Fire detecting system and weight correcting method performed thereby

• US 8,203,456 B2
• Filed: 08/04/2009
• Issued: 06/19/2012
• Est. Priority Date: 08/06/2008
• Status: Active Grant

• Current Assignee: National Taiwan University (Government of The Republic of China)
• Original Assignee: National Taiwan University (Government of The Republic of China)
• Inventors: Luo, Ren-Chyuan, Su, Kuo-Lan, Tzou, Jyh-Hwa
• Primary Examiner(s): Tweel, Jr., John A
• Application Number:
  US12/534,963
• Publication Number:
  US 20100033334A1
• Time in Patent Office: 1,050 Days
• Field of Search: 340/577, 340/506, 340/511, 340/514, 340/628, 340/870.01, 348/143
• US Class Current: 340/577
• CPC Class Codes: G08B 17/10 Actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
• CPC Class Codes: G08B 17/12 Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions
• CPC Class Codes: G08B 29/183 Single detectors using dual technologies G08B13/1672, G08B13/2448, G08B13/2494 take precedence
• CPC Class Codes: G08B 29/188 Data fusion; cooperative systems, e.g. voting among different detectors

Abstract

A fire detecting system includes a plurality of detectors, and a computing unit coupled to the detectors. The detectors are configured for generating a plurality of detecting values, respectively. For each of the detectors, the detecting value is equal to a first predetermined value when a fire state is detected thereby, and is equal to a second predetermined value when otherwise. The computing unit sets a weight value for each of the detectors and a threshold value, and is configured to perform a weight correcting method for correcting the weight value of each of the detectors based on accuracy of operation of the detectors.

Claims

1. A weight correcting method for a fire detecting system that includes a plurality of detectors configured for detecting a fire state, said weight correcting method comprising:

a) setting weight values for the detectors, respectively;

b) setting a threshold value;

c) receiving a plurality of detecting values, each of which is obtained using a respective one of the detectors, wherein, for each of the detectors, the detecting value is equal to a first predetermined value when the fire state is detected thereby, and is equal to a second predetermined value when otherwise;

d) computing a summation of products of each of the detecting values and the weight value of the respective one of the detectors;

e) when the summation computed in step d) is greater than the threshold value, adding a first adjusting value to the weight value corresponding to the detector from which the detecting value equal to the first predetermined value is obtained, and adding a first correcting value to the weight value corresponding to the detector from which the detecting value equal to the second predetermined value is obtained; and

f) when the summation computed in step d) is smaller than the threshold value, adding a second correcting value to the weight value corresponding to the detector from which the detecting value equal to the first predetermined value is obtained, and adding a second adjusting value to the weight value corresponding to the detector from which the detecting value equal to the second predetermined value is obtained.

2. The weight correcting method as claimed in claim 1, further comprising the step of:

g) repeating steps c) to f).

3. The weight correcting method as claimed in claim 2, wherein:

the first adjusting value in step e) is gradually decreased with an increase in the number of detections of the detecting value of the corresponding detector being equal to the first predetermined value; and

the second adjusting value in step f) is gradually decreased with an increase in the number of detections of the detecting value of the corresponding detector being equal to the second predetermined value.

4. The weight correcting method as claimed in claim 3, wherein the first adjusting value is computed based upon the number of detections of the detecting value of the corresponding detector being equal to the first predetermined value, and the second adjusting value is computed based upon the number of detections of the detecting value of the corresponding detector being equal to the second predetermined value.

5. The weight correcting method as claimed in claim 4, wherein the first adjusting value is computed based upon a reciprocal of the number of detections of the detecting value of the corresponding detector being equal to the first predetermined value, and the second adjusting value is computed based upon a reciprocal of the number of detections of the detecting value of the corresponding detector being equal to the second predetermined value.

6. The weight correcting method as claimed in claim 3, wherein:

in step e), adding the first adjusting value to the weight value corresponding to the detector, from which the detecting value equal to the first predetermined value is obtained, is terminated when the first adjusting value corresponding to the detector is smaller than a first limit value; and

in step f), adding the second adjusting value to the weight value corresponding to the detector, from which the detecting value equal to the second predetermined value is obtained, is terminated when the second adjusting value corresponding to the detector is smaller than a second limit value.

7. The weight correcting method as claimed in claim 3, further comprising the step of determining one of the detectors to be in a faulty state if the weight value corresponding to said one of the detectors becomes smaller than a minimum limit.

8. The weight correcting method as claimed in claim 1, the detectors including first and second detector sets, each of the first and second detector sets including a smoke detector, a flame detector and a temperature detector, further comprising the step of comparing the weight value of each of the detectors in the first detector set with the weight value of the detector of the same type in the second detector set to determine relative accuracy therebetween.

9. The weight correcting method as claimed in claim 1, wherein the first predetermined value is equal to 1, the second predetermined value is equal to −

1, and the threshold value is equal to 0.

10. A fire detecting system comprising:

a plurality of detectors for generating a plurality of detecting values, respectively, wherein, for each of said detectors, the detecting value is equal to a first predetermined value when a fire state is detected thereby, and is equal to a second predetermined value when otherwise; and

a computing unit coupled to said detectors, said computing unit setting a weight value for each of said detectors and a threshold value, and being configured to perform a weight correcting method including the steps of

computing a summation of products of each of the detecting values and the weight value of the respective one of said detectors,

when the computed summation is greater than the threshold value, adding a first adjusting value to the weight value corresponding to said detector from which the detecting value equal to the first predetermined value is obtained, and adding a first correcting value to the weight value corresponding to said detector from which the detecting value equal to the second predetermined value is obtained, and

when the computed summation is smaller than the threshold value, adding a second correcting value to the weight value corresponding to said detector from which the detecting value equal to the first predetermined value is obtained, and adding a second adjusting value to the weight value corresponding to said detector from which the detecting value equal to the second predetermined value is obtained.

11. The fire detecting system as claimed in claim 10, wherein said detectors include different types of detectors.

12. The fire detecting system as claimed in claim 11, wherein said detectors include a smoke detector, a flame detector, and a temperature detector.

13. The fire detecting system as claimed in claim 10, wherein said detectors include first and second detector sets, each of said first and second detector sets including a smoke detector, a flame detector and a temperature detector, said computing unit being configured to compare the weight value of each of said detectors in said first detector set with the weight value of said detector of the same type in said second detector set to determine relative accuracy therebetween.

14. The fire detecting system as claimed in claim 10, wherein said computing unit is configured to perform the weight correcting method repeatedly.

15. The fire detecting system as claimed in claim 14, wherein said computing unit gradually decreases the first adjusting value with an increase in the number of detections of the detecting value of the corresponding one of said detectors being equal to the first predetermined value, and gradually decreases the second adjusting value with an increase in the number of detections of the detecting value of the corresponding one of said detectors being equal to the second predetermined value.

16. The fire detecting system as claimed in claim 15, wherein said computing unit computes the first adjusting value based upon the number of detections of the detecting value of the corresponding one of said detectors being equal to the first predetermined value, and computes the second adjusting value based upon the number of detections of the detecting value of the corresponding one of said detectors being equal to the second predetermined value.

17. The fire detecting system as claimed in claim 16, wherein said computing unit computes the first adjusting value based upon a reciprocal of the number of detections of the detecting value of the corresponding one of said detectors being equal to the first predetermined value, and computes the second adjusting value based upon a reciprocal of the number of detections of the detecting value of the corresponding one of said detectors being equal to the second predetermined value.

18. The fire detecting system as claimed in claim 15, wherein:

said computing unit terminates adding the first adjusting value to the weight value corresponding to said detector, from which the detecting value equal to the first predetermined value is obtained, when the first adjusting value corresponding to said detector is smaller than a first limit value; and

said computing unit terminates adding the second adjusting value to the weight value corresponding to said detector, from which the detecting value equal to the second predetermined value is obtained, when the second adjusting value corresponding to said detector is smaller than a second limit value.

19. The fire detecting system as claimed in claim 15, wherein said computing unit is further configured to determine one of said detectors to be in a faulty state if the weight value corresponding to said one of said detectors becomes smaller than a minimum limit.

20. The fire detecting system as claimed in claim 10, wherein the first predetermined value is equal to 1, the second predetermined value is equal to −

1, and the threshold value is equal to 0.