Anti-twist steel wire rope defect automatic detection system for power transmission line

Abstract

The invention discloses an automatic defect detection system for an anti-twisting steel wire rope for a power transmission line, and relates to the technical field of steel wire rope defect detection. Different test speeds are set for uniformly distributed ropes with the same defect and irregularly distributed random ropes with different defects through a rope speed analysis unit; memory magnetic fields on the equipartition rope and the random rope are detected by means of a magnetic field detection unit at different test speeds, the target average speed and the target following speed of the equipartition rope and the random rope are determined, and the average value of the target average speed and the target following speed is marked as the approved target speed; according to the mode, the defects set under the two conditions can be detected, then real-time analysis is carried out according to different detection conditions, and the most suitable test speed can be selected to detect the defects of the steel wire rope under the condition of considering the two properties of randomness and regularity; the method is simple, effective and easy to use.

Description

Technical Field

[0001] The invention belongs to the technical field of steel wire rope defect detection, in particular to an automatic defect detection system for anti-twisting steel wire ropes for power transmission lines. Background Art

[0002] Patent publication number CN111024704B discloses an embodiment of automated defect detection for flexible components using image processing. The technology includes monitoring the flexible component via one or more sensors to obtain sensor data, converting the sensor data from the one or more sensors into image data, and receiving reference image data for comparison with the image data. The technology also includes determining a defect based on the comparison and threshold setting information for the flexible component, and sending a notification based on the defect.

[0003] However, when performing magnetic testing on wire ropes to determine whether there are defects, there are the following difficulties. First, when the rope is reeled in at a fast speed, the detection accuracy will be affected, and when the detection speed is slow, the progress will be full, affecting the detection efficiency. Therefore, this is a problem, based on which a solution is provided. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art; To this end, the present invention proposes an automatic detection system for defects of anti-twist steel wire ropes for transmission lines, comprising: The rope speed analysis unit is used to set different test speeds for the regularly arranged uniform ropes with the same defects and the irregularly arranged random ropes with different defects. At different test speeds, the magnetic field detection unit is used to detect the memory magnetic fields on the uniform ropes and random ropes. The unit automatically obtains the detection ratio (the ratio of the number of measured defects to the actual number of defects) and the total parameter difference (the parameter difference representing the sum of the values ​​of the relevant magnetic field parameters corresponding to the defects). The deviation value representing the degree of dispersion is obtained based on the parameter difference. Determine the evaluation value of the corresponding test speed according to the deviation value, the total parameter difference and the detection ratio; Then, different weights are assigned according to the evaluation value and the test speed, and the selected value is obtained by adding them together. The test speed with the largest selection value is marked as the target average speed and target following speed of the equal-sharing rope and random rope respectively, and the average of the target average speed and the target following speed is marked as the approved target speed.

[0005] Furthermore, it also includes a winding end, which is used to wind the wire rope at a set speed so that the wire rope passes through the magnetic field detection unit.

[0006] Furthermore, the winding end includes a rope-releasing unit for releasing the wire rope according to the rope-reeling speed of the rope-reeling unit.

[0007] Furthermore, the memory magnetic field of the steel wire rope is formed by a magnetic memory planning unit.

[0008] Furthermore, a magnetic field detection unit is provided between the rope-releasing unit and the rope-collecting unit, and is used to measure the magnetic properties of the steel wire rope moving from the rope-releasing unit to the rope-collecting unit, wherein the magnetic properties include magnetic flux density, magnetic field gradient and magnetic potential difference.

[0009] Furthermore, the regularly arranged equally distributed rope of identical defects refers to a rope having the same number of defects, same length of intervals between defects, and same type.

[0010] Furthermore, the random rope with irregularly arranged defects refers to a rope in which parameters such as the interval length and depth between defects are different and randomly set.

[0011] Furthermore, the parameter difference of the relevant magnetic field parameters corresponding to the defect is referred to as: The standard values ​​of the relevant parameters at the defect are obtained, and then the absolute value of the difference between the real-time value and the standard value is obtained, and the value is marked as the parameter difference of the corresponding defect, and the parameter difference of all detected defects is obtained.

[0012] Furthermore, the specific calculation formula for the evaluation value of the test speed is: Evaluation value = 0.53 × W / total parameter difference + 0.47 × detection ratio.

[0013] Furthermore, the calculation formula for the test speed selection is: Selection value = 0.54 × real-time speed + 0.46 × evaluation value.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The rope speed analysis unit sets different test speeds for the regularly arranged equal-shared ropes with the same defects and the irregularly arranged random ropes with different defects. The magnetic field detection unit detects the memory magnetic fields on the equal-shared ropes and the random ropes at different test speeds to determine the target average speed and target follower speed of the equal-shared ropes and the random ropes. The average of the target average speed and target follower speed is marked as the approved target speed. According to the above method, defects set in two situations can be detected, and then real-time analysis can be performed for different detection situations. The most appropriate test speed can be selected to detect wire rope defects while considering both randomness and regularity. This application is simple, effective, and easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a system block diagram of the present invention; Figure 2 It is a structural block diagram of the winding end of the present invention. DETAILED DESCRIPTION

[0016] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1-Figure 2 , the present application provides an automatic defect detection system for anti-twist wire ropes for transmission lines; This application performs defect detection on the wire rope according to the process of adjusting the tension of the unwinding tension machine, weak magnetic detection, identifying the damaged point and rewinding; As the first embodiment of the present application, it specifically includes: The rope speed analysis unit is used to set different test speeds for the regularly arranged uniform ropes with the same defects and the irregularly arranged random ropes with different defects. At different test speeds, the magnetic field detection unit is used to detect the memory magnetic fields on the uniform ropes and random ropes. The unit automatically obtains the detection ratio (the ratio of the number of measured defects to the actual number of defects) and the total parameter difference (the parameter difference representing the sum of the values ​​of the relevant magnetic field parameters corresponding to the defects). The deviation value representing the degree of dispersion is obtained based on the parameter difference. Determine the evaluation value of the corresponding test speed according to the deviation value, the total parameter difference and the detection ratio; Then, different weights are assigned according to the evaluation value and the test speed, and the selected value is obtained by adding them together. The test speed with the largest selection value is marked as the target average speed and target following speed of the equal-sharing rope and random rope respectively, and the average of the target average speed and the target following speed is marked as the approved target speed.

[0018] As a second embodiment of the present application, the system in this embodiment specifically includes: The reeling end includes a rope-releasing unit and a rope-receiving unit, wherein the rope-releasing unit is used to release the rope according to the rope-receiving speed of the rope-receiving unit; The magnetic memory planning unit is used to create a memory magnetic field in the wire rope. The magnetic energy product established along the axial direction of the wire rope is equal, uniform, and continuously distributed. The magnetic energy product within any volume element should also be equal and uniform, with the same magnetic field density and flux, thus forming a given memory magnetic field. Applying an external magnetic field to the wire rope changes the number of magnetic domains in a certain direction in the ferromagnetic material, resulting in a moderately low magnetic energy product for all load materials, thus forming a "memory magnetic field." The memory magnetic field does not disappear with the removal of the external magnetic field and will remain stable for a long time as long as there are no severe mechanical vibrations or high temperatures. The magnetic field detection unit is arranged between the rope-releasing unit and the rope-collecting unit, and is used to measure the magnetic properties of the wire rope moving from the rope-releasing unit to the rope-collecting unit. In specific implementation, one or more of 48-64 Hall elements, differential magnetic probes, and fluxgate sensors arranged in a ring can be used to test the relevant parameters of the memory magnetic field formed by the wire rope. The relevant parameters include the magnetic flux density, magnetic field gradient, and magnetic potential difference of the wire rope; the presence of defects is determined by the relevant parameters, and the specific situation of the defects is determined according to the relevant parameters of the defects; of course, the relevant parameters mentioned here include: Magnetic flux density B, which refers to the number of magnetic lines of force per unit area, can be collected by a Hall sensor array; The magnetic field gradient VB refers to the spatial rate of change of the magnetic flux density, which can be collected by a differential magnetic sensitive probe; The magnetic potential difference Δφm refers to the difference in magnetic potential energy on both sides of the defect, which can be measured by a fluxgate sensor; The three parameters mentioned here express different meanings; The magnetic flux density B is a direct measurement, for example: Normal wire rope surface B=0.8-1.2T (evenly distributed); The leakage magnetic field B at the broken wire suddenly increases to 1.5-2.0T (local peak) Gradient VB is more sensitive to minor damage and can identify broken wires at the 0.1mm level; The magnetic potential difference △φ_m reflects the defect depth and is positively correlated with the amount of metal loss.

[0019] The rope speed analysis unit is used to reasonably analyze the rope speed. Here, the rope speed refers to the speed at which the rope retraction unit retracts the wire rope when the corresponding magnetic field detection unit detects the relevant parameters of the memory magnetic field generated by the wire rope. The specific method of reasonable analysis is as follows: Set up two steel wire ropes, one is an evenly distributed rope and the other is a random rope. The number of defects, the length of intervals between defects, and the type of defects on the evenly distributed rope and the random rope are the same. The difference is that the interval length, depth and other parameters of all defects on the evenly distributed rope are the same; the interval length, depth and other parameters of each defect on the random rope are different and randomly set. The magnetic field detection unit is used to detect the equalizing rope, and the initial speed is set to a preset value, and then the wire rope is tested at this speed; Obtain the number of defects detected at the speed and the real-time values ​​of related parameters; Select any defect and obtain the standard value of the relevant parameters of the defect. The standard value refers to the standard value of the relevant parameters of the corresponding defect. Then, the absolute value of the difference between the real-time value and the standard value is obtained, and the value is marked as the parameter difference of the corresponding defect, and the parameter difference of all detected defects is obtained; The parameter difference is marked as Ci, i = 1, ..., n, which means that the number of defects detected on the evenly distributed rope at this speed is n, and the parameter difference of each defect is Ci; First, get the mean of Ci, mark it as P, and calculate the deviation value W of Ci according to the formula. The specific calculation formula is: ; Obtain the number of defect settings on the averaging rope, divide n by the number of set defects to obtain a value marked as the detection ratio; mark the sum of all Ci values ​​as the total parameter difference; The evaluation value corresponding to the initial velocity is calculated using the formula. The specific calculation formula is: Evaluation value = 0.53 × W / total parameter difference + 0.47 × detection ratio; Get the evaluation value corresponding to the initial speed and mark it as the initial evaluation value; Then the initial speed is increased according to the set increase value, and each time a new speed is generated, it is marked as the real-time speed; Every time a real-time speed is generated, a test is performed to obtain the corresponding evaluation value; Get each real-time speed and its corresponding evaluation value, and automatically calculate the selection value. The specific calculation method is: Selection value = 0.54 × real-time speed + 0.46 × evaluation value; Get the real-time speed with the largest selected value and mark it as the target average speed of the corresponding equalizing rope; Then, the random rope is processed in the same way as the equally divided rope to obtain the most appropriate speed of the random rope, which is marked as the target speed. The average of the target average speed and the target follow-up speed is marked as the approved target speed; The wire rope is tested at the approved target speed using a magnetic field detection unit.

[0020] The above embodiments are only used to illustrate the technical method of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. Automatic detection system for defects of anti-twist wire ropes for transmission lines, characterized by: include: The rope speed analysis unit is used to set different test speeds for the regularly arranged uniform ropes with the same defects and the irregularly arranged random ropes with different defects. At different test speeds, the magnetic field detection unit is used to detect the memory magnetic fields on the uniform ropes and random ropes. The unit automatically obtains the detection ratio (the ratio of the number of measured defects to the actual number of defects) and the total parameter difference (the parameter difference representing the sum of the values ​​of the relevant magnetic field parameters corresponding to the defects). The deviation value representing the degree of dispersion is obtained based on the parameter difference. Determine the evaluation value of the corresponding test speed according to the deviation value, the total parameter difference and the detection ratio; Then, different weights are assigned according to the evaluation value and the test speed, and the selected value is obtained by adding them together. The test speed with the largest selection value is marked as the target average speed and target following speed of the equal-sharing rope and random rope respectively, and the average of the target average speed and the target following speed is marked as the approved target speed.

2. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: It also includes a winding end, which is used to wind the steel wire rope at a set speed so that the steel wire rope passes through the magnetic field detection unit.

3. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: The winding end comprises a rope-releasing unit for releasing the steel wire rope according to the rope-reeling speed of the rope-reeling unit.

4. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: The memory magnetic field of the wire rope is formed by the magnetic memory planning unit.

5. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: The magnetic field detection unit is arranged between the rope-releasing unit and the rope-collecting unit, and is used to measure the magnetic properties of the wire rope moving from the rope-releasing unit to the rope-collecting unit. The magnetic properties include magnetic flux density, magnetic field gradient and magnetic potential difference.

6. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: A regularly distributed rope with identical defects is one in which the number of defects, the length of the intervals between defects, and the type of defects are all the same.

7. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: The random rope with irregularly arranged defects refers to the rope in which the interval length, depth and other parameters between defects are different and randomly set.

8. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: The parameter difference of the relevant magnetic field parameters corresponding to the defect is represented by: The standard values ​​of the relevant parameters at the defect are obtained, and then the absolute value of the difference between the real-time value and the standard value is obtained, and the value is marked as the parameter difference of the corresponding defect, and the parameter difference of all detected defects is obtained.

9. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1 is characterized in that: The specific calculation formula for the evaluation value of the test speed is: Evaluation value = 0.53 × W / total parameter difference + 0.47 × detection ratio.

10. The automatic defect detection system for anti-twisting steel wire ropes for power transmission lines according to claim 1, characterized in that: The calculation formula for test speed selection is: Selection value = 0.54 × real-time speed + 0.46 × evaluation value.

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