Non-contact wire diameter measurement method based on fusion of laser radar and visual technology

Abstract

The invention discloses a non-contact wire diameter measurement method based on fusion of a laser radar and a visual technology, and relates to the technical field of non-contact wire diameter measurement, and the method comprises the following steps: obtaining a binarization threshold value based on a real-time electric wire image; acquiring a wire area based on the real-time wire image and the binarization threshold; acquiring a wire reference midpoint based on the wire region; obtaining a first offset mean value based on the wire reference midpoint; obtaining a second offset mean value based on the first offset mean value; acquiring a real-time radar distance and a real-time radar angle based on the second offset mean value and the laser radar monitoring device; based on the real-time radar distance and the real-time radar angle, a wire contour tangent plane point is obtained; obtaining the wire diameter of the high-voltage wire based on the wire contour section point; the method is used for solving the problems that an existing non-contact wire diameter measurement technology cannot completely adapt to wire diameter measurement of a high-voltage wire through a single visual technology or a laser radar technology, so that the precision is low, and the environmental adaptability is poor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-contact wire diameter measurement, in particular to a non-contact wire diameter measurement method based on the fusion of laser radar and visual technology. BACKGROUND

[0002] High-precision measurement of wire diameter is one of the core quality control links in many industrial fields such as power, communication and manufacturing, so it is necessary to measure the wire diameter.

[0003] The existing wire diameter measurement method is a contact measurement method, such as the patent application with the publication number CN109855585A, which discloses a wire diameter measurement device for cable products and a measurement method. The contact wire diameter measurement method has limitations in some scenarios, for example, high-voltage wires need to be coated with insulation, so the coating equipment needs to know the wire diameter of the high-voltage wire in advance in order to use the corresponding glue head. It is very inconvenient to measure the wire diameter of the live wire by contact, and it requires manual climbing and tower hanging, which is dangerous. Therefore, a non-contact wire diameter measurement method is proposed, which includes visual technology and laser radar technology. Visual technology and laser radar technology have natural complementarity: visual technology provides high-resolution texture and contour context information, while laser radar provides accurate and stable three-dimensional spatial coordinates. The existing non-contact wire diameter measurement technology cannot fully adapt to the wire diameter measurement of high-voltage wires through a single visual technology or laser radar technology, resulting in low precision and poor environmental adaptability. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the prior art. Based on the unmanned aerial vehicle, the high-voltage wire image is obtained and marked as a real-time wire image. Based on the real-time wire image, a binary threshold is obtained. Based on the real-time wire image and the binary threshold, a wire region is obtained. Based on the wire region, a wire reference midpoint is obtained. Based on the wire reference midpoint, a first offset mean is obtained. Based on the first offset mean, a second offset mean is obtained. Based on the second offset mean and the laser radar monitoring device, a real-time radar distance and a real-time radar angle are obtained. Based on the real-time radar distance and the real-time radar angle, a wire contour cross-section point is obtained. Based on the wire contour cross-section point, the wire diameter of the high-voltage wire is obtained, to solve the problem that the existing non-contact wire diameter measurement technology cannot fully adapt to the wire diameter measurement of high-voltage wires through a single visual technology or laser radar technology, resulting in low precision and poor environmental adaptability.

[0005] To achieve the above-mentioned purpose, the present application provides a non-contact wire diameter measurement method based on the fusion of laser radar and visual technology, which includes the following steps:

[0006] Based on the unmanned aerial vehicle, the high-voltage wire image is obtained and marked as a real-time wire image.

[0007] Obtaining a binary threshold value based on the real-time power line image;

[0008] Obtaining a power line region based on the real-time power line image and the binary threshold value;

[0009] Obtaining a power line reference midpoint based on the power line region;

[0010] Obtaining a first offset mean value based on the power line reference midpoint;

[0011] Obtaining a second offset mean value based on the first offset mean value;

[0012] Obtaining a real-time radar distance and a real-time radar angle based on the second offset mean value and the laser radar monitoring device;

[0013] Obtaining a power line profile cross-section point based on the real-time radar distance and the real-time radar angle;

[0014] Obtaining a line diameter of the high-voltage power line based on the power line profile cross-section point.

[0015] Further, obtaining the binary threshold value based on the real-time power line image includes the following sub-steps:

[0016] Obtaining a real-time power line grayscale image by performing grayscale processing on the real-time power line image;

[0017] Marking the grayscale value of the pixel point in the real-time power line grayscale image as a real-time power line grayscale value;

[0018] Dividing the range of the real-time power line grayscale value in the real-time power line grayscale image into a first number of equal range intervals, and marking as a divided range interval;

[0019] Obtaining the frequency of the real-time power line grayscale value in each divided range interval, and marking as a divided range frequency;

[0020] Drawing a histogram with the real-time power line grayscale value as the X-axis, the divided range frequency as the Y-axis, and the divided range interval as the interval of the histogram, and marking as a grayscale distribution histogram.

[0021] Further, obtaining the binary threshold value based on the real-time power line image also includes the following sub-steps:

[0022] In the grayscale distribution histogram, marking the divided range interval greater than the divided range frequency on the left and right sides as a first peak top range;

[0023] Obtaining a first peak top range with the smallest real-time power line grayscale value in the middle of the first peak top range, and marking as a first threshold value range;

[0024] Obtaining a first peak top range with the largest real-time power line grayscale value in the middle of the first peak top range, and marking as a second threshold value range;

[0025] Obtaining a division range interval with the minimum frequency in the range between the first threshold range and the second threshold range, and marking it as a third threshold range;

[0026] Obtaining a middle value of the third threshold range, and marking it as a binary threshold value.

[0027] Further, obtaining the power line region based on the real-time power line image and the binary threshold value comprises the following sub-steps:

[0028] Setting the real-time power line grayscale value less than or equal to the binary threshold value as 0 and the real-time power line grayscale value greater than the binary threshold value as 255 in the real-time power line grayscale image to obtain a real-time power line binary image;

[0029] Marking a continuous region with a grayscale value of 0 in the real-time power line binary image as a power line region.

[0030] Further, obtaining the power line reference midpoint based on the power line region comprises the following sub-steps:

[0031] Establishing a plane rectangular coordinate system, and marking it as a region division coordinate system; and placing any one power line region in the first quadrant of the region division coordinate system;

[0032] Starting from the Y-axis of the region division coordinate system and in the positive direction of the X-axis of the region division coordinate system, drawing a second number of parallel straight lines to the Y-axis of the region division coordinate system at equal intervals, and marking them as first division straight lines;

[0033] Obtaining a line segment intersected by the first division straight lines and the power line region, and marking it as a first intersection line segment;

[0034] Obtaining the midpoints of all the first intersection line segments, and marking them as power line reference midpoints.

[0035] Further, obtaining the first offset mean value based on the power line reference midpoints comprises the following sub-steps:

[0036] Fitting all the power line reference midpoints to obtain a function line, and marking it as a power line reference line;

[0037] Obtaining a point on the power line reference line that can be directly faced by a laser radar monitoring device on the unmanned aerial vehicle, and marking it as a power line monitoring point;

[0038] Starting from the power line monitoring point, drawing a third number of points to both sides of the power line reference line at equal intervals, and marking them as actual reference points;

[0039] Obtaining the distance from the laser radar monitoring point to the actual reference point based on the laser radar monitoring device on the unmanned aerial vehicle, and marking it as a first distance;

[0040] Obtaining the distance from the laser radar monitoring point to the power line monitoring point based on the laser radar monitoring device on the unmanned aerial vehicle, and marking it as a second distance;

[0041] Obtaining the absolute value of the difference between all second distances and first distances, and marking it as a first offset difference value;

[0042] Obtaining the mean value of all first offset difference values, and marking it as a first offset mean value.

[0043] Further, obtaining the second offset mean value based on the first offset mean value includes the following sub-steps:

[0044] The unmanned aerial vehicle flies in place, changes the direction of the unmanned aerial vehicle, the direction is the direction to the two sides of the power line reference line with the power line monitoring point as the midpoint, and obtains the first offset mean value corresponding to the real-time power line image and the new real-time power line image when changing the direction of the unmanned aerial vehicle, and marks it as a second offset mean value.

[0045] Further, based on the second offset mean value and the laser radar monitoring device, the real-time radar distance and the real-time radar angle are obtained, including the following sub-steps:

[0046] Obtaining the power line region, power line reference line and power line monitoring point corresponding to the minimum value of the first offset mean value and the second offset mean value, respectively, and marking them as the real-time monitoring region, the real-time monitoring line and the real-time monitoring point;

[0047] Making a tangent of the real-time monitoring line at the real-time monitoring point, and marking it as a real-time monitoring tangent;

[0048] Making a perpendicular line of the real-time monitoring tangent through the real-time monitoring point, and marking it as a real-time monitoring perpendicular line;

[0049] Obtaining the line segment intersected by the real-time monitoring perpendicular line and the real-time monitoring region, and marking it as a real-time intersection line segment;

[0050] Based on the laser radar monitoring device, obtaining the monitoring distance on the high-voltage power line corresponding to the real-time intersection line segment and the corresponding radar emission adjustment angle, and marking them as a real-time radar distance and a real-time radar angle, respectively.

[0051] Further, based on the real-time radar distance and the real-time radar angle, the power line profile cross-section point is obtained, including the following sub-steps:

[0052] Establishing a plane rectangular coordinate system with the laser radar monitoring point as the origin and the direction of the power line monitoring point as the positive direction of the X axis, and marking it as a fitting reference coordinate system;

[0053] Obtaining the first horizontal coordinate value: F1=cos(a)×H; wherein F1 is the first horizontal coordinate value, a is the real-time radar angle, and H is the real-time radar distance;

[0054] The first longitudinal coordinate value is obtained as: F2=sin(a)×H; wherein F2 is the first longitudinal coordinate value;

[0055] All points (F1, F2) are marked as wire profile section points.

[0056] Further, the wire diameter of the high-voltage wire is obtained based on the wire profile section points, comprising the following sub-steps:

[0057] The wire profile fitting function is set as: (Q1-w1) 2 +(Q2-w2) 2 =r 2 ; wherein Q1 and Q2 are the horizontal and vertical values of the wire profile fitting function, and w1, w2 and r are constants of the wire profile fitting function;

[0058] The wire profile section points are fitted with the wire profile fitting function to obtain the specific value of r;

[0059] 2×r is regarded as the wire diameter of the high-voltage wire.

[0060] The present application has the following advantages: the present application obtains the high-voltage wire image based on the unmanned aerial vehicle, and marks it as the real-time wire image; the binary threshold is obtained based on the real-time wire image; the wire region is obtained based on the real-time wire image and the binary threshold; the wire reference midpoint is obtained based on the wire region; the first offset mean value is obtained based on the wire reference midpoint; the second offset mean value is obtained based on the first offset mean value; the real-time radar distance and the real-time radar angle are obtained based on the second offset mean value and the laser radar monitoring device; the wire profile section points are obtained based on the real-time radar distance and the real-time radar angle; and the wire diameter of the high-voltage wire is obtained based on the wire profile section points, which has the advantages of combining the visual technology or the laser radar technology, being more suitable for the wire diameter measurement of the high-voltage wire, and improving the precision and the environmental adaptability.

[0061] The present application obtains the real-time radar distance and the real-time radar angle based on the second offset mean value and the laser radar monitoring device, which has the advantage of obtaining the profile of the tangent plane of the high-voltage wire, so that the subsequent wire diameter measurement is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 The step flow chart of the method of the present application;

[0063] Figure 2 The schematic diagram of the gray scale distribution histogram of the present application;

[0064] Figure 3 The schematic diagram of the wire reference line of the present application;

[0065] Figure 4 The pulse width scatter plot of the present application. DETAILED DESCRIPTION

[0066] 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.

[0067] Example 1, please refer to Figure 1 As shown, this application provides a non-contact wire diameter measurement method based on the fusion of lidar and vision technology, including the following steps:

[0068] Step S1: Acquire images of high-voltage power lines using a drone and mark them as real-time power line images; fly the drone near the high-voltage power line to be detected, and make the background the sky when acquiring real-time power line images to facilitate the acquisition of the high-voltage power line portion.

[0069] Step S2, obtain the binarization threshold based on the real-time power line image; Step S2 includes the following sub-steps:

[0070] Step S201: Perform grayscale processing on the real-time power line image to obtain a real-time power line grayscale image;

[0071] Step S202: Mark the grayscale values ​​of the pixels in the real-time wire grayscale image as the real-time wire grayscale values;

[0072] Step S203: Divide the range of real-time wire grayscale values ​​in the real-time wire grayscale image into a first number of equal range intervals, and mark them as divided range intervals; the first number of divided range intervals is for observing the distribution of real-time wire grayscale values, for example, the first number is 8;

[0073] Step S204: Obtain the frequency of real-time wire grayscale values ​​within each divided range interval and mark it as the frequency of the divided range;

[0074] Step S205: A histogram is drawn with the real-time wire grayscale value as the X-axis, the frequency of the range division as the Y-axis, and the interval of the range division as the interval of the histogram. This histogram is then marked as a grayscale distribution histogram.

[0075] For practical applications, please refer to Figure 2 As shown, the obtained grayscale distribution histogram.

[0076] Step S206: In the grayscale distribution histogram, the interval of the division range with a frequency greater than that of the left and right sides is marked as the first peak range.

[0077] Step S207: Obtain the first peak range with the smallest real-time wire grayscale value in the middle of the first peak range, and mark it as the first threshold range;

[0078] Step S208: Obtain the first peak range with the largest real-time wire grayscale value in the middle of the first peak range, and mark it as the second threshold range;

[0079] Step S209: Obtain the interval with the smallest frequency of division between the first threshold range and the second threshold range, and mark it as the third threshold range;

[0080] Step S210: Obtain the median value of the third threshold range and mark it as the binarized threshold;

[0081] For practical applications, please refer to Figure 2 As shown, the first threshold range is 31 to 63, the second threshold range is 191 to 223, and the third threshold range is 95 to 127. The median value of the third threshold range is 111, so the binarization threshold is 111.

[0082] Step S3: Obtain the wire region based on the real-time wire image and a binarized threshold; Step S3 includes the following sub-steps:

[0083] Step S301: In the real-time power line grayscale image, set the grayscale values ​​of real-time power lines that are less than or equal to the binarization threshold to 0, and set the grayscale values ​​of real-time power lines that are greater than the binarization threshold to 255 to obtain a real-time power line binarized image; because high-voltage power lines have a black outer sheath, the grayscale value of black is low, while the grayscale value of the background sky is high, so a real-time power line binarized image can be obtained, making it convenient to obtain the high-voltage power lines in the image;

[0084] Step S302: Mark the continuous area with grayscale value of 0 in the real-time wire binarized image as the wire area; because the high-voltage wire has a black outer sheath, the grayscale value of black is low, while the grayscale value of the background sky is high, so the continuous area with grayscale value of 0 is regarded as the wire area.

[0085] Step S4: Obtain the reference midpoint of the wire based on the wire region; Step S4 includes the following sub-steps:

[0086] Step S401: Establish a Cartesian coordinate system and mark it as the region division coordinate system; place any wire region in the first quadrant of the region division coordinate system;

[0087] Step S402: Starting from the Y-axis of the region division coordinate system and with the direction being the positive direction of the X-axis of the region division coordinate system, draw a second number of equally spaced straight lines parallel to the Y-axis of the region division coordinate system, and mark them as the first division lines; the first division lines are used to analyze the center line of the high-voltage power line; for example, the second number is 17.

[0088] Step S403: Obtain the line segment that intersects the first dividing line with the wire area and mark it as the first intersecting line segment;

[0089] Step S404: Obtain the midpoints of all first intersecting line segments and mark them as wire reference midpoints; the wire reference midpoints are points on the center line of the wire in the obtained image; this facilitates the acquisition of wire reference lines.

[0090] For practical applications, please refer to Figure 3 As shown, the obtained reference midpoint of the wire.

[0091] Step S5: Obtain the first offset mean based on the reference midpoint of the wire; Step S5 includes the following sub-steps:

[0092] Step S501: Perform function fitting on all reference midpoints of the power lines to obtain function lines, which are then marked as power line reference lines; the power line reference lines are the center lines of the high-voltage power lines obtained from the image.

[0093] For practical applications, please refer to Figure 3 As shown, the obtained wire reference line.

[0094] Step S502: Obtain a point on the power line reference line that the lidar monitoring device on the UAV can directly face; mark it as the power line monitoring point.

[0095] Step S503: Starting from the power line monitoring point, draw a third number of equally spaced points on both sides of the power line reference line and mark them as actual reference points; set a third number of actual reference points to make the obtained lidar the outline of the vertical cross-section of the high-voltage power line diameter, so as to obtain an accurate wire diameter, for example, the third number is 20.

[0096] Step S504: Obtain the distance from the lidar monitoring point to the actual reference point based on the lidar monitoring device on the UAV, and mark it as the first distance;

[0097] Step S505: Obtain the distance from the lidar monitoring point to the power line monitoring point based on the lidar monitoring device on the UAV, and mark it as the second distance;

[0098] Step S506: Obtain the absolute values ​​of all differences between the second distance and the first distance, and mark them as the first offset difference;

[0099] Step S507: Obtain the mean of all first offset differences and mark it as the first offset mean; in order to obtain the vertical cross-section of the high-voltage power line obtained by the lidar, the accurate wire diameter is obtained; the smaller the first offset mean, the closer it is to the outline of the vertical cross-section of the high-voltage power line obtained by the lidar; ideally, when the first offset mean is 0, the outline of the vertical cross-section of the high-voltage power line obtained by the lidar is the same.

[0100] Step S6: Obtain the second offset mean based on the first offset mean; Step S6 includes the following sub-steps:

[0101] Step S601: The drone flies in place and changes its orientation. The direction is from the wire monitoring point as the midpoint to both sides of the wire reference line. When changing the drone's orientation, the first offset mean value corresponding to the real-time wire image and the new real-time wire image is obtained and marked as the second offset mean value. The angle is adjusted so that the drone is facing the vertical cross-section of the wire diameter, so that the obtained wire diameter is more accurate.

[0102] Step S7: Obtain the real-time radar distance and real-time radar angle based on the second offset mean and the lidar monitoring device; Step S7 includes the following sub-steps:

[0103] Step S701: Obtain the wire region, wire reference line, and wire monitoring point corresponding to the minimum value between the first offset mean and the second offset mean, and mark them as real-time monitoring region, real-time monitoring line, and real-time monitoring point, respectively.

[0104] Step S702: Draw the tangent line of the real-time monitoring line at the real-time monitoring point and mark it as the real-time monitoring tangent line;

[0105] Step S703: Draw a perpendicular line from the real-time monitoring point to the real-time monitoring tangent and mark it as the real-time monitoring perpendicular line;

[0106] Step S704: Obtain the line segment that intersects the real-time monitoring vertical line and the real-time monitoring area, and mark it as the real-time intersecting line segment;

[0107] Step S705: Based on the lidar monitoring device, obtain the real-time monitoring distance on the high-voltage power line corresponding to the intersecting line segment and the corresponding radar transmission adjustment angle, and mark them as real-time radar distance and real-time radar angle respectively; the real-time radar distance and real-time radar angle can be easily converted into coordinate points;

[0108] For practical applications, please refer to Figure 4 As shown, the real-time radar distance is H and the real-time radar angle is a.

[0109] Step S8: Obtain the wire profile cross-section points based on real-time radar distance and real-time radar angle; Step S8 includes the following sub-steps:

[0110] Step S801: Establish a Cartesian coordinate system with the lidar monitoring point as the origin and the direction towards the power line monitoring point as the positive X-axis, and mark it as the fitting reference coordinate system;

[0111] Step S802, obtain the first horizontal coordinate value as: F1=cos(a)×H; where F1 is the first horizontal coordinate value, a is the real-time radar angle, and H is the real-time radar distance;

[0112] Step S803, obtain the first ordinate value as: F2 = sin(a) × H; where F2 is the first ordinate value;

[0113] Step S804: Mark all points (F1, F2) as wire profile sectional points; wire profile sectional points are points on the profile of the vertical section of the high-voltage wire; this facilitates the acquisition of wire diameter.

[0114] For practical applications, please refer to Figure 4 As shown, the obtained wire profile cross-section points.

[0115] Step S9: Obtain the wire diameter of the high-voltage wire based on the wire profile cross-section points; Step S9 includes the following sub-steps:

[0116] Step S901: Set the wire profile fitting function as: (Q1-w1) 2 +(Q2-w2) 2 =r 2 Where Q1 and Q2 are the horizontal and vertical axis values ​​of the wire profile fitting function, respectively, and w1, w2, and r are constants of the wire profile fitting function; the cross-section of a high-voltage wire is usually circular, so the wire profile fitting function is set as: (Q1-w1). 2 +(Q2-w2) 2 =r 2 ;

[0117] Step S902: Fit the wire profile section points with the wire profile fitting function to obtain the specific value of r.

[0118] Step S903: Consider 2×r as the diameter of the high-voltage wire; the cross-section of the high-voltage wire is usually circular, so 2×r can be considered as the diameter of the high-voltage wire.

[0119] For practical applications, please refer to Figure 4 As shown, the obtained r is 9mm, so the wire diameter of the high-voltage wire is 18mm.

[0120] Example 2: This application also provides an electronic device, which may include: a processor, a communication interface, a memory, and a communication bus, wherein the processor, communication interface, and memory communicate with each other through the communication bus. The memory stores computer-readable instructions, and the processor can call the instructions in the memory. When the computer-readable instructions are executed by the processor, steps such as those in the non-contact wire diameter measurement method based on the fusion of lidar and vision technology are performed to achieve the following functions: acquiring high-voltage power line images based on a UAV and marking them as real-time power line images; acquiring a binarized threshold based on the real-time power line images; acquiring a power line region based on the real-time power line images and the binarized threshold; acquiring a reference midpoint of the power line based on the power line region; acquiring a first offset mean based on the reference midpoint of the power line; acquiring a second offset mean based on the first offset mean; acquiring real-time radar distance and real-time radar angle based on the second offset mean and a lidar monitoring device; acquiring power line contour section points based on the real-time radar distance and real-time radar angle; and acquiring the wire diameter of the high-voltage power line based on the power line contour section points.

[0121] 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.

[0122] 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 non-contact wire diameter measurement method based on the fusion of lidar and vision technology provided by the above methods. The method includes: acquiring a high-voltage power line image based on a UAV and marking it as a real-time power line image; acquiring a binarization threshold based on the real-time power line image; acquiring a power line region based on the real-time power line image and the binarization threshold; acquiring a reference midpoint of the power line based on the power line region; acquiring a first offset mean based on the reference midpoint of the power line; acquiring a second offset mean based on the first offset mean; acquiring a real-time radar distance and a real-time radar angle based on the second offset mean and a lidar monitoring device; acquiring a wire profile section point based on the real-time radar distance and the real-time radar angle; and acquiring the wire diameter of the high-voltage power line based on the wire profile section point.

[0123] 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 non-contact wire diameter measurement method based on the fusion of lidar and vision technologies to achieve the following functions: acquiring high-voltage power line images based on a drone and marking them as real-time power line images; acquiring a binarization threshold based on the real-time power line images; acquiring a power line region based on the real-time power line images and the binarization threshold; acquiring a reference midpoint of the power line based on the power line region; acquiring a first offset mean based on the reference midpoint; acquiring a second offset mean based on the first offset mean; acquiring real-time radar distance and real-time radar angle based on the second offset mean and a lidar monitoring device; acquiring power line contour section points based on the real-time radar distance and real-time radar angle; and acquiring the wire diameter of the high-voltage power line based on the power line contour section points.

[0124] 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.

[0125] 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.

[0126] 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 non-contact wire diameter measurement method based on the fusion of lidar and vision technology, characterized in that, Includes the following steps: Images of high-voltage power lines acquired by drones are labeled as real-time power line images. Binarization threshold is obtained based on real-time power line images; The wire region is obtained based on real-time wire images and binarization thresholds; Obtain the reference midpoint of the wire based on the wire region; The first offset mean is obtained based on the reference midpoint of the wire; The second offset mean is obtained based on the first offset mean; Real-time radar distance and real-time radar angle are obtained based on the second offset mean and the lidar monitoring device; The wire profile cross-section points are obtained based on real-time radar distance and real-time radar angle. The diameter of a high-voltage power line is obtained based on the cross-sectional points of the power line profile.

2. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 1, characterized in that, Obtaining a binarization threshold based on real-time power line images includes the following sub-steps: The real-time power line image is converted to grayscale to obtain a real-time power line grayscale image. Mark the grayscale values ​​of pixels in the real-time wire grayscale image as the real-time wire grayscale values; Divide the range of real-time wire grayscale values ​​in the real-time wire grayscale image into a first number of equal range intervals, and mark them as the divided range intervals; Obtain the frequency of real-time wire grayscale values ​​within each defined range interval and mark it as the range frequency; A histogram is plotted with the real-time grayscale value of the wire on the X-axis, the frequency of the range division on the Y-axis, and the intervals of the range division as the histogram intervals. This histogram is then labeled as a grayscale distribution histogram.

3. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 2, characterized in that, Obtaining a binarization threshold based on real-time power line images also includes the following sub-steps: In the gray-scale distribution histogram, the interval of the division range with a frequency greater than that of the left and right sides is marked as the first peak range; The range of the first peak with the smallest real-time wire grayscale value in the middle of the first peak range is identified and marked as the first threshold range. The range of the first peak with the highest real-time wire grayscale value in the middle of the first peak range is marked as the second threshold range; The interval with the smallest frequency of division between the first threshold range and the second threshold range is identified and marked as the third threshold range. Obtain the median value of the third threshold range and mark it as the binarized threshold.

4. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 3, characterized in that, Obtaining the wire region based on real-time wire images and binarization thresholding includes the following sub-steps: In the real-time wire grayscale image, the grayscale values ​​of real-time wires that are less than or equal to the binarization threshold are set to 0, and the grayscale values ​​of real-time wires that are greater than the binarization threshold are set to 255 to obtain the real-time wire binarization image. In the real-time binary image of power lines, continuous areas with grayscale values ​​of 0 are marked as power line regions.

5. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 4, characterized in that, Obtaining the reference midpoint of a wire based on a wire region includes the following sub-steps: Establish a Cartesian coordinate system, labeled as the region division coordinate system; place any wire region in the first quadrant of the region division coordinate system; Starting with the Y-axis of the region division coordinate system and with the direction being the positive direction of the X-axis of the region division coordinate system, draw a second number of equally spaced straight lines parallel to the Y-axis of the region division coordinate system, and mark them as the first dividing lines; Obtain the line segment that intersects the first dividing line with the wire region, and mark it as the first intersecting line segment; Obtain the midpoints of all first intersecting line segments and mark them as the reference midpoints of the wires.

6. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 5, characterized in that, Obtaining the first offset mean value based on the reference midpoint of the wire includes the following sub-steps: The function lines are obtained by fitting a function to the midpoints of all reference wires and marked as wire reference lines. The lidar monitoring device on the drone can be pointed directly at a point on the power line reference line, and this point is marked as the power line monitoring point. Starting from the power line monitoring point, draw a third number of equally spaced points on both sides of the power line reference line, and mark them as actual reference points; The distance from the lidar monitoring point to the actual reference point is obtained based on the lidar monitoring device on the drone and marked as the first distance; The distance from the lidar monitoring point to the power line monitoring point is obtained using the lidar monitoring device on the drone and marked as the second distance; Obtain the absolute value of all differences between the second distance and the first distance, and mark it as the first offset difference; Get the mean of all first offset differences and label it as the first offset mean.

7. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 6, characterized in that, Obtaining the second offset mean based on the first offset mean includes the following sub-steps: The drone flies in place and changes its orientation. The direction is from the power line monitoring point as the midpoint to both sides of the power line reference line. When the drone changes its orientation, the first offset mean value corresponding to the real-time power line image and the new real-time power line image is obtained and marked as the second offset mean value.

8. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 7, characterized in that, Obtaining real-time radar distance and real-time radar angle based on the second offset mean and the lidar monitoring device includes the following sub-steps: Obtain the wire region, wire reference line, and wire monitoring point corresponding to the minimum value between the first offset mean and the second offset mean, and mark them as real-time monitoring region, real-time monitoring line, and real-time monitoring point, respectively. Draw the tangent line of the real-time monitoring line at the real-time monitoring point and mark it as the real-time monitoring tangent line; Draw a perpendicular line from the real-time monitoring point to the real-time monitoring tangent, and mark it as the real-time monitoring perpendicular line; Obtain the line segment that intersects the real-time monitoring vertical line and the real-time monitoring area, and mark it as the real-time intersecting line segment; The monitoring distance on the high-voltage power line corresponding to the intersecting line segment and the corresponding radar transmission adjustment angle are obtained in real time based on the lidar monitoring device, and are marked as real-time radar distance and real-time radar angle, respectively.

9. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 8, characterized in that, Obtaining the wire profile cross-section points based on real-time radar distance and real-time radar angle includes the following sub-steps: With the lidar monitoring point as the origin and the direction towards the power line monitoring point as the positive X-axis, a plane rectangular coordinate system is established and marked as the fitting reference coordinate system; The first horizontal coordinate value is obtained as: F1 = cos(a) × H; where F1 is the first horizontal coordinate value, a is the real-time radar angle, and H is the real-time radar distance. The first ordinate value is obtained as: F2 = sin(a) × H; where F2 is the first ordinate value; Mark all points (F1, F2) as the points on the wire profile section.

10. The non-contact wire diameter measurement method based on the fusion of lidar and vision technology according to claim 9, characterized in that, Obtaining the diameter of a high-voltage power line based on the cross-sectional points of the power line profile includes the following sub-steps: The wire profile fitting function is set as: (Q1-w1) 2 +(Q2-w2) 2 =r 2 Where Q1 and Q2 are the horizontal and vertical axis values ​​of the wire profile fitting function, respectively, and w1, w2 and r are the constants of the wire profile fitting function. The specific value of r is obtained by fitting the wire profile cross-section points with the wire profile fitting function. Consider 2×r as the diameter of the high-voltage power line.

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