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CN-121164280-B - Cable compression coefficient measuring method and system, device, electronic equipment and storage medium

CN121164280BCN 121164280 BCN121164280 BCN 121164280BCN-121164280-B

Abstract

The application relates to the field of cables, and provides a cable compression coefficient measuring method, a system, a device, electronic equipment and a storage medium, wherein the method comprises the steps of obtaining a section image of a target cable to be measured; the method comprises the steps of determining an outer layer profile of a target cable and closed profiles of a plurality of conductor monofilaments in the target cable based on the section image, determining a total profile area of the target cable based on the outer layer profile of the target cable, determining a through-flow area of the target cable based on the closed profiles of the conductor monofilaments, and calculating and determining a compression coefficient of the target cable based on the total profile area and the through-flow area. The method and the device are used for solving the defects that the existing measurement technology is low in precision, poor in efficiency and incapable of being automated, and the scheme of the application is used for accurately measuring the actual flow area and the total profile area of the cable conductor and accurately calculating the compression coefficient of the cable conductor.

Inventors

  • Tian Jieqi
  • DENG HONGLEI

Assignees

  • 华南理工大学

Dates

Publication Date
20260512
Application Date
20251024

Claims (8)

  1. 1. The cable compression coefficient measuring method is characterized by comprising the following steps of: Acquiring a cross-sectional image of a target cable to be tested; determining an outer layer profile of the target cable and a closed profile of a number of conductor filaments in the target cable based on the cross-sectional image; Determining a total profile area of the target cable based on an outer layer profile of the target cable, and determining a flow area of the target cable based on a closed profile of the plurality of conductor filaments; Calculating and determining a compression coefficient of a target cable based on the total contour area and the through-flow area; The obtaining the cross-section image of the target cable to be measured comprises the following steps: Cutting a target cable to be tested; Irradiating the section of the target cable through parallel light beams; acquiring an image of the parallel light beam blocked by the section of the target cable, wherein the image is a section image of the target cable; The collecting the image of the parallel light beam blocked by the section of the target cable, which is the section image of the target cable, comprises the following steps: Acquiring a section image sequence of the target cable from multiple angles according to the set stepping angle; obtaining a projection sequence according to the silhouette width of the section image sequence; Constructing a sinogram based on the projection sequence; Back projecting the sinogram to obtain a cross-sectional image of the target cable; after the cutting is completed, establishing an angle and a geometric standard, and arranging identifiable positioning marks on the side wall of the sample to define Clamping the sample on a Gao Tongxin-degree rotary table to enable a geometric center, a rotary center and an imaging optical axis to be coaxial, ensuring the stability of a centroid track through displacement and angle fine adjustment, radially adopting a self-centering structure for limiting, axially adopting an end face thrust limit and a clamping force to be in reference of no deformation, and establishing a pixel-physical scale mapping with a nominal size to obtain a pixel scale With the origin of coordinates of the image And forms the coordinate conversion relation according to the above: (1); setting the number of projection angles N and confirming The consistency of the coaxiality and the focal plane is checked through the preview image, so that the whole area of the end face is ensured to be in the depth of field; Based on the constructed angle and geometric reference N frames of images are sequentially acquired according to the angle stepping delta theta, and meanwhile, the central registration and the magnification of each angle are consistent under the condition of double telecentric imaging, and an angle sequence is recorded as { ,..., Collecting original image under the condition of locking exposure and gain, making image correction and binarization treatment to obtain B_k (u, v) epsilon {0,1}, according to the pixel scale s and coordinate origin # , ) Establishing conversion from pixels to physical coordinates; mapping pixel rows or columns into projection positions t according to a fixed scanning direction, and counting the silhouette width of each position to obtain one-dimensional projection p (t, theta k ): (2); Calculating a lateral offset deltau_k or deltav_k according to the silhouette centroid, and carrying out sub-pixel level translation on B_k or carrying out consistent compensation on the t axis of p (t, theta k ); Constructing a sinogram S (t, theta) = { p (t, theta k ) } by a projection set of all angles, wherein the t-axis sampling interval deltat=s, and the theta-axis sampling interval deltatheta, which is expressed in radians; After obtaining S (t, θ), applying a high pass filter process to each angular projection to obtain filtered projection data q (t, θ), performing a back projection by calculating, for each angle θ k , the position of that point in the angular projection coordinate system at the reconstruction grid point (x, y): (3); accumulating the sampled values of q (t, theta) to a reconstructed map according to an angle step delta theta And (3) the following steps: (4); The reconstruction resolution is determined by delta t and delta theta together, delta theta multiplied by N (pi) is satisfied, and delta theta is less than or equal to 0.0175rad so as to ensure detail expression.
  2. 2. The method of measuring a cable compaction factor according to claim 1, wherein the determining the outer layer profile of the target cable and the closed profile of the plurality of conductor filaments in the target cable based on the cross-sectional image comprises: Determining the outer layer profile of the target cable based on a subpixel edge detection algorithm; And dividing the cross-section image through distance transformation and marking control watershed to obtain the closed contour of a plurality of conductor monofilaments in the target cable.
  3. 3. The cable compaction factor measurement method according to claim 1, wherein the calculating a compaction factor for a target cable based on the total profile area and the flow area comprises: And calculating the quotient of the total contour area and the through flow area as the compression coefficient of the target cable.
  4. 4. The cable compaction factor measurement method according to claim 1, wherein the calculating a compaction factor for a target cable based on the total profile area and the flow area comprises: calculating the compression coefficient of the target cable for a plurality of times; and calculating the range of the results of the plurality of compression coefficients, and if the range is within a set threshold value range, determining the average value of the results of the plurality of compression coefficients as the compression coefficient of the target cable.
  5. 5. The cable stiction coefficient measurement system is characterized by comprising: the image acquisition module is used for acquiring a cross-sectional image of the target cable to be detected; a profile determination module for determining an outer layer profile of the target cable and a closed profile of a number of conductor filaments in the target cable based on the cross-sectional image; An area determination module for determining a total profile area of the target cable based on an outer profile of the target cable, and determining a flow area of the target cable based on a closed profile of the plurality of conductor filaments; And the compression coefficient calculation module is used for calculating and determining the compression coefficient of the target cable based on the total contour area and the through flow area.
  6. 6. Cable stiction coefficient measuring device, its characterized in that includes: A control terminal for performing the cable compaction factor measurement method according to any one of claims 1-4; The parallel light source is used for emitting parallel light and irradiating the first side of the target cable to be detected; and the industrial camera is arranged at the opposite side of the parallel light source and is used for acquiring a cross-sectional image of the target cable after being irradiated by the parallel light.
  7. 7. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the cable compaction factor measurement method according to any one of claims 1-4 when executing the program.
  8. 8. A non-transitory computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the cable compaction factor measurement method according to any one of claims 1-4.

Description

Cable compression coefficient measuring method and system, device, electronic equipment and storage medium Technical Field The present invention relates to the field of cable technologies, and in particular, to a method and system for measuring a compression coefficient of a cable, an apparatus, an electronic device, and a storage medium. Background The cable compaction coefficient is an important parameter for measuring the compaction degree and the section utilization rate of a conductor, and the size of the cable compaction coefficient directly relates to the operation safety and the economy of the cable. If the compression coefficient is insufficient, the gaps between conductors are larger, deformation and uneven contact are easy to generate in the mechanical extrusion or thermal expansion process, so that the local resistance and the heating risk are increased, and if the compression coefficient is too high, the stress between conductors is concentrated, the structural damage and the local overheating are easy to be caused, and the long-term stable operation of the cable is influenced. Therefore, in the design, manufacturing and laying links of the power cable, accurate measurement and control of the compression coefficient are required. In the field of power transmission, the compression coefficient is closely related to the current-carrying capacity and temperature rise control of the cable. The conductor compactness is too high and can lead to heat dissipation channel to be blocked, and when the operating temperature exceeds the design value, the insulating layer accelerates ageing, and breakdown and conflagration can appear even when serious. CIGR É has shown that when the compression coefficient deviates from the design value by more than +/-5%, the current-carrying capacity calculation error of the cable can reach 10% -15%, and hidden danger is brought to the operation of the power transmission system. Meanwhile, the metal conductor material cost of the high-voltage cable generally occupies more than half of the whole cable cost, and the control precision of the compression coefficient directly relates to the material utilization efficiency. Taking 500kV power transmission engineering as an example, the compression coefficient can be reasonably controlled, and the copper or aluminum consumption can be saved by about 8% -12% while the performance is kept stable, so that obvious economic benefits are brought. In industrial manufacturing scenes, the loosening of conductors can be caused by insufficient compression coefficient, and in the power supply process of high-power equipment such as metallurgy, petrochemical industry or rail transit, local overheating is often caused by the rising of contact resistance, the energy efficiency of a system is reduced if the contact resistance is light, and production shutdown is caused if the contact resistance is heavy. Control of the compression factor is more critical for custom cables required for flexible manufacturing and smart equipment, such as robotic articulation cables and medical device cables. The power, signal and other conductors are required to be integrated in the limited section, so that not only enough electrical performance is ensured, but also mechanical flexibility is considered, and higher requirements are put on accurate measurement and calculation of the space utilization rate and compactness of the section. It has been proposed to obtain stranded conductors with a compression coefficient of about 0.90-0.94 by wire drawing-frame twisting-compression and other procedures, and to maintain a larger contact surface for reducing contact resistance, and to be suitable for use in medium and low voltage cables, overhead insulated conductors and other products. The idea emphasizes manufacturing formulas and process windows, but mainly provides a target compression coefficient range and a forming flow, and lacks disclosure on the standardized measurement caliber and uncertainty budget of the compression coefficient. The design and measurement of the cable compaction coefficients involves multiple dimensions of electrical performance, thermal characteristics, mechanical strength, engineering economy, etc. In the electrical dimension, the dynamic relation between the current-carrying capacity and the temperature rise needs to be coordinated, in the mechanical dimension, the balance between the strength and the flexibility of the conductor needs to be found, and in the economical dimension, the compression coefficient directly influences the material consumption and the operation and maintenance cost. How to realize accurate measurement and optimization of the compression coefficient under the constraint conditions has become a core technical problem in cable design and quality control. Disclosure of Invention The application provides a cable compression coefficient measuring method, a system, a device, electronic equipment and a storage medium, whic