Defect detection method and apparatus for cushion layer of cable, device, and storage medium

A defect detection apparatus for a cushion layer of a cable, comprising:

• a first obtaining module configured to obtain specification parameters of a corrugated sheath of a to-be-detected cable, wherein the specification parameters comprise an inner radius of the corrugated sheath, a first outer radius of the to-be-detected cable containing a cushion layer, a second outer radius of the to-be-detected cable containing a shielding layer, a corrugation pitch, a corrugation depth, and a thickness of a thinnest point of the cushion layer;
• a first volume calculation module configured to calculate, based on the first outer radius of the to-be-detected cable containing the cushion layer, the second outer radius of the to-be-detected cable containing the shielding layer, and the corrugation pitch, a first volume of the cushion layer without deformation;
• a second volume calculation module configured to calculate, based on the inner radius of the corrugated sheath, the first outer radius of the to-be-detected cable containing the cushion layer, the second outer radius of the to-be-detected cable containing the shielding layer, and the thickness of the thinnest point of the cushion layer, a second volume of a deformed portion of the cushion layer when the cushion layer is deformed under stress;
• a stressed-state deformation ratio calculation module configured to calculate a stressed-state deformation ratio of the cushion layer based on the first volume and the second volume;
• a second obtaining module configured to obtain a voltage, a current, an electrode area, an electrode distance, and an initial electrode distance of the cushion layer when the stressed-state deformation ratio is reached;
• a volume resistivity calculation module configured to calculate volume resistivity of the cushion layer based on the voltage, the current, the electrode area, the electrode distance, and the initial electrode distance;
• and
• a defect detection module configured to compare the volume resistivity with a preset evaluation parameter to obtain a defect detection result of the cushion layer;
• wherein the defect detection module is specifically configured to:
• when the volume resistivity is less than or equal to the evaluation parameter, determine that there is no defect in the cushion layer;
• or
• when the volume resistivity is greater than the evaluation parameter, determine that there is a defect in the cushion layer;
• wherein the second obtaining module is specifically configured to:
• place, between upper and lower electrodes of a volume resistivity detection apparatus, a vacuumized electrode package without the cushion layer, apply a low direct voltage (DC) voltage, control the upper electrode to slowly descend at a first speed by a transmission mechanism until the upper and lower electrodes are in full contact with the electrode package, and obtain a distance between the upper and lower electrodes at this time as the initial electrode distance by a position sensor;
• place, between the upper and lower electrodes of the volume resistivity detection apparatus, a vacuumized electrode package with the cushion layer, apply a low DC voltage, and control the upper electrode to slowly descend at the first speed by the transmission mechanism until the upper and lower electrodes are in full contact with the electrode package;
• wherein the cushion layer in the electrode package is in a wrapped and overlapping state;
• control the upper electrode to slowly descend at a second speed by the transmission mechanism until the stressed-state deformation ratio of the cushion layer is reached, wherein the second speed is less than the first speed;
• gradually increase the DC voltage between the upper and lower electrodes until the current detected by a galvanometer reaches a path current threshold and is maintained for a preset time;
• and
• obtain a voltage between the upper and lower electrodes, a current, an electrode area, and an electrode distance between the upper and lower electrodes after the preset time.