Research On Multiple Gases Detection And Identification Methods Based On Wide-band Infrared Spectral Imaging Technology

As the rapid development of industry,a variety of toxic gases are widely used by factories.The premise of ensuring production safety is the safe storage and transportation of gas.Once the toxic and hazardous gases leak,it is very easy to cause an explosion and other accidents with serious consequences.Efficient gas leak detection technology helps to detect and deal with gas leaks at the first time,thus avoiding possible personal injury and property damage.Infrared spectral imaging detection technology is one of the important means of gas leak detection,compared with the traditional point gas sensor,infrared spectral imaging detection technology has the advantages of long detection distance,large coverage,detection of a wide range of gases and can be directly imaged and so on.Existing infrared gas leak detection systems generally cover only the medium wave（3-5μm）or long wave（8-14μm）infrared band,which can detect a limited variety of gas leaks,and because the traces of gas leaks captured by infrared imaging technology are faint,enhancing the display of gas traces from the image is also a difficult research task.The study of gas imaging and detection identification methods in broad band infrared spectroscopy is important to improve the gas detection capability of this method.First,the research results of gas passive infrared imaging detection technology at home and abroad were summarized.An improved infrared imaging detection technology was proposed in this thesis for the identification and detection of toxic and harmful gases in chemical industrial areas.The proposal contains broad-band infrared optical imaging system,sub-band filtering system,image processing and output system and other modules,using the filter rotor system of spectral splitting to obtain infrared images of different spectral channels,according to the infrared absorption characteristics of toxic and harmful gases to discriminate the type and area of gas leakage.Aiming at the characteristics of low contrast and poor quality of infrared detection system imaging,an image enhancement method based on Gaussian filtering and adaptive histogram segmentation is proposed to effectively improve the quality of infrared images and lay the foundation for subsequent gas image feature extraction.The traditional background modeling algorithm is analyzed,and the Vi Be（Visual Background Extractor）algorithm is studied in depth.Based on the advantages and disadvantages of the Vi Be algorithm and the characteristics of gas leak images,a gas leak region detection method based on the improved Vi Be algorithm is proposed,which can quickly establish a background model,segment the gas leak region with motion characteristics,and render the gas leak region in color based on grayscale mapping to achieve automatic detection and enhanced display of gas leaks.Based on the timing information of the filter runner,the imaging results are divided into six video channels according to the spectral channels for gas leak detection,and the leaking gas is coded based on the detection results,matched with the codes in the toxic and hazardous gas database to determine the type of leaking gas.The experimental results of the detection of different gases verify that the system has the ability to detect and identify multiple gas leaks.