JPH07122916B2 - Fire alarm - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a fire alarm device, and more particularly to a fire alarm device itself, or a fire alarm caused by data sent from a fire sensor to a receiver via a transmission path. The present invention relates to a fire alarm device for judging.

[Prior Art and its Problems] As a detector or sensor for detecting a fire, a photoelectric smoke sensor, a thermal sensor using a thermistor, and an ionization or radiation sensor are known. Each of these fire detectors detects a given smoke density, a given temperature, or a given radiant light from a fire,
I am trying to give a fire signal.

However, in such a system, even transient smoke such as cigarette smoke may operate beyond the predetermined detection level.

Therefore, there is also known a storage-type sensor or receiver that does not operate due to such a transient fire phenomenon and that does not operate unless a predetermined output continues for a certain period of time using a timer or the like. However, there was a drawback that fire detection was delayed.

Furthermore, in a room where a ventilator is working, the effect causes, for example, a gradual increase in smoke concentration, and the smoke concentration that finally activates the smoke detector is not reached, and a fire alarm is not issued, that is, a failure is reported. There were also cases such as.

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems, and does not malfunction in a transient, fire-like phenomenon such as cigarette smoke.
Another object of the present invention is to provide a fire alarm device capable of reliably and promptly detecting and issuing an alarm in the case of an actual fire even if the fire is a gradual rise.

[Means for Solving Problems] Therefore, according to the present invention, an ascending function that predicts the sensor output level after a predetermined time is calculated as a reference function with a certain time point as the origin of the coordinate, and the reference function and the actual function are calculated. The fire alarm is generated when the integrated value of the difference between the sensor output level and the sensor output level reaches a predetermined integrated value.

Specifically, according to the present invention, the sensor output level (SL
In a fire alarm device adapted to judge a fire based on V), sampling means for sampling the sensor output level at predetermined time intervals (Δt) (step 103)
And a reference function generating means (ROM3, steps 101, 104, and 10) for generating a reference function (R) that gradually increases as a function of time.
6), and an integrating means for accumulating the difference (SLV-R) between the sampled sensor output level equal to or higher than the reference function and the reference function at each of the predetermined time intervals (step 10).
7) and the value (SI) accumulated by the accumulating means are compared with a predetermined accumulated value (A) to determine when the value accumulated by the accumulating means reaches the predetermined accumulated value. A fire alarm device is provided, which comprises: a determining means (step 108) for outputting a signal indicating an abnormality.

[Operation] The sensor output level SLV is sampled at a predetermined time interval Δt by the sampling means, and the sampled sensor output level equal to or higher than the reference function R gradually increases as a function of the time t, and the reference function. The difference SLV-R from R is calculated by the accumulating means as the predetermined time interval Δ.
Accumulate every t.

The determining means compares the value SI integrated by the integrating means with a predetermined integrated value A to determine when the value SI integrated by the integrating means reaches the predetermined integrated value A. A signal indicating an abnormality is output.

As described above, since a signal indicating an abnormality is output only when the integrated value with respect to the time of the reference function which gradually increases as a function of time and above and the part reaches a predetermined integrated value A, the reference function is used. Compared to the case of using a constant level value, it further reduces the possibility of malfunction due to a sudden rising fire, and nevertheless ensures fire detection for a slowly rising fire. . Therefore, even if the rise of the sensor output level at the time of a fire occurs, stable fire detection is possible.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. 1A
The figure shows the output level of the fire sensor with respect to time. In FIG. 1, the horizontal axis shows the time t, and the vertical axis shows the output level SLV of the fire sensor.

First, when the operation of the present invention is roughly described, first, when the sensor output level SLV (t) which is a function of time is smaller than the initially set reference function, based on the smaller sensor output level, As long as the reference function is updated and thus the increase rate of the sensor output level is smaller than the increase rate of the reference function, the reference function continues to be updated. If the sensor output level SLVx at a certain reception time tx is equal to or higher than the latest reference function, the latest reference function is the sensor output level SLVx.
And f (SLVx, t−tx) based on the time tx,
Then, the sensor output level equal to or higher than the latest reference function f (SLVx, t-tx)) is integrated by SI (t) = ∫ [SLV (t) -f (SLVx, t-tx)] dt. After that, when the integrated value SI (t) reaches a predetermined integrated value, an abnormal signal for generating an alarm is output at that time, and the integrated value SI (t) reaches the predetermined integrated value. If the sensor output level is below the reference function, that is, SLV (t) ≤ f (SLVx, t-tx), the integrated value SI (t) up to that point is cleared and the reference function is updated again. To do.

The reference function is determined in consideration of a change in the sensor output level due to a change in the environment, and various ones can be adopted, but in the following, a linear expression with a coefficient M, f (SLVx, t−t
The case of x) = SLVx + M (t−tx) will be described as an example.

In the embodiment of the present invention described with reference to FIG. 1, the reference function samples the sensor output level SLV at every predetermined time interval Δt, and the sampled value and the time ti _{0 at} each predetermined time interval Δt are used. has to be set on the basis of, in this case, the elapsed time ti-ti ₀ from time ti ₀ is, ti-
It can be represented by ti ₀ = i · Δt. Therefore, in FIG.
Assuming that the sensor output level becomes equal to or higher than the latest reference function R at time t ₀ or immediately thereafter, the reference function R is R = SLV ₀ + M (t−t ₀ ) = SLV ₀ + M · i · Δt Can be represented by From this time t ₀ , the sensor output level SL
The integration of V with respect to the reference function is started with respect to time. Specifically, this integration is performed from the sensor output level SLVi to the latest reference function SLV ₀ + M · i · Δt.
Is added up every time interval Δt, that is, Is calculated. Here, SLVi is the value of the sensor output level SLV at times t ₁ , t ₂ , t ₃ , ..., Ti at each time interval Δt. Therefore, in the case of FIG. 1, i) at time t ₀ ≤t <tk, the integration operation is performed according to equation (1) under the condition of 1≤i≤k, and ii) at time tk, SLVk is the reference function R = SLV ₀ ＋ M ・ k
・ Since it becomes equal to △ t, the integrated value SI accumulated up to the time tk is cleared, and the new reference function SLVk + Mi ・ △
t is set.

iii) At time t (k + 1), since SLV (k + 1) is smaller than the immediately preceding reference function, a new reference function SLV (k
+1) + M · i · Δt is set, and the integrated value remains cleared.

iv) Even at time t (k + 2), since SLV (k + 2) is smaller than the immediately preceding reference function, a new reference function R ′ = SLV (k + 2) + M · i · Δt is set again.
From this point in time, the sensor output level becomes equal to or higher than the reference function, and therefore the integration operation is started according to the following equation until time tm when the sensor output level becomes equal to or lower than the reference function.

v) At times tm, t (m + 1), and t (m + 2), the integrated value is cleared and a new reference function is set as described above, and after time t (m + 2), the reference function R ″ =
The accumulation of the sensor output level SLVi for the excess of SLV (k + 2) + M · i · Δt is started in the same manner as described above.

In FIG. 1, since the integrated value reaches the predetermined integrated value A at the time tn, the abnormal signal is generated at the time tn.

FIG. 2 shows a block circuit diagram of a fire alarm device suitable for carrying out the invention operatively described in FIG. In the figure, the fire alarm device is a summary, the sensor unit 10,
And a discrimination unit 11. The sensor unit 10 here is a photoelectric smoke sensor that operates by sensing smoke. In the smoke detecting chamber of the smoke sensor 10, a light emitting diode LED that is pulse-lighted at a predetermined cycle by an oscillation circuit 12 and a light emitting circuit 14, and a sun that receives scattered light in proportion to its concentration when smoke flows into the smoke detecting chamber. A battery SB is provided, and after the output from the solar battery SB is amplified by the amplifier 18 via the light receiving circuit 16,
The analog / digital (A / D) conversion circuit 20 converts the signal into a digital signal and sends it to the determination unit 11.

The microprocessor unit MPU is included in the determination unit 11 that receives signals from the sensor unit 10 and performs signal processing or determination.
And an interface I / that receives the signal from the sensor unit 10.
F, an oscillator OSC that oscillates a clock, and a program read-only program that stores a signal processing program.
Memory ROM1 and work random access memory RA
M1, a read-only memory ROM2 for storing a predetermined integrated value A, which stores a predetermined integrated value A, and a reference function R = SLVx + M
-Read-only memory ROM3 for storing standard functions that stores Δt-i, and random access memory for storing sensor output to capture and store the sensor output level SLV at predetermined time intervals Δt A RAM2 and a random access memory RAM3 for storing an integrated value for storing an integrated value SI calculated at predetermined time intervals Δt based on the sensor output level SLV fetched in the RAM2 are included. .

The value of the predetermined integrated value A, the value of the coefficient M in the reference function, and the value of the predetermined time interval Δt are the degree of danger of the room, ventilation, air conditioning, the density of people, the time zone, the height, the volume, etc. Those skilled in the art will understand that the setting can be changed appropriately.

The operation of the block circuit diagram shown in FIG. 2 will be described with reference to the flowchart of FIG.

First, the discrimination unit 1 including the microprocessor unit MPU
1 constantly samples the sensor output level SLV based on the program stored in the ROM 1. That is, the sensor output level SLV sent from the sensor unit 10 through the interface I / F is read into the RAM 2 at every predetermined time interval Δt counted based on the clock pulse from the oscillation unit OSC. There is.

First, the sensor output level for giving a constant to the reference function is read into the work RAM 1 as SLVx, and at the same time, the sampling number i for each Δt representing time is set to 1 (step 101). After that, a predetermined time interval Δt
Wait until the next sampling after the elapse ((Step 10
2) When a predetermined time interval Δt has elapsed, a new sensor output level SLV is read into the sensor output level storage RAM 2 (step 103). Next, based on the SLVx read in step 101, the reference function formula R = SLVx + M × Δt
Xi is created (step 104), and the sensor output level SLV read in step 103 is compared with the reference function R (step 105). As a result of the comparison between the reference function R and the sensor output level SLV, when it is determined that the sensor output level SLV is equal to or lower than the reference function R (N in step 105, that is, “No”, the value of SLVx is stored in the RAM2. The sensor output level SLV is updated, and i and the integrated value S are updated.
Clear the value of I (step 106), then step 102
The operation from is repeated.

If it is determined that the sensor output level SLV is higher than the reference function R (Y in step 105, that is, “yes”), then integration is performed. That is, the value of (SLV-R) is added to the previous integrated value SI stored in the RAM3, and the SI value stored in the RAM3 is updated with the added value (step 107). Next, it is determined whether or not the integrated value SI stored in the RAM 3 in this way has reached the predetermined integrated value A stored in the ROM 2 (step 108). Y), an abnormal signal for outputting a fire alarm is output (step 109). If not (N in step 108), the value of i is incremented by 1 (step 110), and the sensor output level SLV read in step 103 is further summed in step 107, thus, Before the sensor output level SLV is determined to be less than or equal to the reference function R in step 105, the integration S is calculated in step 108.
It will be determined whether I reaches A or not.

In the above embodiments, the sensor output level is described as a signal obtained from the photoelectric smoke sensor, but the sensor output level can be obtained from a thermal type, ionization type or radiation type fire sensor using a thermistor. Even in the case of a signal, the same effect as that of the above-described embodiment is obtained.

Further, in the above embodiment, the description has been made assuming that the sensor unit and the fire determination unit of the fire alarm device are integrated.
The fire sensor output digitized by the conversion circuit may be transmitted to a remote receiver via a modem or the like, and the fire judgment may be performed there.

As described above, according to the present invention, the sensor output level
The portion above the reference function is integrated, and an abnormal signal is output when the integrated value reaches a predetermined integrated value, and the reference function has a sensor output level smaller than that of the previously set reference function. In this case, it is updated based on the sensor output level value at that time.Therefore, there is no malfunction in the event of a transient fire, but a fire in which the smoke concentration gradually increases With respect to the above, there is an effect that it is possible to obtain a fire alarm device that can be more reliably operated.

[Brief description of drawings]

FIG. 1 is a graph for explaining the operation of the present invention, FIG. 2 is a block diagram showing a fire alarm device according to an embodiment of the present invention, and FIG. 3 is for explaining the operation of FIG. It is a flowchart of. In the figure, 10 is a smoke sensor section, 11 is a discrimination section, MPU is a microprocessor unit, ROM1 is a read-only memory for program storage, RAM1 is a random access memory for work, SLV is a sensor output level, and SI is SI. Integrated value, A is a predetermined integrated value, R is a reference function, Δ
t is a predetermined time interval.

Claims (3)

[Claims] 1. A fire alarm device for judging a fire based on a sensor output level, comprising: a means for sampling the sensor output level at predetermined time intervals; and a reference function that gradually increases as a function of time. Generating a reference function, integrating means for accumulating a difference between the sampled sensor output level equal to or higher than the reference function and the reference function at each predetermined time interval, and integrating by the integrating means. And a predetermined integrated value, and when the value integrated by the integrating means has reached the predetermined integrated value, a determination means for outputting a signal indicating an abnormality is provided. Fire alarm device characterized by that. 2. The fire alarm device according to claim 1, wherein the reference function that gradually increases as a function of time is a linear function. 3. The reference function generating means updates the reference function based on the sensor output level when the sensor output level is equal to or lower than the reference function. Fire alarm device according to item 2.