System and method of adjusting smoothing

• US 5,969,604 A
• Filed: 07/22/1998
• Issued: 10/19/1999
• Est. Priority Date: 04/29/1997
• Status: Expired due to Term

• Current Assignee: Pittway Corporation (Honeywell International Inc.)
• Original Assignee: Pittway Corporation (Honeywell International Inc.)
• Inventors: Tice, Lee D.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US09/120,444
• Time in Patent Office: 454 Days
• Field of Search: 340/506, 340/514, 340/510, 340/511, 340/588, 340/589, 340/517, 340/521, 340/522, 340/628, 340/632, 340/501, 340/577, 340/600, 340/601
• US Class Current: 340/506
• 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 29/185 Signal analysis techniques for reducing or preventing false alarms or for enhancing the reliability of the system
• CPC Class Codes: G08B 29/188 Data fusion; cooperative systems, e.g. voting among different detectors

Abstract

An ambient condition detector includes a sensor for a first ambient condition and a second, sensor which is responsive to a second ambient condition not necessarily correlated to the first condition. Control circuitry, coupled to both sensors, processes an output from the first sensor to reduce transients and/or noise therein which are not correlated to the first ambient condition. Processing characteristics are altered in response to an output from the second sensor. The processing can take place at the detector or, in part, at the detector and, in part, at a displaced, common control element.

Claims

1. An apparatus comprising:

a first sensor of a first ambient condition wherein the sensor generates a first output indicative of the first condition;

a second sensor of a second ambient condition wherein the sensor generates a second output indicative of the second condition; and

a control element which receives signals indicative of the outputs of both sensors wherein the control element includes circuitry for adjusting a filtering process associated with the first output thereby producing a processed first output signal, in response to the second output.

2. An apparatus as in claim 1 wherein the first sensor is a fire sensor and the second sensor is a gas sensor.

3. An apparatus as in claim 1 wherein the first sensor is a smoke sensor and the second sensor is a non-smoke sensor.

4. An apparatus as in claim 1 wherein the control element includes a programmed processor and a set of instructions which, when executed by the processor, carry out the filtering process.

5. An apparatus as in claim 4 wherein the first sensor comprises a smoke sensor and the second sensor comprises a gas sensor.

6. An apparatus as in claim 1 wherein the first sensor comprises a fire sensor selected from a class which includes a smoke sensor, a thermal sensor and a gas sensor and wherein the second sensor comprises a non-fire sensor.

7. An apparatus as in claim 1 which includes a housing, wherein the sensors are carried by the housing.

8. An apparatus as in claim 7 wherein at least a portion of the control element, comprising local control circuitry, is carried by the housing.

9. An apparatus as in claim 8 wherein the control circuitry carries out the filtering process at the housing and includes circuitry, responsive to the output of the second sensor, for modifying at least one coefficient thereof.

10. A monitoring system comprising:

a housing;

a smoke sensor carried by the housing wherein the sensor generates a first output signal;

a second sensor, carried by the housing, wherein the second sensor is selected from a class which includes at least a smoke sensor, a gas sensor, a thermal sensor, a dust sensor, a humidity sensor, a velocity sensor; and

control circuitry, in communication with the sensors for processing a representation of the first output signal and for adjusting at least one processing parameter in response to a representation of an output from the second sensor.

11. A system as in claim 10 wherein the control circuitry includes circuitry for carrying out a filtering process specified by at least one coefficient and wherein that coefficient is modified by the representation of the output from the second sensor.

12. A system as in claim 11 wherein the control circuitry is carried, at least in part, by the housing.

13. A system as in claim 10 wherein the control circuitry implements a filtering process using, at least in part, a running average and wherein the process is modified by the representation of the output from the second sensor.

14. A system as in claim 10 wherein the control circuitry adjusts the parameter at the housing.

15. A monitoring system comprising;

a plurality of ambient condition detectors; and

a plurality of function executing electrical units wherein the members of both pluralities include circuitry for bidirectional communication, via a medium, and wherein at least some of the detectors each include first and second ambient condition sensors wherein an output from one of the sensors of a respective detector is processed using a variable filter and wherein an output from the other of the sensors is coupled to circuitry for varying the characteristics of the respective filter in response thereto.

16. A system as in claim 15 wherein the medium comprises one of an electrical cable, an optical cable and a wireless link.

17. A system as in claim 15 which includes a common control element coupled to the pluralities of detectors and units via the medium wherein the control element includes the variable filter.

18. A system as in claim 17 wherein the control element includes a programmed processor and prestored instructions for implementing the variable filter.

19. A system as in claim 15 wherein each member of a second plurality of detectors includes a respective programmed processor and each of the processors has associated therewith instructions for implementing, at least in part, a respective variable filter.