Ultraviolet imaging test device and ultraviolet imaging test correction method

Abstract

The invention relates to the technical field of ultraviolet imaging testing, and particularly discloses an ultraviolet imaging testing device and an ultraviolet imaging testing correction method.The ultraviolet imaging testing device comprises a window material, a spectroscope, a visible light camera and an ultraviolet camera, visible light and ultraviolet light in the field angle range are received through the window material and then transmitted to the spectroscope; the spectroscope reflects short-wave ultraviolet light to the optical axis direction of the ultraviolet camera based on the reflection and transmission characteristics of the spectroscope, the ultraviolet camera specially receives the short-wave ultraviolet light so as to detect corona discharge and other weak signals, meanwhile, visible light penetrates through the spectroscope and is received by the visible light camera, and the component is used for capturing background visible light information to facilitate follow-up image fusion processing. The system integrates ultraviolet and visible light data to comprehensively evaluate the insulation state of equipment, is suitable for long-distance or weak discharge detection, and enhances the inspection efficiency and reliability of electric power facilities.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultraviolet imaging test, in particular to an ultraviolet imaging test device and an ultraviolet imaging test correction method. BACKGROUND

[0002] In power facilities such as power generation plants, power transmission and distribution lines, and substations, uneven field intensity distribution of equipment may occur due to structural defects, surface contamination, and poor conductor contact during operation of high-voltage equipment, resulting in discharge phenomena such as arcs and coronas. At this time, light, electricity, heat, and sound waves may be generated. The method for detecting light generated by partial discharge of electrical equipment usually uses ultraviolet imaging test method.

[0003] Ultraviolet imaging technology is an important means to detect hidden troubles of electrical equipment corona discharge faults. Abnormal corona and other weak discharge phenomena may be early signs of partial defect faults. This technology can timely, intuitively, and effectively detect discharge phenomena caused by defects or faults in high-voltage equipment, and can be used for insulation state evaluation of equipment.

[0004] In the prior art, such as the electric spark intensity ultraviolet tester disclosed in Chinese Patent No. CN203476584U, ultraviolet light is directly detected by an ultraviolet light-sensitive device. However, during detection, there is usually interference from visible light and some ultraviolet light with longer wavelengths, which is not conducive to long-distance target detection and weak signal detection.

[0005] Therefore, the above problems need to be solved. SUMMARY

[0006] In view of the shortcomings of the prior art, the purpose of the present application is to provide an ultraviolet imaging test device and an ultraviolet imaging test correction method to solve the above problems.

[0007] An ultraviolet imaging test device, comprising: a window material comprising an incident light side and an exit light side, for receiving visible light and ultraviolet light within a field of view angle range; a beam splitter located at the exit light side of the window material, forming an included angle greater than 0° with the window material, the beam splitter having a first surface and a second surface, the first surface being covered with a silicon dioxide coating layer, the silicon dioxide coating layer reflecting 45° incident ultraviolet light in the 200-400 nm wavelength band, while transmitting visible light in the 420-760 nm wavelength band; the second surface being covered with a hafnium dioxide coating layer, the hafnium dioxide coating layer transmitting 45° exit visible light in the 420-760 nm wavelength band; a visible light camera arranged on the second surface side of the beam splitter, for receiving visible light in the 420-760 nm wavelength band passing through the first surface and the second surface; An ultraviolet camera is arranged corresponding to the first surface of the spectroscope, and is used to receive ultraviolet light in a 200-400 nm wave band reflected by the first surface; A temperature and humidity sensor and a laser ranging sensor are arranged on one side of the window material, the temperature and humidity sensor is used to collect temperature and humidity information of a test environment, and the laser ranging sensor is used to collect test distance information.

[0008] Specifically, the spectroscope and the window material form an included angle of 45°, and the ultraviolet camera and the spectroscope form an included angle of 45°.

[0009] Specifically, the window material, the optical axis direction of the visible light camera and the optical axis direction of the ultraviolet camera are all perpendicular.

[0010] Specifically, at least one layer of ultraviolet filter film is arranged in the ultraviolet camera, and the ultraviolet filter film is used to filter ultraviolet light in a wave band equal to or greater than 300 nm.

[0011] Specifically, the ultraviolet filter film has multiple layers.

[0012] Specifically, the ultraviolet imaging test device further comprises a housing, a handle connected to the lower end of the housing, and a display screen arranged at the front end of the housing. The window material, the spectroscope, the visible light camera and the ultraviolet camera are all arranged in the housing. The rear end of the housing is provided with a light inlet window, and the window material is located on the inner side of the light inlet window. The rear end of the housing is provided with a first detection hole and a second detection hole located below the light inlet window, the temperature and humidity sensor is arranged in the first detection hole, and the laser ranging sensor is arranged in the second detection hole.

[0013] Specifically, a battery is arranged in the handle, and is used to supply power to the visible light camera, the ultraviolet camera and the display screen.

[0014] Specifically, the window material is a planar light-transmitting glass.

[0015] An ultraviolet imaging test correction method using the ultraviolet imaging test device, comprising the following steps: S1, actively receiving visible light and ultraviolet light in a field of view angle range through the window material; S2, the spectroscope transmits visible light in a 420-760 nm wave band from the window material, and reflects ultraviolet light in a 200-400 nm wave band to the ultraviolet camera; S3, the ultraviolet camera receives reflected ultraviolet light in a 200-400 nm wave band, and filters background noise through the ultraviolet filter film to obtain ultraviolet light in a wave band below 300 nm; S4, generating an ultraviolet optical image based on the ultraviolet light of less than 300 nm and generating a visible light optical image based on the visible light of 420-760 nm; S5, collecting temperature and humidity information and test distance information of the test environment by using a temperature and humidity sensor and a laser ranging sensor, and obtaining ultraviolet photon number, detection distance, instrument gain and environmental humidity parameters in the ultraviolet optical image; according to the obtained parameters, the ultraviolet photon number is normalized and corrected by using a distance correction algorithm, a gain correction algorithm and a humidity correction algorithm respectively, and the ultraviolet optical image is updated based on the corrected ultraviolet photon number; S6, aligning the ultraviolet optical image and the visible light optical image by using an image registration algorithm, and then performing multi-scale decomposition processing on the aligned ultraviolet optical image and visible light optical image by using a non-subsampled shearlet transform method to obtain low-frequency subbands of the two images and high-frequency subbands of the two images; S7, selectively fusing the low-frequency subbands of the two images and the high-frequency subbands of the two images by using an adaptive sparse representation method to obtain fused low-frequency subbands and fused high-frequency subbands; S8, performing NSST inverse transform on the fused low-frequency subbands and the fused high-frequency subbands to reconstruct a final fused image and display the final fused image through a display screen.

[0016] Specifically, the step S5 specifically includes the following steps: S51, distance correction: correcting the ultraviolet photon number at different detection distances to a 10-meter reference distance, the formula is: y2=0.01y1 / x1 -2 wherein x1 is the detection distance (unit: m), y1 is the ultraviolet photon number detected at x1 distance, and y2 is the ultraviolet photon number converted to 10-meter standard distance; S52, gain correction: according to the instrument gain value g (percentage value of 0 to 1), the gain correction is segmented: when g ≤20%, it is prompted that the gain is low and no compensation is made; when 20% <g ≤ 60%时，公式为y2="y1e^{3.4325(0.6-g)}；当g">60%, the formula is y2=y1e^{4.15(g-0.6)}; wherein y1 is the number of ultraviolet photons detected at the gain g, and y2 is the number of ultraviolet photons converted to the standard gain of 60%; S53, humidity correction: correct the number of ultraviolet photons at different humidity to 65% standard humidity, the formula is: when x<=0.8, y=y1[1+((x-0.65) / 0.05) x 0.0618]; when x>0.8, y=y1[1-(x-0.8) / 0.05) x 0.0865]; wherein x is the actual humidity value (such as 65% is 0.65), y1 is the number of ultraviolet photons detected at humidity x, and y is the number of ultraviolet photons converted to 65% standard humidity The beneficial effects of the present application are: The ultraviolet imaging test device and the ultraviolet imaging test correction method of the present application receive visible light and ultraviolet light in the field of view range through the window material, and then transmit them to the spectroscope; the spectroscope reflects the short-wave ultraviolet light to the optical axis direction of the ultraviolet camera based on its reflection and transmission characteristics, which is specially received by the ultraviolet camera to detect weak signals such as corona discharge; at the same time, the visible light transmits through the spectroscope and is received by the visible light camera, which is used to capture background visible light information, facilitating subsequent image fusion processing, integrating ultraviolet and visible light data to comprehensively evaluate the insulation state of the equipment, and being suitable for long-distance or weak discharge detection, enhancing the efficiency and reliability of power facility inspection; Moreover, the present application realizes the normalization processing of the detection data by identifying key parameters and combining multi-dimensional correction algorithms, effectively eliminates the interference of factors such as distance, gain and environmental humidity on the measurement results, significantly improves the accuracy and reliability of ultraviolet photon number detection, and provides a more accurate data basis for defect diagnosis. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The structure schematic diagram of the window material, the spectroscope, the visible light camera and the ultraviolet camera of the embodiment of the present application is shown in the figure, and the light paths of the visible light and the ultraviolet light are also shown in the figure; Figure 2 The structure schematic diagram of the spectroscope of the present embodiment is shown in the figure, and the light path of the ultraviolet light in the 200-400nm wave band reflected by the spectroscope is also shown in the figure; Figure 3 The spectral curve of the first surface of the spectroscope is shown in the figure; Figure 4 The spectral curve of the second surface of the spectroscope is shown in the figure; Figure 5 The front view of the ultraviolet imaging test device of the present embodiment is shown in the figure; Figure 6 The Figure 5 The cross-sectional view along line A-A is shown in the figure; Figure 7 A perspective view of the ultraviolet imaging testing device of the present embodiment Figure 1 ; Figure 8 A perspective view of the ultraviolet imaging testing device of the present embodiment Figure 2 .

[0018] The reference signs are: window material 10, beam splitter 20, visible light camera 30, ultraviolet camera 40, ultraviolet filter film 41, housing 51, light inlet window 511, first detection hole 512, second detection hole 513, handle 52, display screen 53. DETAILED DESCRIPTION

[0019] The present application provides an ultraviolet imaging testing device and an ultraviolet imaging testing correction method. To make the purpose, technical solutions and effects of the present application clearer and more explicit, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0020] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0021] As shown in Figure 1 and Figure 8 , the present embodiment discloses an ultraviolet imaging testing device, which comprises a window material 10, a beam splitter 20, a visible light camera 30 and an ultraviolet camera 40; the window material 10 comprises a light inlet side and a light outlet side, and the window material 10 is used to receive visible light and ultraviolet light within a field of view angle range; the beam splitter 20 is located on the light outlet side of the window material 10, and the beam splitter 20 forms an included angle greater than 0° with the window material 10; the beam splitter 20 has a first surface and a second surface, the first surface is covered with a silicon dioxide coating layer, the silicon dioxide coating layer reflects ultraviolet light of a 200-400 nm wave band at an incident angle of 45°, and transmits visible light of a 420-760 nm wave band; the second surface is covered with a hafnium dioxide coating layer, the hafnium dioxide coating layer transmits visible light of a 420-760 nm wave band at an exit angle of 45°; the visible light camera 30 is arranged on the side of the second surface of the beam splitter 20, and is used to receive visible light of a 420-760 nm wave band passing through the first surface and the second surface; the ultraviolet camera 40 is arranged corresponding to the first surface of the beam splitter 20, and is used to receive ultraviolet light of a 200-400 nm wave band after being reflected by the first surface.

[0022] After the visible and ultraviolet light within the field of view is actively received by the window material 10, it is transmitted to the beam splitter 20. Based on its reflection and transmission characteristics, the beam splitter 20 reflects the ultraviolet light to the optical axis of the ultraviolet camera 40, which specifically receives it to detect weak signals such as corona discharge. At the same time, the visible light passes through the beam splitter 20 and is received by the visible light camera 30. This component is used to capture background visible light information, which is convenient for subsequent image fusion processing. It integrates ultraviolet and visible light data to comprehensively evaluate the insulation status of the equipment. It is suitable for long-distance or weak discharge detection and enhances the efficiency and reliability of power facility inspection.

[0023] The first and second surfaces of the spectroscope 20 were coated using an ion-assisted coating process with a coating machine provided by Kosei Corporation of Japan. The coating material for the first surface was silicon dioxide (SiO2), and the coating material for the second surface was hafnium dioxide (HfO2). After coating, the spectral curves were measured using a UV-3600 PIus spectrophotometer provided by Shimadzu Corporation of Japan. The measurement results of the first side are as follows Figure 3 As shown, the first surface has a reflectivity (average reflectivity 99.5%) in the 200-400 nm range and a transmittance (average transmittance 97%) in the 420-760 nm range, with an incident angle of 45°. That is, the first surface reflects light of 200~400 nm incident at a 45° angle (preventing it from being transmitted), while transmitting light of 420~760 nm.

[0024] The measurement results of the second side are as follows Figure 4 As shown, the second surface transmits light in the 420-760 nm range (average reflectivity <1%) at an incident angle of 45°. That is, the second surface transmits light with wavelengths of 420~760 nm out at a 45° angle.

[0025] Furthermore, the beam splitter 20 forms a 45° angle with the window material 10, and the ultraviolet camera 40 forms a 45° angle with the beam splitter 20; the optical axis directions of the window material 10 and the visible light camera 30 are both perpendicular to the optical axis direction of the ultraviolet camera 40.

[0026] When ultraviolet light received by window material 10 is horizontally incident on beam splitter 20 at a 45° angle to it, based on the optical principle that the reflection angle equals the incident angle, the 200-400nm ultraviolet light, after being reflected by the first surface of beam splitter 20, has its propagation direction turn at a 90° angle to the incident light and enters parallel to the optical axis of the vertically placed ultraviolet camera 40, ensuring that ultraviolet photons are efficiently focused into the ultraviolet camera 40. Visible light and long-wave ultraviolet light are directly transmitted to the horizontally oriented visible light camera 30, forming a spatially separated dual-channel imaging basis.

[0027] The 45° included angle design realizes the right-angle directional deflection of the light path, which not only ensures that the ultraviolet light is vertically incident on the ultraviolet camera 40 to eliminate aberration, but also makes the optical axes of the visible light camera 30 and the ultraviolet camera 40 strictly perpendicular, forming a compact right-angle light path structure. This layout folds the traditional horizontal light path into a three-dimensional right-angle configuration, significantly reducing the device depth size, providing a physical basis for ergonomic holding design; at the same time, the precisely controlled light path turning avoids energy loss, combined with the blocking of background noise by the solar blind ultraviolet filter film 41, maintaining high sensitivity while reducing volume, especially suitable for single-hand fine operation in narrow spaces such as power transmission towers and substation structures.

[0028] The ultraviolet camera 40 is provided with a plurality of layers of ultraviolet filter films 41; the ultraviolet filter film 41 can filter ultraviolet light of a wavelength of 300 nm or more, and the ultraviolet camera 40 can effectively filter noise, improve signal-to-noise ratio and detection accuracy, and filter ultraviolet light of a wavelength of 300 nm or more, suitable for long-distance or weak discharge detection, enhancing the efficiency and reliability of power facility inspection.

[0029] The ultraviolet imaging test device further comprises a housing 51, a handle 52 connected to the lower end of the housing 51, and a display screen 53 arranged at the front end of the housing 51; the window material 10, the beam splitter 20, the visible light camera 30 and the ultraviolet camera 40 are all arranged in the housing 51; the rear end of the housing 51 is provided with a light inlet window 511, and the window material 10 is located inside the light inlet window 511. The housing 51 serves as the main frame, and the rear end is provided with a light inlet window 511; the window material 10 is a flat transparent glass, and the window material 10 is located inside to actively receive external light; the housing 51 is internally integrated with the beam splitter 20, the visible light camera 30 and the ultraviolet camera 40, and these components realize compact layout through vertical light path design; the front end of the housing 51 is configured with the display screen 53 for real-time display of imaging results, and the lower end is connected with the handle 52 to form an ergonomic holding structure. This vertical integration scheme significantly reduces the overall volume and weight, enabling the operation and maintenance personnel to operate with one hand in outdoor complex terrain, avoiding space occupation and physical consumption caused by horizontal design, while the handle 52 is internally provided with a large-capacity battery to prolong the continuous use time; the battery is used to power the visible light camera 30, the ultraviolet camera 40 and the display screen 53, combined with the precise light path control of the beam splitter 20 and the ultraviolet camera 40, to ensure high ultraviolet sensitivity for effective detection of weak signals such as corona discharge, improving the portability and reliability of power facility inspection.

[0030] Further, the application also provides a temperature and humidity sensor and a laser ranging sensor, a first detection hole 512 and a second detection hole 513 are arranged at the rear end of the shell 51 below the light inlet window 511, the temperature and humidity sensor is arranged in the first detection hole 512, and the laser ranging sensor is arranged in the second detection hole 513; the temperature and humidity sensor and the laser ranging sensor are located on one side of the window material 10, the temperature and humidity sensor is used for collecting temperature and humidity information of a test environment, and the laser ranging sensor is used for collecting test distance information.

[0031] The embodiment also discloses a UV imaging test correction method, which uses the UV imaging test device and comprises the following steps: S1, actively receiving visible light and ultraviolet light in a field of view angle range through the window material 10; S2, the spectroscope 20 transmits visible light in a 420-760 nm wave band from the window material 10 and reflects ultraviolet light in a 200-400 nm wave band to the ultraviolet camera 40; S3, the ultraviolet camera 40 receives the reflected ultraviolet light in the 200-400 nm wave band and filters background noise through the ultraviolet filter film 41 to obtain ultraviolet light in a wave band below 300 nm; S4, generating an ultraviolet optical image based on the ultraviolet light in the wave band below 300 nm and generating a visible light optical image based on the visible light in the 420-760 nm wave band; Specifically, the ultraviolet light in the field of view angle range is received through the window material 10, after the light reaches the spectroscope 20, the ultraviolet light in the 200-400 nm wave band is reflected by the spectroscope and is transmitted to the optical axis direction of the ultraviolet camera 40 in a directional manner and is received by the ultraviolet camera 40; the ultraviolet filter film 41 is arranged in the ultraviolet camera 40 and can filter background noise above the wave band above or equal to 300 nm, significantly improves the signal-to-noise ratio and reduces the false alarm rate, and ensures that only effective ultraviolet signals (such as ultraviolet radiation generated by equipment discharge) are reserved; after the ultraviolet camera 40 detects ultraviolet photons, the ultraviolet photons are converted into electric signals; then, through electronic image conversion technology, the electric signals are converted into an ultraviolet optical image; The window material 10 simultaneously receives visible light in the field of view angle range, after the light reaches the spectroscope 20, the visible light can directly pass through the spectroscope and is transmitted to the visible light camera 30 in a directional manner; after the visible light passing through the spectroscope 20 is captured by the visible light camera 30, the visible light is converted into electric signals; after image processing, the electric signals are converted into a visible light optical image recognizable by the human eye.

[0032] S5, collecting temperature and humidity information and test distance information of the test environment by using the temperature and humidity sensor and the laser ranging sensor, and obtaining the ultraviolet photon number, the detection distance, the instrument gain and the environmental humidity parameter in the ultraviolet optical image; according to the obtained parameters, the ultraviolet photon number is normalized and corrected by using the distance correction algorithm, the gain correction algorithm and the humidity correction algorithm respectively, and the ultraviolet optical image is updated based on the corrected ultraviolet photon number; specifically comprising the following steps: S51, distance correction: correcting the ultraviolet photon number under different detection distances to 10 meter reference distance, the formula is: y2=0.01y1 / x1 -2 Wherein x1 is the detection distance (unit: m), y1 is the ultraviolet photon number detected at x1 distance, and y2 is the ultraviolet photon number converted to 10 meter standard distance; S52, gain correction: segmented correction according to the instrument gain value g (0 to 1 percentage value): when g ≤20%, prompt the gain is low and do not compensate; when 20% <g ≤ 60%时，公式为y2="y1e^{3.4325(0.6-g)}；当g">60%, the formula is y2=y1e{4.15(g-0.6)}; wherein y1 is the number of ultraviolet photons detected at gain g, and y2 is the number of ultraviolet photons converted to 60% standard gain; S53, humidity correction: correct the number of ultraviolet photons at different humidity to 65% standard humidity, the formula is: when x≤0.8, y=y1[1+((x-0.65) / 0.05)×0.0618]; when x>0.8, y=y1[1-(x-0.8) / 0.05)×0.0865]; wherein x is the actual humidity value (e.g. 65% is 0.65), y1 is the number of ultraviolet photons detected at humidity x, and y is the number of ultraviolet photons converted to 65% standard humidity.

[0033] In the ultraviolet imaging test correction method of the embodiment, after generating the ultraviolet optical image, the steps of key parameter identification and data correction are further included: the ultraviolet optical image is preprocessed (including grayscale, binarization, denoising and tilt correction) by OCR (optical character recognition) technology, and the photon number, detection distance, instrument gain and environmental humidity parameters are extracted; then a defect comprehensive diagnosis algorithm is used to normalize and correct the test results in real time: the ultraviolet photon numbers at different detection distances are uniformly corrected to 10 meters standard distance (formula y2=0.01y1 / x1 -2 ), the gain deviation is compensated by gain correction algorithm (including low gain prompt, exponential compensation, etc.), and the influence of environmental humidity is eliminated by humidity correction algorithm (segmented linear compensation). These correction methods significantly improve the accuracy and comparability of the detection data, and provide a reliable data basis for subsequent image fusion and defect diagnosis.

[0034] S6, the ultraviolet optical image and the visible light optical image are aligned and processed by using an image registration algorithm, and then the aligned ultraviolet optical image and visible light optical image are subjected to multi-scale decomposition processing by using a non-subsampled shearlet transform method, to obtain low-frequency subbands of the two kinds of images and high-frequency subbands of the two kinds of images; Specifically, in order to ensure that the ultraviolet optical image and the visible light optical image are completely aligned in spatial position (like one-to-one correspondence of pixels of a device region), and avoid ghosting or misplacement after fusion, the ultraviolet optical image and the visible light optical image need to be aligned. The alignment can be implemented by using a feature-based registration algorithm or a mutual information-based registration algorithm. The feature-based registration algorithm includes a SIFT (Scale-Invariant Feature Transform) or SURF (Speeded-Up Robust Features) algorithm. Taking SIFT as an example, first, key features (such as device edges, corners, insulator profiles, etc.) of the ultraviolet optical image and the visible light optical image are extracted, and feature descriptors are generated by using the SIFT algorithm, containing scale, direction, and gray information of the features. Then, the feature descriptors are subjected to nearest neighbor matching, and the random sample consensus (RANSAC) algorithm is used to remove false matches, and a spatial transformation matrix is calculated to map the ultraviolet optical image into the coordinate system of the visible light optical image, so as to achieve alignment.

[0035] The non-subsampled shearlet transform (NSST) method is an efficient multi-scale and multi-directional decomposition tool, which can preserve the details such as edges and textures of an image, and avoid artifacts caused by subsampling. In this embodiment, the non-subsampled shearlet transform method is used to perform multi-scale decomposition on the aligned ultraviolet optical image and visible light optical image, so as to obtain low-frequency subbands of the two images and high-frequency subbands of the two images. The low-frequency subbands contain smooth regions and overall structure information of the images, such as the overall profile of the device. The high-frequency subbands contain detailed information of the images, such as the discharge point edges of the ultraviolet image and the device textures of the visible light image. In this embodiment, the NSST method is used to decompose the images into subbands of different scales and different directions, so as to facilitate processing of overall information and detailed information respectively, and improve fusion accuracy.

[0036] S7, selectively fusing the low-frequency subbands of the two images and the high-frequency subbands of the two images by using an adaptive sparse representation method, to obtain fused low-frequency subbands and fused high-frequency subbands; In the embodiment, adaptive sparse representation (ASR) is used as an image fusion algorithm combined with non-subsampled shearlet transform (NSST), mainly for differential processing of high-frequency subbands and low-frequency subbands of ultraviolet light and visible light images to improve the effect of image fusion, including subjective visual experience and objective evaluation index. Specifically, sample data of ultraviolet light low-frequency subbands and visible light low-frequency subbands are trained, and an over-complete dictionary suitable for low-frequency information is generated through ASR learning (the dictionary needs to represent the overall characteristics of the discharge area and the overall characteristics of the device structure); then the ultraviolet light low-frequency subbands and the visible light low-frequency subbands are respectively sparsely represented through the over-complete dictionary to obtain their respective sparse coefficients, that is, the overall information of the subbands is represented by a small number of non-zero coefficients; the coefficients that can reflect the spatial correlation of the device structure (visible light) and the discharge area (ultraviolet light), such as the overall distribution coefficient of the discharge within the device contour range, are preferentially retained; for the coefficients of the overlapping area (such as the part where the device surface and the discharge area overlap), weighted average (the weight is based on the energy proportion of the low-frequency information of the two images) is adopted to ensure the coherence of the overall information; the fused sparse coefficients are reconstructed through the dictionary to obtain the fused low-frequency subband, which simultaneously retains the overall structure of the device and the overall distribution of the discharge area.

[0037] Similarly, sample data (emphasis on detail features, such as discharge point edges and device textures) of ultraviolet light high-frequency subbands and visible light high-frequency subbands are trained, and an over-complete dictionary suitable for high-frequency details is generated through ASR learning; the ultraviolet light high-frequency subbands (containing discharge point edges and weak discharge details) and the visible light high-frequency subbands (containing device textures and edge details) are respectively sparsely represented through the above dictionary to obtain their respective detail sparse coefficients; in the ultraviolet light high-frequency subband, high-energy coefficients corresponding to discharge point edges and strong signal details are preferentially retained (highlighting the local features of discharge positions); in the visible light high-frequency subband, high-contrast coefficients corresponding to device textures and clear edges are preferentially retained (highlighting the detail features of the device structure); detail coefficients without conflict (such as device textures in non-discharge areas) are directly retained, and the maximum value selection is adopted for conflict areas (such as overlapping of discharge points and device edges) to retain more significant details; the fused detail sparse coefficients are reconstructed through the dictionary to obtain the fused high-frequency subband, which simultaneously highlights discharge details and device texture details.

[0038] S8, performing NSST inverse transformation on the fused low-frequency subband and the fused high-frequency subband to reconstruct a final fused image and displaying the final fused image through the display screen 53.

[0039] Specifically, the low-frequency sub-band fusion and the high-frequency sub-band fusion are subjected to inverse non-subsampled shearlet (NSST) transform, which is the inverse operation of NSST decomposition, and the multi-scale and multi-directional fused sub-bands are recombined to restore a complete two-dimensional image, so that the overall structure and detail information after fusion are re-integrated in space, forming a fusion image. The fusion image can be sent to the display screen 53 through the signal transmission module to be presented to the operation and inspection personnel in a visual form. The fusion image clearly retains the visible light structure details and the ultraviolet discharge signal of the equipment, and can directly present the detection result of the ultraviolet imaging test, thereby providing a direct basis for the equipment insulation state evaluation.

[0040] The ultraviolet imaging test correction method of the embodiment actively receives visible light and ultraviolet light in the field of view range through the window material 10, and the light is efficiently separated by the beam splitter 20: the visible light in the 420-760 nm band is transmitted to the visible light camera, and the ultraviolet light in the 200-400 nm band is reflected to the direction of the ultraviolet camera 40; the ultraviolet camera 40 filters the daytime background noise by using the built-in ultraviolet filter film 41, converts the ultraviolet light below 300 nm into an ultraviolet electrical signal, and then generates an electronic image, which is further processed into an optical image visible to the human eye; then, the non-subsampled shearlet (NSST) is applied for multi-scale decomposition and adaptive sparse representation to differentially process the high-frequency and low-frequency sub-bands, thereby realizing double optimization of image quality and generating a clear ultraviolet imaging test image; finally, the result is displayed in real time through the display screen 53. The method combines the compact optical path design, significantly improves the single-hand operation portability and outdoor adaptability, reduces the physical energy consumption of operation and inspection, reduces the false alarm rate and improves the signal-to-noise ratio through high-precision algorithms, ensures the reliability of remote weak discharge detection, and enhances the efficiency and accuracy of the insulation state evaluation of power facilities.

[0041] Moreover, by introducing the OCR parameter recognition and multi-dimensional correction algorithm, the data preprocessing link is enhanced in the traditional image processing process, the real-time normalization correction of the test result is realized, the ultraviolet photon detection is not affected by the distance, gain and humidity changes, and thus the accuracy and reliability of the insulation state evaluation of power equipment are greatly improved.

[0042] The above describes the preferred embodiments of the application, but the application is not limited to the embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the application. These equivalent modifications or replacements are all included in the scope defined by the claims of the application.< / g> < / g>

Claims

1. An ultraviolet imaging test device, characterized by, The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device.

2. The ultraviolet imaging test device of claim 1, wherein, The application relates to an ultraviolet imaging test device.

3. The ultraviolet imaging test device of claim 1, wherein, The application relates to an ultraviolet imaging test device.

4. The ultraviolet imaging test device of claim 1, wherein, The application relates to an ultraviolet imaging test device.

5. The ultraviolet imaging test device of claim 4, wherein, The application relates to an ultraviolet imaging test device.

6. The ultraviolet imaging test device of claim 1, wherein, The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device.

7. The ultraviolet imaging test device of claim 1, wherein, The application relates to an ultraviolet imaging test device.

8. The ultraviolet imaging test device of claim 1, wherein, The application relates to an ultraviolet imaging test device.

9. A method of UV imaging test correction using the UV imaging test device of any one of claims 1 to 8, characterized in that, The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. 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The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application relates to an ultraviolet imaging test device. The application S2, the spectroscope (20) transmits the 420~760nm band of visible light from the window material (10), and reflects the 200~400nm band of ultraviolet light to the ultraviolet camera (40); S3, the ultraviolet camera (40) receives the reflected 200~400nm band of ultraviolet light, and filters background noise through the ultraviolet filter film (41) to obtain the 300nm band of ultraviolet light below; S4, generate an ultraviolet optical image based on the 300nm band of ultraviolet light below, and generate a visible light optical image based on the 420~760nm band of visible light; S5, collect the temperature and humidity information and test distance information of the test environment by using the temperature and humidity sensor and the laser ranging sensor, and obtain the ultraviolet photon number, detection distance, instrument gain and environmental humidity parameters in the ultraviolet optical image; according to the obtained parameters, the ultraviolet photon number is normalized and corrected by using the distance correction algorithm, the gain correction algorithm and the humidity correction algorithm respectively, and the ultraviolet optical image is updated based on the corrected ultraviolet photon number; S6, align the ultraviolet optical image and the visible light optical image by using an image registration algorithm, and then perform multi-scale decomposition processing on the aligned ultraviolet optical image and visible light optical image by using a non-subsampled shearlet transform method to obtain low-frequency subbands of the two images and high-frequency subbands of the two images; S7, selectively fuse the low-frequency subbands and high-frequency subbands of the two images by using an adaptive sparse representation method to obtain fused low-frequency subbands and fused high-frequency subbands; S8, perform NSST inverse transformation on the fused low-frequency subbands and fused high-frequency subbands to reconstruct a final fused image and display it through the display screen (53).

10. The method of claim 9, wherein, The step S5 specifically includes the following steps: S51, Distance correction: correct the ultraviolet photon number at different detection distances to the 10-meter reference distance, the formula is: y2=0.01y1 / x1 -2 wherein x1 is the detection distance (unit: m), y1 is the ultraviolet photon number detected at x1 distance, and y2 is the ultraviolet photon number converted to the 10-meter standard distance; S52, gain correction: according to the instrument gain value g (0 to 1 percentage value), the gain is corrected by segmentation: when g ≤20%, it is prompted that the gain is low and no compensation is made; when 20% < g ≤ 60%, the formula is y2=y1e^{3.4325(0.6-g)}; when g>60%, the formula is y2= y1e^{4.15(g-0.6)}; wherein y1 is the ultraviolet photon number detected when the gain g is y2, which is the ultraviolet photon number converted to 60% standard gain; S53, humidity correction: correct the ultraviolet photon number under different humidity to 65% standard humidity, the formula is: when x≤0.8, y= y1[1+((x-0.65) / 0.05)×0.0618]; when x>0.8, y=y1[1-(x-0.8) / 0.05)×0.0865]; wherein x is the actual humidity value (such as 65% is 0.65), y1 is the ultraviolet photon number detected when the humidity x is y, which is the ultraviolet photon number converted to 65% standard humidity.

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