18 to 1n, and the average value data added to each address by 1q every sampling period. are memorized sequentially.

On the other hand, the calculation data of the average value calculation circuit 8 is given to the comparison circuit 10, and the comparison circuit 10 compares the average value data with a threshold value Dr set as a predetermined alarm level. 1-11 is a difference value calculation circuit, and calculation is started by the comparison output of the comparison circuit 1O, and the current detection data (average value) Δ
Difference Sn between n and previous detection data (average value) A n-1
Calculate the slope α, α=Sn/(sampling period)
(1) Do it. Divide the danger level, for example, the value obtained by subtracting the current detection data (average value) Δ[) from the danger temperature Td, by this slope α to calculate the danger level R from R=<Td−An>/α (2>).

Reference numeral 12 denotes a risk level determination circuit using a difference method, which compares the risk level R calculated by the difference value calculation circuit 11 with a lower limit threshold R1 and an upper limit threshold R2 of the level of risk, and the smaller the value of the level of risk, the higher the level of danger. Therefore, if it is less than the lower limit threshold R1, the alarm display circuit 15 is activated, and if it is between R1 and R2, an output is generated that instructs the calculation of the degree of danger by the following function approximation method, and furthermore, if the upper limit amount (iQ is more than R2) In some cases, no output is generated.

Reference numeral 13 denotes an approximation formula calculation circuit, which performs a calculation when the risk level 1 (is between threshold values R1 and R2) in the risk level determination circuit 12, and calculates the level of risk using a function approximation method.

As a function approximation method using this approximation formula calculation circuit 13, for example, if we take temperature as analog detection data, we define an approximation formula that becomes F (X) −gaX +l)X+c (3) i'/) , , Constants a and b in equation (1).

C stored in the memory circuit 9 (from 10), if the dangerous temperature corresponding to the degree of danger is Td, the dangerous temperature Td
The risk level R, defined as the time it takes to reach F, is
(x)=Td, so R= l-b ± ++
4a(Td-c))/2a (4).

Reference numeral 14 denotes a risk level judgment circuit, which sets a predetermined time period until the environmental condition reaches a dangerous state for humans in the near future due to the temperature caused by the occurrence of a fire as a risk level threshold value Rs. The risk R calculated in step 13 is the threshold R
When it becomes 3 or less, it is determined that there is a fire and the alarm display circuit 15 is activated.
I am trying to make it work.

Next, the operation will be explained with reference to flowcharts 1 to 1 in FIG.

First, the receiving circuit 6 sequentially samples the detection data from the analog detectors 1a to 1n. For example, taking the detection data of the analog detector 1a as an example, as shown in block a of FIG. 2, the sampling data D1 ．． D2.・・・
After detecting []n and digitally converting it in the A/D conversion circuit 7, as shown in block b, the average value calculation circuit 8 calculates the average value A1 . A2.・
. . 80 is calculated and sequentially stored in the memory circuit 9.

The average value △n calculated by the average value calculation circuit 8 is calculated by the block C
As shown in FIG.
) r, and if the average value 〇 is smaller than the threshold 1) r, repeat the process of block a and 1).

On the other hand, when the detected data exceeds the threshold value Qr at time t2 as shown in the graph of FIG. It commands the start of the subsequent arithmetic processing by the port section.

This arithmetic processing is performed by calculating the difference value 3n using the differential circuit 11 as shown in blocks d, e, and f, as shown in −4.
As the difference between 1Δn and the previous average value An-+, the above 1(
1) Obtain the slope α from equation (2) and finally calculate the risk R using the difference method.

Next, as a process of the risk level discrimination circuit 12, a discrimination block 9 compares it with the lower limit threshold value R1, and if the risk level R is less than the lower limit threshold level R1, the process proceeds to block k, where the alarm display circuit 15 detects the fire alarm display by analog detection. Do this together with the outbreak area corresponding to the container.

1) If it exceeds 1, the upper limit threshold R2 is compared in the determination block h. In decision block h, danger II R
If it exceeds 1 (2), it returns to block a again, and on the other hand,
When the risk level R is equal to or lower than R2, that is, when the risk level R is between R1 and R2, the process proceeds to block i and calculates the level of risk using the function approximation method based on equation (4).

Next, as shown in the judgment block J, the risk judgment circuit 1
The risk level R calculated by 4 is the predetermined risk level threshold R.
3 or less, and if it is less than @l+fl Rs, it is determined that there is a fire and a warning is displayed for the ship's side. Of course, if the drawing risk melon 1R is greater than the risk threshold R3 in the determination block j, the process returns to block a again to sample the next detection data.

In this way, in the embodiment shown in FIG. 1, the risk calculation process for the difference method and function approximation method is not executed until the detected data (average value) reaches the alarm level I), and the detected data ( When the average value) exceeds the alarm level l)r, calculation of the degree of danger using the difference value and function approximation method is executed for the first time, so if data from multiple analog 1 cog detectors are sampled sequentially. Since a fire judgment is made by calculating the degree of danger using the difference method and function approximation method only for the detection data of analog detectors for which detection data exceeding the fire alarm level was obtained, arithmetic processing was performed on all detection data. Compared to the case where the fire is calculated, the time delay required to calculate the fire is shorter, and early detection of the fire can be realized through predictive calculation.

FIG. 4 is a flowchart showing another embodiment of the present invention, and this embodiment further sets a predetermined level Qs below the alarm level [)r at which predictive calculation is started, as shown in FIG. For example, at time [1, the detected data reaches a predetermined level Qs
When the detection data reaches the danger level Dr, the danger level is calculated using the difference method and the function approximation method, and when the danger level becomes below the threshold value, a pre-alarm is issued and the next detection data is below the danger level Dr. The present invention is characterized in that a fire alarm (main alarm) is issued if the alarm level Dr is exceeded as shown at time t2.

That is, following the data sampling and calculation of the average value in blocks a and b, the discrimination block C compares the average value An of the horizontal hole data with a predetermined level [S, and calculates the average of detected data+tl! An is the predetermined level 1. If it is JDS or higher, proceed to judgment block d and determine the risk level 1 using the two-part method.
The calculation of R, namely block d of the flowchart in FIG.
Execute processing 3g with the contents shown in e and f, and then determine the risk level R in decision blocks e and f]; III! Comparison judgment with threshold value R1 and upper limit threshold value R2 is carried out (1).
Compare the average value) A port and the alarm level [)r, and if it is below the alarm level Dr, perform a pre-alarm in block j\, while if it exceeds the alarm level [)r, the block will be activated. Displays the alarm (main alarm).

Further, when it is determined in the discrimination blocks e and f that the risk level R is between R1 and R2, the risk level R is calculated by the function approximation method in block 9, and the risk level threshold is set in the discrimination block i. Compare R and S, and if R3 or less, the detection data at that time in discrimination block i (average t@) A
Compare n with the alarm level Dr, and if it is lower than the alarm level l)r, a pre-alarm is issued in block j, and if it is higher than the alarm level Qr, an alarm is displayed (main alarm) in the block.

According to the embodiment shown in FIG. 4, when a predetermined level is reached before the alarm level is reached, a pre-alarm is issued based on the fire judgment based on the calculation of the degree of danger. Countermeasures can be prepared in advance for the actual warning when a fire is determined based on the calculation of the degree of risk using the function approximation method, and prompt countermeasures can be taken based on the actual warning.

As explained above, according to the present invention, in a fire alarm system that detects physical changes in the surrounding environment due to the occurrence of a fire in an analog manner, and determines a fire by calculating the degree of danger from this detection data, a predetermined Since a command is given to start calculation of the degree of danger when the detection data sampled at each cycle exceeds a predetermined value, the calculation of the degree of danger continues until the detection data reaches a certain level. , l't
Even if a fire judgment is made by sequentially sambling the detection data from multiple analog detectors, the sampling period of the detection data can be shortened by the fact that calculation processing of the degree of danger is not performed, and the fire judgment This can prevent time delays.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and FIG.
The figures are flowcharts 1 to 1 showing the operation of Fig. 1, Fig. 3 is a graph showing the setting state of alarm levels and predetermined levels in response to changes in detected values, and Fig. 4 shows another embodiment of the present invention. The flowchart shown is i~. 18 to 1n; Analog detector 2: Detection unit 3: Transmission circuit 4: Receiver 7: A/D conversion circuit 8: Average value calculation circuit 9: Storage circuit 1O: Comparison circuit 11: Difference value calculation circuit 12: Risk level Judgment circuit 13: Approximate formula calculation circuit 14: Risk level '1' 1 constant circuit 15; Alarm display circuit Patent applicant: Hochiki Co., Ltd. Agent, Patent attorney Susumu Takeuchi

Claims (1)

[Scope of Claims] A fire alarm device that detects changes in physical phenomena in the surrounding environment due to the occurrence of a fire in an analog manner, samples the detected data at predetermined intervals, and determines whether there is a fire; risk determination means for determining a fire by calculating the degree of danger to humans due to physical changes in the surrounding environment, and prohibiting the calculation of the degree of danger in the danger determination means until the detected data reaches a predetermined level. . A fire alarm device, further comprising calculation control means for instructing the start of calculation of the degree of danger when detected data exceeds a predetermined level.