JP2006202080A - Fire alarm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire alarm capable of preventing false alarms and fatal fires. <P>SOLUTION: An alarm signal indicating the occurrence of a fire is generated based upon comparison between a fire sensor signal outputted from a predetermined fire sensor 2 and a fire threshold for determining fires. A fire is reported in response to the alarm signal. In particular, the fire threshold is controlled so that the sensitivity for generating the alarm signal is higher when a human sensing means 3 does not sense the presence of a person moving than when it senses the presence of a person moving. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fire alarm device, and more particularly to a fire alarm device capable of achieving both a false alarm prevention and a fatal fire prevention.

  In recent years, house fires have been increasing. In particular, late night rooms and kitchens are often used as fire places. For this reason, conventionally, a heat-sensing fire alarm that senses and alarms heat generated by a fire, and a smoke-sensitive fire alarm that senses and alarms smoke are equipped in a living room or kitchen.

  This type of fire alarm basically outputs a temperature sensor that outputs a temperature signal according to the ambient temperature, a smoke sensor that outputs a concentration signal according to the smoke concentration, and a concentration signal according to the CO concentration. Fire sensor such as a CO sensor, fire detection signal generating means for generating a fire detection signal whose value increases as the degree of fire increases based on these temperature signals and concentration signals, and the value and fire of this fire detection signal are determined And a warning signal generating means for generating a warning signal indicating the occurrence of a fire when the value of the fire detection signal exceeds the fire determination threshold value. A fire alarm is issued in response to the alarm signal.

The conventional fire alarm is as follows.
JP 2000-132761 A

  By the way, if there is a person in the room at midnight but is sleeping, or if the person is absent even if the stove is on in the kitchen, etc., it will be late to notice that the fire has occurred, the response will be delayed, and it will be fatal May result in a fire. As one measure for preventing this, the sensitivity for detecting the fire may be increased. That is, if the fire determination threshold is set low, it is possible to detect a fire early and issue a fire alarm before a fatal accident is reached. However, if the fire detection threshold is set low and the detection sensitivity is increased, there will be no major problems at midnight, but there will be no daylight or other conditions that are likely to cause fire-like conditions such as cigarette smoke or use of combustion equipment. False alarms frequently occur in the evening.

  Therefore, in view of the present situation described above, an object of the present invention is to provide a fire alarm capable of preventing a false alarm and also preventing a fatal fire.

  The fire alarm device according to claim 1, which has been made to solve the above-described problem, is a fire sensor signal acquisition unit configured to acquire a fire sensor signal output from a predetermined fire sensor, and to determine the fire sensor signal and fire. Alarm signal generating means for generating an alarm signal indicating the occurrence of a fire based on a comparison with a fire determination threshold of the alarm, and an alarm device for alarming a fire in response to the alarm signal, Human sensing means for sensing the presence of a moving person within a range and sensitivity for generating the warning signal are detected when the presence of the moving person is not sensed by the human sensing means. And a threshold value control means for controlling the fire determination threshold value so as to be more sensitive than when it is set.

  According to the first aspect of the present invention, an alarm signal indicating the occurrence of a fire is generated based on a comparison between a fire sensor signal output from a predetermined fire sensor and a fire determination threshold value for determining a fire. In response to a fire alarm. In particular, the fire determination threshold is set so that the sensitivity for generating the alarm signal is higher when the presence of a moving person is not detected by the human means than when the presence of a moving person is detected. Is controlled. Therefore, when there is no moving person, the sensitivity of the fire alarm becomes high.

  In order to solve the above-mentioned problem, the fire alarm device according to claim 2 is characterized in that in the fire alarm device according to claim 1, the human sensation means samples the human body in response to the moving person by sampling at a predetermined interval. It includes a human sensor that generates a human sensor signal, and detects the presence of the moving person based on the number of human sensor signals generated at a plurality of sampling times.

  According to the second aspect of the present invention, since the presence of the moving person is detected based on the number of occurrences of the human sensor signal at a plurality of sampling times, the presence of the moving person can be detected more reliably.

  The fire alarm device according to claim 3, which has been made to solve the above problem, is the fire alarm device according to claim 2, wherein the threshold value control means is a sensitivity for generating the alarm signal based on the number of occurrences. The fire determination threshold value is controlled so as to fluctuate stepwise.

  According to the third aspect of the present invention, the fire determination threshold value is controlled so that the sensitivity for generating the alarm signal varies stepwise based on the number of occurrences of the human sensor signal. Can control.

  According to the first aspect of the present invention, an alarm signal indicating the occurrence of a fire is generated based on a comparison between a fire sensor signal output from a predetermined fire sensor and a fire determination threshold value for determining a fire. In response to a fire alarm. In particular, the fire determination threshold is set so that the sensitivity for generating the alarm signal is higher when the presence of a moving person is not detected by the human means than when the presence of a moving person is detected. Is controlled. Therefore, when there is no moving person, the sensitivity for generating the alarm signal is high, and a fire can be alarmed early, so that a fatal fire can be prevented. On the other hand, since there is no high sensitivity when there is a moving person, a false alarm can be prevented.

  According to the second aspect of the present invention, since the presence of the moving person is detected based on the number of occurrences of the human sensor signal at a plurality of sampling times, the presence of the moving person can be detected more reliably. Accordingly, it is possible to further reduce false alarms and reliably fire alarms.

  According to the third aspect of the present invention, the fire determination threshold value is controlled so that the sensitivity for generating the alarm signal varies stepwise based on the number of occurrences of the human sensor signal. Can control. Accordingly, it is possible to further reduce false alarms and reliably fire alarms.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a fire alarm according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a first fire determination threshold value and a second fire determination threshold value stored in the storage circuit unit.

  As shown in FIG. 1, the fire alarm 10 includes a control circuit unit 1, a fire sensor 2, a human sensor 3, a sensor drive circuit unit 4, a storage circuit unit 5, an alarm output circuit unit 6, and an external output circuit unit 7. Consists of including.

  The control circuit unit 1 is basically composed of a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (A Read / Write Memory as needed). The CPU executes various processes including control according to the present embodiment in accordance with a control program stored in the ROM. The RAM appropriately stores data, programs, and the like necessary for the CPU to execute various processes.

  Based on the fire sensor signal output from the fire sensor 2, the control circuit unit 1 fires a fire detection signal whose value increases as the degree of fire increases, for example, a light extinction rate, temperature rise rate, temperature, CO A signal indicating the density is generated. These depend on the type of sensor employed as the fire sensor 2.

  In addition, the control circuit unit 1 compares the value of the fire detection signal with a fire determination threshold value for determining a fire, and when the value of the fire detection signal exceeds the fire determination threshold value, an alarm indicating the occurrence of a fire Generate a signal. In response to this alarm signal, a command is given to alarm the fire.

  In particular, the control circuit unit 1 makes the fire determination threshold lower based on the output signal from the human sensor 3 when the moving person is not present in the kitchen or the living room than when the moving person is present. Control. For this purpose, the control circuit unit 1 switches between the first fire determination threshold value stored in advance in the memory circuit unit 5 and the second fire determination threshold value greater than this in accordance with the presence or absence of a moving person, Set as threshold.

  The fire sensor 2 is, for example, a known smoke sensor, temperature sensor, or CO sensor that outputs a fire sensor signal in response to an event that occurs with a fire. The smoke sensor includes a photoelectric element that outputs a light amount signal corresponding to a light amount on a predetermined optical path. The temperature sensor includes a thermistor whose resistance value varies depending on the ambient temperature, and outputs a temperature signal corresponding to the ambient temperature based on this resistance value. The CO sensor includes a detection element that reduces the internal resistance value when the CO gas is adsorbed, and outputs a concentration signal corresponding to the CO gas concentration based on the internal resistance value. However, each sensor need not stick to the above-described principle as long as it can accurately measure smoke, temperature, and CO that are detection targets.

  The human sensor 3 includes, for example, a pyroelectric element that detects infrared rays caused by a human body temperature, and outputs human sensor signals in response to the infrared rays detected by the pyroelectric elements. The predetermined range is, for example, a range corresponding to a kitchen or a living room where the fire alarm 10 is installed, and the human sensor 3 having a performance that covers this range is selected.

  The sensor drive circuit unit 4 is a circuit that is commanded by the control circuit unit 4 and drives the fire sensor 2 and the human sensor 3 intermittently at predetermined intervals.

  The memory circuit unit 5 is composed of, for example, an EEPROM (Electrically Erasable and Programmable ROM), and stores at least a first fire determination threshold value L and a second fire determination threshold value H. The second fire determination threshold H is a fire determination threshold corresponding to the presence of a moving person, the first fire determination threshold L is lower than the second fire determination threshold H, and there is a moving person. It is a fire judgment threshold value corresponding to when it is not sensed. The storage circuit unit 5 corresponds to the threshold value storage means in the claims.

  For example, as shown in FIG. 2, when a smoke sensor is employed as the fire sensor 2, the first fire determination threshold L is a dimming rate of 15%, and the second fire determination threshold H is a dimming rate of 30. %. When a temperature sensor is employed as the fire sensor 2, the first fire determination threshold L is a temperature increase rate of 10 ° C./min (50 ° C. in the case of a constant temperature type), and the second fire determination threshold H is a temperature. The rate of increase is 15 ° C./min (65 ° C. in the case of the constant temperature type). When a CO sensor is employed as the fire sensor 2, the first fire determination threshold L is a CO concentration of 30 ppm, and the second fire determination threshold H is a CO concentration of 150 ppm.

  The alarm output circuit unit 6 responds to the alarm signal output from the control circuit unit 1 to output a fire alarm, such as a sound output circuit such as a buzzer or a speech processor, a display output circuit such as an LED or LCD, etc. It is. The external output circuit unit 7 includes a communication circuit that responds to an alarm signal output from the control circuit unit 1 and transmits a message indicating that to an external system or a security center.

  Note that the power supply circuit, interface circuit, display circuit, switch, and the like provided in this type of fire alarm are not necessary for understanding the present invention, and are omitted.

  Next, a processing procedure performed by the fire alarm having the above configuration will be described below. FIG. 3 is a flowchart showing a processing procedure of the control circuit unit according to the embodiment of the present invention.

  In step S <b> 1 of FIG. 3, the control circuit unit 1 acquires a human sensor signal generated by the human sensor 3. Next, in step S2, the control circuit unit 1 determines the presence / absence of a moving person based on the human sensor signal. For this purpose, the control circuit unit 1 detects a change in the human sensor signal, for example, as shown in a later-described modification. For example, when a change of a predetermined amount or more is recognized in the human sensor signal, it is determined that there is a moving person. If it is determined that there is a moving person, the process proceeds to step S3. If it is determined that there is no moving person, the process proceeds to step S4.

  In step S3 and step S4, the control circuit unit 1 refers to the memory circuit unit 5 and sets the second fire determination threshold value H and the first fire determination threshold value L as the fire determination threshold value, respectively. In reality, the second fire determination threshold value H is often set, for example, during the daytime or in the evening when there is a moving person, and the first fire determination threshold value L is not present when there is a moving person. In this case, for example, it is often set at midnight.

  As shown in FIG. 2, when the fire sensor 2 is a smoke sensor, the fire determination threshold is 15% (first fire determination threshold L) or 30% (second fire determination) as shown in FIG. In the case where the threshold value H) is set and the fire sensor 2 is a temperature sensor, the temperature increase rate is 10 ° C./min, or in the case of the constant temperature type, 50 ° C. (first fire determination threshold L) or the temperature increase rate is 15 ° C./min or the constant temperature. In the case of the equation, when the fire sensor 2 is a smoke sensor, a CO concentration of 30 ppm (first fire determination threshold L) or a CO concentration of 150 ppm (second fire determination threshold H) is set. ) Is set.

  Next, in step S5, the control circuit unit 1 acquires a fire sensor signal output from the fire sensor 2, and generates a fire detection signal in step S6. The value of the fire detection signal increases as the degree of fire increases. For example, when the fire sensor 2 is a smoke sensor, the value is a dimming rate, and when the fire sensor 2 is a temperature sensor, the temperature increase rate or temperature When the fire sensor 2 is a CO sensor, it is the CO concentration. The light attenuation rate can be obtained from the light quantity signal output from the smoke sensor, the temperature increase rate can be obtained from the temperature signal output from the temperature sensor, and the CO concentration is obtained from the concentration signal output from the CO sensor. be able to.

  Next, in step S7, the control circuit unit 1 compares the value of the fire detection signal with the fire determination threshold value set in step S6. For example, when the fire sensor 2 is a smoke sensor, the dimming rate obtained in step S6 and the dimming rate of 15% (when the first fire determination threshold L is set) shown in FIG. 30% (when the second fire determination threshold value H is set) is compared. When the fire sensor 2 is a temperature sensor, the temperature rise rate obtained at step S6 or the temperature in the case of the constant temperature type, and the temperature rise rate shown in FIG. When the threshold value L is set), the temperature increase rate is 15 ° C./min, or 65 ° C. (when the second fire determination threshold value H is set) in the case of the constant temperature type. When the fire sensor 2 is a CO sensor, the CO concentration obtained in step S6 and the CO concentration of 30 ppm shown in FIG. 2 (when the first fire determination threshold L is set) or the CO concentration of 150 ppm (second fire determination) (When threshold H is set).

  If it is determined in step S7 that the value of the fire detection signal exceeds the fire determination threshold (Y in step S7), the control circuit unit 1 proceeds to step S9 and generates an alarm signal indicating the occurrence of a fire. In response to the alarm signal, the alarm output circuit unit 6 warns of a fire, or the external output circuit unit 7 sends a message indicating the occurrence of a fire to an external system or a security center.

  On the other hand, when it is determined in step S7 that the value of the fire detection signal does not exceed the fire determination threshold (N in step S7), the control circuit unit 1 proceeds to step S8 and waits for the next timing (in step S8). N) When the next timing comes (Y in step S8), the process returns to step S1 and the above process is repeated. The next timing is visited at intervals of about 5 minutes, for example.

  Subsequently, a modification based on the above embodiment will be described below. FIG. 4 is a time chart showing a human sensor signal and a fire determination threshold value for explaining a modified example. FIG. 5 is a time chart showing a human sensor signal and a fire determination threshold value for explaining another modified example.

  As shown in FIG. 4, in one modification, it is assumed that human sensor signals are captured at intervals of 5 minutes, for example, at time points t1, t2,. Then, in order to determine the presence or absence of a moving person, for example, the human sensor signal between the time point T1, T2, T3,... The fire determination threshold value is determined based on the number of times of presence or absence. For example, as shown in periods T1 and T2 in FIG. 4, if there is no human sensor signal even once in 30 minutes, the fire determination threshold is set to L (increase detection sensitivity), and in 30 minutes, If all human sensor signals are present, the fire determination threshold is set to H (detection sensitivity is lowered). That is, in this modification, the presence of a moving person is detected based on the number of occurrences of the human sensor signal at a plurality of sampling times. Therefore, false alarms can be further reduced and fire can be more reliably alarmed. The number of presence / absence of the human sensor signal and the number of times of the fire determination threshold HL are not limited to the above example, and are appropriately determined according to the performance of the device, the environment, and the like.

  Further, as shown in FIG. 5, in another modification, it is assumed that human sensor signals are captured at intervals of 5 minutes, for example, at time points t1, t2,. Then, in order to determine the presence or absence of a moving person, the number of presence / absence of human sensor signals is counted every 30 minutes, for example, during periods T1, T2, T3,. For example, as shown in the period T1 in FIG. 5, if there are human sensor signals all six times in 30 minutes, the fire determination threshold is set to H (the detection sensitivity is lowered most), and the period T2 is reached. As shown, if there is a human sensor signal only 2 to 5 times in 30 minutes, the fire determination threshold is set to M (detection sensitivity is set to an intermediate level), and as shown in the period T3, 30 minutes Among them, if there is no human sensor signal in all six times, the fire determination threshold is set to L (the detection sensitivity is maximized). That is, in this modification, the fire determination threshold is controlled so that the sensitivity varies stepwise based on the number of occurrences of the human sensor signal. Therefore, false alarms can be further reduced and fire can be more reliably alarmed. Note that the number of presence / absence of the human sensor signal and the number of fire determination threshold values HML are not limited to the above example, and are appropriately determined according to the performance and environment of the device.

  As yet another modification, when the human sensor signal is generated suddenly continuously (2 to 3 times) after the human sensor signal generation number 0 has continued for several hours, as described above. Without waiting for 30 minutes, immediately set the fire determination threshold to H (decrease detection sensitivity). Thereby, the false alarm immediately after returning home can be prevented effectively.

  As described above, according to the embodiment of the present invention, when there is no moving person, the fire judgment threshold is lowered to increase the sensitivity for fire detection, thereby making it possible to prevent a fire in a kitchen or a room at night. It can be detected early and can prevent a fatal fire. As a supplement, the fire judgment threshold is low mainly in the middle of the night when there are no moving people in the kitchen or living room, but usually smoke or combustion equipment is used in the kitchen or living room during this time. Therefore, no false alarm is issued even if the fire judgment threshold is low. Therefore, it is possible to prevent a fatal fire while preventing false alarms.

  Note that lowering the fire determination threshold when there is no moving person may mean that the fire determination threshold is increased when there is a person moving in the kitchen or room, such as during the daytime or evening. . This makes fire detection less sensitive when there is a moving person, making it harder to generate a fire alarm, but there will be a moving person even if a fire alarm is issued late at this time. So it can respond immediately to fire. Therefore, also in this case, it is possible to prevent a fatal fire while preventing false alarms.

  The sensors exemplified as the fire sensor may be other types of fire sensors such as a flame-sensitive fire sensor. In addition, the sensors exemplified as the fire sensor may be used alone or in combination. For example, at least one of a smoke sensor, a temperature sensor, and a CO sensor is used as the fire sensor, and the fire determination thresholds respectively assigned to the smoke sensor, the temperature sensor, and the CO sensor are individually controlled. This makes it possible to more reliably alert the fire when there is no moving person. Further, the first fire determination threshold and the second fire determination threshold can be appropriately changed depending on the size of the kitchen or the living room, or other types of thresholds may be used.

It is a block which shows the fire alarm device which concerns on one Embodiment of this invention. It is a figure which shows the 1st fire determination threshold value and 2nd fire determination threshold value which concern on one Embodiment of this invention. It is a flowchart which shows the process sequence of the control circuit part which concerns on one Embodiment of this invention. It is a time chart which shows a human sensitive sensor signal and a fire judgment threshold for explaining a modification. It is a time chart which shows the human sensitive sensor signal and fire determination threshold value for demonstrating another modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control circuit part 2 Fire sensor 3 Human sensor 4 Sensor drive circuit part 5 Memory circuit part 6 Alarm output circuit part 7 External output circuit part 10 Fire alarm

Claims (3)

Fire sensor signal acquisition means for acquiring a fire sensor signal output from a predetermined fire sensor;
An alarm signal generating means for generating an alarm signal indicating the occurrence of a fire based on a comparison between the fire sensor signal and a fire determination threshold value for determining a fire;
An alarm device for alarming a fire in response to the alarm signal,
A human means for sensing the presence of a moving person within a predetermined range;
The fire is set such that the sensitivity for generating the alarm signal is higher when the presence of the moving person is not detected by the human means than when the presence of the moving person is detected. Threshold control means for controlling the determination threshold;
Fire alarm device characterized by having. The fire alarm according to claim 1,
The human means is
It includes a human sensor that generates a human sensor signal in response to the moving person by sampling at a predetermined interval, and detects the presence of the moving person based on the number of occurrences of the human sensor signal at a plurality of sampling times. To
A fire alarm characterized by that. The fire alarm according to claim 2,
The threshold control means includes
Controlling the fire determination threshold so that the sensitivity for generating the alarm signal varies stepwise based on the number of occurrences;
A fire alarm characterized by that.

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