Active spectral imaging system and method for insulator pollution degree grading

Abstract

The invention relates to an active spectral imaging system and method for insulator pollution degree grading, and the system comprises a parameter-adjustable halogen pulse light source, a power supply, a short-wave infrared imaging unit, a control unit, and an image processing unit, the control unit, the power supply, and the parameter-adjustable halogen pulse light source are connected in sequence, and the image processing unit is connected with the power supply. The short wave infrared imaging unit is connected with the image processing unit and the control unit. According to the invention, an active light source is used to irradiate and heat the insulator, and then the short wave infrared imaging technology is used to continuously photograph the surface of the irradiated insulator. Due to the fact that the thermal change rates of the insulators with different contamination degrees after irradiation are obviously different, the contamination degrees can be judged by analyzing the thermal change rates, and then visual analysis of the contamination degrees is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of unmanned aerial vehicle power line inspection, and in particular to an active spectral imaging system and method for grading the degree of insulator contamination. Background Art

[0002] With the rapid development of the power system, the scale and complexity of power lines are increasing, which puts higher requirements on the maintenance and management of power lines. The reliability of power lines directly affects the stable operation of the power grid and the safety of power supply. Among them, insulators, as key components in power lines, undertake the important task of isolating conductors from towers and preventing current leakage. However, insulators are easily affected by external environmental factors such as dust, smoke, industrial pollution, etc. during long-term operation. These pollutants will adhere to the surface of the insulator to form a dirty layer, which will reduce the insulation performance of the insulator and increase the risk of line failure.

[0003] Traditional methods for detecting insulator contamination mainly include the following: manual inspection: visual inspection of insulators by climbing poles manually or using tools such as telescopes. This method is inefficient and has great safety hazards; online monitoring system: real-time monitoring using sensors installed on poles and towers, but these systems can only monitor the surface condition of insulators and it is difficult to accurately assess the degree of contamination; ultrasonic detection: detecting defects inside insulators through the principle of ultrasonic reflection, but the detection effect on surface contamination is limited; infrared thermal imaging: using infrared thermal imagers to detect the heat distribution on the surface of insulators can indirectly reflect the degree of contamination, but it is greatly affected by the ambient temperature and requires professional personnel to analyze. The existing technology has the following deficiencies in insulator contamination detection: low detection efficiency: manual inspection is time-consuming and labor-intensive, and it is impossible to quickly complete the detection of large-scale lines; insufficient detection accuracy: some online monitoring systems and ultrasonic detection are difficult to accurately assess the thickness and distribution of the contamination layer; poor environmental adaptability: infrared thermal imaging is affected by the ambient temperature, and may not have good detection results in high or low temperature environments; strong professional dependence: data analysis and judgment by professionals are required, which increases the detection cost and time. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and propose an active spectral imaging system and method for grading the degree of insulator contamination. The system and method can irradiate the contamination visualization device with an active light source carried by an unmanned aerial vehicle, quickly and accurately analyze the degree of contamination of porcelain insulators and composite insulators on power lines, and realize a visual display of the degree of contamination. At the same time, the present invention improves detection efficiency, accuracy and environmental adaptability while reducing dependence on professionals, providing a more advanced and reliable technical means for the maintenance and management of power lines.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] An active spectral imaging system for grading the degree of insulator contamination is installed on a drone and includes a parameter-adjustable halogen pulse light source, a power supply, a short-wave infrared imaging unit, a control unit and an image processing unit, wherein the control unit, the power supply and the parameter-adjustable halogen pulse light source are connected in sequence, and the short-wave infrared imaging unit is respectively connected to the image processing unit and the control unit.

[0007] Moreover, the spectrum of the parameter-adjustable halogen pulse light source covers the range of 360nm to 2500nm, the peak luminous power is adjustable within the range of 900W to 1600W, the luminous pulse width is 0.3s to 5s, and the luminous peak and luminous pulse width parameters are set by the control unit through the power module.

[0008] Moreover, the spectral response of the short-wave infrared imaging unit covers the range of 900nm to 2500nm, the resolution is not less than 1.3MP pixels, the output frame rate is not less than 134fps, and the exposure time and start timing are set by the control unit. The short-wave infrared imaging unit starts the shooting program after the halogen pulse light source irradiation is completed.

[0009] Furthermore, the control unit is used to control the peak light power and pulse width of the halogen pulse light source, and is also used to control the short-wave infrared imaging unit to capture and save infrared images.

[0010] Furthermore, the image processing unit is used to retrieve the infrared image data in the short-wave infrared imaging unit, and process and analyze the image.

[0011] An active spectral imaging method of an active spectral imaging system for grading the degree of insulator contamination comprises the following steps:

[0012] Step 1: Use a halogen pulse light source to irradiate the target area of ​​the insulator, and set the light pulse width W and the light peak power P.

[0013] Step 2: Start the short-wave infrared imaging unit to continuously shoot the insulator target area, maintain the shooting interval dT = 0.02 × m × [(0.4 × P × W) / 5], and mark the captured infrared grayscale images F1, F2, ..., Fn according to the time series, where m is the line AC frequency, n is the number of shots,

[0014] Step 3: The gray value S at the same pixel position (x, y) of the insulator target area in the infrared images F1, F2, ..., Fn is x,y The sequence S x,y (1,2,…,n);

[0015] Step 4: Use the exponential decay form with positive bias (S(t) = S0·exp(-λt)+a) to calculate S x,y (1,2,…,n) is fitted to obtain the parameter matrix λ at each pixel position (x,y) x,y ;

[0016] Step 5: Substitute the parameter matrix λ x,y Transformed into the normalized root mean square deviation NRMSD matrix λ' x,y , where the matrix unit

[0017] in m is the number of pixels;

[0018] Step 6: Substitute the matrix λ' x,y Each unit λ' x,y The results are divided into k levels: Generate k new matrices λ1' xy ,λ2' xy ,λn' xy ,…,λk' xy ;

[0019] Step 7: The matrix λn' of k levels xy The superposition is a reconstructed pseudo-color image that can display k different levels of contamination, thus completing the visualization analysis of insulator contamination classification.

[0020] The advantages and positive effects of the present invention are:

[0021] 1. The present invention includes a parameter-adjustable halogen pulse light source, a power supply, a short-wave infrared imaging unit, a control unit and an image processing unit, wherein the control unit, the power supply and the parameter-adjustable halogen pulse light source are connected in sequence, and the short-wave infrared imaging unit is connected to the image processing unit and the control unit, respectively. The present invention utilizes an active light source to irradiate and heat the insulator, and then uses short-wave infrared imaging technology to continuously photograph the irradiated surface of the insulator. Since there are significant differences in the thermal change rates of insulators with different degrees of contamination after irradiation, the degree of contamination can be determined by analyzing these thermal change rates, thereby achieving a visual analysis of the degree of contamination.

[0022] 2. The present invention uses drones to quickly cover a large area of ​​power lines, significantly improving detection efficiency.

[0023] 3. The present invention utilizes transient radiant heating and short-wave infrared continuous imaging technology to accurately capture the thermal changes of the contamination layer and achieve accurate assessment of the degree of contamination.

[0024] 4. The short-wave infrared imaging technology used in the present invention is insensitive to changes in ambient temperature, can work stably under various climatic conditions, and is not affected by ambient temperature;

[0025] 5. The system of the present invention can realize automatic shooting, image processing and pollution degree analysis, reducing the dependence on professionals;

[0026] 6. The present invention converts the analysis results into reconstructed images of different pollution levels to intuitively display the pollution distribution of insulators, making it easier for managers to make decisions quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a system structure diagram of the present invention;

[0028] Figure 2 This is a schematic diagram of the operation site of the UAV equipped with the active light source irradiation pollution visualization device of the present invention;

[0029] Figure 3 Reconstructed images of insulators showing five levels of contamination according to the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings.

[0031] An active spectral imaging system for grading the degree of insulator contamination, mounted on a drone, such as Figure 1 As shown, it includes a parameter-adjustable halogen pulse light source, a power supply, a short-wave infrared imaging unit, a control unit and an image processing unit, wherein the control unit, the power supply and the parameter-adjustable halogen pulse light source are connected in sequence, and the short-wave infrared imaging unit is respectively connected to the image processing unit and the control unit.

[0032] The spectrum of the parameter-adjustable halogen pulse light source covers the range of 360nm to 2500nm, the peak power of the light should be adjustable within the range of 900W to 1600W, the pulse width of the light can be adjusted within 0.3s to 5s, and the peak power and pulse width parameters are set by the control unit through the power module;

[0033] The spectral response of the short-wave infrared imaging unit covers the range of 900nm to 2500nm, the resolution is not less than 1.3MP pixels, and the output frame rate is not less than 134fps. The exposure time and start timing are set by the control unit. Generally, the shooting program is started after the halogen pulse light source irradiation is completed;

[0034] The control unit is used to control the peak power and pulse width of the halogen pulse light source, and is also used to control the short-wave infrared imaging unit to capture and save infrared images;

[0035] The image processing unit is used to retrieve the infrared image data in the short-wave infrared imaging unit and process and analyze the image.

[0036] An active spectral imaging method of an active spectral imaging system for grading the degree of insulator contamination comprises the following steps:

[0037] Step 1: Use a halogen pulse light source to irradiate the target area of ​​the insulator, and set the light pulse width W and the light peak power P.

[0038] Step 2: Start the short-wave infrared imaging unit to continuously shoot the insulator target area, maintain the shooting interval dT = 0.02 × m × [(0.4 × P × W) / 5], and mark the captured infrared grayscale images F1, F2, ..., Fn according to the time series, where m is the line AC frequency, n is the number of shots,

[0039] Step 3: The gray value S at the same pixel position (x, y) of the insulator target area in the infrared images F1, F2, ..., Fn is x,y The sequence S x,y (1,2,…,n);

[0040] Step 4: Use the exponential decay form with positive bias (S(t) = S0·exp(-λt)+a) to calculate S x,y (1,2,…,n) is fitted to obtain the parameter matrix λ at each pixel position (x,y) x,y ;

[0041] Step 5: Substitute the parameter matrix λ x,y Transformed into the normalized root mean square deviation NRMSD matrix λ' x,y , where the matrix unit

[0042] in m is the number of pixels;

[0043] Step 6: Substitute the matrix λ' x,y Each unit λ' x,y The results are divided into k levels: Generate k new matrices λ1' xy ,λ2' xy ,λn' xy ,…,λk' xy ;

[0044] Step 7: The matrix λn' of k levels xy The superposition is a reconstructed pseudo-color image that can display k different levels of contamination, thus completing the visualization analysis of insulator contamination classification.

[0045] According to the above-mentioned active spectral imaging system and method for grading the degree of insulator contamination, the composite contaminated insulators of a certain line are detected by using an unmanned aerial vehicle equipped with the active spectral imaging system for grading the degree of insulator contamination to verify the effect of the present invention.

[0046] 1. The active spectral imaging system for grading the degree of insulator contamination of the present invention is mounted on a power line inspection drone system, and is moved near the insulator of the high-voltage line, and the halogen light source and the short-wave infrared imaging unit are aimed at the insulator target through a wireless preview method.

[0047] 2. The power supply of the halogen pulse light source is controlled by the control unit, and a composite insulator running on a high-voltage line is irradiated, with the light pulse width W set to 0.5s and the light peak power P set to 1100W.

[0048] 3. After the halogen light source is irradiated, the short-wave infrared imaging unit is immediately started through the control unit to continuously shoot the target area of ​​the insulator irradiated by the light source and set the shooting interval A total of 25 infrared grayscale images are marked in time series, F1, F2, …, F25.

[0049] 4. The gray value S at the same position (x, y) of the insulator target area in the infrared images F1, F2, ..., F25 is x,y The sequence S x,y (1,2,…,25).

[0050] 5. Use the exponential decay form with positive bias (S(t) = S0·exp(-λt)+a) to calculate S x,y (1,2,…,25) to get the parameter matrix λ at each pixel position (x,y) x,y , for example, the parameter matrix λ at pixel position (301,420) x,y Unit λ 301,420 =3.51.

[0051] 6. The above parameter matrix λ x,y Transformed into the normalized root mean square deviation NRMSD matrix λ' x,y , for example, where the matrix unit

[0052] 7. The matrix λ' x,y Each unit λ' x,y The results are divided into k = 5 levels: 0 ≤ λ' x,y <0.2,0.2≤λ' x,y <0.4,…,0.8≤λ' x,y≤1, generate 5 new matrices λ1' xy ,λ2' xy ,λ3' xy ,λ4' xy ,λ5' xy .

[0053] 8. The five matrices λn' xy The superposition is a reconstructed pseudo-color image that can display 5 different levels of contamination. This completes the visualization analysis of insulator contamination classification, such as Figure 3 shown.

[0054] Figure 3 The 25 infrared grayscale images taken according to the above time series markings are pseudo-colored and reconstructed according to the above steps 4, 5, 6, 7, and 8 to obtain images reflecting the 6 levels of contamination distribution, so that the operation and maintenance personnel can make an intuitive judgment on the contamination status of the insulator.

[0055] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. An active spectral imaging system for grading the degree of insulator contamination, characterized in that: It is installed on a UAV and includes a parameter-adjustable halogen pulse light source, a power supply, a short-wave infrared imaging unit, a control unit and an image processing unit, wherein the control unit, the power supply and the parameter-adjustable halogen pulse light source are connected in sequence, and the short-wave infrared imaging unit is respectively connected to the image processing unit and the control unit.

2. The active spectral imaging system for insulator contamination degree classification according to claim 1, characterized in that: The spectrum of the parameter-adjustable halogen pulse light source covers the range of 360nm to 2500nm, the peak luminous power is adjustable within the range of 900W to 1600W, the luminous pulse width is 0.3s to 5s, and the luminous peak and luminous pulse width parameters are set by the control unit through the power module.

3. The active spectral imaging system for insulator contamination degree classification according to claim 1 is characterized in that: The spectral response of the short-wave infrared imaging unit covers the range of 900nm to 2500nm, the resolution is not less than 1.3MP pixels, the output frame rate is not less than 134fps, and the exposure time and start timing are set by the control unit. The short-wave infrared imaging unit starts the shooting program after the halogen pulse light source irradiation is completed.

4. The active spectral imaging system for insulator contamination degree classification according to claim 1, characterized in that: The control unit is used to control the peak light power and pulse width of the halogen pulse light source, and is also used to control the short-wave infrared imaging unit to capture and save infrared images.

5. The active spectral imaging system for insulator contamination degree classification according to claim 1, characterized in that: The image processing unit is used to retrieve the infrared image data in the short-wave infrared imaging unit, and process and analyze the image.

6. An active spectral imaging method of an active spectral imaging system for grading the degree of insulator contamination according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Use a halogen pulse light source to irradiate the target area of ​​the insulator, and set the light pulse width W and the light peak power P. Step 2: Start the short-wave infrared imaging unit to continuously shoot the insulator target area, maintain the shooting interval dT = 0.02 × m × [(0.4 × P × W) / 5], and mark the captured infrared grayscale images F1, F2, ..., Fn according to the time series, where m is the line AC frequency, n is the number of shots, Step 3: The gray value S at the same pixel position (x, y) of the insulator target area in the infrared images F1, F2, ..., Fn is x,y The sequence S x,y (1,2,…,n); Step 4: Use the exponential decay form with positive bias (S(t) = S0·exp(-λt)+a) to calculate S x,y (1,2,…,n) is fitted to obtain the parameter matrix λ at each pixel position (x,y) x,y ; Step 5: Substitute the parameter matrix λ x,y Transformed into the normalized root mean square deviation NRMSD matrix λ' x,y , where the matrix unit in m is the number of pixels; Step 6: Substitute the matrix λ' x,y Each unit λ' x,y The results are divided into k levels: Generate k new matrices λ1' xy ,λ2' xy ,λn' xy ,…,λk' xy ; Step 7: The matrix λn' of k levels xy The superposition is a reconstructed pseudo-color image that can display k different levels of contamination, thus completing the visualization analysis of insulator contamination classification.

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