JPH01239698A - Fire alarming device - Google Patents

Abstract

PURPOSE:To prevent an effect caused by the deterioration of a noise and an element at the time of fire decision by triggering a fire discriminating routine when the inclination of an analog quantity signal level in time exceeds reference inclination. CONSTITUTION:An LED is emitted at every two seconds, a sensor SB receives light, it is sampled, A/D-converted, and a fine alarm phenomenon detecting signal is sent. The signal is read through an interface IF1 to the RAM 1 of a microprocessor MPU, and former information is abandoned. With the use of the latest information, based on the memory values in a prescribed number, the inclination (m) of a sensor output level is obtained by a minimum square method. When the value (m) exceeds a reference value A, it is decided to be a fire, and a signal sending part TRAX sends a fire alarm and a self-address through an interface IF2. A receiver RE displays a fire generating place. In such a constitution, since the discriminating routine is triggered based on the result of the comparison between the inclination of the sensor output level in time and the reference inclination, the circumferential noise, etc., are difficult to receive the effect.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fire alarm device that determines a fire abnormality based on physical quantities such as heat, smoke, or gas, and particularly relates to a fire alarm device that determines a fire abnormality based on physical quantities such as heat, smoke, or gas. The present invention relates to a fire alarm device that is activated or triggered to start a fire discrimination routine for determining a fire, such as arithmetic processing such as integration, differentiation, or difference, or pattern discrimination.

[Prior art and problems] For example, a digitalized analog quantity signal outputted by a fire phenomenon detection means is processed by integration, calculation processing (component or difference, etc.), or pattern discrimination, etc. to perform fire discrimination. is considered.

If such a fire discrimination routine is kept running all the time, there are problems such as an increase in current consumption, a time consuming process for the discrimination process, and a delay in other processes.

For this reason, normally the fire discrimination routine is left in a dormant state, and when the analog quantity signal exceeds a predetermined level, that is, exceeds a fixed level, the fire discrimination routine is triggered and fire discrimination such as calculation processing is executed. It is possible that

However, in this case, fluctuations in environmental noise components such as temperature, humidity, dust, light, or volatile liquids (e.g., paint emitting gas components) (for example, in general, temperature and the amount of dust in the air are The difference between the level of the analog quantity signal and the fixed level is not constant and constantly fluctuates due to dirt or deterioration of detection elements such as light receiving elements (high during the middle of the day and low during the night), or due to dirt or deterioration of detection elements such as light receiving elements. Therefore, when the difference is large, for example at night when there are few environmental noise components, the level of the analog quantity signal does not easily reach the fixed level, causing a significant delay in triggering the fire discrimination routine. In addition, when the difference is small or O, for example during the daytime when there are many environmental noise components, the fire discrimination routine may be triggered immediately or may not be triggered at all, thus causing an error in the fire detection result. This results in problems such as the inability to make correct fire judgments.

[Means for Solving the Problems] The present invention attempts to detect a state in which the environment changes from normal to abnormal, that is, a state exhibiting signs of abnormality, from the temporal slope of a physical quantity, that is, an analog quantity signal level. The present invention attempts to provide a fire alarm device that is not affected by environmental noise, element dirt, deterioration, etc. by triggering or starting a fire discrimination routine when the slope exceeds a predetermined slope.

Therefore, according to a specific aspect of the present invention, there is provided a rate-of-change determining means for determining a rate of change in a physical quantity of a fire phenomenon detected by a fire-phenomenon detecting means based on a plurality of latest samples; holding means for holding one of the physical quantities of the plurality of samples as a reference physical quantity when the rate of change determined by exceeds a predetermined value; and the holding means holds the reference physical quantity. From the time it was
A fire alarm device is provided, characterized in that it includes a fire discrimination means that starts an operation for fire discrimination based on the physical quantity of the reference and the physical quantity detected by the fire phenomenon detection means.

[Function] The rate of change determining means determines the temporal slope, or rate of change, of the physical quantity, that is, the analog quantity signal level, based on the latest samples of the analog quantity signal level, using, for example, the least squares method, the mean vector method, or the simple method. Determined by the method of calculating the slope, etc.

In addition, since the holding means holds one of the plurality of samples as a reference physical quantity, the reference physical quantity held in this way is, for example, the first data of the data determined to exceed a predetermined slope, that is, the level change. This allows the fire discrimination means to perform stable fire discrimination processing without malfunctions.

[Example] An embodiment 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 figure, RE is a receiver, and DE is a plurality of °sensors connected to the receiver RE. , 11th
Only one of them is shown in EJ. L, ~Ln are
For example, a pair of power supply/signal lines are connected to each of the plurality of sensors DE.

In the sensor DE, MPU is a microprocessor, ROM1 is a storage area for programs, an example of which is shown in the flowchart of FIG. An area for storing the analog quantity signal level shown, that is, the sensor output level is provided.

FS is a fire phenomenon detection means - an optical smoke detector is shown 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 a predetermined time interval, and SB is a solar light emitting device that receives scattered light due to smoke of light emitted from the light emitting diode LED. A light receiving element such as a battery, AM is an amplifier, SH is a sampling/holding circuit that holds the output of the amplifier AM in synchronization with the light emission of the light emitting diode LED, and AD is a digital signal that converts an analog signal into an analog quantity signal. The analog-to-digital converter, TRX, is a fire signal sending unit, and IFI and IF5 are interfaces.

The operation shown in FIG. 1 will be explained with reference to the flowchart shown in FIG.

5 light emitting circuits DR to read the sensor output level SLV
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 smoke is received by the solar cell SB, the solar cell SB generates an electric signal corresponding to the received light and samples it via the amplifier AM.・
The signal is applied to a hold circuit SH, where it is held at predetermined time intervals. The signal held in the sampling/holding circuit SH is converted into a digital analog quantity signal by the analog/digital converter AD, and the signal is sent to the fire phenomenon detection means F.
The detection output level at S, ie, the sensor output level SLV, is output to the interface IFI.

In this way, the sensor output level SLV is read from the fire phenomenon detection means FS to the microprocessor MPU at predetermined time intervals via the interface IFI. storage area RAM1 (step 20
2). At that time, the oldest data will be discarded.

A sensor output level storage area for storing sensor output levels in the working area RAM1 is shown in FIG. 3, and includes N data or sensor output level storage locations. The latest data, that is, the sensor output level, is stored at the top of the storage area, and the data that has been stored up to that point is sequentially shifted down one by one until it is stored at the end, that is, at the bottom. Data will be discarded. In this way, the latest N
Here, the sensor output level storage area is updated by giving a new senna output level at predetermined time intervals. may be updated not at predetermined time intervals, but at longer time intervals, such as once every 30 samples, or every minute.

The latest sensor output level SLv is stored in work area RAM1.
When the sensor output level is stored at the top of the sensor output level storage area, the sensor output level is then stored in the least squares method based on the N sensor output levels stored in the sensor output level storage area. Find the rising trend of the sensor output level, that is, the slope III of the sensor output level with respect to time (
Step 203).

The sensor output level of N data is 5LVn (n=
1 to N), and assuming that the time between data, that is, the sampling interval, is 1, the slope signal can be obtained for N data using the least squares method as follows. The inclination thus determined is conceptually shown in FIG.

Note that although the least squares method is shown here as a method for determining the slope, various methods can be considered as methods for determining the slope. For example, an average vector method or a simple slope (for example, a ratio between two points or a difference between two points divided by a time interval between them) may be used.

Once the slope m based on N pieces of data is found, the slope theory can be expressed as
Step 204) is compared with a reference value A of the slope at which a trigger should be applied, which is exemplarily shown in FIG. If the slope theory is smaller than the slope reference value A (N in step 204),
For example, if the slope is as indicated by the arrow B in FIG. 4, the next new sensor output level is read in step 201, and the same operations from step 202 are performed.

If the inclination of the valve becomes greater than the reference value A of inclination (
In step 204 (Y), a fire determination routine is performed to track and monitor the senna output level in order to determine whether or not there is a fire abnormality (step 205). As a fire determination routine that can be adopted here, for example, there is one described in a patent application specification entitled "Fire Alarm System" filed on March 1, 1986 by the applicant of the present invention. This patent application specification states that in order to avoid false alarms, an increasing function is generated when a trigger is applied, that is, when the slope exceeds a reference value A of the slope, and after the trigger, the sensor output level is lower than the increasing function by C. The figure shows a system in which it is determined that a fire has occurred if the value exceeds a large value. As another example, the sensor output level is integrated from the time when the output tilt pupil exceeds the tilt reference value A at the trigger point level, and the integrated value reaches a predetermined reference integrated value. It is also possible to use a routine that sometimes determines that there is a fire, and various known fire determination routines may be employed here.

Here, the fire determination routine of step 205 described in the above-mentioned patent application It(ll) will be explained in more detail.In other words, as shown in FIG. 2A, if the inclination Ill exceeds the reference value A of inclination Y), the sensor output level V1 at that time is held as the trigger point level VT (step 211), and the increasing function V T+ a T − is calculated based on the value of the trigger point level VT.
V ) is generated (step 213). Here, T is the number of times the sensor output level is sampled after the trigger point,
a is a constant determined by environmental conditions. If the sensor output level V1 after the trigger becomes smaller than the increasing function value ■3 (N at step 214), the trigger is released; however, if the sensor output level V1 after the trigger becomes smaller than the increasing function V , if the difference is greater than C (step 20
6 Y), it is determined that there is a fire. The device described in this patent application monitors a constant range from a rising function that rises as a function of time after the trigger, so it can be used under environmental conditions such as a sudden rise in temperature. Significantly reduces the possibility of false alarms.

After the fire determination routine in step 205, if it is not determined that there is a fire (N in step 206), the process returns to step 201 and reads the next sensor output level.
The slope In is stored at the top of the sensor output level storage area in the figure (step 203), and the slope In is similarly determined by the least squares method based on the new N sensor output levels.

If it is determined that there is a fire (Y in step 206), a so-called fire operation is performed in which the fire signal sending unit TRX is operated via the interface IF2 and a fire signal is sent to the receiver RE (step 207). At this time, the fire signal sending unit TRX may send out its own address along with the fire signal.

When a fire signal from a fire detector is received by the receiver RE, the receiving 1fl RE determines from which line L1 to Ln the fire signal was received, and displays the fire warning area where the fire occurred. In addition, if the fire detector also sends out its own address, the location of the fire or the activated fire detector is determined from the received address signal and displayed together.

In the above embodiment, the present invention is applied to a fire alarm device in which a fire detector performs fire discrimination and sends a fire signal and/or an address signal to a receiver. is an analog fire detector that sends out a physical signal of the detected fire phenomenon, and a receiver or repeater uses the physical signal sent from the analog fire detector to identify a fire, which is a so-called analog fire alarm. It is also possible to apply the present invention to a device.

When the present invention is applied to a fire alarm system in which fire discrimination is performed using a receiver or repeater, the fire detector DE in FIG. 1 becomes an analog fire detector (fire sensor), and each fire sensor ROM1 and RAM1 in DE are relocated to receiver RE. The receiver RE is provided with a microprocessor, and the RA in the reception 1fiRE
M1 is provided with sensor output level storage areas as shown in FIG. 4 for the number of connected sensors. and receiver RE
A program is added to the internal ROM 1 to poll connected sensors to collect analog quantity signals, and to execute the flowchart shown in FIG. 2 each time data is collected.

On the other hand, the sensor DE receives the receiver RE by polling.
A ROM that stores a program for determining whether or not a call has been received from the fire phenomenon detecting means FS, and transmitting the detected analog quantity signal of the fire phenomenon detection means FS to the receiving units IF R and E through the transmitting/receiving unit TRX when the call is received, and a working ROM. A RAM is provided.

[Effects of the Invention] As described above, according to the present invention, the temporal slope of the analog quantity signal level, that is, the sensor output level is determined, and when the slope exceeds a predetermined slope, that is, a reference slope, the fire discrimination routine is triggered. This has the effect that when determining a fire, there is no influence from environmental noise, element dirt, deterioration, etc.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing a fire alarm system according to an embodiment of the present invention, FIGS. 2 and 2A are flowcharts for explaining the operation of FIG. 1, and FIG. 3 is a working area. A diagram showing a sensor output level storage area in RAM1,
FIG. 4 is a graph conceptually showing the slope of the sensor output level determined by the least squares method. In the figure, R
E 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 a fire phenomenon detection means. Sagi 2A Sekimeatua 2Q7・＼

Claims (1)

[Scope of Claims] Change rate determining means for determining the rate of change in the physical quantity of a fire phenomenon detected by the fire phenomenon detection means based on a plurality of latest samples; and a change determined by the change rate determining means. holding means for holding one of the physical quantities of the plurality of samples as a reference physical quantity when the ratio exceeds a predetermined value; and from the time when the reference physical quantity is held by the holding means,
A fire alarm device comprising: fire discrimination means that starts an operation for fire discrimination based on the physical quantity of the reference and the physical quantity detected by the fire phenomenon detection means.