Fire detection device and method of detecting fire

• US 9,928,709 B2
• Filed: 05/26/2016
• Issued: 03/27/2018
• Est. Priority Date: 06/05/2015
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Takasu, Ryozo, Iwata, Jiyunichi
• Primary Examiner(s): Wu, Zhen Y
• Application Number:
  US15/164,937
• Publication Number:
  US 20160358442A1
• Time in Patent Office: 670 Days
• Field of Search: 340577
• 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 measurement 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 smoke exists in the measurement space,

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

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

2. The fire detection device according to claim 1,

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

3. The fire detection device according to claim 2, wherein the processor is configured to

determine whether the 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 measurement instrument, to acquire a second instance of the distribution data from the measurement instrument, upon determining that the smoke does not exist in the measurement space when a predetermined condition of timing is satisfied,

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

determine, on basis of a difference between the determination value and the first instance of the 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 measurement 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 measurement instrument upon acquiring the first instance of the distribution data from the measurement instrument.

8. The fire detection device according to claim 1, wherein the processor is configured to

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

stop the supply of the operation power to the measurement instrument upon acquiring the first instance of the distribution data from the measurement 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 measurement 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 smoke exists in the measurement space;

starting a measurement instrument upon determining that the smoke exists in the measurement space, the measurement 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 a first instance of the distribution data acquired from the measurement 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 measurement instrument upon acquiring the first instance of the distribution data from the measurement instrument.

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

starting the measurement instrument, to acquire a second instance of the distribution data from the measurement instrument, upon determining that the smoke does not exist in the measurement space when a predetermined condition of timing is satisfied;

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

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

15. A non-transitory 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 smoke exists in the measurement space;

starting a measurement instrument upon determining that the smoke exists in the measurement space, the measurement 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 a first instance of the distribution data acquired from the measurement instrument, whether a fire has occurred.