Spectral Image Acquisition Method and Device Based on Programmable Uniform Light Source

Abstract

The present invention provides a method and device for obtaining spectral images based on a programmable uniform light source, which can be applied to the technical field of detecting the pollution characteristics of insulating equipment. The method for obtaining spectral images includes: obtaining the reflected spectral information of insulating pollution, the camera parameters of a wide-spectrum industrial camera, and the laser source power information; determining the working parameters of the programmable uniform light source generating device according to the laser source power information, the reflected spectral information of insulating pollution, and the camera parameters; using the programmable multi-channel square-wave voltage source in the programmable uniform light source generating device to synchronously generate multi-channel square-wave signals, and processing the multi-channel square-wave signals to output a target light source; using the wide-spectrum industrial camera to capture the surface of the target insulator during the output of the target light source to obtain a spectral image of the surface of the target insulator.

Description

Technical Field

[0001] The present invention relates to the technical field of detecting the pollution characteristics of insulating equipment, and particularly to a method and device for obtaining spectral images based on a programmable uniform light source. Background Art

[0002] Insulators are one of the most important external insulating equipment in high-voltage transmission systems, undertaking the mechanical support and electrical insulation between transmission conductors and towers, as well as between conductors and in-station structures. However, since insulators are long-term exposed to the atmospheric environment, their surfaces will inevitably be contaminated with dirt under the action of combined environmental stresses, and the dirt will ultimately lead to the occurrence of flashovers. Since the losses caused by flashovers are relatively large, it is very necessary to reduce the occurrence of flashover accidents. The fouling of the insulator surface is a prerequisite for flashover. Although the application of anti-fouling measures such as pollution-resistant materials and hydrophobic materials has reduced the risk of flashover accidents to a certain extent, the flashover accidents in some local areas have not been completely eliminated. Therefore, it is crucial to monitor and evaluate the pollution characteristics of insulators.

[0003] At present, hyperspectral imaging technology has shown certain application prospects in the evaluation of insulator pollution status, but there are still the following problems: complex daylight conditions such as region, altitude, season, atmospheric conditions, and solar altitude make there are many influencing factors for obtaining reflected hyperspectral data. It is difficult to control the insulator pollution reflectivity and spectral composition both under laboratory conditions and outdoor conditions; according to the technical conditions of existing hyperspectral imaging instruments, the time span required for one hyperspectral imaging of insulator pollution under daylight conditions is relatively large, and the stability of the daylight light source is poor. During this period, the daylight illumination conditions may have large errors due to factors such as solar altitude, cloud changes, and UAV attitude movement; the calibration of daylight under laboratory conditions or outdoor conditions often fails to accurately cover the pollution reflection-sensitive spectral region, and the fusion result of the obtained reflection spectral image will lose the determination accuracy due to calibration errors. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method for obtaining spectral images based on a programmable uniform light source.

[0005] According to a first aspect of the present invention, there is provided a method for obtaining a spectral image based on a programmable uniform light source, including: obtaining insulation pollution reflection spectral information, camera parameters of a wide-spectrum industrial camera, and laser source power information; determining operating parameters of a programmable uniform light source generating device according to the laser source power information, the insulation pollution reflection spectral information, and the camera parameters; using a programmable multi-channel square-wave voltage source in the programmable uniform light source generating device to synchronously generate multi-channel square-wave signals, and processing the multi-channel square-wave signals to output a target light source; wherein, the high-potential duration of each square wave in the target light source is the same as each exposure duration in the shooting cycle of the wide-spectrum industrial camera; and using the wide-spectrum industrial camera to shoot the surface of the target insulator during the output of the target light source to obtain a spectral image of the surface of the target insulator.

[0006] According to an embodiment of the present invention, the insulation pollution reflection spectral information includes a reflection spectral band, each reflectivity of the insulation pollution in each spectral range, and the lowest reflectivity of the insulation pollution in each spectral range; the camera parameters include a minimum exposure photometric value; determining the operating parameters of the programmable uniform light source generating device according to the laser source power information, the insulation pollution reflection spectral information, and the camera parameters includes: determining the high-potential duration of the multi-channel square-wave signals according to the laser source power information, the lowest reflectivity of the insulation pollution imaging, and the minimum exposure photometric value; determining the intensity of each square-wave signal output by each square-wave voltage source according to the reflection spectral band, each reflectivity, and a predetermined spectral width; so that the power amplification gain of each path is the same, and the power amplification gain of each path can make the reflectivity of the insulation pollution in each spectral range greater than the lowest reflectivity of the insulation pollution imaging; and determining the light transmission range of each unit of the grouped filter according to the reflection spectral band and the predetermined spectral width.

[0007] According to an embodiment of the present invention, the programmable uniform light source generating device includes: a programmable multi-channel square-wave voltage source, multi-channel power amplifiers, multi-channel intensity-adjustable laser sources, a grouped filter, a multi-core optical fiber grouping, a light homogenizer, and a light expander; using the multi-channel square-wave voltage source in the programmable uniform light source generating device to synchronously generate multi-channel square-wave signals, and processing the multi-channel square-wave signals to output a target light source includes: adjusting the output time sequence of each square-wave signal of the programmable multi-channel square-wave voltage source based on the operating parameters; each square-wave signal passes through the multi-channel power amplifiers to drive the multi-channel intensity-adjustable laser sources to generate lasers of various intensities according to the intensity of each square-wave signal; the lasers of various intensities pass through the grouped filter and are filtered according to the light transmission range of each unit to form spectral light beams; the spectral light beams are introduced into the light homogenizer through the multi-core optical fiber grouping to output a combined light beam; and radiating the combined light beam outward through the light expander to generate a target light source for insulation pollution reflection spectral imaging.

[0008] According to an embodiment of the present invention, during the output of a target light source, a wide-spectrum industrial camera is used to photograph the surface of a target insulator to obtain a spectral image of the surface of the target insulator, including: in response to detecting that the square wave signal output by the programmable uniform light source generating device is at a high potential, controlling the wide-spectrum industrial camera to photograph the surface of the target insulator to obtain a spectral image.

[0009] According to an embodiment of the present invention, the spectral response range of the wide-spectrum industrial camera includes: 400~950nm.

[0010] According to an embodiment of the present invention, the adjustable exposure duration range of the wide-spectrum industrial camera includes: 0.05~1s.

[0011] Another aspect of the present invention provides a programmable uniform light source generating device, including: a programmable multi-channel square wave voltage source for outputting each square wave signal; a multi-channel power amplifier electrically connected to the programmable multi-channel square wave voltage source for adjusting the power amplification gain of each square wave signal; a multi-channel intensity adjustable laser source electrically connected to the multi-channel power amplifier for generating lasers of various intensities according to the intensities of the square wave signals under the drive of the square wave signals with the power amplification gain of each channel; a grouping filter connected to the multi-channel intensity adjustable laser source for filtering according to the light passing range of each unit to form a spectral light beam sequence; a multi-core optical fiber grouping respectively connected to the grouping filter and the light homogenizer for guiding the spectral light beams into the light homogenizer and outputting a combined light beam; a light expander connected to the light homogenizer for radiating outward to generate a target light source for insulating contamination reflection spectral imaging.

[0012] According to an embodiment of the present invention, each optical fiber bundle in the multi-core optical fiber grouping includes: a plastic polymer material wrapped with an absorbent material coating; the light passing rate of the multi-core optical fiber grouping in the spectral range of 410~950nm ≥ 95%; the absorption rate of the multi-core optical fiber grouping in the spectral range of 410~950nm ≥ 90%.

[0013] According to an embodiment of the present invention, the number of channels of the programmable multi-channel square wave voltage source ≥ 5.

[0014] According to an embodiment of the present invention, the number of channels of the multi-channel power amplifier is the same as the number of units of the laser light sources of the multi-channel intensity adjustable laser source.

[0015] According to an embodiment of the present invention, based on the laser source power information, the insulating contamination reflection spectrum information, and the camera parameters, the operating parameters of the programmable uniform light source generating device can be adjusted specifically. The programmable uniform light source generating device is used to generate multiple square wave signals, and the multiple square wave signals are processed to output a target light source, achieving synchronous output of multi-band spectra at the light source output end, without the need to add a spectral filter in front of the camera to capture the reflection spectrum image of the insulating contamination, increasing the selectivity of the camera and reducing the influence of sunlight fluctuations and spectral fusion calibration errors on the accuracy of the spectral image. Description of the Drawings

[0016] Through the following description of the embodiments of the present invention with reference to the drawings, the above content and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0017] Figure 1 A schematic diagram of a programmable uniform light source generating device according to an embodiment of the present invention is shown;

[0018] Figure 2 A flowchart of a spectral image acquisition method based on a programmable uniform light source according to an embodiment of the present invention is shown;

[0019] Figure 3 A flowchart of a method for determining the operating parameters of a programmable uniform light source generating device according to an embodiment of the present invention is shown;

[0020] Figure 4 A flowchart of using a programmable uniform light source generating device to output a target light source according to an embodiment of the present invention is shown;

[0021] Figure 5 A schematic diagram of the cooperation timing of a programmable multi-channel square wave voltage source and a camera according to an embodiment of the present invention is shown;

[0022] Figure 6a The reflection spectrum image captured by a time-width spectral industrial camera when the spectral band is λ 1 is shown;

[0023] Figure 6b The reflection spectrum image captured by a time-width spectral industrial camera when the spectral band is λ 2 is shown;

[0024] Figure 6c The reflection spectrum image captured by a time-width spectral industrial camera when the spectral band is λ 3 is shown;

[0025] Figure 6d The reflection spectrum image captured by a time-width spectral industrial camera when the spectral band is λ 4 is shown;

[0026] Figure 6e shows the reflected spectral image captured by a time-width spectral industrial camera in the spectral band of λ 5 ;

[0027] Figure 6f shows the reflected spectral image captured by a time-width spectral industrial camera in the spectral band of λ 6 ; Detailed implementation manners

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth in order to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0029] The terms used herein are merely for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0030] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0031] In the case of using expressions such as "at least one of A, B, and C", generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0032] Insulators are one of the most important external insulation devices in high-voltage transmission systems, undertaking the mechanical support and electrical insulation between transmission conductors and towers, and between conductors and in-station frameworks. However, since insulators are long-term exposed to the atmospheric environment, their surfaces will inevitably be contaminated by dirt under the action of combined environmental stresses. Along with the increase in the operation time of insulators, the dirt accumulated on their surfaces will become more and more serious.

[0033] When encountering bad weather such as dew, fog, and drizzle, the surface contamination layer of the insulator will absorb water and become moist, accompanied by the dissolution of soluble contaminants to form conductive ions. The leakage current distributed along the insulator surface will increase significantly due to the increase in the conductivity of the contamination layer, and unevenly distributed dry bands will be formed due to the thermal effect. The dry bands will form local field strength concentration areas and eventually cause local breakdown to form local arcs. After meeting the critical conditions for the development of local arcs, it will finally develop into contamination flashover (abbreviated as flashover).

[0034] According to data statistics, among external insulation accidents, flashover accidents account for 40%, second only to lightning flashover (accounting for 50%). However, contamination defects cannot be eliminated in the short term. Therefore, the success rate of reclosing for flashover tripping is only 10%, while the success rate of reclosing for lightning flashover tripping reaches more than 90%. Therefore, although the failure rate of lightning flashover is higher than that of flashover, due to the wide range of faults and long power outage time, the losses caused by flashover reach nearly 10 times that of lightning flashover.

[0035] The accumulation of contamination on the insulator surface is a prerequisite for flashover. Although the application of anti-contamination measures such as pollution-resistant materials and hydrophobic materials has reduced the risk of flashover accidents to a certain extent, flashover accidents in some local areas have not been completely eliminated. Therefore, the monitoring and evaluation of the contamination characteristics of the insulator surface have attracted the attention of many researchers.

[0036] The flashover characteristics of insulators are affected by the degree and distribution characteristics of contamination, the humidity of the contamination layer, and the contamination composition. At present, a variety of detection methods based on electrical characteristic quantities and non-electrical characteristic quantities have been proposed to monitor and evaluate the contamination characteristics of insulators. Among them, the detection of the degree of contamination has experienced a development process from electrical characteristic quantity detection methods to non-electrical characteristic quantity detection methods such as optical characteristic quantities. Table 1 lists the basic characteristics and comparisons of 8 insulator contamination degree detection methods. As shown in Table 1, hyperspectral imaging technology has great technical advantages in obtaining the contamination distribution characteristics and contamination composition.

[0037] Table 1 is the basic characteristics and comparison of insulator contamination degree detection methods:

[0038]

[0039] According to the electromagnetic wave theory, when the radiation light reaches the object surface, the substance reflects, absorbs, transmits, and radiates electromagnetic waves with its inherent characteristics. Among them, reflection refers to the characteristic of the substance generating a reflection spectrum with a strict physical mechanism under the irradiation of light sources with different wavelengths according to its surface structure, chemical composition, material composition, etc. Therefore, the inherent reflection spectrum characteristics of insulating contamination can be utilized, combined with hyperspectral imaging technology, and applied to the detection of external insulation contamination of power equipment.

[0040] Although hyperspectral imaging technology has shown certain application prospects in the assessment of insulator contamination status and has attracted the attention of scholars and power grid operation and maintenance practitioners, generally speaking, related applications are still in the initial stage of exploration and there are still technical problems:

[0041] (1) Complex sunlight conditions such as region, altitude, season, atmospheric conditions, and sunlight height make there are many influencing factors for obtaining reflected hyperspectral data. It is difficult to control the insulator contamination reflectivity and spectral components under both laboratory conditions and outdoor conditions;

[0042] (2) According to the technical conditions of existing hyperspectral imaging instruments, the time span required for a single hyperspectral imaging of insulator contamination under sunlight conditions is relatively large, and the stability of the sunlight source is poor. During this period, the sunlight illumination conditions may have large errors due to factors such as sunlight height, cloud changes, and UAV attitude movement;

[0043] (3) Simulating sunlight conditions in the laboratory or calibrating sunlight under outdoor conditions is a secondary calibration of the spectral images collected under sunlight conditions or outdoor conditions. Since the calibration parameters are generally determined based on expert experience, it is often difficult to accurately cover the spectral regions sensitive to contamination reflection. The fusion result of the obtained reflected spectral images will lose the judgment accuracy due to calibration errors.

[0044] In view of the above problems, the embodiments of the present invention provide a method for obtaining spectral images based on a programmable uniform light source. According to the laser source power information, insulator contamination reflection spectral information, and camera parameters, the working parameters of the programmable uniform light source generating device can be adjusted specifically. The programmable uniform light source generating device is used to generate multiple square wave signals, and the multiple square wave signals are processed to output a target light source, realizing the synchronous output of multi-band spectra at the light source output end, without adding a spectral filter in front of the camera to capture the reflected spectral image of insulator contamination, increasing the selectivity of the camera, and at the same time reducing the influence of sunlight fluctuations and spectral fusion calibration errors on the accuracy of spectral images.

[0045] Figure 1 The schematic diagram of the programmable uniform light source generating device according to the embodiment of the present invention is shown.

[0046] As Figure 1As shown in the figure, the programmable uniform light source generating device 100 according to this embodiment includes: a programmable multi-channel square wave voltage source 101, a multi-channel power amplifier 102, a multi-channel intensity adjustable laser source 103, a grouping filter 104, a multi-core optical fiber grouping 105, a light beam homogenizer 106, and a light expander 107. Among them, the programmable multi-channel square wave voltage source 101 is used to output square wave signals of each channel; the multi-channel power amplifier 102 is electrically connected to the programmable multi-channel square wave voltage source 101 and is used to adjust the power amplification gain of the square wave signals of each channel; the multi-channel intensity adjustable laser source 103 is electrically connected to the multi-channel power amplifier 102 and is used to generate lasers of various intensities under the drive of the square wave signals with the power amplification gain of each channel; the grouping filter 104 is connected to the multi-channel intensity adjustable laser source 103 and is used to filter according to the light passing range of each unit to form a spectral beam sequence; the multi-core optical fiber grouping 105 is respectively connected to the grouping filter 104 and the light beam homogenizer 106 and is used to introduce the spectral beam into the light beam homogenizer 106 and output a combined beam; the light expander 107 is connected to the light beam homogenizer 106 and is used to radiate outward to generate a target light source for insulating contamination reflection spectral imaging, where the target light source is an artificial multi-spectral light source sequence.

[0047] According to an embodiment of the present invention, each optical fiber bundle in the multi-core optical fiber grouping includes: a plastic polymer material wrapped with an absorbent material coating; among them, the plastic polymer material can be a polymethyl methacrylate (PolymethylMethacrylate, abbreviated as PMMA) resin material.

[0048] The light passing rate of the multi-core optical fiber grouping in the spectral range of 410~950nm ≥ 95%; the absorption rate of the multi-core optical fiber grouping in the spectral range of 410~950nm ≥ 90%. The multi-core optical fiber grouping introduces each beam of light into the light beam homogenizer, and the light beam homogenizer generates and outputs a uniform light source.

[0049] According to an embodiment of the present invention, the number of channels of the programmable multi-channel square wave voltage source ≥ 5.

[0050] The number of channels of the programmable multi-channel square wave voltage source can be represented by n, which is determined by the main distribution band of the insulating contamination reflection spectrum. Among them, the number of channels of the programmable multi-channel square wave voltage source represented by n is an integer. For example: n can be 5, 6, 7, and it needs to be determined according to the actual characteristics of the insulating contamination.

[0051] According to an embodiment of the present invention, the number of channels of the multi-channel power amplifier is the same as the number of units of the laser light source of the multi-channel intensity adjustable laser source.

[0052] In addition, the number of channels of the programmable multi-channel square wave voltage source is also the same as the number of channels of the multi-channel power amplifier.

[0053] For example, set the number of channels of the programmable multi-channel square wave voltage source to n = 6. Correspondingly, the number of channels of each multi-channel power amplifier is 6, and the number of units of the laser light source of the multi-channel intensity-adjustable laser source is also 6.

[0054] According to an embodiment of the present invention, by adjusting the working parameters of the programmable uniform light source generating device, a uniform and stable target light source is generated and output by using a programmable multi-channel square wave voltage source, a multi-channel power amplifier, a multi-channel intensity-adjustable laser source, a grouping filter, a multi-core optical fiber grouping, a light ray homogenizer, and a light expander. By using the above device, an artificial light source with flexible spectral combination, adjustable light power, and adjustable illumination time can be provided for the simulation experiment of the insulating pollution reflection spectrum. Compared with the actual sunlight illumination conditions, the stability of the light source is improved, and the influence of sunlight fluctuation and spectral fusion calibration error on the accuracy of the spectral image is reduced. At the same time, synchronous output of multi-band spectra is realized at the light source output end, and there is no need to add a spectral filter in front of the camera to take the reflection spectrum image of the insulating pollution, increasing the selectivity of the camera.

[0055] Based on the above programmable uniform light source generating device, the present invention also provides a spectral image acquisition method based on a programmable uniform light source.

[0056] Figure 2 The flowchart of the spectral image acquisition method based on a programmable uniform light source according to an embodiment of the present invention is shown.

[0057] As Figure 2 shown, the spectral image acquisition method 200 based on a programmable uniform light source in this embodiment includes operations S210 to S240.

[0058] In operation S210, obtain the insulating pollution reflection spectrum information, the camera parameters of the wide-spectrum industrial camera, and the laser source power information.

[0059] In operation S220, determine the working parameters of the programmable uniform light source generating device according to the laser source power information, the insulating pollution reflection spectrum information, and the camera parameters.

[0060] In operation S230, use the programmable multi-channel square wave voltage source in the programmable uniform light source generating device to synchronously generate multi-channel square wave signals, and process the multi-channel square wave signals to output a target light source.

[0061] In operation S240, use the wide-spectrum industrial camera to take pictures of the surface of the target insulator during the output of the target light source to obtain a spectral image of the surface of the target insulator.

[0062] According to an embodiment of the present invention, the insulating contamination reflection spectral information includes the reflection spectral band, the reflectivity of the insulating contamination in each spectral range, and the minimum reflectivity of the insulating contamination in each spectral range. The camera parameters include the minimum exposure photometric value.

[0063] According to an embodiment of the present invention, the working parameters include the high-potential duration of the multi-channel square wave signal, the intensity of each square wave signal output by each square wave voltage source, and the light passing range of each unit of the grouped filter.

[0064] According to an embodiment of the present invention, the processing of synchronously generating multi-channel square wave signals by the programmable multi-channel square wave voltage source includes that each square wave signal forms a combined beam through a multi-channel power amplifier, a multi-channel intensity-adjustable laser source, a grouped filter, and a light homogenizer, and finally outputs a target light source through a light expander.

[0065] According to an embodiment of the present invention, the high-potential duration of each square wave in the target light source is the same as each exposure duration in the shooting cycle of the wide-spectrum industrial camera.

[0066] According to an embodiment of the present invention, according to the laser source power information, the insulating contamination reflection spectral information, and the camera parameters, the working parameters of the programmable uniform light source generating device can be adjusted specifically. The programmable uniform light source generating device is used to generate multi-channel square wave signals, and the multi-channel square wave signals are processed to output a target light source, realizing the synchronous output of multi-band spectra at the light source output end, without adding a spectral filter in front of the camera to shoot the reflection spectral image of the insulating contamination, increasing the selectivity of the camera, and at the same time reducing the influence of sunlight fluctuations and spectral fusion calibration errors on the accuracy of the spectral image.

[0067] Figure 3 The flowchart showing the method for determining the working parameters of the programmable uniform light source generating device according to an embodiment of the present invention is shown.

[0068] As Figure 3 shown, the method 300 for determining the working parameters of the programmable uniform light source generating device in this embodiment includes operations S321 to S323.

[0069] In operation S321, according to the laser source power information, the minimum reflectivity of the insulating contamination imaging, and the minimum exposure photometric value, determine the high-potential duration of the multi-channel square wave signal.

[0070] In operation S322, according to the reflection spectral band, the reflectivities, and the predetermined spectral width, determine the intensity of each square wave signal output by each square wave voltage source.

[0071] In operation S323, according to the reflection spectral band and the predetermined spectral width, determine the light passing range of each unit of the grouped filter.

[0072] According to an embodiment of the present invention, the multiplex square-wave signals generated by the programmable multiplex square-wave voltage source are generated sequentially, and the high-potential duration of the square-wave signals of each channel remains consistent. The high-potential duration of the square-wave signals generated by the programmable multiplex square-wave voltage source can be jointly determined by the laser source power information, the minimum reflectivity of the insulating contamination imaging, and the minimum exposure photometric value. The specific parameter relationship is shown in the following formula (1):

[0073] (1)

[0074] Wherein, t represents the high-potential duration of the multiplex square-wave signals, q min represents the minimum exposure photometric value, w represents the laser source power, and f r, min represents the minimum reflectivity of the insulating contamination imaging.

[0075] According to an embodiment of the present invention, in the above method for obtaining a spectral image based on a programmable uniform light source, it is required that the intensities of the square-wave signals generated by the programmable multiplex square-wave voltage source remain unchanged, so that the power amplification gains of each path are the same, and the power amplification gains of each path can make the reflectivity of the insulating contamination in each spectral range greater than the minimum reflectivity of the insulating contamination imaging. The intensity of each square-wave signal is determined by the reflectivities of the insulating contamination in different spectral ranges, the reflection spectral band, and the spectral range obtained from the predetermined spectral width. The specific parameter relationship is shown in the following formula (2):

[0076] (2)

[0077] Wherein, represents the intensity of each square-wave signal, f r,1 , f r,2 ,…, f r,n represent the reflectivities of the insulating contamination in different spectral ranges, represents the reflection spectral band, represents the predetermined spectral width, represents the spectral range, and a represents the predetermined intensity proportionality coefficient.

[0078] In particular, there is no crossover overlap between the spectral ranges.

[0079] According to an embodiment of the present invention, each unit of the grouped filter can cover the laser source outlet. According to the reflection spectral band and the predetermined spectral width (Δλ), the light transmission range of each unit of the grouped filter can be determined, including the light transmission center band (λ i ) and the spectral range (λ i ± 0.5Δλ, i = 1:n) of each filter.

[0080] According to an embodiment of the present invention, based on the laser source power information, the insulating contamination reflection spectrum information, and the camera parameters, the high-potential duration of the multi-channel square wave signals, the intensities of the square wave signals output by each square wave voltage source, and the light transmission ranges of the respective units of the grouped filter are determined to determine the operating parameters of the programmable uniform light source generating device, so as to achieve targeted adjustment of the light source, provide an artificial light source with flexible spectral combination, adjustable light power, and adjustable illumination time for the simulation experiment of the insulating contamination reflection spectrum, improve the stability of the light source compared with the actual sunlight illumination conditions, and reduce the influence of sunlight fluctuations and spectral fusion calibration errors on the accuracy of the spectral image.

[0081] Using the above programmable uniform light source generating device, multi-channel square wave signals are synchronously generated and processed to output a target light source.

[0082] Figure 4 The flowchart showing the output of the target light source using the programmable uniform light source generating device according to an embodiment of the present invention is shown.

[0083] As Figure 4 shown, the method 400 for outputting the target light source using the programmable uniform light source generating device in this embodiment includes operations S431 to S435.

[0084] In operation S431, based on the operating parameters, the output time sequence of the square wave signals of each channel of the programmable multi-channel square wave voltage source is adjusted.

[0085] In operation S432, each square wave signal passes through a multi-channel power amplifier to drive the multi-channel intensity-adjustable laser sources to generate lasers of various intensities according to the intensities of the square wave signals.

[0086] In operation S433, the lasers of various intensities pass through the grouped filter and are filtered according to the light transmission ranges of the respective units to form spectral light beams.

[0087] In operation S434, the spectral light beams are grouped and introduced into the light homogenizer through multi-core optical fibers to output a combined light beam.

[0088] In operation S435, the combined light beam is radiated outward through the introduced light expander to generate a target light source for insulating contamination reflection spectrum imaging.

[0089] The workflow for outputting the target light source using the above programmable uniform light source generating device is as follows: First, the operating parameters of the programmable uniform light source generating device are determined. For example, the high-potential duration of the multi-channel square wave signals is 0.25 s, the number of channels of the programmable multi-channel square wave voltage source is 5, the intensities of the square wave signals output by each square wave voltage source are (a, b, c, d, e), and the light transmission ranges of the respective units of the grouped filter are λ 1 ±25 nm, λ 2 ±25 nm, λ3 ±25 nm, λ 4 ±25 nm, λ 5 ±25 nm. Based on the above working parameters, adjust the output time series of signals of each path of the programmable multi-channel square wave voltage source. The signals drive multi-channel intensity-adjustable laser light sources through multi-channel power amplifiers. Different-intensity lasers are emitted from each path of the light source, and spectral light beams are formed after passing through the corresponding filters. All the lasers are grouped and introduced into the light homogenizer through multi-core optical fibers, and an artificial synthesized light beam is output. Then, the synthesized light beam is introduced into the light expander to radiate outward to generate a light source for insulating contamination reflection spectral imaging.

[0090] According to an embodiment of the present invention, determine the working parameters of the programmable uniform light source generating device according to the laser source power information, the insulating contamination reflection spectral information, and the camera parameters. Based on the above working parameters, use the programmable multi-channel square wave voltage source, the multi-channel power amplifier, the multi-channel intensity-adjustable laser source, the grouped filter, the multi-core optical fiber grouping, the light homogenizer, and the light expander to gradually and orderly generate and output a uniform and stable target light source, which improves the flexibility and adjustability of the light source. At the same time, compared with the outdoor sunlight light source, the stability is increased, and the influence of sunlight fluctuation and spectral fusion calibration error on the spectral image accuracy is reduced. At the same time, synchronous output of multi-band spectra is realized at the light source output end, and there is no need to add a spectral filter in front of the camera to capture the reflection spectral image of the insulating contamination.

[0091] According to an embodiment of the present invention, use a wide-spectrum industrial camera to capture the surface of the target insulator during the output of the target light source to obtain a spectral image of the surface of the target insulator, including: in response to detecting that the square wave signal output by the programmable uniform light source generating device is at a high potential, control the wide-spectrum industrial camera to capture the surface of the target insulator to obtain a spectral image.

[0092] According to an embodiment of the present invention, the spectral response range of the wide-spectrum industrial camera includes: 400~950 nm. For example, the spectral response range of the wide-spectrum industrial camera is 450 ±25 nm. The adjustable exposure duration range of the wide-spectrum industrial camera includes: 0.05~1 s. For example, the adjustable exposure duration of the wide-spectrum industrial camera is 0.2 s.

[0093] According to an embodiment of the present invention, when the square wave signal output by the programmable uniform light source generating device is at a high potential, the duration of the high potential of each square wave in the target light source is controlled to be consistent with the exposure duration of each shot in the shooting cycle of the wide-spectrum industrial camera. The surface of the target insulator is photographed by the wide-spectrum industrial camera to obtain a spectral image, so as to detect and analyze the optical characteristics of the contamination through the reflection spectral imaging technology. By outputting a target light source that precisely covers the contamination reflection-sensitive spectral region through the programmable uniform light source generating device, in practical applications, there is no need to add a spectral filter in front of the camera to capture the reflection spectral image of the insulation contamination, increasing the selectivity of the camera.

[0094] Figure 5 Fig. shows the timing schematic diagram of the cooperation between the programmable multi-channel square wave voltage source and the camera according to an embodiment of the present invention.

[0095] As Figure 5 shown, the surface of the target insulator is photographed by the wide-spectrum industrial camera during the output of the square wave signal by the programmable multi-channel square wave voltage source. The duration of the high potential of each square wave in the target light source is consistent with the exposure duration of each shot in the shooting cycle of the wide-spectrum industrial camera. Six hyperspectral images can be obtained in one set of shots.

[0096] The present invention will be described in detail below through a specific embodiment: Using the programmable uniform light source generating device, images of the composite insulator rubber material sample are taken under artificial light. The specific process of the spectral image acquisition method based on the programmable uniform light source is as follows:

[0097] According to the optical power of each laser light source (w = 15W), the minimum reflectivity requirement for insulation contamination imaging (f r, min = 0.29) and the minimum exposure photometric value (q min = 0.5 lx), the duration of the high potential of the square wave signal is determined. As calculated by the following formula, the high potential duration t of the square wave signal is set to 0.15 s.

[0098]

[0099] According to the main distribution band of the insulation contamination reflection spectrum, the number of channels of the programmable multi-channel square wave voltage source is set to n = 6.

[0100] According to each intensity ( ), the synchronous signal intensity of each channel of the programmable multi-channel square wave voltage source is set to (0.45, 0.71, 0.59, 1, 0.67, 0.81) according to the reflectivity of the insulation contamination in different spectral ranges and the spectral range.

[0101] According to the number of laser light source units \(n = 6\), select that the number of channels of each multi-channel power amplifier is also 6, and keep the power amplification gain of each channel consistent. According to the minimum reflectivity \(f\) of the insulating contamination in different spectral ranges r, min \(= 0.29\), adjust the power amplification gain to 52 dB according to the photoelectric conversion efficiency of the laser light source itself;

[0102] According to the spectral distribution of the insulating contamination (\(\lambda\) 1 \(= 450\ nm\), \(\lambda\) 2 \(= 505\ nm\), \(\lambda\) 3 \(= 563\ nm\), \(\lambda\) 4 \(= 710\ nm\), \(\lambda\) 5 \(= 890\ nm\), \(\lambda\) 6 \(= 915\ nm\)) and the spectral width of the artificial light source (\(\Delta\lambda = 50\ nm\)), select the light passing range of each unit of the grouped filter.

[0103] Import each laser beam into the light homogenizer through the PMMA multi-core optical fiber grouping, and the light homogenizer generates and outputs a uniform light source.

[0104] Set the exposure time of the wide-spectrum industrial camera to 0.15 s, which is consistent with the output high-level time of the programmable multi-channel square-wave voltage source; and take pictures of the insulating contamination sample area during the high-level period output by the square-wave voltage source. Since the number of spectra \(n = 6\), 6 reflection spectral images in different spectral ranges can be obtained after one group of shooting is completed, as Figure 6a - Figure 6f shown.

[0105] As Figure 6a shown, this image is the reflection spectral image obtained by the wide-spectrum industrial camera when the spectral band is 450 nm. Figure 6b Shows the reflection spectral image obtained by the wide-spectrum industrial camera when the spectral band is \(\lambda\) 2 . Figure 6c Shows the reflection spectral image obtained by the wide-spectrum industrial camera when the spectral band is \(\lambda\) 3 . Figure 6d Shows the reflection spectral image obtained by the wide-spectrum industrial camera when the spectral band is \(\lambda\) 4 . Figure 6e Shows the reflection spectral image obtained by the wide-spectrum industrial camera when the spectral band is \(\lambda\) 5 . Figure 6f Shows the reflection spectral image obtained by the wide-spectrum industrial camera when the spectral band is \(\lambda\) 6 .

[0106] The programmable uniform light source generating device provided by the present invention provides an artificial light source with flexible spectral combination, adjustable optical power, and adjustable illumination time for the simulation experiment of the insulating contamination reflection spectrum. By adjusting the spectral composition and the optical power of the artificial light source, the incident spectrum of the insulating contamination under various illumination conditions can be simulated, and the contamination reflectivity information under a specific spectrum can be obtained through a calibration-free method.

[0107] According to information such as the insulating contamination reflection spectrum distribution range, wavelength, reflectivity, camera exposure time, and exposure, a wide-spectrum camera was used in conjunction with the square-wave light source timing to collect images of the insulating contamination samples, and 6 reflection spectrum images within different spectral ranges were obtained. The results show that this method can be based on an artificial light source rather than the calibration process of spectral images in related examples, so it can obtain more accurate multi-spectral imaging information of insulating contamination. Compared with using the actual sunlight source, using an artificial multi-spectral uniform light source can quantitatively verify and analyze the optical characteristics of insulating contamination, providing a new means for the analysis of the insulating contamination composition, contamination distribution, and image fusion.

[0108] Those skilled in the art can understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present invention.

[0109] The above describes the embodiments of the present invention. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present invention. Although the embodiments are described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present invention.

Claims

1. A spectral image acquisition method based on a programmable uniform light source, characterized in that: The spectral image acquisition method comprises: Obtain insulation contamination reflection spectrum information, camera parameters of wide-spectrum industrial cameras, and laser source power information; According to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters, the operating parameters of the programmable uniform light source generating device are determined; the programmable uniform light source generating device comprises: a programmable multi-channel square wave voltage source, a multi-channel power amplifier, a multi-channel intensity adjustable laser source, a grouping filter, a multi-core optical fiber grouping, a light homogenizer and a light expander; Utilizing the programmable multi-channel square wave voltage source in the programmable uniform light source generating device to synchronously generate multi-channel square wave signals, and processing the multi-channel square wave signals to output a target light source; wherein the high potential duration of each square wave in the target light source is the same as each exposure duration of the wide spectrum industrial camera in a shooting cycle; and Using the wide spectrum industrial camera to photograph the target insulator surface during the output of the target light source to obtain a spectrum image of the target insulator surface; The insulation contamination reflectance spectrum information includes the reflectance spectrum band, each reflectance of the insulation contamination in each spectrum range and the minimum reflectance of the insulation contamination in each spectrum range; the camera parameters include the minimum exposure light value; The step of determining the operating parameters of the programmable uniform light source generating device according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters comprises: According to the laser source power information, the minimum reflectivity of the insulating contamination in each spectral range and the minimum exposure light value, the high potential duration of the multi-channel square wave signal is determined as follows: Among them, t represents the duration of the high potential of the multi-channel square wave signal, q min represents the minimum exposure light value, w represents the laser light source power, f r, min Indicates the minimum reflectivity of insulation pollution in each spectral range; According to the reflection spectrum band, each reflectivity and the predetermined spectrum width, the intensity of each square wave signal produced by each square wave voltage source is determined; so that the power amplification gain of each channel is the same, and the power amplification gain of each channel can make the reflectivity of the insulating contamination in each spectrum range greater than the minimum reflectivity of the insulating contamination in each spectrum range, as shown below: in, Indicates the strength of each square wave signal, f r,1 , f r,2 ,…, f r,i，… f r,n Indicates the reflectivity of insulation pollution in different spectral ranges, represents the reflectance spectrum band, represents the predetermined spectral width, represents the spectral range, and a represents the predetermined intensity proportional coefficient; The light transmission range of each unit of the grouped filter is determined according to the reflection spectrum band and the predetermined spectrum width.

2. The spectral image acquisition method according to claim 1, characterized in that: The method of using the wide spectrum industrial camera to photograph the target insulator surface during the output of the target light source to obtain a spectral image of the target insulator surface includes: In response to detecting that the square wave signal output by the programmable uniform light source generating device is at a high potential, the wide spectrum industrial camera is controlled to photograph the surfaces of the pair of target insulators to obtain the spectrum image.

3. The spectral image acquisition method according to claim 1 or 2, characterized in that: The spectral response range of the wide spectrum industrial camera includes: 400~950nm.

4. The spectral image acquisition method according to any one of claims 1 to 3, characterized in that: The adjustable exposure time range of the wide spectrum industrial camera is: 0.05~1s.

5. The spectral image acquisition method according to claim 1, wherein: The method of synchronously generating multiple square wave signals using multiple square wave voltage sources in the programmable uniform light source generating device, and processing the multiple square wave signals to output a target light source includes: Based on the working parameters, adjusting the output time sequence of each square wave signal of the programmable multi-channel square wave voltage source; The square wave signals of each channel pass through the multi-channel power amplifier to drive the multi-channel intensity-adjustable laser source to generate lasers of different intensities according to the intensities of the square wave signals of each channel; The laser beams of various intensities are filtered according to the light transmission range of each unit through the grouping filter to form a spectral beam; The spectral light beam is introduced into the light homogenizer through the multi-core optical fiber grouping, and a synthetic light beam is output; and The synthesized light beam is introduced into the light expander and radiated outward to generate a target light source for insulation contamination reflection spectrum imaging.

6. A programmable uniform light source generating device, used in the spectral image acquisition method according to any one of claims 1 to 5, characterized in that: include: Programmable multi-channel square wave voltage source, used to output square wave signals of various channels; A multi-channel power amplifier, electrically connected to the programmable multi-channel square wave voltage source, and used to adjust the power amplification gain of each channel of square wave signal; A multi-channel intensity adjustable laser source is electrically connected to the multi-channel power amplifier and is used to generate lasers of various intensities according to the intensities of the square wave signals of the power amplifiers of the channels; A grouping filter connected to the multi-channel intensity adjustable laser source, used for filtering according to the light transmission range of each unit to form a spectral beam sequence; A multi-core optical fiber group is connected to the grouping filter and the light homogenizer respectively, and is used to guide the spectral light beam into the light homogenizer and output a synthetic light beam; The light expander is connected to the light homogenizer and is used for radiating outward to generate a target light source for insulation pollution reflection spectrum imaging.

7. The programmable uniform light source generating device according to claim 6, characterized in that: Each optical fiber bundle in the multi-core optical fiber group comprises: a plastic polymer material wrapped in a light absorbing material coating; The transmittance of the plastic polymer material of each optical fiber bundle in the multi-core optical fiber group is ≥95% in the spectral range of 410~950nm; the absorption rate of the light-absorbing material coating of each optical fiber bundle in the multi-core optical fiber group is ≥90% in the spectral range of 410~950nm.

8. The programmable uniform light source generating device according to claim 6, characterized in that: The number of channels of the programmable multi-channel square wave voltage source is ≥5.

9. The programmable uniform light source generating device according to claim 6, characterized in that: The number of channels of the multi-channel power amplifier is the same as the number of units of the laser light source of the multi-channel intensity adjustable laser source.

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