Low-cost sulfur hexafluoride gas leakage infrared imaging detection system
阅读说明：本技术 一种低成本的六氟化硫气体泄漏红外成像检测系统 (Low-cost sulfur hexafluoride gas leakage infrared imaging detection system ) 是由 胡梦竹 韩方源 唐彬 樊雄伟 朱立平 李建新 喻敏 罗宗昌 梁沁沁 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种低成本的六氟化硫气体泄漏红外成像检测系统,涉及气体检测技术领域,通过宽波段红外光学镜头将气体及背景的红外辐射信号进行采集；窄带滤光片对红外镜头收集到的辐射信号进行滤波处理；宽波段非制冷红外焦平面探测器对背景、透过红外镜头和位于窄带滤光片光路上的红外辐射进行成像,得到原始SF-(6)红外图像；信号处理与输出模块采用基于混合滤波的SF-(6)红外图像增强方法对得到原始SF-(6)红外图像进行细节增强处理,并将处理后的图像以视频信号格式输出,并通过显示屏显示。六氟化硫气体泄漏红外成像检测系统可以在几十米外,不用靠近设备,不必接近泄漏点,就可以发现气体泄漏。(The invention discloses a low-cost sulfur hexafluoride gas leakage infrared imaging detection system, which relates to the technical field of gas detection, and is characterized in that infrared radiation signals of gas and background are collected through a broadband infrared optical lens; the narrow-band filter filters the radiation signals collected by the infrared lens; imaging the background, the infrared lens and the infrared radiation on the light path of the narrow-band filter by the broadband uncooled infrared focal plane detector to obtain the original SF 6 Infrared image; the signal processing and output module adopts SF based on mixed filtering 6 Infrared image enhancement method for obtaining original SF 6 Carrying out detail enhancement processing on the infrared image, and processing the processed imageThe image is output in a video signal format and displayed through a display screen. The sulfur hexafluoride gas leakage infrared imaging detection system can find gas leakage in tens of meters without approaching equipment or leakage points.)
1. The utility model provides a sulfur hexafluoride gas leakage infrared imaging detecting system of low-cost which characterized in that includes:
the broadband infrared optical lens is used for collecting infrared radiation signals of gas and background;
the narrow-band filter is a narrow-band filter with a sulfur hexafluoride gas infrared spectral band, and the narrow-band filter carries out filtering processing on the radiation signals collected by the infrared lens;
the broadband uncooled infrared focal plane detector is used for imaging infrared radiation penetrating through the broadband infrared optical lens and positioned on a light path of the narrow-band filter to obtain original SF6Infrared image;
a signal processing and output module, the signal processing and output module adopts SF based on mixed filtering6Infrared image enhancement method for said SF6The infrared image is processed by detail enhancement, and the processed image is used as a video signalOutputting the format; and
and the display screen displays the image transmitted by the signal processing and output module.
2. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein the spectrum of said broadband infrared optical lens includes 10.6。
3. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1 or 2, wherein the spectral coverage range of the broadband infrared optical lens is 10-11。
4. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein the broadband infrared optical lens is made of germanium glass, zinc selenide or zinc sulfide.
5. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein the diameter of the narrow band filter is larger than the size of the front end face of the broadband uncooled infrared focal plane detector, and the narrow band filter is installed next to the protection window of the broadband uncooled infrared focal plane detector.
6. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein said hybrid filtering based SF6The infrared image enhancement method comprises the following steps:
processing raw SF using guided filtering algorithm6Obtaining a basic image by an infrared image;
optimizing a low-frequency background of the basic image through a self-adaptive Gaussian filter, inhibiting random noise of the background, and simultaneously preventing an unnecessary gradient inversion effect to obtain an optimized basic image;
subtracting the basic image from the original image to obtain a detail image;
enhancing the detail image by adopting platform histogram equalization to enhance the contrast and detail information of the leakage area to obtain an enhanced detail image;
and performing weighted fusion on the enhanced basic image and the optimized detail image to obtain an enhanced image.
7. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein the imaging mode of the wide-band uncooled infrared focal plane detector is staring.
8. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein the response spectrum of the broadband uncooled infrared focal plane detector is 8-14 m.
9. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein said broadband uncooled infrared focal plane detector has a thermal sensitivity of less than 30 mK.
10. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system of claim 1, wherein said broadband uncooled infrared focal plane detector has a non-uniformity correction function.
Technical Field
The invention belongs to the technical field of gas detection, and particularly relates to a low-cost sulfur hexafluoride gas leakage infrared imaging detection system.
Background
Sulfur Hexafluoride (SF, Sulfur Hexafluoride)6) The gas is a colorless, tasteless, nontoxic and chemically extremely stable inert gas, and has excellent insulating property and arc extinguishing capability. SF since the 80 s of the 20 th century6Electrical equipment (e.g. SF)6Circuit breaker, SF6Mutual inductor, GIS and SF6Load switches) are widely used in the power industry. Over time, SF may be present due to manufacturing processes, material quality, and natural environment6SF in electrical equipment6Gas leakage sometimes occurs, leaked SF6The gas can cause the whole power grid to be incapable of operating normally, and great economic pressure is generated on a power system. In addition, SF6Belongs to one of 6 kinds of greenhouse effect gases, and has 23900 times of effect on greenhouse effect compared with equal specific gravity of carbon dioxide (CO 2). At present, SF6The maintenance of the electrical equipment mainly adopts the bundling method and the soap brushingBubble method, hand-held infrared imaging detector and the like. Infrared imaging detector (e.g., FLIR GF306) using SF6The gas and air have different absorption capacities for infrared radiation of specific wave bands, and colorless SF6The gas is treated to become colored imaged so that the SF is not normally seen under visible light6The gas leak becomes clearly visible under the infrared camera view. However, the functions of the infrared gas leakage detector are limited by the performance of the detector, which results in high price and inconvenience in carrying (such as GF306, the price is about 100 ten thousand).
In the process of power inspection, the infrared imaging gas leakage detector is widely applied. But the price is high and the carrying is inconvenient, so the application and popularization of the medicine are limited. Meanwhile, the infrared imaging detector does not support automatic detection of leaked gas, and needs to artificially judge whether SF occurs according to recorded video data6The phenomena of misdiagnosis and missed diagnosis may exist in the gas leakage and the leakage degree; digital interfaces cannot be provided, and the development of high-level applications such as data mining and automatic diagnosis is needed. Simultaneous SF6The gas leakage infrared imaging intelligent detection technology is also closely related to the construction of a smart power grid. Therefore, a low-cost sulfur hexafluoride gas leakage infrared imaging detection system is needed.
Disclosure of Invention
The invention aims to provide a sulfur hexafluoride gas leakage infrared imaging detection system with low cost, so that the defect that an infrared imaging gas leakage detector is expensive in the conventional power inspection process is overcome.
In order to achieve the above object, the present invention provides a low-cost sulfur hexafluoride gas leakage infrared imaging detection system, including:
the broadband infrared optical lens is used for collecting infrared radiation signals of gas and background;
the narrow-band filter is a narrow-band filter with a sulfur hexafluoride gas infrared spectral band, and the narrow-band filter carries out filtering processing on the radiation signals collected by the infrared lens;
wide bandThe wide-band uncooled infrared focal plane detector is used for imaging infrared radiation penetrating through the wide-band infrared optical lens and positioned on the light path of the narrow-band filter to obtain original SF6Infrared image;
a signal processing and output module, the signal processing and output module adopts SF based on mixed filtering6Infrared image enhancement to the SF6Performing detail enhancement processing on the infrared image, and outputting the processed image in a video signal format; and
and the display screen displays the image transmitted by the signal processing and output module.
Further, the spectrum of the broadband infrared optical lens comprises 10.6 μm.
Furthermore, the spectral coverage range of the broadband infrared optical lens is 10-11 μm.
Furthermore, the broadband infrared optical lens is made of germanium glass, zinc selenide or zinc sulfide.
Furthermore, the diameter of the narrow-band filter is larger than the size of the front end face of the broadband uncooled infrared focal plane detector, and the narrow-band filter is installed next to the protection window of the broadband uncooled infrared focal plane detector.
Further, the mixed filtering based SF6The infrared image enhancement method comprises the following steps:
processing raw SF using guided filtering algorithm6Obtaining a basic image by an infrared image;
optimizing a low-frequency background of the basic image through a self-adaptive Gaussian filter, inhibiting random noise of the background, and simultaneously preventing an unnecessary gradient inversion effect to obtain an optimized basic image;
subtracting the basic image from the original image to obtain a detail image;
enhancing the detail image by adopting platform histogram equalization to enhance the contrast and detail information of the leakage area to obtain an enhanced detail image;
and performing weighted fusion on the enhanced basic image and the optimized detail image to obtain an enhanced image.
Furthermore, the imaging mode of the broadband uncooled infrared focal plane detector is a staring type.
Furthermore, the response spectrum of the broadband uncooled infrared focal plane detector is 8-14 m.
Further, the thermal sensitivity of the broadband uncooled infrared focal plane detector is less than 30 mK.
Furthermore, the broadband uncooled infrared focal plane detector has a non-uniformity correction function.
Compared with the prior art, the invention has the following beneficial effects:
the low-cost sulfur hexafluoride gas leakage infrared imaging detection system provided by the invention collects infrared radiation signals of gas and background through the band infrared optical lens; a narrow-band filter with a sulfur hexafluoride gas infrared band filters the radiation signals collected by the infrared lens; imaging the background, the infrared lens and the infrared radiation on the light path of the narrow-band filter by the broadband uncooled infrared focal plane detector to obtain the original SF6Infrared image and will get the original SF6The infrared image is transmitted to a signal processing and output module; the signal processing and output module adopts SF based on mixed filtering6Infrared image enhancement method for obtaining original SF6And performing detail enhancement processing on the infrared image, outputting the processed image in a video signal format, and displaying the processed image through a display screen. The sulfur hexafluoride gas leakage infrared imaging detection system with low cost can find gas leakage in tens of meters without approaching equipment or leakage points. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system has the advantages of small volume, low cost, high sensitivity and the like, and has wide application prospect in an electric power system.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only one embodiment of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is SF6Gas infrared absorption spectrogram;
FIG. 2 is a schematic structural diagram of a low-cost sulfur hexafluoride gas leakage infrared imaging detection system of the present invention;
FIG. 3 is a hybrid filtering based SF of the present invention6Flow chart of infrared image enhancement method.
Detailed Description
The technical solutions in the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The infrared imaging detector mainly utilizes SF6For detection. Electromagnetic waves with a wavelength of between 0.75 and l000 μm are called infrared light, and when infrared light with continuous wavelengths passes through a substance, certain wavelengths of light are absorbed to form a specific infrared absorption spectrum, SF6The infrared absorption spectrum of the gas is shown in FIG. 1.
As can be seen from FIG. 1, SF6The gas has stronger radiation intensity in a wave band of 10-11 mu m, the radiation intensity reaches the maximum at 10.6 mu m, and the air has weaker radiation in the wave band. Thus, SF6The gas and air will show different colors under the irradiation of infrared light. SF6The radiation intensity of the gas reaches a maximum at 10.6 μm. Thus, SF can be achieved with features at 10.6 μm6High sensitivity imaging and detection of gases. And the working wave band is adjusted to a state of clear imaging through a narrow band filter (10.6 mu m +/-60 nm) on the basis of finishing imaging and dispersion of the diffractive optical element by matching with a high-performance and high-sensitivity detector and an image processing technology, so that the imaging can be realizedColorless, odorless SF6The gas is different from the background image and can be clearly seen on the display screen.
The invention relates to sulfur hexafluoride (SF)6) Based on the principle and application of a passive infrared thermal imaging technology, the optical performance of the gas is combined with the performance of various uncooled focal plane infrared detectors and narrow-band filters, a high-gain low-noise image enhancement algorithm is researched, a display device is used for assisting, and a low-cost sulfur hexafluoride gas leakage infrared imaging detection system is developed. FIG. 2 shows a low-cost sulfur hexafluoride gas leakage infrared imaging detection system according to one embodiment of the invention, including: broadband infrared optical lens, narrowband optical filter, broadband uncooled infrared focal plane detector, signal processing and output module and display screen
The broadband infrared optical lens is used for collecting infrared radiation signals of gas and background and gathering the infrared radiation signals to an imaging surface, namely an uncooled infrared focal plane detector;
the narrow-band filter is a narrow-band filter with a sulfur hexafluoride gas infrared band, and carries out filtering processing on the radiation signals collected by the infrared lens;
the broadband uncooled infrared focal plane detector is used for imaging infrared radiation transmitted through the broadband infrared optical lens and positioned on the light path of the narrow-band filter to obtain original SF6Infrared image;
the signal processing and output module adopts SF based on mixed filtering6Infrared image enhancement method for said SF6Performing detail enhancement processing on the infrared image, and outputting the processed image in a video signal format;
and the display screen displays the image transmitted by the signal processing and output module.
According to the low-cost sulfur hexafluoride gas leakage infrared imaging detection system, infrared radiation of gas to be detected is collected through the broadband infrared optical lens, radiation signals collected by the infrared lens are filtered through the narrow-band optical filter, and then are gathered to the imaging plane, namely the broadband uncooled infrared focal plane detector, and the sulfur hexafluoride gas leakage infrared imaging detection system is obtained through the broadband uncooled infrared focal plane detectorTo the original SF6The infrared image, signal processing and output module adopts SF based on mixed filtering6Infrared image enhancement method for said SF6And performing detail enhancement processing on the infrared image, outputting the processed image in a video signal format, and finally displaying on a display screen. The infrared image of the leaked gas is transmitted to an upper computer end provided with the signal processing and output module for further processing, and an advanced image gain algorithm is used for assisting, so that extremely tiny gas leakage can be observed, and the gas leakage can be found out in dozens of meters without approaching equipment or approaching a leakage point. The low-cost sulfur hexafluoride gas leakage infrared imaging detection system has the advantages of small volume, low cost, high sensitivity and the like, and has wide application prospect in an electric power system.
One example of this is SF6The gas has stronger radiation intensity in a wave band of 10-11 mu m, the sensitivity of the uncooled infrared focal plane detector is lower than that of a refrigerating type, and the broadband infrared optical lens has the following characteristics in comprehensive consideration:
(1) the broadband infrared optical lens has good optical performance (high transmittance) in a 10-11 μm waveband, and particularly has the transmittance as high as possible in a 10.6 μm nearby waveband.
(2) Because the sensitivity of the broadband uncooled infrared focal plane detector is lower than that of a refrigeration type, the broadband infrared optical lens is required to ensure that the system has higher sensitivity within the range of the size, the imaging quality and the allowable processing technology.
(3) The narrow-band filter is positioned between the broadband infrared optical lens and the broadband uncooled infrared focal plane detector, and the selection of parameters such as focal length, back intercept, F number, field angle, distortion and the like is fully considered according to actual needs.
(4) The broadband infrared optical lens is made of germanium glass, zinc selenide or zinc sulfide
(5) The broadband infrared optical lens reduces the loss of infrared radiation energy as much as possible.
(6) The influence of the ambient temperature on the infrared optical material is large, so that the image plane, the focal length and the aberration of the optical system are different from those of the optical system at normal temperature, and the imaging quality of the system is reduced. Therefore, for the broadband infrared optical lens, not only the chromatic aberration correction problem but also the influence of the environmental temperature change on the optical performance of the broadband infrared optical lens need to be considered, namely, the sulfur hexafluoride gas leakage infrared imaging detection system with low cost should simultaneously realize achromatic aberration, meet the design requirement of thermal aberration elimination, and realize the athermalization design of the sulfur hexafluoride gas leakage infrared imaging detection system with low cost.
In one embodiment, the filters with cut-off regions on both sides of the transmission band of the spectral characteristic curve are called bandpass filters, and can be divided into a broadband filter and a narrowband filter according to the spectral characteristics. The narrow-band filter can realize the selection of a specific spectral band, and although the narrow-band filter reduces the total radiant quantity received by the detector and reduces the signal-to-noise ratio of the system, the narrow-band filter greatly improves the percentage of the radiant quantity absorbed by the gas in the total radiant quantity received by the detector, so that the system has higher overall sensitivity. Specifically, the narrowband filter has the following characteristics:
(1) the transmission waveband of the narrow-band filter is 10.6 microns +/-60 nm, and specifically, parameters such as peak transmittance, passband half-width, cut-off wavelength and central wavelength of the narrow-band filter can be properly selected according to actual application requirements.
(2) The narrow-band filter should have a high transmittance in the transmission band, so as to reduce the attenuation of radiation transmission in the optical path as much as possible, and simultaneously effectively filter out ineffective radiation in other bands.
(3) The diameter of the optical filter is larger than the size of the heating front end face of the broadband uncooled infrared focal plane detector, and the optical filter is installed next to the protection window of the broadband uncooled infrared focal plane detector, so that the purpose of effectively filtering stray light is achieved.
In one embodiment, the infrared detector is the core of a low-cost sulfur hexafluoride gas leakage infrared imaging detection system, and the infrared detector is a light sensor capable of responding to external infrared radiation. The broadband uncooled infrared focal plane detector is gradually developed, the performance of the uncooled infrared focal plane detector is gradually close to the level of a refrigeration type detector, the sensitivity of the uncooled infrared focal plane detector is improved, the uncooled infrared focal plane detector is low in price, the uncooled infrared focal plane detector is simple in system structure, and the uncooled infrared focal plane detector is gradually replaced by the uncooled infrared focal plane detector. Meanwhile, the broadband uncooled infrared focal plane detector belongs to a thermoelectric detector, so that the broadband imaging detection from middle infrared to far infrared can be realized by a single detector, and the use value of the sulfur hexafluoride gas leakage infrared imaging detection system with low cost is greatly improved. In order to meet the requirements of a sulfur hexafluoride gas leakage infrared imaging detection system with low cost, the key characteristics of the broadband uncooled infrared focal plane detector are as follows:
TABLE 1 Key characteristics of broadband uncooled infrared focal plane detector
Area array specification
640×512
Pixel size/. mu.m
17/20
Frame frequency/Hz
50
Thermal sensitivity (NETD)/mK
＜30
Thermal response time/ms
＜16
Response spectrum/. mu.m
8～14
Image forming system
Staring type
(1) The area array specification is 640 x 512
(2) Frame frequency of 50Hz
(3) The thermal sensitivity (NETD) should be less than 30mK
(4) The thermal response time should be less than 30ms
(5) The response spectrum is (8-14) mu m
(6) The imaging modality is of the staring type.
Because the detector, the circuit processing system, the optical system and other components in the infrared detection system all contain noise sources, the signal-to-noise ratio and SF in the acquired infrared video image6The contrast of the gas is low. So that extremely small gas leaks are often buried in the background or noise and are not easily observable on the display screen. Therefore, the signal processing and output module adopts SF based on mixed filtering6Infrared image enhancement method for said SF6And performing detail enhancement processing on the infrared image, outputting the processed image in a video signal format, and making invisible gas clearly visible.
In particular, mixed filtering based SF6The infrared image enhancement method comprises the following steps:
processing raw SF using guided filtering algorithm6Obtaining a basic image by an infrared image; the guide filtering algorithm has excellent edge retention characteristic, and the basic layer image obtained by the guide filtering algorithm retains SF (sulfur hexafluoride) well6The edge information of the infrared image and the halo of the image are effectively reduced;
optimizing a low-frequency background of the basic image through a self-adaptive Gaussian filter, inhibiting random noise of the background, and simultaneously preventing an unnecessary gradient inversion effect to obtain an optimized basic image;
subtracting the basic image from the original image to obtain a detail image;
enhancing the detail image by adopting platform histogram equalization to enhance the contrast and detail information of the leakage area to obtain enhanced detailsAn image; after the equalization processing of the platform histogram, the visual effect of the detail image is good, and SF6The gas leakage area is clear and visible, the edge outline is well reserved, and the detailed image is not obviously over-enhanced and noise-amplified;
and performing weighted fusion on the optimized basic image and the enhanced detail image to obtain an enhanced image. The fused image has the excellent characteristics of the optimized basic image and the enhanced detail image, and obtains excellent SF6The gas leakage area enhances the effect.
Hybrid filtering based SF6The main task of the infrared image enhancement method comprises the completion of background suppression and SF of the infrared image6And the enhancement of a gas leakage area improves the signal-to-noise ratio of the infrared image and increases the dynamic range of the image. For the fixed pattern noise of the infrared image, the noise needs to be suppressed through a corresponding non-uniformity correction algorithm. The broadband uncooled infrared focal plane detector of the sulfur hexafluoride gas leakage infrared imaging detection system structure with low cost has the function of non-uniformity correction and does not need to be processed. In practical situations, whether the sky or the ground, the background of the infrared image has large fluctuation, the clutter is more, and interference such as illumination change may exist. Therefore, noise in the infrared image mainly comes from random noise caused by a complex background, and therefore the low-frequency background of the basic image is optimized through the self-adaptive Gaussian filter, the random noise of the background is suppressed, meanwhile, unnecessary gradient inversion effect is prevented, and the optimized basic image is obtained.
In addition, due to SF6The contrast of the gas leakage area is low, and the contrast of the gas leakage area is improved by adopting a traditional image enhancement method, although the contrast of the gas leakage area is improved. But also enhances the contrast of the background. Therefore, to increase SF6Visibility of gas leakage area to SF6And carrying out local enhancement processing on the infrared image. Subtracting the basic image from the original image to obtain a detail image; and enhancing the detail image by adopting platform histogram equalization so as to enhance the contrast and detail information of the leakage area and obtain an enhanced detail image. Finally, theAnd fusing the processed basic image and the processed detailed image to obtain an enhanced image, so that the obtained detected gas leakage image is more obvious.
In one embodiment, the adaptive gaussian filter uses a gaussian low-pass-trilateral combination filter.
In conclusion, the invention provides a low-cost sulfur hexafluoride gas leakage infrared imaging detection system, and belongs to the technical field of gas detection. The system can find gas leakage in tens of meters without approaching equipment or leakage points. The system has the advantages of small volume, low cost, high sensitivity and the like, and has wide application prospect in a power system.
The above disclosure is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of changes or modifications within the technical scope of the present invention, and shall be covered by the scope of the present invention.
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