LOW NUISANCE FAST RESPONSE HAZARD ALARM

• US 20140015678A1
• Filed: 05/13/2013
• Published: 01/16/2014
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Walter Kidde Portable Equipment Incorporated (Carrier Global Corporation)
• Original Assignee: Walter Kidde Portable Equipment Incorporated (Carrier Global Corporation)
• Inventors: Zribi, Anis, Chandler, Bill, Bush, Dave, Buchholz, Matthew J.
• Granted Patent: US 9,330,550 B2
• Time in Patent Office: Days
• US Class Current: 340/589
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• 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 29/183 Single detectors using dual technologies G08B13/1672, G08B13/2448, G08B13/2494 take precedence
• CPC Class Codes: G08B 29/185 Signal analysis techniques for reducing or preventing false alarms or for enhancing the reliability of the system
• CPC Class Codes: G08B 29/26 by updating and storing reference thresholds

Abstract

Embodiments relate to systems for, and methods of, providing low nuisance, fast response hazard notification. Advantageously, the disclosed techniques avoid sounding an alarm in response to typical nuisance events, such as burnt food.

Claims

1. A hazard safety device comprising:

an electronic processor;

at least one smoke sensor communicatively coupled to the processor, wherein the at least one smoke sensor is configured to produce a smoke sensor signal;

a temperature sensor communicatively coupled to the processor, wherein the temperature sensor is configured to produce a temperature sensor signal;

wherein the processor is configured to increase a smoke sensor signal threshold from a first smoke sensor signal threshold value to a second smoke sensor signal threshold value in response to a combination of parameter values comprising a smoke sensor signal value of at least the first smoke sensor signal threshold value, a rate of change of the smoke sensor signal below a smoke sensor rate of change threshold, and a rate of change of the temperature sensor signal below a temperature sensor rate of change threshold.

2. The hazard safety device of claim 1, further comprising a timer, wherein the processor is further configured to start the timer upon the increase of the smoke sensor signal threshold from the first smoke sensor signal threshold value to the second smoke sensor signal threshold value, and wherein the processor is configured to decrease the smoke sensor signal threshold from the second smoke sensor signal threshold value to the first smoke sensor signal threshold value upon both expiration of the timer and a smoke sensor signal value below the first smoke sensor signal threshold value.

3. The hazard safety device of claim 2, wherein the processor is configured to issue an alarm prior to expiration of the timer in response to a combination of parameter values comprising a smoke sensor signal value above the second smoke sensor signal threshold value.

4. The hazard safety device of claim 1, further comprising a carbon monoxide sensor communicatively coupled to the processor, wherein the carbon monoxide sensor is configured to produce a carbon monoxide sensor signal, and wherein the combination of parameter values further comprises a carbon monoxide sensor signal value below a carbon monoxide sensor signal threshold value and a rate of change of the carbon monoxide sensor signal below a carbon monoxide sensor rate of change threshold.

5. The hazard safety device of claim 1 further comprising a carbon monoxide sensor communicatively coupled to the processor, wherein the carbon monoxide sensor is configured to produce a carbon monoxide sensor signal, and wherein the processor is configured to decrease the smoke sensor signal threshold from a first smoke sensor signal threshold value to a third smoke sensor signal threshold value in response to a combination of parameter values comprising a smoke sensor signal value below the first smoke sensor signal threshold and a carbon monoxide sensor signal value above a carbon monoxide sensor signal threshold value.

6. The hazard safety device of claim 5, further comprising a timer, wherein the processor is further configured to start the timer upon the decrease of the smoke sensor signal threshold from the first smoke sensor signal threshold value to the third smoke sensor signal threshold value, and wherein the processor is configured to increase the smoke sensor signal threshold from the third smoke sensor signal threshold value to the first smoke sensor signal threshold value upon both expiration of the timer and a carbon monoxide sensor signal value below the carbon monoxide sensor signal threshold value.

7. The hazard safety device of claim 6, wherein the processor is configured to issue an alarm prior to expiration of the timer in response to a combination of parameter values comprising a carbon monoxide signal value above the carbon monoxide sensor signal threshold value, and a smoke sensor signal value above the third smoke sensor signal threshold value.

8. The hazard safety device of claim 1, wherein the combination of parameter values and the second smoke sensor signal threshold value are determined using empirical data and a computer learning technique.

9. The hazard safety device of claim 8, wherein the computer learning technique comprises using a discriminant analysis model or a support vector machine.

10. The hazard safety device of claim 1, wherein the processor is configured to issue an alarm in response to both the smoke sensor signal value above the first smoke sensor signal threshold value and a rate of change of the temperature sensor signal above a temperature sensor rate of change threshold.

11. The hazard safety device of claim 1, wherein the processor is configured to increase a smoke sensor signal threshold from a first smoke sensor signal threshold value to a fourth smoke sensor signal threshold value in response to a combination of parameter values comprising a smoke sensor signal value of at least the first smoke sensor signal threshold value, and a rate of change of the temperature sensor signal above a temperature sensor rate of change threshold.

12. The hazard safety device of claim 1, wherein the processor is configured to increase a smoke sensor signal threshold from a first smoke sensor signal threshold value to a fourth smoke sensor signal threshold value in response to a difference between smoke sensor signal values for adjacent time samples exceeding a temporally adjacent smoke sensor sample difference threshold.

13. A method comprising:

obtaining a smoke sensor signal from at least one smoke sensor;

obtaining a temperature sensor signal from a temperature sensor; and

increasing a smoke sensor signal threshold from a first smoke sensor signal threshold value to a second smoke sensor signal threshold value in response to a combination of parameter values comprising a smoke sensor signal value of at least the first smoke sensor signal threshold value, a rate of change of the smoke sensor signal below a smoke sensor rate of change threshold, and a rate of change of the temperature sensor signal below a temperature sensor rate of change threshold.

14. The method of claim 13, further comprising:

starting a timer upon the increase of the smoke sensor signal threshold from the first smoke sensor signal threshold value to the second smoke sensor signal threshold value; and

decreasing the smoke sensor signal threshold from the second smoke sensor signal threshold value to the first smoke sensor signal threshold value upon both expiration of the timer and a smoke sensor signal value falling below the first smoke sensor signal threshold value.

15. The method of claim 13, further comprising:

issuing an alarm prior to expiration of the timer in response to a combination of parameter values comprising a smoke sensor signal value rising above the second smoke sensor signal threshold value.

16. The method of claim 13, further comprising:

obtaining a carbon monoxide sensor signal value from a carbon monoxide sensor; and

obtaining a rate of change of a carbon monoxide sensor signal;

wherein the combination of parameter values further comprises a carbon monoxide sensor signal value falling below a carbon monoxide sensor signal threshold value and a rate of change of a carbon monoxide sensor signal falling below a carbon monoxide sensor rate of change threshold.

17. The method of claim 13, further comprising:

obtaining a carbon monoxide sensor signal value from a carbon monoxide sensor; and

decreasing the smoke sensor signal threshold from a first smoke sensor signal threshold value to a third smoke sensor signal threshold value in response to a combination of parameter values comprising a smoke sensor signal value falling below the first smoke sensor signal threshold and a carbon monoxide sensor signal value rising above a carbon monoxide sensor signal threshold value.

18. The method of claim 17, further comprising:

starting a timer upon the decreasing the smoke sensor signal threshold from the first smoke sensor signal threshold value to the third smoke sensor signal threshold value; and

increasing the smoke sensor signal threshold from the third smoke sensor signal threshold value to the first smoke sensor signal threshold value upon both expiration of the timer and the carbon monoxide sensor signal value falling below the carbon monoxide sensor signal threshold value.

19. The method of claim 18, further comprising:

issuing an alarm prior to expiration of the timer in response to a combination of parameter values comprising a carbon monoxide signal value rising above the carbon monoxide sensor signal threshold value, and a smoke sensor signal value falling above the third smoke sensor signal threshold value.

20. The method of claim 13, further comprising:

issuing an alarm in response to both the smoke sensor signal value rising above the first smoke sensor signal threshold value and a rate of change of the temperature sensor signal rising above a temperature sensor rate of change threshold.

21. The method of claim 13, further comprising:

increasing a smoke sensor signal threshold from a first smoke sensor signal threshold value to a fourth smoke sensor signal threshold value in response to a combination of parameter values comprising detecting a smoke sensor signal value of at least the first smoke sensor signal threshold value, and detecting a rate of change of the temperature sensor signal above a temperature sensor rate of change threshold.

22. The method of claim 13, further comprising:

increasing a smoke sensor signal threshold from a first smoke sensor signal threshold value to a fourth smoke sensor signal threshold value in response to detecting a difference between smoke sensor signal values for adjacent time samples exceeding a temporally adjacent smoke sensor sample difference threshold.