Spectral image acquisition method and device based on programmable uniform light source

Abstract

The invention provides a spectral image acquisition method and device based on a programmable uniform light source, which can be applied to the technical field of insulation equipment pollution characteristic detection, and the spectral image acquisition method comprises the following steps: acquiring insulation pollution reflection spectrum information, camera parameters of a wide-spectrum industrial camera and laser source power information; determining working parameters of a programmable uniform light source generation device according to the laser source power information, the insulation pollution reflection spectrum information and the camera parameters; a programmable multi-path square wave voltage source in the programmable uniform light source generation device is used for synchronously generating multi-path square wave signals, the multi-path square wave signals are processed, and a target light source is output; and shooting the surface of the target insulator by using the wide-spectrum industrial camera during the output period of the target light source so as to obtain a spectral image for the surface of the target insulator.

Description

Technical Field

[0001] The invention relates to the technical field of contamination characteristic detection of insulating equipment, and in particular to a method and a device for acquiring a spectral image based on a programmable uniform light source. Background Art

[0002] Insulators are one of the most important external insulation equipment in high-voltage power transmission systems, and they are responsible for the mechanical support and electrical insulation between transmission conductors and pole towers, and between conductors and station structures. However, due to the long-term exposure of insulators to the atmospheric environment, their surfaces will inevitably be contaminated by dirt under the action of composite environmental stress, and the dirt will eventually lead to the occurrence of pollution flashover. Since the losses caused by pollution flashover are large, it is very necessary to reduce the occurrence of pollution flashover accidents. The accumulation of dirt on the surface of insulators is a prerequisite for the occurrence of pollution flashover. Although the application of anti-pollution measures such as pollution-resistant materials and hydrophobic materials has reduced the risk of pollution flashover accidents to a certain extent, pollution flashover accidents in local areas have not been completely eliminated. Therefore, it is very important to monitor and evaluate the pollution characteristics of insulators.

[0003] At present, hyperspectral imaging technology has shown certain application prospects in the assessment of insulator contamination status, but the following problems still exist: complex daylight conditions such as region, altitude, season, atmospheric conditions, and sunshine height make the acquisition of reflective hyperspectral data affected by many factors, and it is difficult to control the reflectivity and spectral composition of insulator contamination under both laboratory conditions and outdoor conditions; according to the technical conditions of existing hyperspectral imaging instruments, the time span required to carry out an insulator contamination hyperspectral imaging under daylight conditions is relatively large, and the stability of the daylight light source is poor. During this period, the daylight exposure conditions may produce large errors due to factors such as sunshine height, cloud changes, and drone posture movement; it is often difficult to accurately cover the contamination reflection sensitive spectral area by simulating daylight conditions in the laboratory or calibrating the daylight under outdoor conditions. The fusion result of the obtained reflective spectrum image will lose the judgment accuracy due to calibration errors. Summary of the invention

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

[0005] According to a first aspect of the present invention, a spectral image acquisition method based on a programmable uniform light source is provided, comprising: acquiring insulation contamination reflection spectrum information, camera parameters of a wide-spectrum industrial camera and laser source power information; determining working parameters of a programmable uniform light source generating device according to the laser source power information, the insulation contamination reflection spectrum 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 a multi-channel square wave signal, and processing the multi-channel square wave signal 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 shoot the surface of a 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 contamination reflection spectrum information includes the reflection spectrum band, each reflectivity of the insulation contamination in each spectrum range and the minimum reflectivity of the insulation contamination in each spectrum range; the camera parameters include the minimum exposure light value; according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters, the working parameters of the programmable uniform light source generating device are determined, including: according to the laser source power information, the minimum reflectivity of the insulation contamination imaging and the minimum exposure light value, the high potential duration of the multi-channel square wave signal is determined; 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 insulation contamination in each spectrum range greater than the minimum reflectivity of the insulation contamination imaging; and according to the reflection spectrum band and the predetermined spectrum width, the light transmission range of each unit of the grouped filter is determined.

[0007] According to an embodiment of the present invention, a 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 an optical expander; the multi-channel square wave voltage source in the programmable uniform light source generating device is used to synchronously generate a multi-channel square wave signal, and the multi-channel square wave signal is processed to output a target light source, including: based on working parameters, adjusting the output time sequence of each square wave signal of the programmable multi-channel square wave voltage source; each square wave signal is passed through a multi-channel power amplifier to drive the multi-channel intensity adjustable laser source to generate lasers of various intensities according to the intensity of each square wave signal; the lasers 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 beam is introduced into the light homogenizer through the multi-core optical fiber grouping to output a synthetic beam; and the synthetic beam is radiated outwardly by introducing it into the optical expander to generate a target light source for insulation contamination reflection spectral imaging.

[0008] According to an embodiment of the present invention, a wide-spectrum industrial camera is used to photograph the surface of a target insulator during the output of a target light source to obtain a spectral image of the target insulator surface, including: in response to detecting that a square wave signal output by a 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 time 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, comprising: a programmable multi-channel square wave voltage source, used to output each channel of square wave signals; a multi-channel power amplifier, electrically connected to the programmable multi-channel square wave voltage source, used to adjust the power amplification gain of each channel of square wave signals; a multi-channel intensity-adjustable laser source, electrically connected to the multi-channel power amplifier, used to generate lasers of various intensities according to the intensity of each channel of square wave signals under the drive of the square wave signals of each channel of power amplification gain; a grouping filter, connected to the multi-channel intensity-adjustable laser source, used to filter according to the light transmission range of each unit to form a spectral beam sequence; a multi-core optical fiber group, respectively connected to the grouping filter and the light homogenizer, used to guide the spectral beam into the light homogenizer and output a synthetic beam; and a light expander, connected to the light homogenizer, used to radiate outward to generate a target light source for insulation contamination reflection spectral imaging.

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

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

[0015] According to the embodiment of the present invention, the working parameters of the programmable uniform light source generator can be adjusted in a targeted manner according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters. The programmable uniform light source generator generates multiple square wave signals, processes the multiple square wave signals, outputs the target light source, and realizes the synchronous output of multi-band spectra at the light source output end, without adding a spectral filter in front of the camera to realize the shooting of the insulation contamination reflection spectrum image, thereby 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

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

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

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

[0020] Figure 4 A flow chart showing outputting a target light source by using a programmable uniform light source generating device according to an embodiment of the present invention is shown;

[0021] Figure 5 A schematic diagram of the timing of cooperation between 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 reflected spectrum image captured by the wide spectrum industrial camera when the spectral band is λ1 is shown;

[0023] Figure 6b The reflected spectrum image captured by the wide spectrum industrial camera when the spectral band is λ2 is shown;

[0024] Figure 6c The reflected spectrum image captured by the wide spectrum industrial camera when the spectral band is λ3 is shown;

[0025] Figure 6d The reflected spectrum image captured by the wide spectrum industrial camera when the spectral band is λ4 is shown;

[0026] Figure 6e The reflected spectrum image captured by the wide spectrum industrial camera when the spectral band is λ5 is shown;

[0027] Figure 6f The figure shows the reflection spectrum image captured by the wide spectrum industrial camera when the spectral band is λ6. DETAILED DESCRIPTION

[0028] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0029] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence 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] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0032] Insulators are one of the most important external insulation equipment in high-voltage power transmission systems, and they provide mechanical support and electrical insulation between transmission lines and towers, and between lines and station structures. However, due to long-term exposure to the atmosphere, insulators will inevitably become contaminated by the combined environmental stresses. As the insulators are used for longer periods of time, the contaminants accumulated on their surfaces will become more and more serious.

[0033] When encountering bad weather such as dew, fog, drizzle, etc., the dirt layer on the surface of the insulator will absorb water and become damp, and the soluble dirt will dissolve to form conductive ions. The leakage current distributed along the surface of the insulator will increase significantly due to the increase in the conductivity of the dirt layer, and due to the thermal effect, an unevenly distributed dry zone will be formed. The dry zone will form a local field concentration area and eventually break down locally to form a local arc. After meeting the critical conditions for the development of the local arc, it will eventually develop into a pollution flashover (referred to as pollution flashover).

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

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

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

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

[0038]

[0039] According to electromagnetic wave theory, when the radiation reaches the surface of an object, the substance reflects, absorbs, transmits and radiates electromagnetic waves with its inherent characteristics. Reflection refers to the characteristics of the reflection spectrum with strict physical mechanism produced by the substance under the irradiation of light sources of different wavelengths according to its surface structure, chemical composition, material composition and other characteristics. Therefore, the inherent reflection spectrum characteristics of insulation contamination can be used in combination with hyperspectral imaging technology to detect 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 also attracted the attention of scholars and power grid operation and maintenance practitioners, overall, related applications are still in the initial and exploratory stages and there are still technical problems:

[0041] (1) Complex sunlight conditions such as region, altitude, season, atmospheric conditions, and sunshine height make the acquisition of reflectance hyperspectral data difficult to control the insulator contamination reflectivity and spectral composition, whether in laboratory conditions or outdoor conditions;

[0042] (2) According to the technical conditions of existing hyperspectral imaging instruments, the time span required to carry out hyperspectral imaging of insulator pollution under daylight conditions is relatively long. The stability of the daylight light source is poor. During this period, the daylight illumination conditions may produce large errors due to factors such as sunlight height, cloud changes, and drone posture movement.

[0043] (3) Calibration of spectral images collected under daylight conditions or outdoor conditions by simulating daylight conditions in the laboratory is a secondary calibration of spectral images collected under daylight conditions or outdoor conditions. Since the calibration parameters are generally determined based on expert experience, it is often difficult to accurately cover the spectral region that is sensitive to pollution reflection. The fusion result of the obtained reflection spectrum image will lose the judgment accuracy due to calibration errors.

[0044] In view of the above problems, an embodiment of the present invention provides a spectral image acquisition method based on a programmable uniform light source, which can adjust the working parameters of a programmable uniform light source generator in a targeted manner according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters. The programmable uniform light source generator generates multiple square wave signals, processes the multiple square wave signals, outputs the target light source, and realizes the synchronous output of multi-band spectra at the light source output end, without adding a spectral filter in front of the camera to realize the shooting of the insulation contamination reflection spectrum image, thereby 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.

[0045] Figure 1 FIG. 4 is a schematic diagram showing a programmable uniform light source generating device according to an embodiment of the present invention.

[0046] like Figure 1As shown, 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 group 105, a light homogenizer 106 and a light expander 107. Among them, a programmable multi-channel square wave voltage source 101 is used to output each square wave signal; a 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 each square wave signal; a 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 according to the intensity of each square wave signal under the drive of the square wave signal of each power amplification gain; a grouping filter 104 is connected to the multi-channel intensity adjustable laser source 103 and is used to filter according to the light transmission range of each unit to form a spectral beam sequence; a multi-core optical fiber group 105 is respectively connected to the grouping filter 104 and the light homogenizer 106 to guide the spectral beam into the light homogenizer 106 and output a synthetic beam; a light expander 107 is connected to the light homogenizer 106 and is used to radiate outward to generate a target light source for insulation contamination reflection spectrum imaging, wherein 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 group includes: a plastic polymer material wrapped by a light-absorbing material coating; wherein the plastic polymer material may be a polymethyl methacrylate (PMMA) resin material.

[0048] The transmittance of the multi-core optical fiber group in the 410~950nm spectral range is ≥95%; the absorption rate of the multi-core optical fiber group in the 410~950nm spectral range is ≥90%. The multi-core optical fiber group guides each light beam into the light homogenizer, and the light 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 is ≥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 insulation pollution reflection spectrum. Among them, the number of channels of the programmable multi-channel square wave voltage source can be represented by n as an integer, for example: n can be 5, 6, 7, which needs to be determined according to the characteristics of the actual insulation pollution.

[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, the number of channels of the programmable multi-channel square wave voltage source is set to n=6, and 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 adjustable intensity laser source is also 6.

[0054] According to the embodiment of the present invention, the working parameters of the programmable uniform light source generating device are adjusted, and a uniform and stable target light source is generated and outputted 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 homogenizer and an optical expander. The above device can provide an artificial light source with flexible spectrum combination, adjustable light power and adjustable illumination time for the simulation experiment of the insulation pollution reflection spectrum. Compared with the actual daylight illumination conditions, the stability of the light source is improved, and the influence of daylight fluctuations and spectrum fusion calibration errors on the accuracy of the spectrum image is reduced. At the same time, the synchronous output of multi-band spectrum is realized at the output end of the light source, and there is no need to add a spectrum filter in front of the camera to realize the shooting of the reflection spectrum image of the insulation pollution, which increases the selectivity of the camera.

[0055] Based on the above-mentioned 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 A flow chart of a spectral image acquisition method based on a programmable uniform light source according to an embodiment of the present invention is shown.

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

[0058] In operation S210 , insulation contamination reflection spectrum information, camera parameters of a wide spectrum industrial camera, and laser source power information are acquired.

[0059] In operation S220, the operating parameters of the programmable uniform light source generating device are determined according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters.

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

[0061] In operation S240 , a wide spectrum industrial camera is used to photograph the target insulator surface during the output of the target light source to obtain a spectrum image of the target insulator surface.

[0062] According to an embodiment of the present invention, the insulation contamination reflectance spectrum information includes reflectance spectrum bands, reflectances of insulation contamination in each spectrum range, and the minimum reflectance of insulation contamination in each spectrum range. The camera parameters include the minimum exposure light value.

[0063] According to an embodiment of the present invention, the operating parameters include the duration of high potential of multiple square wave signals, the strength of each square wave signal generated by each square wave voltage source, and the light transmission range of each unit of the grouped filter.

[0064] According to an embodiment of the present invention, a programmable multi-channel square wave voltage source synchronously generates a plurality of square wave signals for processing, including each square wave signal passing through a multi-channel power amplifier, a multi-channel intensity adjustable laser source, a grouping filter, and a light homogenizer to form a synthetic light beam, and finally outputting a target light source through a light expander.

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

[0066] According to the embodiment of the present invention, the working parameters of the programmable uniform light source generator can be adjusted in a targeted manner according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters. The programmable uniform light source generator generates multiple square wave signals, processes the multiple square wave signals, outputs the target light source, and realizes the synchronous output of multi-band spectra at the light source output end, without adding a spectral filter in front of the camera to realize the shooting of the insulation contamination reflection spectrum image, thereby 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.

[0067] Figure 3 A flow chart of a method for determining working parameters of a programmable uniform light source generating device according to an embodiment of the present invention is shown.

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

[0069] In operation S321, the high potential duration of the multi-channel square wave signals is determined according to the laser source power information, the minimum reflectivity of the insulation contamination imaging, and the minimum exposure light value.

[0070] In operation S322, the intensity of each square wave signal generated by each square wave voltage source is determined according to the reflection spectrum band, each reflectivity and the predetermined spectrum width.

[0071] In operation S323, the light transmission range of each unit of the grouped filter is determined according to the reflection spectrum band and the predetermined spectrum width.

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

[0073] (1)

[0074] 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 for imaging insulation contamination.

[0075] According to an embodiment of the present invention, in the above-mentioned spectral image acquisition method based on a programmable uniform light source, it is required that the intensity of each square wave signal generated by the programmable multi-channel square wave voltage source remains unchanged, 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 spectral range greater than the minimum reflectivity of the insulating contamination imaging. The intensity of each square wave signal is determined by the reflectivity of the insulating contamination in different spectral ranges, the reflection spectrum band and the spectral range obtained by the predetermined spectral width. The specific parameter relationship is shown in the following formula (2):

[0076] (2)

[0077] in, Indicates the strength of each square wave signal, f r,1 , f r,2 ,…, 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.

[0078] In particular, the overlap between the spectral ranges is avoided.

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

[0080] According to an embodiment of the present invention, based on laser source power information, insulation contamination reflection spectrum information and camera parameters, the high potential duration of multiple square wave signals, the strength of each square wave signal produced by each square wave voltage source and the light transmission range of each unit of the grouping filter are determined to determine the working parameters of the programmable uniform light source generating device, so as to achieve targeted adjustment of the light source and provide an artificial light source with flexible spectral combination, adjustable optical power and adjustable illumination time for the simulation experiment of insulation contamination reflection spectrum. Compared with actual daylight illumination conditions, the stability of the light source is improved, and the influence of daylight fluctuations and spectral fusion calibration errors on the accuracy of spectral images is reduced.

[0081] The programmable uniform light source generating device is used to synchronously generate multiple square wave signals, process the multiple square wave signals, and output a target light source.

[0082] Figure 4 A flow chart of outputting a target light source by using a programmable uniform light source generating device according to an embodiment of the present invention is shown.

[0083] like Figure 4 As shown, the method 400 for outputting a target light source by using a 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 each square wave signal 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 a multi-channel intensity-adjustable laser source to generate lasers of various intensities according to the intensities of each square wave signal.

[0086] In operation S433, laser beams of various intensities are filtered according to the light transmission range of each unit through a group filter to form a spectral beam.

[0087] In operation S434, the spectrum light beams are introduced into the light homogenizer through the multi-core optical fiber grouping, and a composite light beam is output.

[0088] In operation S435, the synthesized light beam is radiated outwardly through the introduction expander to generate a target light source for insulation contamination reflectance spectrum imaging.

[0089] The workflow of using the above-mentioned programmable uniform light source generating device to output the target light source is as follows: first, determine the working parameters of the programmable uniform light source generating device. For example, the duration of the high potential of the multi-channel square wave signal is 0.25s, the number of channels of the programmable multi-channel square wave voltage source is 5, the intensity of each square wave signal produced by each square wave voltage source is (a, b, c, d, e), and the light transmission range of each unit of the grouping filter is λ1±25nm, λ2±25nm, λ3±25nm, λ4±25nm, λ5±25nm. Based on the above working parameters, adjust the output time sequence of each signal of the programmable multi-channel square wave voltage source, and the signal drives the multi-channel intensity adjustable laser light source through a multi-channel power amplifier. Different intensities of laser light are emitted from each light source, and a spectral beam is formed after passing through the corresponding filter. All lasers are introduced into the light homogenizer through the multi-core optical fiber grouping, and an artificial synthetic beam is output. The synthetic beam is then introduced into the expander to radiate outward to generate a light source for insulating contamination reflection spectrum imaging.

[0090] According to an embodiment of the present invention, the working parameters of the programmable uniform light source generating device are determined according to the laser source power information, the insulation contamination reflection spectrum information and the camera parameters. Based on the above working parameters, 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 are used to gradually and orderly generate and output a uniform and stable target light source, thereby improving the flexibility and adjustability of the light source. At the same time, compared with the outdoor daylight light source, the stability is increased, and the influence of daylight fluctuations and spectrum fusion calibration errors on the accuracy of the spectral image is reduced. At the same time, the synchronous output of multi-band spectra is realized at the output end of the light source, and there is no need to add a spectral filter in front of the camera to realize the shooting of the reflection spectrum image of the insulation contamination.

[0091] According to an embodiment of the present invention, a wide-spectrum industrial camera is used to photograph the surface of a target insulator during the output of a target light source to obtain a spectral image of the target insulator surface, including: in response to detecting that a square wave signal output by a 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.

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

[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 high potential duration of each square wave in the target light source is controlled to be consistent with each exposure duration of the wide spectrum industrial camera in the shooting cycle, and the surface of the target insulator is photographed by the wide spectrum industrial camera to obtain a spectral image, thereby realizing the detection and analysis of the optical characteristics of the contamination by the reflection spectrum imaging technology. The programmable uniform light source generating device outputs a targeted and precise target light source covering the contamination reflection sensitive spectral region, so that in actual application, there is no need to add a spectral filter in front of the camera to realize the shooting of the reflection spectrum image of the insulation contamination, thereby increasing the selectivity of the camera.

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

[0095] like Figure 5 As shown, a wide-spectrum industrial camera is used to photograph the surface of the target insulator during the period when the programmable multi-channel square wave voltage source outputs a square wave signal. The high potential duration of each square wave in the target light source is consistent with each exposure duration of the wide-spectrum industrial camera in the shooting cycle. A set of shooting can obtain 6 multi-spectral images.

[0096] The present invention is described in detail below through a specific embodiment: using a programmable uniform light source generating device, an image of a composite insulator rubber material sample is captured under an artificial light source, and the specific process of the spectrum image acquisition method based on the programmable uniform light source is as follows:

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

[0098]

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

[0100] According to the intensity ( ) The reflectivity of the insulating dirt in different spectral ranges and the spectral range are used to set the programmable multi-channel square wave voltage source to have a synchronous signal strength of (0.45, 0.71, 0.59, 1, 0.67, 0.81).

[0101] According to the number of laser light source units n=6, the number of channels of the multi-channel power amplifier is also selected to be 6, and the power amplification gain of each channel is kept consistent. According to the minimum reflectivity f of insulation contamination in different spectral ranges r, min =0.29, according to the photoelectric conversion efficiency of the laser light source itself, the power amplification gain is adjusted to 52dB;

[0102] According to the spectral distribution of insulation pollution (λ1=450nm, λ2=505nm, λ3=563nm, λ4=710nm, λ5=890nm, λ6=915nm) and the spectral width of artificial light source (Δλ=50nm), select the light transmission range of each unit of the grouped filter.

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

[0104] The exposure time of the wide spectrum industrial camera is set to 0.15s, which is consistent with the setting of the high level time of the programmable multi-channel square wave voltage source output; and the insulating contaminated sample area is photographed during the high level period of the square wave voltage source output. Because the number of spectra n=6, after a set of shooting is completed, 6 reflection spectrum images in different spectral ranges can be obtained, such as Figure 6a-6f shown.

[0105] like Figure 6a As shown, the image is a reflection spectrum image captured by a wide spectrum industrial camera when the spectral band is 450nm. Figure 6b The figure shows the reflection spectrum image captured by the wide spectrum industrial camera when the spectral band is λ2. Figure 6c The figure shows the reflection spectrum image captured by the wide spectrum industrial camera when the spectral band is λ3. Figure 6d The figure shows the reflection spectrum image captured by the wide spectrum industrial camera when the spectral band is λ4. Figure 6e The figure shows the reflection spectrum image captured by the wide spectrum industrial camera when the spectral band is λ5. Figure 6f The figure shows the reflection spectrum image captured by the wide spectrum industrial camera when the spectral band is λ6.

[0106] The programmable uniform light source generating device provided by the present invention provides an artificial light source with flexible spectrum combination, adjustable light power and adjustable illumination time for the simulation experiment of insulation pollution reflection spectrum. By adjusting the spectral components and the light power of the artificial light source to simulate the insulation pollution incident spectrum under various lighting conditions, the pollution reflectivity information under a specific spectrum can be obtained in a calibration-free manner.

[0107] According to the distribution range, wavelength, reflectivity, camera exposure time, exposure degree and other information of the insulator contamination reflection spectrum, a wide spectrum camera was used in conjunction with a square wave light source timing to collect images of the insulator contamination samples, and 6 reflection spectrum images in different spectral ranges were obtained. The results show that this method can be based on artificial light sources instead of the calibration processing of spectral images in related examples, so it can more accurately obtain multi-spectral imaging information of insulator contamination. Compared with the actual daylight light source, the use of artificial multi-spectral uniform light source can quantitatively check and analyze the optical characteristics of insulation contamination, providing a new means for insulator contamination component analysis, contamination distribution analysis and image fusion.

[0108] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may 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 may be combined and / or combined in various ways. All of these combinations and / or combinations fall within the scope of the present invention.

[0109] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all 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; Determine the working 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; 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 The wide spectrum industrial camera is used to photograph the target insulator surface during the output of the target light source to obtain a spectrum image of the target insulator surface.

2. The spectral image acquisition method according to claim 1, characterized in that: The insulation contamination reflection spectrum information includes reflection spectrum band, each reflectivity of insulation contamination in each spectrum range and the minimum reflectivity of insulation contamination in each spectrum range; the camera parameters include 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: Determine the duration of the high potential of the multi-channel square wave signal according to the laser source power information, the minimum reflectivity of the insulation contamination imaging and the minimum exposure light value; Determine the intensity of each square wave signal generated by each square wave voltage source according to the reflection spectrum band, each reflectivity and the predetermined spectrum width; so that each power amplification gain is the same, and each power amplification gain can make the reflectivity of the insulation contamination in each spectrum range greater than the minimum reflectivity of the insulation contamination imaging; and The light transmission range of each unit of the grouped filter is determined according to the reflection spectrum band and the predetermined spectrum width.

3. The spectral image acquisition method according to claim 2, characterized in that: 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; Using the multiple square wave voltage sources in the programmable uniform light source generating device to synchronously generate multiple square wave signals, and processing the multiple square wave signals to output a target light source, including: 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.

4. 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.

5. The spectral image acquisition method according to any one of claims 1 to 4, characterized in that: The spectral response range of the wide spectrum industrial camera includes: 400~950nm.

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

7. A programmable uniform light source generating device, used in the spectral image acquisition method according to any one of claims 1 to 6, 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.

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

9. The programmable uniform light source generating device according to claim 7, characterized in that: The number of channels of the programmable multi-channel square wave voltage source is ≥5.

10. The programmable uniform light source generating device according to claim 7, 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.

Images