Eccentricity detection method for power cable

Abstract

The invention relates to an eccentricity detection method, in particular to an eccentricity detection method for a power cable. The purpose of the invention is to provide a method for automatically calculating and judging the eccentricity of a cable insulation layer slice based on an image identification technology. The method comprises the following steps of (a) performing image extraction: converting the cable insulation layer slice into a digital image for subsequent analysis; (b) performing image identification: preprocessing the obtained image, converting image pixels into grayscale values, performing comparison with a typical cable slice, and determining whether the obtained slice image meets a requirement or not; (c) performing image processing: calculating a maximum connected interval, a core, a standard vector, a distribution minimum value and a thickness value of the image meeting the requirement; and (d) performing eccentricity calculation and judgment: according to an imageprocessing result, judging the eccentricity of the cable, if the eccentricity is greater than 10%, judging that the cable is unqualified, and if the eccentricity is smaller than 10%, judging that thecable is qualified.

Description

technical field [0001] The invention relates to an eccentricity detection method, in particular to a power cable eccentricity detection method. Background technique [0002] According to the national standards, all power cables should be sampled after delivery to ensure product quality. One of the testing items is the "eccentricity" of the power cable, which is an indicator for evaluating the uniformity of the insulation layer of the cable. Eccentricity is the percentage of the difference between the maximum thickness and the minimum thickness of the insulating layer measured on the same section and the maximum thickness ratio. According to GB / T2951.11 and Q / GDW371, the index should not exceed 10%. [0003] At present, our commonly used testing instrument is a measuring projector. The method of using the measuring projector is to project the slice of the cable insulation layer onto the upper screen through optical projection, and then read the points at different positions...

AI Technical Summary

Problems solved by technology

[0004] 1. Manual calculation is complicated

[0005] The staff need to manually calculate the xy coordinate value and the coordinate distance between the bright spots, the amount of calculation is large, the calculation time is long, and manual calculation is prone to errors

[0006] 2. Judging the maximum and minimum values ​​by naked eyes is not accurate enough

[0007] The maximum and minimum values ​​of the insulation layer thickness are selected by human eyes. The selected maximum and minimum points may not be the real extreme points, and there are deviations from the actual

[0008] 3. The operation of the instrument is complicated

The whole process of adjusting the instrument takes a long time

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