Method and system for fire detection

• US 7,969,296 B1
• Filed: 08/01/2008
• Issued: 06/28/2011
• Est. Priority Date: 08/01/2008
• Status: Active Grant

• Current Assignee: WilliamsRDM, Inc.
• Original Assignee: Williams-Pyro Incorporated
• Inventors: Stell, Andrew W.
• Primary Examiner(s): Mehmood; Jennifer
• Application Number:
  US12/184,724
• Time in Patent Office: 1,061 Days
• Field of Search: 340/539.22, 340/539.24, 340/539.26, 340/539.27, 340/517, 340/521, 340/522, 340/577, 340628-630, 706/2
• US Class Current: 340/522
• 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 17/117 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 29/186 Fuzzy logic; neural networks

Abstract

A method and system are provided, which provides reliable fire detection. In one implementation, the automated system includes a combination of sensors configured to measure various factors associated with a hazard, such as a fire or gas leakage, and generate sensor readings. Factors measured can include smoke, carbon monoxide and heat. The system further includes a detection device that is configured to determine whether a hazard or fire exists by performing a fuzzy analysis of sensor readings. The fuzzy analysis includes categorizing respective sensor readings into fuzzy sets, and determining whether the hazard exists based on a combination of the categorizations. In addition the size and direction of a fire can be determined from multiple sensors.

Claims

1. A method for detecting a hazardous condition, the method comprising:

receiving sensor readings from a plurality of sensors for attributes related to the hazardous condition; and

determining whether the hazardous condition exists based on a fuzzy analysis of the sensor readings, wherein;

the sensor readings include temperature readings; and

the fuzzy analysis comprises;

determining a temperature rise rate from the temperature readings;

classifying the temperature rise rate by assigning a classification value in the range 0 to 1;

categorizing the temperature rise rate and the temperature readings into respective fuzzy set categories; and

combining the respective fuzzy set categories into an output that indicates whether the hazardous condition exists or not.

2. The method of claim 1, wherein the categorizing comprises:

assigning membership levels for one or more fuzzy set categories to the classification value;

determining a probability of the classification value belonging to the one or more fuzzy set categories; and

categorizing the classification value into a fuzzy set category for which the classification value has the highest probability.

3. A hazard detection system, the system comprising:

a plurality of sensors configured to measure attributes associated with a hazard and generate sensor readings; and

a detection device configured to determine whether the hazard exists or not based on a fuzzy analysis of the sensor readings, wherein;

the sensor readings include temperature readings; and

the fuzzy analysis comprises;

determining a temperature rise rate from the temperature readings;

classifying the temperature rise rate by assigning a classification value in the range 0 to 1;

categorizing the temperature rise rate and the temperature readings into respective fuzzy set categories; and

combining the respective fuzzy set categories into an output that indicates whether the hazardous condition exists or not.

4. The hazard detection system of claim 3, wherein:

the categorizing comprises;

assigning membership levels for one or more fuzzy set categories to the classification value;

determining a probability of the classification value belonging to the one or more fuzzy set categories; and

categorizing the classification value into a fuzzy set category for which the classification value has the highest probability.