FIRE DETECTION DEVICE AND METHOD OF DETECTING FIRE

• US 20160358442A1
• Filed: 05/26/2016
• Published: 12/08/2016
• Est. Priority Date: 06/05/2015
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Iwata, Jiyunichi, Takasu, Ryozo
• Granted Patent: US 9,928,709 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G08B 17/117 by using a detection device for specific gases, e.g. combustion products, produced by the fire G08B17/103, G08B17/11 take precedence
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: G08B 25/14 Central alarm receiver or annunciator arrangements

Abstract

A fire detection device includes a gas sensor, a measuring instrument, and a control device. The gas sensor is configured to detect a gaseous substance in a measurement space. The gas sensor is configured to output a first result of the detection. The measuring instrument is configured to measure a diameter of each particle existing in the measurement space and count a number of particles for each of diameter ranges to generate distribution data. The control device includes a processor. The processor is configured to determine, on basis of the first result acquired from the gas sensor, whether a smoke exists in the measurement space. The processor is configured to start the measuring instrument upon determining that a smoke exists in the measurement space. The processor is configured to determine, on basis of first distribution data acquired from the measuring instrument, whether a fire has occurred.

Claims

1. A fire detection device, comprising:

a gas sensor configured to

detect a gaseous substance in a measurement space, and

output a first result of the detection;

a measuring instrument configured to

measure a diameter of each particle existing in the measurement space, and

count a number of particles for each of diameter ranges to generate distribution data; and

a control device including;

a processor configured to

determine, on basis of the first result acquired from the gas sensor, whether a smoke exists in the measurement space,

start the measuring instrument upon determining that a smoke exists in the measurement space, and

determine, on basis of first distribution data acquired from the measuring instrument, whether a fire has occurred.

2. The fire detection device according to claim 1, wherein

the gas sensor includes a metal-oxide semiconductor (MOS) gas sensor.

3. The fire detection device according to claim 2, wherein

the processor is configured to

determine whether a smoke exists in the measurement space on basis of a similarity between a first pattern of temporal change in a resistance value of the MOS gas sensor and a predetermined change pattern, the first pattern being calculated on basis of the first result acquired from the MOS gas sensor, the first result including the resistance value.

4. The fire detection device according to claim 2, wherein

the gas sensor includes a plurality of MOS gas sensors to detect different gaseous substances.

5. The fire detection device according to claim 1, wherein

the processor is configured to

start the measuring instrument, to acquire second distribution data, upon determining that no smoke exists in the measurement space when a predetermined condition of timing is satisfied,

update a determination value on basis of the second distribution data acquired from the measuring instrument, and

determine, on basis of a difference between the determination value and the first distribution data, whether a fire has occurred.

6. The fire detection device according to claim 1, wherein

the diameter ranges are obtained by dividing diameters of particles into two or more classes, and

the measuring instrument counts the number of particles for each of the classes.

7. The fire detection device according to claim 1, wherein

the processor is configured to

stop the measuring instrument upon acquiring the first distribution data from the measuring instrument.

8. The fire detection device according to claim 1, wherein

the processor is configured to

supply an operation power to the measuring instrument to start the measuring instrument, and

stop the supply of the operation power to the measuring instrument upon acquiring the first distribution data from the measuring instrument.

9. The fire detection device according to claim 1, further comprising:

a secondary battery used as a power supply of the gas sensor, the measuring instrument, and the control device;

a photovoltaic power generation panel configured to charge the secondary battery; and

a charge/discharge controller configured to control charge/discharge of the secondary battery.

10. The fire detection device according to claim 1, wherein

the processor is configured to

generate, upon determining that a fire has occurred, a fire occurrence signal containing identification information for identifying the fire detection device, and

transmit the generated fire occurrence signal to a predetermined server.

11. A method of detecting a fire, the method comprising:

acquiring, by a computer, a first result of detecting a gaseous substance in a measurement space, the first result being output from a gas sensor;

determining, on basis of the first result, whether a smoke exists in the measurement space;

starting a measuring instrument upon determining that a smoke exists in the measurement space, the measuring instrument being configured to measure a diameter of each particle existing in the measurement space and to count a number of particles for each of diameter ranges to generate distribution data; and

determining, on basis of first distribution data acquired from the measuring instrument, whether a fire has occurred.

12. The method according to claim 11, further comprising:

generating, upon determining that a fire has occurred, a fire occurrence signal containing an identification information for identifying the computer; and

transmitting the generated fire occurrence signal to a predetermined server.

13. The method according to claim 11, further comprising:

stopping the measuring instrument upon acquiring the first distribution data from the measuring instrument.

14. The method according to claim 11, further comprising:

starting the measuring instrument, to acquire second distribution data, upon determining that no smoke exists in the measurement space when a predetermined condition of timing is satisfied;

updating a determination value on basis of the second distribution data acquired from the measuring instrument; and

determining, on basis of a difference between the determination value and the first distribution data, whether a fire has occurred.

15. A computer-readable recording medium having stored therein a program that causes a computer to execute a process, the process comprising:

acquiring a first result of detecting a gaseous substance in a measurement space, the first result being output from a gas sensor;

determining, on basis of the first result, whether a smoke exists in the measurement space;

starting a measuring instrument upon determining that a smoke exists in the measurement space, the measuring instrument being configured to measure a diameter of each particle existing in the measurement space and to count a number of particles for each of diameter ranges to generate distribution data; and

determining, on basis of first distribution data acquired from the measuring instrument, whether a fire has occurred.