FOREST FIRE EARLY-WARNING SYSTEM AND METHOD BASED ON INFRARED THERMAL IMAGING TECHNOLOGY

• US 20140192184A1
• Filed: 06/05/2012
• Published: 07/10/2014
• Est. Priority Date: 06/09/2011
• Status: Active Grant

• Current Assignee: Guangzhou Sat Infrared Technology Co., Ltd.
• Original Assignee: Guangzhou Sat Infrared Technology Co., Ltd.
• Inventors: Wu, Jiping, Li, Yuenian
• Granted Patent: US 9,666,050 B2
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: A62C 3/0271 Detection of area conflagration fires fire alarms for forest fires G08B17/005
• CPC Class Codes: G08B 17/005 for forest fires, e.g. detecting fires spread over a large or outdoors area fire fighting forest fires A62C3/02
• CPC Class Codes: G08B 17/125 by using a video camera to detect fire or smoke
• CPC Class Codes: G08B 25/14 Central alarm receiver or annunciator arrangements
• CPC Class Codes: G08B 29/26 by updating and storing reference thresholds

Abstract

A forest fire early-warning system based on infrared thermal imaging technology comprising: an infrared camera erected at a key height in a forest used to capture infrared thermal images of an area being monitored, said camera comprising a frontal temperature detection and alarm module for calculating the alarm temperature value by using a temperature monitoring mathematical model, and for transmitting an excessive temperature alarm signal when there are abnormalities in said area; a video conversion device connected to the infrared camera for converting an infrared thermal image analog signal outputted by the camera into an infrared digital signal, and for receiving from the camera said alarm signal and converting same into a digital signal; a monitoring computer for generating and transmitting an infrared camera control signal, and for receiving, analyzing and processing the infrared digital signal to ascertain the location in the monitoring area that triggered the infrared camera alarm, and for automatically generating a solution and reporting to the control center. The present invention can adapt to the complex environmental conditions and monitoring requirements of forest fire monitoring and automated early-warning, guaranteeing alarm accuracy.

Claims

1. A forest fire alarm system based on infrared thermal imaging technology comprising:

an infrared camera located within a monitored area for monitoring and early fire warning in a forest, the infrared camera configured to capture infrared thermal images of said monitored area, and to transmit infrared thermal analog signals which contain temperature measurement values T relating to the infrared thermal images of the monitored area, and wherein the infrared camera includes a frontal temperature measurement and alarm module configured to calculate, based on changes of environmental temperature parameters including at least one of distance, temperature difference and alternate seasons, an alarm temperature value T_alarm, the frontal temperature measurement and alarm module configured to interpret the changes using a built-in temperature monitoring mathematical model, and to transmit excessive temperature alarm signals when there is an emergence of abnormality;

a video conversion device connected to the infrared camera configured to transform the infrared thermal image analog signals transmitted by the infrared camera into infrared digital signals for standard network transmission, and to receive and convert the excessive temperature alarm signals outputted from the infrared camera into excessive temperature alarm digital signals; and

a monitoring computer configured to generate and output control signals in order to control the infrared camera, and to receive, analyze and process the infrared digital signals to ascertain a location in the monitored area that triggered an infrared camera alarm based on the excessive temperature alarm digital signals.

2. The forest fire alarm system according to claim 1, wherein the frontal temperature measurement and alarm module further comprises an alarming unit in which it holds a temperature monitoring mathematical model for calculating, based on said model and said temperature measurement value T, in order to determine:

a preset alarm temperature T_set either set as a constant value or a variable constant value based on both statistical values of temperature measurement and fire temperature in the monitored area;

an isothermal allowed width δ

t either set as a constant temperature difference value or a variable temperature difference value based on both the statistical values of temperature measurement and the fire temperature in the monitored area;

a reference area S set based on the monitoring parameter of the infrared camera and its mounted area, a minimum area of the reference area being the area monitored by a pixel of the infrared camera, while a maximum one being a full-screened area; and

an average temperature of the reference area T_S automatically captured from the monitored pictures of the reference area S; and

a hottest temperature spot T_h automatically captured based on the real-time monitored pictures of the monitored area and its temperature measurement value T, wherein

the alarm temperature value T_alarm=average temperature of the reference area T_S+isothermal allowed width δ

t.

3. The forest fire alarm system according to the claim 2, wherein, a condition for alarming the anomaly is:

when the hottest temperature spot T_h≧

alarm temperature value T_alarm, the frontal temperature measurement and alarm module alarms;

or

when the hottest temperature spot T_h≧

preset alarm temperature T_set, the frontal temperature measurement and alarm module alarms.

4. The forest fire alarm system according to claim 2, wherein, the frontal temperature measurement and alarm module comprising the lens, detector, AD plates and pseudo colored plates, wherein said pseudo colored plates further comprising a temperature measurement unit and the alarm unit, wherein, the temperature value T measured by the temperature measurement unit is transmitted to the alarm unit for being calculated to gain the alarm temperature value T_alarm by using the temperature monitoring mathematical module in the alarm unit, the alarm unit also outputs the excessive temperature alarm signals of the anomaly to the video conversion device.

5. The forest fire alarm system according to claim 1, wherein, the system further comprising:

a CCD camera fixed in the vicinity of the infrared camera is configured to capture visible images of the monitored area and to transmit the visible image analog signals relating to the visible images of the monitored area, wherein

said video conversion device for being connected to said CCD camera is configured to transform the visible image analog signals from the CCD camera into visible digital signals which can be transmitted through a standard network; and

the monitoring computer is also configured to generate and to output the control signals in order to control a plurality of said CCD cameras, and to receive said visible digital signals, and to combine the received visible digital signals and the infrared digital signals for analyzing and processing so as to alarm an anomaly and to ascertain the location where a danger situation is triggered.

6. The forest fire alarm system according to claim 5 wherein a shooting orientation of the infrared camera and the CCD cameras changes with the operating of the pan-tilt which is installed and integrated with the infrared camera and the CCD cameras, the pan-tilt connects to said video conversion device through 485 serial port so as to realize the data communication between them.

7. The forest fire alarm system according to claim 5 wherein the system further comprising:

a casing configured to cover the infrared camera and the visible camera and their internal powers respectively integrated into the casing.

8. The forest fire alarm system according to the claim 6, wherein, the video conversion device further comprising:

a network data conversion unit configured to transform analog signals emitted by cameras into digital signals for standard network transmission wherein the cameras contain the infrared camera and the CCD camera while the analog signals include infrared imaging analog signals and visible imaging analog signals, and the digital signals encompass infrared digital signals and visible signals; and

a pan and tilt control unit configured to transform a pan-and-tilt control signals from a network into 485 serial port control signals in order to control a corresponding pan and tilt to operate and to receive the status of the pan and tilt through 485 serial port, and then to transmit these information to the monitoring computer.

9. The forest fire alarm system according to claim 6, wherein the monitoring computer comprises:

a data input interface configured to receive digital signals transmitting from the video conversion device; and

a data analysis module configured to intercept and analyze the digital signals from the data input interface by using forest fire disaster analysis and process software and to determine and locate the fire area within the monitored region based on the processed data and to generate the pan and tilt control signals to control the infrared camera and the visible camera.

10. The forest fire alarm system of claim 9, wherein, the monitoring computer further comprising:

a storage module configured to store the processed data and the determined conclusion; and

a display module configured to directly present infrared video pictures, fire triggering places and recommending disposal solutions within the monitored region.

11. The forest fire alarm system of claim 9, wherein, the data input interface of the monitoring computer transmits the data and does network communication with the video conversion device through EPON optical chain circuit.

12. The forest fire alarm system of claim 1, wherein, the frontal temperature measurement and alarm module further comprising IR lens, detector, AD plates and pseudo colored plates for achieving precise far distance infrared image capture and temperature measurement within the monitored region.

13. The forest fire alarm system of claim 1, wherein, the system further comprises a switcher or HUB for being connected to the video conversion device by network cables so as to achieve the network communication between the two.

14. A forest fire alarm method based on an infrared imaging technology utilizing a forest fire alarm system, wherein, the method comprises the following steps:

S1) starting an infrared camera, a visible camera, and a video conversion device which are mounted at a woodland commanding heights of an for fire early-warning monitoring for capturing infrared thermal images and visible images;

S2) receiving pan and tilt control signals from a monitoring computer through either wireless or network cable communication so as to control a shooting orientation of the infrared camera and the visible camera;

S3) calculating and obtaining an alarm temperature value T_alarm by using a frontal temperature measurement and alarm module based on application of a temperature monitoring mathematical model so as to output excessive temperature alarm signals of the anomalies;

S4) transmitting in real-time the infrared image analog signals which includes the temperature measurement value T, visible image analog signals as well as the excessive temperature alarm signals to the video conversion device thereon, the video conversion device transforms them into the digital signals and outputs to the monitoring computer;

S5) the monitoring computer intercepting and analyzing the received digital data;

S6) the monitoring computer, based on the foregoing analysis, pinpointing the fire triggering area and alarms on excessive temperature when receiving the excessive temperature alarm signals, otherwise, back to step S2.

15. The forest fire alarm method of claim 14, wherein, in step S3, the frontal temperature measurement and alarm module, based on its built-in temperature monitoring mathematical model and the temperature measurement value T, computes to determine:

a preset alarm temperature T_set, which is a constant value or a variable constant value set based on the temperature measurement statistical value of the monitoring region and the fire risk temperature statistical value;

an isothermal allowed width δ

t, which is a constant temperature difference value or a variable temperature difference value set based on the temperature measurement statistical value and the fire risk temperature statistical value;

a reference area S, which is set based on the monitoring reference of the infrared camera and the install location of which a minimum size of the reference area being the monitoring area of one pixel of the infrared camera while a maximum one the monitored area of full-screen monitoring picture of the infrared camera; and

an average temperature T_S of the reference area is the average temperature T_S automatically captured within the reference area based on the monitored pictures of the foregoing reference area; and

a hottest spot temperature T_h is automatically captured based on the real time monitored pictures of the monitored region and the temperature measurement value T within those pictures, wherein;

alarm temperature value T_alarm=average temperature of the reference area T_S+isothermal allowed width δ

t.

16. The forest fire alarm method of claim 15, wherein, the condition for alarming aimed at said anomaly is:

when the hottest spot temperature value T_h≧

alarm temperature value T_alarm, the frontal temperature measurement and alarm module will alarm on excessive temperature;

or

when the hottest spot temperature value T_h≧

preset alarm temperature value T_set, the frontal temperature measurement and alarm module will alarm on excessive temperature.

17. The forest fire alarm method of claims 14, further comprises steps as follows:

the monitoring computer visualizing pictures of danger of the monitored area, relative data and the attempted disposal solution which will be automatically stored into the storage module and/or the forest fire analysis treatment software so as to do the post-fire analysis and treatment.