A contact resistance on-line abnormality detection method for a brush holder grounding system
Patent Information
- Application Number
- CN202611088333.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-22
- Publication Date
- 2026-08-18
AI Technical Summary
[0003]本发明旨在至少在一定程度上解决现有技术中的技术问题之一，通过获取待检测的接触电阻的红外图像，标识为实时电阻红外图像；将实时电阻红外图像转化为实时电阻红外灰度图，依据实时电阻红外灰度图获取实时电阻区域；依据实时电阻区域构建第一检测区域；依据第一检测区域获取实时灰度对照值；依据实时灰度对照值获取实时检测温度；依据刷握接地系统中采集数据与实时检测温度获取实时修正接触电阻；依据正常接触电阻运行数据获取第一历史基准值和第二历史基准值；依据第一历史基准值和第二历史基准值获取第一基准函数与第二基准函数；实时检测温度、实时修正接触电阻、第一基准函数以及第二基准函数判断待检测的接触电阻是否异常，以解决现有技术中接触电阻的温度获取不够准确，导致获取的接触电阻异常阈值不准确的问题
[0014]本发明的有益效果：本发明通过获取待检测的接触电阻的红外图像，标识为实时电阻红外图像；将实时电阻红外图像转化为实时电阻红外灰度图，依据实时电阻红外灰度图获取实时电阻区域；依据实时电阻区域构建第一检测区域；依据第一检测区域获取实时灰度对照值；依据实时灰度对照值获取实时检测温度；依据刷握接地系统中采集数据与实时检测温度获取实时修正接触电阻；依据正常接触电阻运行数据获取第一历史基准值和第二历史基准值；依据第一历史基准值和第二历史基准值获取第一基准函数与第二基准函数；实时检测温度、实时修正接触电阻、第一基准函数以及第二基准函数判断待检测的接触电阻是否异常，优势在于，获取接触电阻合适的温度表示值，依据实时检测温度获取接触电阻的异常阈值，提升接触电阻在线异常检测的准确度；
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Figure CN122591070A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of resistance anomaly detection technology, specifically to an online anomaly detection method for contact resistance in a brush-grip grounding system. Background Technology
[0002] The entire brush holder grounding system includes the sliding contact surface between the carbon brush and the slip ring. The contact state is affected by a combination of factors, such as spring pressure decay, oxide film growth on the contact surface, carbon brush wear, oil adhesion, and temperature changes. When the contact state deteriorates, the contact resistance increases abnormally, causing the shaft voltage to fail to dissipate effectively, which in turn leads to serious problems such as carbon brush overheating, arcing, and arc erosion. Real-time and accurate monitoring of the contact resistance of the brush holder grounding system is a key means to predict potential contact deterioration in advance. Then, the contact resistance is prone to temperature changes, which affect the normal resistance range of the measurement. The existing fixed threshold for abnormality does not take into account the temperature effect, resulting in inaccurate detection of abnormal contact resistance. The temperature of the contact resistance varies at different locations, and the temperature of a single acquisition point cannot represent the temperature of the contact resistance, resulting in inaccurate adaptive threshold for temperature acquisition. The temperature acquisition of contact resistance in the existing technology is not accurate enough, resulting in inaccurate abnormal contact resistance thresholds. Summary of the Invention
[0003] This invention aims to at least partially solve one of the technical problems in the prior art. It acquires an infrared image of the contact resistance to be detected, identifying it as a real-time resistance infrared image; converts the real-time resistance infrared image into a real-time resistance infrared grayscale image; obtains a real-time resistance region based on the real-time resistance infrared grayscale image; constructs a first detection region based on the real-time resistance region; obtains a real-time grayscale reference value based on the first detection region; obtains a real-time detection temperature based on the real-time grayscale reference value; obtains a real-time corrected contact resistance based on data collected in the brush-grip grounding system and the real-time detection temperature; obtains a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtains a first reference function and a second reference function based on the first historical reference value and the second historical reference value; and uses the real-time detection temperature, real-time corrected contact resistance, first reference function, and second reference function to determine whether the contact resistance to be detected is abnormal. This solves the problem in the prior art where the temperature acquisition of the contact resistance is not accurate enough, leading to inaccurate abnormal contact resistance thresholds.
[0004] To achieve the above objectives, this application provides an online abnormal detection method for contact resistance in a brush-grip grounding system, comprising the following steps: S100: Acquire an infrared image of the contact resistance to be detected and label it as a real-time resistance infrared image; convert the real-time resistance infrared image into a real-time resistance infrared grayscale image and obtain the real-time resistance region based on the real-time resistance infrared grayscale image. S200: Construct a first detection area based on the real-time resistance area; obtain a real-time grayscale comparison value based on the first detection area; obtain the real-time detection temperature based on the real-time grayscale comparison value; S300 obtains real-time corrected contact resistance based on data collected in the brush grip grounding system and real-time temperature detection. S400: Obtain a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtain a first reference function and a second reference function based on the first historical reference value and the second historical reference value; The S500 detects temperature in real time, corrects contact resistance in real time, and uses a first reference function and a second reference function to determine whether the contact resistance to be detected is abnormal.
[0005] Furthermore, S100 includes the following sub-steps: The real-time resistance infrared image is a white-heated infrared image; The real-time resistance infrared image is converted to grayscale to obtain a grayscale image, which is then labeled as the real-time resistance infrared grayscale image; the contact resistance area in the real-time resistance infrared grayscale image is then labeled as the real-time resistance area.
[0006] Furthermore, S200 includes the following sub-steps: Establish a Cartesian coordinate system and label it as the first plane coordinate system; Obtain the X-axis of the first planar coordinate system and label it as the first X-axis; Obtain the Y-axis of the first planar coordinate system and label it as the first Y-axis; Obtain the first quadrant of the first planar coordinate system and label it as the first target quadrant; In the first target quadrant, establish two sets of parallel straight lines, labeled as the first parallel line segments; make the adjacent and parallel first parallel line segments spaced by a first distance, with one set of first parallel line segments parallel to the first X-axis and the other set of first parallel line segments parallel to the first Y-axis; Obtain the unit rectangle between the two sets of first parallel line segments and label it as the first unit rectangle; Place the real-time resistance region in the first target quadrant, and ensure that the entire real-time resistance region is within the first unit rectangle; The area where the real-time resistance region intersects with the first unit rectangle is identified as the first detection region.
[0007] Furthermore, S200 also includes the following sub-steps: Obtain the area of any one of the first detection regions and label it as the first detection area; Get the area of the first unit rectangle and label it as the first unit area; The first reference value for each first detection region is calculated as: D1 = S1 ÷ S2; where D1 is the first reference value for a first detection region, S1 is the first detection area of the corresponding first detection region, and S2 is the first unit area. Obtain the grayscale value of each pixel in the real-time resistive infrared grayscale image and identify it as the first grayscale value; Obtain a first number of first grayscale values within any first detection region and identify them as first detection grayscale values; The first weight grayscale value of each first detection region is calculated as: Q1 = D1 × H1; where Q1 is the first weight grayscale value of a first detection region; and H1 is the first detection grayscale value. Obtain the sum of all first reference values and mark it as the first calculated value; Obtain the sum of all grayscale values of the first weight, and label it as the second calculated value; The real-time grayscale comparison value is calculated as follows: H2 = J2 ÷ J1; where H2 is the real-time grayscale comparison value, J1 is the first calculated value, and J2 is the second calculated value.
[0008] Furthermore, S200 also includes the following sub-steps: Obtain the temperature relationship corresponding to each gray value in the real-time resistive infrared grayscale image and mark it as the grayscale temperature correspondence. Based on the grayscale-temperature correspondence, the temperature corresponding to the real-time grayscale reference value is obtained and identified as the real-time detection temperature.
[0009] Furthermore, S300 includes the following sub-steps: Acquire the current in the brush gripper grounding system and mark it as real-time acquired current; Acquire the voltage in the brush grip grounding system and mark it as real-time acquired voltage; The total resistance of the loop in the brush-grip grounding system is labeled as the real-time total resistance. The formula for calculating the real-time total resistance is: R1=U1÷I1; where R1 is the real-time total resistance, U1 is the real-time acquired current, and I1 is the real-time acquired voltage. The real-time total resistance is divided into contact resistance and other resistances, labeled as real-time contact resistance and real-time line resistance, respectively. The specific numerical relationship of real-time line resistance at different temperatures is denoted as temperature-line resistance relationship. Based on the temperature-line resistance relationship, the specific value of the real-time line resistance at the real-time detection temperature is obtained and identified as the real-time line correction resistance; Obtain the difference between the real-time total resistance and the real-time line correction resistance, and label it as the real-time correction contact resistance.
[0010] Furthermore, S400 includes the following sub-steps: When the contact resistance is normal under the same temperature, the minimum and maximum values of the real-time corrected contact resistance are obtained and identified as the first historical reference value and the second historical reference value, respectively. Obtain the first and second historical baseline values corresponding to different temperatures.
[0011] Furthermore, S400 also includes the following sub-steps: A Cartesian coordinate system is established with temperature as the horizontal axis and the first historical baseline value as the vertical axis, and this system is marked as the first baseline coordinate system. The coordinate points where the temperature and the corresponding first historical baseline value are respectively the x-axis and y-axis are marked as the first baseline coordinate points; The first reference coordinate point is plotted in the first reference coordinate system, and then all the first reference coordinate points are fitted with a function to obtain a function, which is marked as the first reference function.
[0012] Furthermore, S400 also includes the following sub-steps: A Cartesian coordinate system is established with temperature as the horizontal axis and the second historical baseline value as the vertical axis, and this system is marked as the second baseline coordinate system. The coordinate points where the temperature and the corresponding second historical baseline value are respectively the x-axis and y-axis are marked as the second baseline coordinate points; The second reference coordinate points are plotted in the second reference coordinate system. Then, all the second reference coordinate points are fitted with a function to obtain a function, which is then labeled as the second reference function.
[0013] Furthermore, S500 includes the following sub-steps: The real-time detected temperature is substituted into the first reference function and the second reference function respectively to obtain the value, which is identified as the first contact resistance reference value and the second contact resistance reference value respectively. Determine whether the real-time corrected contact resistance is within the range of the first contact resistance reference value to the second contact resistance reference value. If it is, it indicates that the contact resistance to be tested is normal; if it is not, it indicates that the contact resistance to be tested is abnormal.
[0014] The beneficial effects of this invention are as follows: This invention acquires an infrared image of the contact resistance to be detected, which is then identified as a real-time resistance infrared image; converts the real-time resistance infrared image into a real-time resistance infrared grayscale image, and obtains a real-time resistance region based on the real-time resistance infrared grayscale image; constructs a first detection region based on the real-time resistance region; obtains a real-time grayscale reference value based on the first detection region; obtains a real-time detection temperature based on the real-time grayscale reference value; obtains a real-time corrected contact resistance based on data collected in the brush-grip grounding system and the real-time detection temperature; obtains a first historical reference value and a second historical reference value based on normal contact resistance operating data; and obtains a first reference function and a second reference function based on the first historical reference value and the second historical reference value. The real-time detection temperature, real-time corrected contact resistance, first reference function, and second reference function are used to determine whether the contact resistance to be detected is abnormal. The advantage lies in obtaining a suitable temperature representation value for the contact resistance and obtaining an abnormal threshold for the contact resistance based on the real-time detection temperature, thereby improving the accuracy of online abnormal contact resistance detection. The present invention obtains the real-time detection temperature based on the real-time grayscale comparison value. Its advantage lies in obtaining a suitable temperature representation value for the contact resistance and obtaining the abnormal threshold of the contact resistance based on the real-time detection temperature, thereby improving the accuracy of online abnormal detection of contact resistance. Attached Figure Description
[0015] Figure 1 This is a flowchart illustrating the steps of the method of the present invention; Figure 2 This is a schematic diagram of the first unit rectangle and the first detection area of the present invention; Figure 3 This is a schematic diagram of the first reference function of the present invention; Figure 4 This is a schematic diagram of the second reference function of the present invention. Detailed Implementation
[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0017] Example 1, please refer to Figure 1 As shown, this application provides an online abnormal contact resistance detection method for a brush-grip grounding system, comprising the following steps: S100: Acquire an infrared image of the contact resistance to be detected, and label it as a real-time resistance infrared image; convert the real-time resistance infrared image into a real-time resistance infrared grayscale image, and obtain the real-time resistance region based on the real-time resistance infrared grayscale image; step S100 includes the following sub-steps: S101, wherein the real-time resistance infrared image is a white-hot infrared image; the real-time resistance infrared image is converted to grayscale to obtain a grayscale image, which is marked as the real-time resistance infrared grayscale image; the contact resistance area in the real-time resistance infrared grayscale image is marked as the real-time resistance area; the white-hot infrared image means that the higher the heat, the higher the brightness, that is, the larger the grayscale value; it is convenient to obtain the temperature of the contact resistance area.
[0018] S200: Construct a first detection area based on the real-time resistance area; obtain a real-time grayscale comparison value based on the first detection area; obtain the real-time detection temperature based on the real-time grayscale comparison value; Step S200 includes the following sub-steps: S201, Establish a plane rectangular coordinate system and label it as the first plane coordinate system; S202, obtain the X-axis of the first planar coordinate system and label it as the first X-axis; obtain the Y-axis of the first planar coordinate system and label it as the first Y-axis; obtain the first quadrant of the first planar coordinate system and label it as the first target quadrant; S203, in the first target quadrant, establish two sets of parallel straight lines, labeled as the first parallel line segments; make the adjacent and parallel first parallel line segments spaced by a first distance, one set of first parallel line segments parallel to the first X-axis, and the other set of first parallel line segments parallel to the first Y-axis; in order to establish the first unit rectangle, it is convenient to divide the real-time resistance area into the first unit rectangle, and convenient to obtain the grayscale representation value of the contact resistance area, for example, the first distance is 2mm; S204, obtain the unit rectangle between the two sets of first parallel line segments, and label it as the first unit rectangle; S205, place the real-time resistance region in the first target quadrant, and ensure that the entire real-time resistance region is within the first unit rectangle; obtain the area where the real-time resistance region intersects with the first unit rectangle, and mark it as the first detection area; For practical applications, please refer to Figure 2 As shown, the first unit rectangle and the first detection area are obtained; S206, Obtain the area of any first detection region and label it as the first detection area; Obtain the area of the first unit rectangle and label it as the first unit area; For practical applications, please refer to Figure 2 The diagram shows how to obtain a rectangle with a first unit rectangle size of 2mm. Therefore, the area of the first unit rectangle is 4mm². 2 If a first detection region intersects completely with a first unit rectangle, then the first detection area is 4 mm. 2 If the edge of the real-time resistance region does not occupy the entire first unit rectangle, then the first detection area is less than 4 mm². 2 ; S207, calculate the first reference value for each first detection area as: D1=S1÷S2; where D1 is the first reference value for a first detection area, S1 is the first detection area of the corresponding first detection area, and S2 is the first unit area; In practical applications, for example, the first reference value for each first detection region is calculated as: D1 = 4 ÷ 4 = 1; S208, acquire the grayscale value of the pixel in the real-time resistive infrared grayscale image and mark it as the first grayscale value; acquire a first number of first grayscale values in any first detection area and mark them as the first detected grayscale value; conveniently and quickly acquire grayscale values without calculating the grayscale value of each pixel in the image, for example, the first number is 1000; S209, calculate the first weight gray value of each first detection region as: Q1=D1×H1; where Q1 is the first weight gray value of a first detection region; H1 is the first detection gray value; In practical applications, for example, if the first weight gray value of the first detection region is Q1 = 1 × 71, then the first weight gray value is 71. S210, obtain the sum of all first reference values and mark it as the first calculated value; obtain the sum of all first weight grayscale values and mark it as the second calculated value; S211, calculate the real-time grayscale reference value as: H2=J2÷J1; where H2 is the real-time grayscale reference value, J1 is the first calculated value, and J2 is the second calculated value; quickly and accurately obtain the grayscale mean of the contact resistance area; conveniently and quickly obtain grayscale values without calculating the grayscale value of each pixel in the image, the real-time grayscale reference value is the calculated real-time resistance area grayscale representation value; In practical applications, for example, the real-time grayscale comparison value is calculated as: H2 = 11520 ÷ 160 = 72.
[0019] S212, obtain the temperature relationship corresponding to each gray value in the real-time resistive infrared grayscale image and mark it as grayscale temperature correspondence; because the higher the temperature, the brighter the grayscale image, that is, the larger the grayscale value, there is a grayscale temperature correspondence. S213. According to the gray-scale temperature correspondence, obtain the temperature corresponding to the real-time gray-scale reference value and mark it as the real-time detection temperature. In practical applications, if the real-time grayscale reference value of 72 corresponds to 50℃, then the real-time detection temperature is 50℃.
[0020] S300, obtain the real-time corrected contact resistance based on the data collected in the brush-grip grounding system and the real-time detected temperature; step S300 includes the following sub-steps: S301: Obtain the current in the brush grip grounding system and mark it as real-time current acquisition; obtain the voltage in the brush grip grounding system and mark it as real-time voltage acquisition. S302, the total circuit resistance in the brush-grip grounding system is identified as the real-time total resistance; the formula for calculating the real-time total resistance is: R1=U1÷I1; where R1 is the real-time total resistance, U1 is the real-time acquired current, and I1 is the real-time acquired voltage; the real-time total resistance is divided into contact resistance and other resistances, which are identified as real-time contact resistance and real-time line resistance respectively; the brush-grip grounding system has not only real-time contact resistance, so the real-time total resistance must be divided. S303, the specific numerical relationship of the real-time line resistance at different temperatures, is identified as the temperature-line resistance relationship; the real-time line resistance is a stable resistance, hence the existence of the temperature-line resistance relationship. S304, based on the temperature-line resistance relationship, obtains the specific value of the real-time line resistance at the real-time detection temperature, and identifies it as the real-time line correction resistor; S305, obtain the difference between the real-time total resistance and the real-time line correction resistance, and mark it as the real-time correction contact resistance; In practical applications, the real-time current is 0.02A and the real-time voltage is 1.86mV; therefore, the formula for calculating the real-time total resistance is: R1=1.86÷0.02=93μΩ; the real-time temperature is 50℃, and the corresponding real-time line correction resistance is 33μΩ, so the real-time correction contact resistance is 93-33=60μΩ.
[0021] S400: Obtain a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtain a first reference function and a second reference function based on the first historical reference value and the second historical reference value; step S400 includes the following sub-steps: S401, when the contact resistance is normal under the same temperature, the minimum and maximum values of the real-time corrected contact resistance are obtained and identified as the first historical reference value and the second historical reference value, respectively. S402, obtain the first historical reference value and the second historical reference value corresponding to different temperatures; S403, with temperature as the horizontal axis and the first historical reference value as the vertical axis, establish a plane rectangular coordinate system, which is marked as the first reference coordinate system; S404, mark the coordinate points where the temperature and the corresponding first historical reference value are the x-axis and y-axis, respectively, as the first reference coordinate points; S405, plot the first reference coordinate points in the first reference coordinate system, and then perform function fitting on all the first reference coordinate points to obtain a function, which is marked as the first reference function; this facilitates the accurate acquisition of the minimum value of normal contact resistance corresponding to different temperatures; For practical applications, please refer to Figure 3 The diagram shown illustrates the acquisition of the first benchmark function. S406. A Cartesian coordinate system is established with temperature as the horizontal axis and the second historical reference value as the vertical axis. This system is marked as the second reference coordinate system. S407, mark the coordinate points where the temperature and the corresponding second historical reference value are the x-axis and y-axis, respectively, as the second reference coordinate points; S408: Plot the second reference coordinate points in the second reference coordinate system, and then perform function fitting on all the second reference coordinate points to obtain a function, which is marked as the second reference function; this facilitates the accurate acquisition of the maximum value of the normal contact resistance corresponding to different temperatures; For practical applications, please refer to Figure 4 The diagram shown illustrates the acquisition of the second benchmark function.
[0022] S500 involves real-time temperature detection, real-time correction of contact resistance, and determination of whether the contact resistance to be detected is abnormal using a first reference function and a second reference function. Step S500 includes the following sub-steps: S501, substitute the real-time detected temperature into the first reference function and the second reference function respectively to obtain the values, which are respectively identified as the first contact resistance reference value and the second contact resistance reference value; S502, determine whether the real-time corrected contact resistance is within the range of the first contact resistance reference value to the second contact resistance reference value. If it is, it means that the contact resistance to be detected is normal. If it is not, it means that the contact resistance to be detected is abnormal. In practical applications, the real-time detected temperature of 50℃ is substituted into the first and second reference functions to obtain values of 55μΩ and 73μΩ, respectively. Then, the first and second contact resistance reference values are 55μΩ and 73μΩ, respectively. If the real-time corrected contact resistance of 60μΩ is within the range of 55μΩ to 73μΩ, it indicates that the contact resistance to be tested is normal.
[0023] Example 2: An electronic device may include a processor, a communication interface, a memory, and a communication bus. The processor, communication interface, and memory communicate with each other via the communication bus. The memory stores computer-readable instructions. The processor can call the instructions in the memory. When the processor executes a computer-readable instruction, it performs steps as described in a method for online anomaly detection of contact resistance in a brush-grip grounding system, to achieve the following functions: acquiring an infrared image of the contact resistance to be detected and identifying it as a real-time resistance infrared image; converting the real-time resistance infrared image into a real-time resistance infrared grayscale image and obtaining a real-time resistance region based on the real-time resistance infrared grayscale image; constructing a first detection region based on the real-time resistance region; obtaining a real-time grayscale reference value based on the first detection region; obtaining a real-time detection temperature based on the real-time grayscale reference value; obtaining a real-time corrected contact resistance based on data collected in the brush-grip grounding system and the real-time detection temperature; obtaining a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtaining a first reference function and a second reference function based on the first historical reference value and the second historical reference value; and determining whether the contact resistance to be detected is abnormal based on the real-time detection temperature, the real-time corrected contact resistance, the first reference function, and the second reference function.
[0024] Furthermore, when the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0025] Example 3: This application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the online anomaly detection method for contact resistance in a brush-grip grounding system provided by the above methods. The method includes: acquiring an infrared image of the contact resistance to be detected and identifying it as a real-time resistance infrared image; converting the real-time resistance infrared image into a real-time resistance infrared grayscale image and obtaining a real-time resistance region based on the real-time resistance infrared grayscale image; constructing a first detection region based on the real-time resistance region; obtaining a real-time grayscale reference value based on the first detection region; obtaining a real-time detection temperature based on the real-time grayscale reference value; obtaining a real-time corrected contact resistance based on the data collected in the brush-grip grounding system and the real-time detection temperature; obtaining a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtaining a first reference function and a second reference function based on the first historical reference value and the second historical reference value; and determining whether the contact resistance to be detected is abnormal based on the real-time detection temperature, the real-time corrected contact resistance, the first reference function, and the second reference function.
[0026] Example 4: This application also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program performs the steps of the above-described online anomaly detection method for contact resistance in a brush-grip grounding system to achieve the following functions: acquiring an infrared image of the contact resistance to be detected and identifying it as a real-time resistance infrared image; converting the real-time resistance infrared image into a real-time resistance infrared grayscale image and obtaining a real-time resistance region based on the real-time resistance infrared grayscale image; constructing a first detection region based on the real-time resistance region; obtaining a real-time grayscale reference value based on the first detection region; obtaining a real-time detection temperature based on the real-time grayscale reference value; obtaining a real-time corrected contact resistance based on the data collected in the brush-grip grounding system and the real-time detection temperature; obtaining a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtaining a first reference function and a second reference function based on the first historical reference value and the second historical reference value; and determining whether the contact resistance to be detected is abnormal based on the real-time detection temperature, the real-time corrected contact resistance, the first reference function, and the second reference function.
[0027] Based on the above description of the embodiments, the embodiments of the present invention can be provided as methods, systems, or computer program products. Based on this understanding, the above technical solutions, in essence or in terms of their contribution to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or certain parts of the embodiments.
[0028] In the embodiments provided in this application, it should be understood that the disclosed system or method can be implemented in other ways. The embodiments described above are merely illustrative. For example, the division of modules or units is only a logical functional division, and there may be other division methods in actual implementation. Furthermore, multiple modules or units may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interfaces. The indirect coupling or communication connection between systems, modules, and units may be electrical, mechanical, or other forms.
[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A method for online anomaly detection of contact resistance in a brush-grip grounding system, characterized in that, Includes the following steps: S100: Acquire an infrared image of the contact resistance to be detected and label it as a real-time resistance infrared image; convert the real-time resistance infrared image into a real-time resistance infrared grayscale image and obtain the real-time resistance region based on the real-time resistance infrared grayscale image. S200: Construct a first detection area based on the real-time resistance area; obtain a real-time grayscale comparison value based on the first detection area; obtain the real-time detection temperature based on the real-time grayscale comparison value; S300 obtains real-time corrected contact resistance based on data collected in the brush grip grounding system and real-time temperature detection. S400: Obtain a first historical reference value and a second historical reference value based on normal contact resistance operating data; obtain a first reference function and a second reference function based on the first historical reference value and the second historical reference value; The S500 detects temperature in real time, corrects contact resistance in real time, and uses a first reference function and a second reference function to determine whether the contact resistance to be detected is abnormal.
2. The method for online anomaly detection of contact resistance in a brush-grip grounding system according to claim 1, characterized in that, S100 includes the following sub-steps: The real-time resistance infrared image is a white-heated infrared image; The real-time resistance infrared image is converted to grayscale to obtain a grayscale image, which is then labeled as the real-time resistance infrared grayscale image; the contact resistance area in the real-time resistance infrared grayscale image is then labeled as the real-time resistance area.
3. The method for online anomaly detection of contact resistance in a brush-grip grounding system according to claim 2, characterized in that, S200 includes the following sub-steps: Establish a Cartesian coordinate system and label it as the first plane coordinate system; Obtain the X-axis of the first planar coordinate system and label it as the first X-axis; Obtain the Y-axis of the first planar coordinate system and label it as the first Y-axis; Obtain the first quadrant of the first planar coordinate system and label it as the first target quadrant; In the first target quadrant, establish two sets of parallel straight lines, labeled as the first parallel line segments; make the adjacent and parallel first parallel line segments spaced by a first distance, with one set of first parallel line segments parallel to the first X-axis and the other set of first parallel line segments parallel to the first Y-axis; Obtain the unit rectangle between the two sets of first parallel line segments and label it as the first unit rectangle; Place the real-time resistance region in the first target quadrant, and ensure that the entire real-time resistance region is within the first unit rectangle; The area where the real-time resistance region intersects with the first unit rectangle is identified as the first detection region.
4. The method for online abnormal detection of contact resistance in a brush-grip grounding system according to claim 3, characterized in that, S200 also includes the following sub-steps: Obtain the area of any one of the first detection regions and label it as the first detection area; Get the area of the first unit rectangle and label it as the first unit area; The first reference value for each first detection region is calculated as: D1 = S1 ÷ S2; where D1 is the first reference value for a first detection region, S1 is the first detection area of the corresponding first detection region, and S2 is the first unit area. Obtain the grayscale value of each pixel in the real-time resistive infrared grayscale image and identify it as the first grayscale value; Obtain a first number of first grayscale values within any first detection region and identify them as first detection grayscale values; The first weight grayscale value of each first detection region is calculated as: Q1 = D1 × H1; where Q1 is the first weight grayscale value of a first detection region; and H1 is the first detection grayscale value. Obtain the sum of all first reference values and mark it as the first calculated value; Obtain the sum of all grayscale values of the first weight, and label it as the second calculated value; The real-time grayscale comparison value is calculated as follows: H2 = J2 ÷ J1; where H2 is the real-time grayscale comparison value, J1 is the first calculated value, and J2 is the second calculated value.
5. The method for online anomaly detection of contact resistance in a brush-grip grounding system according to claim 4, characterized in that, S200 also includes the following sub-steps: Obtain the temperature relationship corresponding to each gray value in the real-time resistive infrared grayscale image and mark it as the grayscale temperature correspondence. Based on the grayscale-temperature correspondence, the temperature corresponding to the real-time grayscale reference value is obtained and identified as the real-time detection temperature.
6. The method for online anomaly detection of contact resistance in a brush-grip grounding system according to claim 5, characterized in that, S300 includes the following sub-steps: Acquire the current in the brush gripper grounding system and mark it as real-time acquired current; Acquire the voltage in the brush grip grounding system and mark it as real-time acquired voltage; The total resistance of the loop in the brush-grip grounding system is labeled as the real-time total resistance. The formula for calculating the real-time total resistance is: R1=U1÷I1; where R1 is the real-time total resistance, U1 is the real-time acquired current, and I1 is the real-time acquired voltage. The real-time total resistance is divided into contact resistance and other resistances, labeled as real-time contact resistance and real-time line resistance, respectively. The specific numerical relationship of real-time line resistance at different temperatures is denoted as temperature-line resistance relationship. Based on the temperature-line resistance relationship, the specific value of the real-time line resistance at the real-time detection temperature is obtained and identified as the real-time line correction resistance; Obtain the difference between the real-time total resistance and the real-time line correction resistance, and label it as the real-time correction contact resistance.
7. The method for online anomaly detection of contact resistance in a brush-grip grounding system according to claim 6, characterized in that, S400 includes the following sub-steps: When the contact resistance is normal under the same temperature, the minimum and maximum values of the real-time corrected contact resistance are obtained and identified as the first historical reference value and the second historical reference value, respectively. Obtain the first and second historical baseline values corresponding to different temperatures.
8. The method for online abnormal detection of contact resistance in a brush-grip grounding system according to claim 7, characterized in that, S400 also includes the following sub-steps: A Cartesian coordinate system is established with temperature as the horizontal axis and the first historical baseline value as the vertical axis, and this system is marked as the first baseline coordinate system. The coordinate points where the temperature and the corresponding first historical baseline value are respectively the x-axis and y-axis are marked as the first baseline coordinate points; The first reference coordinate point is plotted in the first reference coordinate system, and then all the first reference coordinate points are fitted with a function to obtain a function, which is marked as the first reference function.
9. The method for online abnormal detection of contact resistance in a brush-grip grounding system according to claim 8, characterized in that, S400 also includes the following sub-steps: A Cartesian coordinate system is established with temperature as the horizontal axis and the second historical baseline value as the vertical axis, and this system is marked as the second baseline coordinate system. The coordinate points where the temperature and the corresponding second historical baseline value are respectively the x-axis and y-axis are marked as the second baseline coordinate points; The second reference coordinate points are plotted in the second reference coordinate system. Then, all the second reference coordinate points are fitted with a function to obtain a function, which is then labeled as the second reference function.
10. The method for online abnormal detection of contact resistance in a brush-grip grounding system according to claim 9, characterized in that, S500 includes the following sub-steps: The real-time detected temperature is substituted into the first reference function and the second reference function respectively to obtain the value, which is identified as the first contact resistance reference value and the second contact resistance reference value respectively. Determine whether the real-time corrected contact resistance is within the range of the first contact resistance reference value to the second contact resistance reference value. If it is, it indicates that the contact resistance to be tested is normal; if it is not, it indicates that the contact resistance to be tested is abnormal.