JP3081028B2 - Fire alarm system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fire alarm system.

[0002]

2. Description of the Related Art Conventionally, an analog sensing output from an analog photoelectric smoke detector or an analog ion smoke detector is returned to a receiver (or a repeater) using time division multiplex transmission or the like, and the receiver (or relay) is returned. The repeater counts for a predetermined time (hereinafter referred to as accumulation time) from the time when the returned sensed output exceeds a preset level, and at the end of the accumulation time, the sensed output exceeds a certain level. There is a fire alarm system that issues an alarm.

[0003]

By the way, in the conventional system, when the analog detection output level of the analog fire detector falls below the alarm level within the storage time, the storage is simply canceled at that point and returns to the initial state. It has become. Therefore, when the analog detection output level exceeds the alarm level once again after lowering, the same accumulation time as the first time is set.

However, in such a situation, the risk of fire occurrence is considered to be increased, and there is a problem in that if the same accumulation time as that for the first time is waited, the timing of issuing an alarm will be delayed. The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a fire alarm system capable of detecting a fire at an early stage.

[0005]

In order to achieve the above object, the invention according to claim 1 counts an accumulation time when an analog detection output level of an analog fire detector reaches a preset alarm level. In the fire alarm system for determining whether or not to issue an alarm based on the analog sensing output at the end of the counting, a first accumulation time is set when the level of the analog sensing output first exceeds the alarm level. When the level of the analog sensing output falls below the alarm level within the first accumulation time and rises again within a certain period and exceeds the alarm level, a second accumulation time shorter than the first accumulation time is set. is there.

The time obtained by subtracting the time from when the level of the analog sensing output first exceeds the alarm level to when the level of the analog sensing output falls below the alarm level from the first accumulation time may be used as the second accumulation time. The accumulation time may be the minimum accumulation time.

[0007]

According to the present invention, after the level of the analog sensing output first exceeds the alarm level and counting of the accumulation time is started, the level of the analog sensing output falls below the alarm level within the accumulation time, If a situation in which the alarm starts to rise again within a certain period of time and exceeds the alarm level again, that is, a situation with a high degree of danger occurs, the second accumulation time can be shortened to expedite fire detection.

[0008]

The present invention will be described below with reference to examples. FIG. 1 shows a schematic configuration diagram of a fire alarm system of the present invention.
It comprises an analog fire detector 1, which is, for example, a photoelectric or ionic smoke detector installed at a guard place, and a receiver 2 for receiving analog detection output data of the analog fire detector 1. A known time division multiplex transmission or the like is used between the receiver 2 and the analog fire detector 1 to transmit analog detection output data from the analog fire detector 1 to the receiver 2.
The receiver 2 receives the analog sensing output by an appropriate method such as returning to the receiver 2.

The receiver 2 receives the data of the analog sensing output in a time-series manner, processes the time-series data, and extracts a characteristic amount of the time-series data. The confidence level determining unit 4 that determines the fire confidence level and the non-fire confidence level based on the fire / non-fire decision rule described below, and the respective confidence levels determined by the confidence level decision unit 4, A risk calculator 6 for calculating a risk or the like based on the likelihood of occurrence of a false report determined from a frequency of occurrence of a false forecast generated from the server, and an accumulation time according to the risk calculated by the risk calculator 6. The accumulation time determination unit 7 to be determined and the pre-alarm level used for obtaining a certainty factor based on the fire determination rule, the start of accumulation time counting, and the like, and the alarm level are determined by the human presence / absence sensor 10, the air conditioner operation detection unit 11, and the like. Set according to detection status A fire level determination unit which counts the accumulation time determined by the accumulation time determination unit and outputs a signal for generating a fire alarm if the analog detection output level at the end of the count is equal to or higher than the alarm level. The unit 9 updates the false forecast occurrence frequency for each time zone which is initially set based on the installation location of the analog fire detector 1 based on the collection of false forecast occurrence data after installation. A false forecast frequency update storage unit 5 that gives the updated occurrence frequency data to the risk degree calculation unit 6 as data on the likelihood of false reports, and a fire notification unit that performs a fire report based on a signal from the fire determination unit 9. 12, and a microcomputer is actually used.

Next, the degree of danger used in the system of the present invention,
The determination rules and the like will be described. First, the risk is a scale that takes a value from 0 to 100 when a fire report is generated as 100, and this risk varies through three stages. First warning level L ₀ to the level of the analog sensor output as shown in FIG. 2, that is, the stage until the sensing smoke density reaches a first stage, generating the ease of false alarm in the first stage (analog fire detector 1 (According to the installation situation, environment, time zone, season, and frequency of occurrence of past misforecasts), the degree of danger is increased in proportion to the value of the detected smoke density.

[0011] the warning level L ₀ to the sensing smoke stage concentration reaches the second stage, in the second Sureji, by the time series data sensed smoke density to reach a warning level L _0, a preselected decision rule Then, it is determined whether or not there is a fire based on the result, and the degree of danger is raised or lowered based on this determination. Then the alarm level L ₀ from beyond the sensing smoke density and the third stage, in the third stage, the accumulation time is set by the risk determined by the second stage, the count of the storage time has expired if you leave the warning level L ₀ is sensed smoke density exceeds at issuing an alarm as risk 100.

The risk is calculated by the risk calculator 6 under the above conditions. The determination rule is for determining the degree of risk in the second stage, and is determined as follows. The rules for determining the degree of certainty that water vapor is present based on the time series data of the detected smoke concentration are as follows.

First, the smoke density corresponding to the water vapor is characterized by a sharp rise from 0%. So the pre-warning level set at substantially half of the level for warning level L ₀ L
Time T until the sensing smoke density to ₁ reaches from beyond the 1%
p is short as shown in FIG. 3, and this time range is set to a range from 0 to 9 seconds as shown in FIG.
1, when more than 9 seconds, and confidence 0, determining a first confidence X ₁ in accordance with the measured time. And the pre-alarm level L ₁
Shorter time Tpa that beyond reaching the warning level L _0, and the range of the time range from 0 seconds as shown in FIG. 5 to 9 seconds, confidence when confidence than 1, 9 seconds at 0 seconds It is set to 0, and the second certainty factor X ₂ is determined according to the actual measurement time. Then, the average value (X ₁ + X ₂ ) of these two confidence factors X ₁ and X ₂ /
2 is defined as the water vapor certainty factor X.

Similarly, the rules for determining the certainty factor of the cigarette smoke based on the time series data of the detected smoke density are as follows. The perceived smoke density corresponding to the smoke of the cigarette is, as shown in FIG.
There is a characteristic that the state of 2% continues. Therefore, when the detected smoke density is sampled a certain number of times (20 times) in the past minute, the ratio a / 20 of the number a of data a in the range of 0.5 to 2.5% is defined as the first certainty factor Y ₁ , Concentration is about 2.5%
7 until the alarm level L ₀ is reached,
As shown in the above, the confidence is set to 1 when it is 0, and the confidence is set to 0 when the maximum allowable time of 9 seconds to be judged as cigarette smoke is exceeded,
Sensing smoke density is calculated confidence factor Y ₂ from the measured time of the second to reach the warning level L ₀ exceeds 2.5% approximately, these first and second certainty factor Y _1, Y ₂ mean value ( Y ₁ + Y ₂ ) /
From 2, the tobacco certainty factor Y due to the cigarette smoke is determined.

[0015] The above water vapor confidence X, tobacco confidence Y is used to risk determination determined in the second stage as a non-fire confidence. In this case employed are determined rule location, i.e. or generated easy-place steam as kitchen, or tobacco is selected by well sucked location is, in a place where both are established to adopt towards the confidence greater . The rules for determining the degree of certainty that a fire has occurred are as follows. That bisects the range of up to a predetermined time before (for example, three minutes ago) up to the point of exceeding the pre-warning level L ₁ shown in FIG. 8, smoke in the previous time range (3 minutes 1.5 minutes ago ago) the average value M ₁ of the concentration, the difference between the average value M ₂ of the sensing smoke density in the time range (from 1.5 minutes prior to the point reached) the later from as large 8, as shown in FIG. 9 If the maximum value (3%) that can be judged as a fire is more than 1 and the confidence is 1,
The degree of certainty is set to 0 when the value is equal to or less than the minimum value (1.5%), and the first certainty Z determined from the average value actually measured under this condition.
_As shown in FIG. 10, as shown in FIG. 10, the average value M until the detected smoke density reaches the pre-alarm level L ₁ from 0% is equal to or more than the maximum value (3%) that can be judged as a fire, and the confidence is set to 1 and the minimum value the confidences case (1.5%) or less and 0, to determine the minimum value among the second certainty factor Z ₂ determined from the mean value actually measured by this condition as fire confidence Z.

The update of the erroneous forecast frequency in the erroneous forecast frequency update storage unit 5 is performed as follows. First, the occurrence of a false forecast is determined, for example, by the occurrence of an analog sensing output exceeding the pre-alarm level. The false forecast frequency update storage unit 5 divides 24 hours a day into time zones having a fixed time width as shown in FIG. Thus, the number of erroneous forecast occurrences is totaled for each time zone, and the erroneous forecast frequency for each time zone is updated once a month, for example, based on data for the past three months.

The risk calculating section 6 stores the false forecast frequency update storage section 1
Based on the false forecast frequency data for each time zone of ₀ , the degree of danger when the alarm level L ₀ is reached is 40 to 8 as shown in FIG.
The inclination of the increase in the degree of danger according to the smoke density detected in the stage 1 is determined so as to be any one of 0. Next, the operation of the fire alarm system of the present invention will be described with reference to FIGS.

Now, the fire alarm system is started, and the initial value of the frequency of false forecasts for each time zone is set in each location corresponding to the installation location of each analog fire sensor 1.
Select and set the fire judgment rule to be applied according to the installation location use. Now, when entering the alert state, the alarm level L ₀ and the pre-alarm level L ₁ are set to standard values by the level setting unit 8 when the air conditioner is not operating and a person is present,
Set slightly higher than the standard value when no person is present. When the air conditioner is operating and a person is present, the value is set higher than the standard. When no person is present, the value is set to be twice as high as when a person is present.

Now, when the smoke density detected by the analog fire detector 1 starts to increase, the danger calculation unit 6 sets the danger for the smoke density determined based on the false forecast frequency from the false forecast frequency update storage unit 5. Calculate the risk based on the slope of the degree. Eventually the sensing smoke density reaches a warning level L _0, enters the second stage, the risk calculator 6 this time, determines whether to change the risk in determining the contents of the confidence determining unit 4.

The certainty determining unit 4 calculates the non-fire and fire certainty based on the time series data of the detected smoke density in the first stage according to the selected judgment rule. When the fire certainty determined by the certainty determining unit 4 is equal to or more than a certain value, the risk calculating unit 6 increases the risk within a range of 80 to 90 according to the fire certainty. For example, if the fire certainty is 1, the risk is increased to 90.

When the fire certainty is equal to or less than a certain value, the risk is increased to a maximum of 80 in accordance with the non-fire certainty (cigarette certainty, water vapor certainty). For example, the non-fire confidence is 1
In the case of, the risk is set as it is, and when the non-fire certainty is 0, the risk is set to 80. In this way, the risk calculating unit 6 calculates the amount of change in the risk based on the content determined by the certainty determining unit 4 in the second stage.

[0022] Referring now sensed smoke density exceeds a warning level L _0, enters the third stage, the accumulation time determining unit 7 determines the accumulation time based on the risk of the second stage. In other words, if the risk is 90, which is the highest in the second stage, the accumulation time is 10 seconds, if the risk is 80, 20 seconds, if the risk is about 60, 40 seconds, and if the risk is 40, the risk is 40. 60
The greater the degree of danger, such as seconds, the shorter the accumulation time and the sooner a fire is detected. Conversely, the shorter the degree of danger, the longer the danger is to prevent non-fire reports.

When the accumulation time is determined, the fire judging section 9 counts the accumulation time, and the smoke density detected by the analog fire detector 1 at the end of the count indicates the alarm level L.
If it exceeds ₀ , a signal is sent to the fire notification unit 12 indicating that the degree of danger has reached 100, and a fire alarm is issued. At the same time as the fire judgment, the change of the alarm level L ₀ is instructed to the level setting unit 8.

[0024] Also consider the transition of sensing smoke density after determining the cumulative time, after falling sensed smoke density than the warning level L ₀ once the warning level L ₀ within a certain period of time (for example, within 3 minutes) again If it exceeds, the risk calculation unit 6 increases the risk at that time because the possibility of fire is high. Due to this rise, the accumulation time determination unit 7 makes the accumulation time shorter than the first accumulation time. Therefore, the discovery of the fire becomes faster.

Here, when the risk is set to a minimum time that can be set in the system, for example, 5 seconds, the second accumulation time can generate a fire report very quickly. From The example first count start accumulation time, the time until the time when the sensed smoke density than the warning level L ₀ is lowered, set the risk so that the time obtained by subtracting from the initial accumulation time is a second accumulation time You may.

[0026] Note that once sensed smoke density is lowered than the warning level L _0, if there be even after 3 minutes exceeds an alarm level L _0, the risk calculation in stage 2 of the next normal as Done. FIG. 13 shows a flow of the operation of each of the above-described units of the alarm system of the present invention. Square boxes indicate input / output variables, and long circles indicate inference control.

[0027]

According to the present invention, the accumulation time is counted when the analog detection output level of the analog fire detector reaches a preset alarm level, and an alarm is issued based on the analog detection output at the end of the counting. In the fire alarm system for judging whether or not the analog detection output level exceeds the alarm level for the first time, a first accumulation time is set, and within this first accumulation time the analog detection output level is lower than the alarm level. If it falls and rises again within a certain period of time and exceeds the alarm level, the second accumulation time shorter than the first accumulation time
Since the analog sensing output level first exceeds the alarm level and starts counting the accumulation time, the analog sensing output level falls below the alarm level within the accumulation time and then within a certain time Even if a situation that starts rising again and exceeds the alarm level again, that is, a situation of high risk, occurs, the second accumulation time is shortened,
There is an effect that a fire detection can be hastened and a highly reliable system can be constructed.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram showing a decision transition of a risk and an accumulation time according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a water vapor judgment rule according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a water vapor judgment rule according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a water vapor judgment rule according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a rule for determining tobacco smoke according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram of a rule for determining tobacco smoke according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of a fire judgment rule according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a fire judgment rule according to one embodiment of the present invention.

FIG. 10 is an explanatory diagram of a fire judgment rule according to an embodiment of the present invention.

FIG. 11 is an explanatory diagram of counting the frequency of false forecasts according to one embodiment of the present invention.

FIG. 12 is an explanatory diagram of the gradient of the smoke density and the degree of danger of Strategy 1 according to one embodiment of the present invention.

FIG. 13 is a flowchart for explaining the overall operation of one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Analog fire detector 2 Receiver 3 Processing part 4 Confidence determination part 6 Risk calculation part 7 Storage time determination part 9 Fire determination part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G08B 17/00

Claims (3)

(57) [Claims] When the analog detection output level of the analog fire detector reaches a preset alarm level, the accumulation time is counted, and it is determined whether or not an alarm is to be issued based on the analog detection output at the end of the counting. In the fire alarm system, a first accumulation time is set when the level of the analog detection output first exceeds the alarm level, and within this first accumulation time, the level of the analog detection output falls below the alarm level, and is set for a certain period of time. A second accumulation time shorter than the first accumulation time when the temperature rises again within the alarm level. 2. The second accumulation time is defined as a time obtained by subtracting the time from when the level of the analog sensing output first exceeds the alarm level to when it falls below the alarm level from the first accumulation time. The fire alarm system according to claim 1. 3. The fire alarm system according to claim 1, wherein the second accumulation time is a minimum accumulation time.