Method, device, electronic equipment and computer program product for detecting defects of a cable

Abstract

The application is suitable for the field of defect detection, and provides a cable defect detection method and device, electronic equipment and computer program product, wherein the method comprises the following steps: determining detection point coordinates of at least one target detection point located on a surface of an armored layer of a cable; calculating, based on cable parameters, detection wave transmitting device parameters and the detection point coordinates of each target detection point, an incident coordinate and an incident angle of a detection wave to be transmitted corresponding to each target detection point; transmitting a detection wave based on the incident coordinate and the incident angle corresponding to each target detection point, to obtain a target reflection echo of each target detection point; and determining a defect detection result of each target detection point on the surface of the armored layer based on the target reflection echo. The scheme improves the receptivity of the reflection echo and the defect detection efficiency of the cable.

Description

Technical Field

[0001] This application belongs to the field of defect detection, and in particular relates to a method, apparatus, electronic device and computer program product for detecting defects in cables. Background Technology

[0002] Cables, as important carriers of power transmission and communication data transmission, play an indispensable role in various power grid and communication infrastructure constructions. Taking high-voltage cables as an example, their advantages such as high transmission capacity, low loss, and long-distance transmission have made them an indispensable and important component of modern power grid construction.

[0003] Cables face various safety hazards during operation, among which the ablation defect of the buffer layer is particularly prominent. Whether it's a high-voltage cable or other types of cable, the ablation defect of the buffer layer poses a serious threat to the safe operation of the cable due to its high frequency, strong concealment, and significant destructiveness. Currently, it is difficult to directly detect ablation defects in the cable buffer layer; therefore, the presence of ablation defects is usually determined indirectly by utilizing the defect detection results of the cable armor layer.

[0004] Currently, defects in the armor layer of cables can be detected using methods such as frequency domain response characteristic testing and X-ray inspection. However, these methods are time-consuming, complex to operate, and have low accuracy. Some non-destructive testing (NDT) techniques, such as terahertz wave testing, are simple to operate and can achieve rapid and high-precision testing. However, NDT techniques based on terahertz waves are often used for defect detection in flat structures. Cables are complex, non-flat structures with an outer sheath (such as an outer jacket) and an armor layer (such as an aluminum corrugated pipe). When performing defect detection on non-flat structures like cables, it is difficult to receive reflected echoes, resulting in low efficiency in detecting defects in the armor layer. Summary of the Invention

[0005] This application provides a method, apparatus, electronic device, and computer program product for detecting defects in cables, in order to solve the problem that existing non-destructive testing technologies based on terahertz waves and other detection waves have difficulty receiving reflected echoes and have low efficiency in detecting defects in the armor layer when performing defect detection on non-flat structures such as cables.

[0006] The first aspect of this application provides a method for detecting defects in cables, including:

[0007] Determine the coordinates of at least one target detection point located on the surface of the cable's armor layer;

[0008] Based on the cable parameters, the parameters of the detection wave transmitting device, and the detection point coordinates of each target detection point, the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point are calculated.

[0009] Based on the incident coordinates and incident angle corresponding to each target detection point, a detection wave is emitted to obtain the target reflected echo of each target detection point.

[0010] Based on the reflected echo from the target, the defect detection results of each target detection point on the surface of the armor layer are determined.

[0011] A second aspect of this application provides a cable defect detection device, comprising:

[0012] A coordinate determination module is used to determine the coordinates of at least one target detection point located on the surface of the cable's armor layer.

[0013] The calculation module is used to calculate the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point based on cable parameters, detection wave transmitting device parameters, and the detection point coordinates of each target detection point.

[0014] The transmitting module is used to transmit a detection wave based on the incident coordinates and the incident angle corresponding to each target detection point, so as to obtain the target reflected echo of each target detection point.

[0015] The defect detection module is used to determine the defect detection results of each target detection point on the surface of the armor layer based on the target reflected echo.

[0016] A third aspect of this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described in the first aspect.

[0017] A fourth aspect of this application provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the method as described in the first aspect.

[0018] A fifth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method described in the first aspect.

[0019] As can be seen from the above, this application utilizes cable parameters, detection wave transmitting equipment parameters, and the detection point coordinates of each target detection point on the armor layer surface to calculate the incident coordinates and incident angle of the detection wave to be emitted for each target detection point. Subsequently, the detection wave is emitted according to the calculated incident coordinates and incident angle. This method ensures that the detection wave illuminates the target detection point at an optimal angle and position, improving the receptivity of the reflected echo. After receiving the reflected echo from the target detection point, defects on the armor layer surface are accurately detected by analyzing the reflected echo. This application, through precise calculation and positioning, effectively solves the problem that non-destructive testing techniques based on terahertz waves and other detection waves struggle to receive reflected echoes when detecting defects in non-planar structures such as cables. It achieves the goal of detecting defects in cable armor layers using terahertz waves and other detection waves, and improves the efficiency and accuracy of the detection. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a detection path for a flat plate structure provided in an embodiment of this application. Figure 1 ;

[0022] Figure 2 This is a schematic diagram of a detection path for a flat plate structure provided in an embodiment of this application. Figure 2 ;

[0023] Figure 3 This is a schematic diagram of a detection path for a non-flat structure object provided in an embodiment of this application. Figure 1 ;

[0024] Figure 4 This is a flowchart of a cable defect detection method provided in an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of a cable coordinate system provided in an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of a detection wave path relationship provided in an embodiment of this application;

[0027] Figure 7 This is a schematic diagram of a detection path for a non-flat structure object provided in an embodiment of this application. Figure 2 ;

[0028] Figure 8This is a structural diagram of a cable defect detection device provided in an embodiment of this application;

[0029] Figure 9 This is a structural diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0031] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0032] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0034] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0035] In specific implementations, the terminals described in the embodiments of this application include, but are not limited to, other portable devices such as mobile phones, laptop computers, or tablet computers with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads). It should also be understood that in some embodiments, the device is not a portable communication device, but a desktop computer with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads).

[0036] The following discussion describes terminals that include displays and touch-sensitive surfaces. However, it should be understood that terminals may include one or more other physical user interface devices such as physical keyboards, mice, and / or joysticks.

[0037] The terminal supports a variety of applications, such as one or more of the following: drawing applications, presentation applications, word processing applications, website creation applications, disc burning applications, spreadsheet applications, game applications, telephone applications, video conferencing applications, email applications, instant messaging applications, exercise support applications, photo management applications, digital camera applications, digital camcorder applications, web browsing applications, digital music player applications, and / or digital video player applications.

[0038] Various applications that can run on a terminal can use at least one common physical user interface device, such as a touch-sensitive surface. One or more functions of the touch-sensitive surface and the corresponding information displayed on the terminal can be adjusted and / or changed between and / or within applications. In this way, the terminal's common physical architecture (e.g., the touch-sensitive surface) can support various applications with user interfaces that are intuitive and transparent to the user.

[0039] It should be understood that the sequence number of each step in this embodiment does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application embodiment.

[0040] Cables come in various categories, including high-voltage cables and fiber optic cables, and are an important component of power grid and communication infrastructure. As cable operating time increases and the complexity of working environments grows, cable defects are becoming increasingly prominent. Detecting cable defects allows for the timely identification and prevention of potential safety hazards, thereby ensuring the stable operation of power grids and communications.

[0041] Among various cable defects, the ablation defect of the cable buffer layer is a major safety hazard during cable operation due to its high frequency of occurrence, strong concealment, and great harm.

[0042] Cables consist of multiple layers, including an outer sheath (such as an outer jacket) and an armor layer (such as an aluminum corrugated pipe). Currently, it is difficult to directly detect ablation defects in the cable buffer layer. Studies have shown that micropores and microcracks on the surface of the armor layer provide pathways for moisture to enter the buffer layer. Detection of defects on the armor layer surface can be a powerful early screening method for the presence of ablation defects in the buffer layer. Therefore, the results of defect detection in the cable armor layer are often used to indirectly determine whether ablation defects exist in the cable buffer layer. Traditional defect detection methods include frequency domain response characteristic testing and X-ray inspection. These methods are time-consuming, complex to operate, and have low accuracy for small defects.

[0043] Terahertz (THz) waves are electromagnetic waves with frequencies ranging from 0.1 to 10 THz and wavelengths between 0.03 and 3 mm. Terahertz wave detection technology, as an emerging non-destructive testing technique, offers numerous advantages: it can penetrate various non-polar materials, requires no coupling agent, and achieves non-contact testing; it has low energy and will not harm the human body or the target object; it possesses rich characteristic parameters, containing a wealth of information about the sample; it has strong spectral resolution and rapid response, making it ideal for imaging the internal and external surfaces of various objects. Detection waves like terahertz waves are simple to operate and can achieve rapid and high-precision detection when performing defect inspection. However, non-destructive testing techniques based on terahertz waves are commonly used for defect inspection of flat plate structures and are not frequently used for defect inspection of non-flat structures such as cables.

[0044] like Figure 1 As shown, Figure 1 This is a schematic diagram of a detection path for a flat plate structure provided in an embodiment of this application. Figure 1 .exist Figure 1 In this model, it is assumed that the surface and internal interfaces of the sample to be tested are all flat plate structures. The detection probe emits a detection wave above the sample and receives the reflected echo. That is, after the detection probe emits a detection wave perpendicular to the surface of the sample, the reflected echo perpendicular to the surface of the sample can be received by the detection probe. Figure 1 The scanning path is distributed in a regular serpentine pattern, and the probe angle is always perpendicular to the sample surface. That is, when receiving the reflected echo at each position, the position of the detection probe when receiving the echo does not change compared to the position when transmitting the detection wave.

[0045] like Figure 2 As shown, Figure 2 This is a schematic diagram of a detection path for a flat plate structure provided in an embodiment of this application. Figure 2 . Figure 2The incident and reflection path of the detection wave inside the sample is shown. This type of plate-shaped object with a regular structure can be considered as having an ideal plane perpendicular to the light path. When detected by the detection wave, the reflected echo can be reflected along the incident path, making it easy to receive the reflected echo and resulting in good detection performance.

[0046] However, most cables are not flat structures, and their internal structure cannot be considered an ideal plane perpendicular to the optical path. Therefore, after a detection wave is emitted into them, the detection probe cannot receive the echo at the emission location. For example... Figure 3 As shown, Figure 3 This is a schematic diagram of a detection path for a non-flat structure object provided in an embodiment of this application. Figure 1 . Figure 3 The outer sheath of the cable is the outer coating layer, and the corrugated aluminum tube is the armor layer. The detection probe moves parallel to the surface and emits detection waves in a scanning manner similar to that used for flat objects. Due to the complexity of the cable structure, some reflected signals will be lost, meaning that the reflected echoes from these locations will not be received.

[0047] Currently, non-destructive testing technologies based on terahertz waves and other detection waves are not commonly used for defect detection of non-planar structures such as cables. This is mainly because when using terahertz waves and other detection waves to detect defects in non-planar structures such as cables, it is difficult to receive reflected echoes, resulting in low efficiency in detecting defects in the armor layer.

[0048] In order to apply terahertz waves and other detection waves to the defect detection of non-planar structures such as cables, and to promptly detect defects in the cable armor layer, this application provides a cable defect detection method, device, electronic equipment and computer program product.

[0049] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0050] See Figure 4 , Figure 4 This is a flowchart of a cable defect detection method provided in an embodiment of this application. Figure 4 As shown, a defect detection method for cables includes the following steps:

[0051] Step 401: Determine the coordinates of at least one target detection point located on the surface of the cable's armor layer.

[0052] The target inspection points are the locations on the cable armor layer where defect detection is required. Before conducting defect detection, the coordinates of the target inspection points located on the cable armor layer must be determined.

[0053] Although cables are not flat structures, they are non-flat structures with regular patterns. Firstly, a cable is a symmetrical object; a cross-section taken from any point on the cable with a plane perpendicular to its axial centerline is circular, with the center point (corresponding to the axial centerline) as its center, and this cross-section is perfectly symmetrical. Secondly, the distance between the outer sheath and the armor layer is usually constant, meaning their shapes and lines are similar. Thirdly, the lines of a cable exhibit periodic variations.

[0054] Based on the structural characteristics of the cable, a coordinate system can be constructed and the coordinates of the detection points can be determined.

[0055] In some embodiments, the cable has various parameters, including a first shape function of the armor layer and a second shape function of the outer sheath layer.

[0056] In some embodiments, before determining the detection point coordinates of at least one target detection point located on the surface of the cable's armor layer, the method further includes: constructing a reference coordinate system using the axial centerline of the cable as a first coordinate axis and a predetermined radial line of the cable as a second coordinate axis to obtain a reference two-dimensional plane; the target detection point being either within or outside the reference two-dimensional plane; determining the first shape function of the armor layer based on the reference coordinate system, the outer diameters at the crests and troughs of the armor layer surface, and the distance between two adjacent crests / troughs; and determining the second shape function of the outer sheath layer based on the reference coordinate system, the outer diameters at the crests and troughs of the outer sheath surface, and the distance between two adjacent crests / troughs.

[0057] like Figure 5 As shown, Figure 5 This is a schematic diagram of a cable coordinate system provided in an embodiment of this application. For ease of explanation of the coordinate system, Figure 5 The cable structure was disassembled and simplified, showing the outer sheath, i.e., the cable outer jacket, and the armor layer, i.e., the corrugated aluminum tube. Figure 5 The axial centerline of the cable is taken as the first coordinate axis, i.e., the x-axis, and the radial line passing through the outer sheath (i.e., the cable outer sheath) and the armor layer (i.e., the aluminum corrugated pipe) is taken as the second coordinate axis, i.e., the y-axis.

[0058] When constructing the coordinate system, the set radial line can be a radial line passing through a certain point, such as the first target detection point, or a radial line passing through a peak / trough. Figure 5 The radial line passing through a certain wave peak is used as the set radial line to establish the second coordinate axis, namely the y-axis.

[0059] By establishing a coordinate system, a reference coordinate system and a reference two-dimensional plane are obtained. The coordinates of various points within the cable armor layer and the coordinates of other points outside the armor layer are determined using the reference coordinate system and the reference two-dimensional plane containing it. The reference coordinate system is a two-dimensional coordinate system, and the reference two-dimensional plane is one of multiple two-dimensional planes of the cable. The target detection point may be located within or outside the reference two-dimensional plane.

[0060] by Figure 5 Taking the cable structure in the example, the shapes of the cable's outer sheath and armor layer are approximated as sinusoidal functions. Based on a reference coordinate system, the outer diameters at the crests and troughs of the armor layer surface, and the distance between two adjacent crests / troughs, a first shape function of the armor layer in the reference two-dimensional plane is determined. Based on the reference coordinate system, the outer diameters at the crests and troughs of the outer sheath surface, and the distance between two adjacent crests / troughs, a second shape function of the outer sheath layer is determined. Figure 5 The corresponding first shape function y1 and second shape function y2 are shown in equations (1) and (2).

[0061]

[0062] Where y1 and y2 are the surface shape functions of the armor layer and the outer layer, respectively; r1 and r2 are the outer diameters of the crests and troughs of the armor layer surface, respectively; R1 and R2 are the outer diameters of the crests and troughs of the outer layer surface, respectively; and D is the distance between two adjacent crests / troughs.

[0063] In some embodiments, the outer diameter of the outer sheath is obtained by measurement, and the outer diameter of the armor layer is obtained by consulting relevant cable parameters.

[0064] In some embodiments, the magnitude relationship between R1 and r1, and between R2 and r2 is determined by detecting the reflected echoes of the wave at the crests and troughs of the cable, and then the outer diameter at the crests and troughs of the armor layer surface is calculated based on the magnitude relationship.

[0065] By considering the symmetry and periodicity of the cable, the shape functions of the cable's armor layer and outer sheath in a two-dimensional plane are determined. The shape function of the armor layer is consistent in multiple two-dimensional planes containing the cable's axial centerline; similarly, the shape function of the outer sheath is also consistent. The shape function corresponding to the reference two-dimensional plane is applicable to the armor layer and outer sheath lines in other two-dimensional planes containing the cable's axial centerline.

[0066] In some embodiments, determining the detection point coordinates of at least one target detection point located on the surface of the cable armor layer includes: acquiring a first coordinate value and a target rotation angle for each target detection point; the first coordinate value is the coordinate value of the target detection point on the first coordinate axis, and the target rotation angle is the angle between the target two-dimensional plane formed by the target detection point and the first coordinate axis and the reference two-dimensional plane along a set rotation direction; calculating a second coordinate value for each target detection point based on the first shape function and the first coordinate value of each target detection point; the first coordinate value, the second coordinate value, and the target rotation angle of each target detection point constitute the detection point coordinates of the target detection point.

[0067] It should be noted that the coordinates involved in this application include not only the x and y values ​​determined based on the x-axis and y-axis, but also angle values, i.e., the coordinates are represented as (x, y, α). α is the angle between the two-dimensional plane formed by the corresponding point and the first coordinate axis (i.e., the axial centerline) and the reference two-dimensional plane along the set rotation direction. The axial centerline is the rotation axis, and the set rotation direction is not limited in this application. The target rotation angle ranges from [0° to 360°].

[0068] After obtaining the first coordinate value (x-value) of the target detection point and the target rotation angle (α), the first coordinate value is substituted into the first shape function to calculate the second coordinate value (y-value) of the target detection point.

[0069] The first coordinate value, the second coordinate value, and the target rotation angle together constitute the detection point coordinates of the target detection point.

[0070] The construction of a reference coordinate system and a reference two-dimensional plane helps to determine the shape function and the coordinates of the target detection point, enabling efficient coordinate determination for accurate positioning and faster defect detection.

[0071] Step 402: Based on the cable parameters, the parameters of the detection wave transmitting device, and the detection point coordinates of each target detection point, calculate the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point.

[0072] The cable parameters, in addition to the first and second shape functions, also include the refractive index of the outer sheath, where the incident medium is air and the exit medium is the outer sheath. The parameters of the detection wave emitting device include the focal length of the emitting lens, and the detection wave emitting device can be a detection device including a detection probe. The incident coordinates and incident angle are the coordinates of the detection probe and the detection wave emission angle, respectively. The detection wave emitting device can realize the emission of detection waves and the reception of the target reflected echo.

[0073] In some embodiments, the outer layer surface has detection association points corresponding one-to-one with the target detection points. The detection association line segment formed by each target detection point and the corresponding detection association point is perpendicular to the tangent at the target detection point. The calculation of the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point, based on cable parameters, detection wave transmitting device parameters, and the detection point coordinates of each target detection point, includes: calculating a third shape function of the detection association line segment based on the detection point coordinates of each target detection point and the first shape function; and calculating the intersection point based on the second shape function and the third shape function to obtain the third shape function of the detection association point. The coordinates of the detection associated point are formed by the third coordinate value, the fourth coordinate value, and the target rotation angle. The first derivative of the first shape function at the target detection point and the second derivative of the second shape function at the detection associated point are calculated. Based on the coordinates of the detection point, the coordinates of the detection associated point, the first derivative, the second derivative, the refractive index of the outer coating, and the focal length of the emitting lens, the incident coordinates and the incident angle of the detection wave to be emitted corresponding to the target detection point are calculated. The incident coordinates, the detection point coordinates, and the coordinates of the detection associated point corresponding to each target detection point are all located in the same two-dimensional plane of the target, that is, they share a common angle value α.

[0074] like Figure 6 As shown, Figure 6 This is a schematic diagram of a detection wave path relationship provided in an embodiment of this application. The following is in conjunction with... Figure 6 Explain the calculation process for the incident coordinates and incident angle.

[0075] It should be noted that since the incident coordinates, detection point coordinates, and detection associated point coordinates of each target detection point are all located in the same two-dimensional plane of the target, the target rotation angle α is omitted in the calculation, and only the x and y values ​​are reflected. Figure 6 The terahertz probe in the example is a detection wave emitting device that can emit terahertz waves and receive the reflected echo from the target. The terahertz probe here is just an example; the specific equipment and detection wave used will depend on the actual situation.

[0076] Let the target detection point be point P, and the coordinates of point P be (x, y). p ,f1(x p )),Right now Figure 6 P(x) p ,y p The detected associated point is point Q, and the coordinates of point Q are (x, y, y). q ,f2(x q )),Right now Figure 6 Q(x) q ,yq The position of the detection probe, i.e., the incident point of the detection wave, is point S, and the coordinates of point S are (x...). s ,y s ),Right now Figure 6 S(x) s ,y s ).

[0077] Figure 6 The horizontal line is parallel to the first coordinate axis, the x-axis; the vertical line is parallel to the second coordinate axis, the y-axis; and the interface normal is the normal at point Q. The outer sheath is the outer coating layer, and the aluminum tube is the armor layer. Figure 6 In the diagram, S→Q→P is the incident path, and P→Q→S is the reflection path.

[0078] In some embodiments, the incident path and the reflection path have the same route but different wave directions.

[0079] Depend on Figure 6 It can be seen that there is a detection association point (point Q) on the surface of the outer layer that corresponds to the target detection point (point P). The detection association line segment PQ formed by the target detection point and the corresponding detection association point is perpendicular to the tangent at the target detection point.

[0080] The derivative of the first shape function at point P is equal to the slope of the tangent line to the first shape function at point P. Line segment PQ is perpendicular to the tangent line at point P. If two lines are perpendicular, then the product of their slopes is -1; correspondingly, the product of the slope of line segment PQ and the derivative of the first shape function at point P is also -1.

[0081] Given the coordinates of the detection point, i.e. the coordinates of point P on line segment PQ, the analytical expression of the line PQ containing line segment PQ can be obtained using the two-point formula. The slope of the line is the tangent of its tilt angle. Considering that the propagation path of the detection wave may be in the vertical direction, the tilt angle is 90°, and the tangent value does not exist, i.e., the slope of the line does not exist. In order to still represent the position of the line in this case, the analytical expression of the line PQ is expressed in the form of x = f(y), and the third shape function is obtained, i.e., the following formula (3).

[0082] x pq =-f1'(x p )(y-f1(x p ))+x p (3)

[0083] The straight line PQ in the same two-dimensional plane intersects the second shape function at point Q. By combining the second shape function (equation (2)) and the third shape function (equation (3), the third coordinate value (x) of the detection associated point, i.e., point Q, is obtained. q ) and the fourth coordinate value (y qThe expressions for the third and fourth coordinate values ​​are more complex. For ease of analysis and representation, we will directly use (x... q ,f2(x q )) represents the coordinates of the detected associated point, i.e., point Q, where the target rotation angle in the coordinates has been omitted.

[0084] The interface normal at point Q is perpendicular to the tangent at point Q, meaning the product of the slope of the interface normal and the derivative of the second shape function at point Q is -1. Given the coordinates of point Q, the analytical expression of the interface normal can be obtained according to the slope relationship and the two-point equation, as shown in equation (4) below.

[0085] x 界面法线 =-f2'(x q )(y-f2(x q ))+x q (4)

[0086] The angle between the incident detection wave and the interface normal is called the first angle, i.e. Figure 6 In this context, θ1 represents the angle between the refracted detection wave and the interface normal, which is called the second angle. Figure 6 θ2 in the equation. According to Snell's law, θ1 and θ2 satisfy the following equation (5).

[0087]

[0088] Where, n 外被层 is the refractive index of the outer coating, and is the relative refractive index of the outer coating of the exit medium and the air of the incident medium.

[0089] Assume the slope k of line PQ PQ The slope k of the normal to point Q ⊥ Both exist, and the exterior angle of a triangle is equal to the sum of the two interior angles that are not adjacent to it. Combining corresponding angles and equations (3) and (4), we can obtain the following equation (6).

[0090]

[0091] Where, θ PQ Let θ be the horizontal inclination angle of line PQ. ⊥ Let be the horizontal inclination angle of the interface normal, i.e., the angle relative to the first coordinate axis. In k... PQ and k ⊥ It does not exist, i.e., f'1(x) p ) = 0 and f'2(x q When ) = 0, equation (6) still holds true.

[0092] Combining equations (5) and (6), we can obtain equation (7).

[0093] θ1=arcsin(n 外被层sin(arccot(-f2'(x q ))-arccot(-f1'(x p )))) (7)

[0094] Given the coordinates of point Q, based on θ ⊥ The slope of the line containing line segment SQ can be obtained from θ1. Similarly, according to the two-point formula, the analytical expression of line SQ can be obtained, as shown in equation (8) below.

[0095]

[0096] Given that the focal length of the transmitting lens is f d The sum of line segment SQ and line segment PQ is the focal length, and the following formula (9) can be obtained.

[0097]

[0098] Based on equations (7), (8), and (9), the x-coordinate in the incident coordinates can be obtained. s and y s And the incident angle, as shown in equations (10), (11) and (12) below.

[0099]

[0100] x s =(cot(arccot(-f'2(x)) q ))-θ1))(y s -y q )+x q (11)

[0101]

[0102] Among them, the incident angle θ0 is the tilt angle of the detection wave emitting device, such as the detection probe, relative to the vertical line in the two-dimensional plane of the target, which is different from the target rotation angle α in the complete incident coordinate system.

[0103] By substituting the angles in equations (10), (11), and (12), we obtain equations (13), (14), and (15) below.

[0104]

[0105] x s =(cot(arccot(-f2'(x)) q ))-arcsin(n 外被层 sin(arccot(-f2'(x q ))-arccot(-f1'(x p ))))))(ys -y q )+x q (14)

[0107]

[0108] Based on equations (13), (14), and (15), it can be seen that, according to the coordinates of the detection point, the coordinates of the detection associated point, the first derivative of the first shape function at the target detection point (i.e., point P), the second derivative of the second shape function at the detection associated point (i.e., point Q), the refractive index of the outer coating, and the focal length of the emitting lens, the incident angle of the wave to be emitted at the target detection point and the fifth coordinate value (x) in the incident coordinates can be calculated. s ) and the sixth coordinate value (y s ).

[0109] Target rotation angle, fifth coordinate value (x) s ) and the sixth coordinate value (y s Together, they constitute the incident coordinates.

[0110] The cable has symmetry and periodicity. Based on equations (13), (14) and (15), the incident coordinates and incident angles corresponding to any target detection point in the cable armor layer can be calculated.

[0111] The accurate incident coordinates and incident angles are obtained through formula calculation, thereby improving detection efficiency.

[0112] Step 403: Based on the incident coordinates and incident angle corresponding to each target detection point, emit a detection wave to obtain the target reflected echo of each target detection point.

[0113] After obtaining the incident coordinates and incident angle corresponding to each target detection point, a detection wave can be emitted based on the incident coordinates and incident angle to obtain the target reflected echo reflected by each target detection point. The target reflected echo and the detection wave belong to the same waveband type. For example, if the emitted detection wave is a terahertz wave, the corresponding target reflected echo is also a terahertz wave.

[0114] In some embodiments, the step of transmitting a detection wave based on the incident coordinates and incident angle corresponding to each target detection point to obtain the target reflected echo of each target detection point includes: transmitting a detection wave according to the incident coordinates and incident angle corresponding to each target detection point to obtain a plurality of first reflected echoes; and performing band filtering based on the plurality of first reflected echoes to obtain the target reflected echo of the target detection point.

[0115] During the production, laying, and operation of cables, the surface of the cable may undergo slight deformation, and air gaps may form in the outer sheath. As a result, the incident and reflection paths of the armor layer will change, meaning that the actual reflection path of some target reflected echoes will differ slightly from the predicted reflection path, and thus cannot be received by the detection wave emitting device, i.e., the detection probe. Therefore, a secondary, refined scan can be performed on the non-signal areas, i.e., the target detection points, in the first scan.

[0116] In some embodiments, after performing band filtering based on multiple first reflected echoes, the method further includes: if the target reflected echo is not present among the multiple first reflected echoes, adjusting the incident angle based on correction parameters to obtain a correction angle; emitting a detection wave according to the incident coordinates and the correction angle to obtain multiple second reflected echoes; performing band filtering based on the multiple second reflected echoes; if the target reflected echo is present among the multiple second reflected echoes, performing the step of determining the defect detection result of each target detection point on the surface of the armor layer based on the target reflected echo; if the target reflected echo is not present among the multiple second reflected echoes, returning to the step of adjusting the incident angle based on correction parameters to obtain a correction angle.

[0117] Considering that deformation interference and air gap interference are usually small, and the outer sheath is thin, the overall change to the detection wave optical path is minimal. Therefore, only one or more minor corrections are needed based on the incident angle. The number of corrections is determined by whether the target reflected echo is collected. This solves the problem of target reflected echo loss caused by minor cable deformation and air gaps in the outer sheath.

[0118] The correction parameter is the adjustment angle range, which is within 5°. That is, the correction angle is any angle value in [θ0-5°, θ0+5°].

[0119] The detection wave itself has a certain width, for example, about 2 to 3 mm for terahertz waves. Therefore, with slight adjustments, the reflected echo from the target can be received.

[0120] Points on the cable that are in phase form concentric circles with the cable's axial centerline (the cable's center) as the center. The fifth coordinate value (x) of the target detection point located within the same concentric circle is... s ) and the sixth coordinate value (y s The incident angles are the same, but the target rotation angles differ.

[0121] After obtaining the incident coordinates and incident angle of a target detection point, defect detection can be performed on all points in the same phase as that point based on the incident coordinates and incident angle.

[0122] If the incident angle of the target detection point is adjusted, defect detection can be achieved for all points in the same phase as the target point based on the incident coordinates and the correction angle.

[0123] In some embodiments, if the incident angle is slightly corrected, and the final detection wave emission is achieved at the corrected angle, then the influence of the correction parameters needs to be considered during imaging. This is based on the correction angle relative to the incident coordinates, specifically the fifth coordinate value (x). s ) and the sixth coordinate value (y s Correct the fifth coordinate value (x) by combining the correction angle. s ) and the sixth coordinate value (y s The formula is expanded using Taylor series. Considering the small correction parameter, higher-order terms can be ignored to achieve linear simplification, resulting in the corrected correction coordinates. When detecting defects at points on the armor layer surface in the same phase as the target detection point, the corrected correction coordinates and fine-tuned correction angles can be used as a reference for defect detection.

[0124] By limiting the coordinates and angles of the detection wave emission, the detection wave is emitted and reaches the target detection point along a preset path. At the same time, the echo is reflected along the preset path, which improves the acceptability of the target reflected echo and the efficiency of defect detection.

[0125] In some embodiments, a detection wave emitting device is controlled to rotate around the axial centerline of the cable by a rotating platform or robotic arm, emitting a detection wave to achieve defect detection at the same phase point. The rotating platform or robotic arm can control the detection wave emitting device to move forward and backward, left and right, and up and down, allowing the detection wave emitting device to move flexibly in space, facilitating defect detection at various locations.

[0126] In some embodiments, the detection wave is a terahertz wave.

[0127] In some embodiments, the terahertz wave is a reflected terahertz wave.

[0128] The detection wave is emitted based on the incident coordinates and incident angle, or based on the incident coordinates and a slightly corrected angle. The incident and reflection paths of the detection wave are shown in the following example. Figure 7 .like Figure 7 As shown, Figure 7 This is a schematic diagram of a detection path for a non-flat structure object provided in an embodiment of this application. Figure 2 .Depend on Figure 7 It is understood that by determining the incident coordinates and incident angle / correction angle of the detection wave through the method described in this application, and then realizing the emission of the detection wave, the target reflected echo can be received at the emission position of the detection wave.

[0129] The outer sheath and armor layers of a cable exhibit certain regularity and periodicity in shape. Considering this periodicity, determining the incident coordinates and angles of other target detection points can be achieved by analyzing the incident coordinates and angles from the crest to the trough of a single segment of the cable. Through theoretical calculations, the incident coordinates and incident angle / correction angle corresponding to the detection wave propagation path being perpendicular to the armor layer surface are obtained. Based on the incident coordinates and incident angle / correction angle, a single-angle scan of the target detection points on the cable can complete the defect detection of the cable armor layer. At this point, the presence of defects along the detection wave propagation path and whether the defect surface is perpendicular to the propagation path can be identified through the target reflected echo.

[0130] This application uses the geometric characteristics of the cable and the propagation characteristics of the detection wave inside the cable to deduce the incident coordinates and incident angle of the detection wave, enabling imaging detection of surface defects in the cable armor layer. This solves the problem that two-dimensional terahertz wave imaging methods cannot image non-planar structures like cables. Points that do not require angle adjustment only need one incident detection. Compared with the existing multi-angle scanning method of terahertz three-dimensional imaging scanning, this saves a lot of detection time and data space, reduces data dimensions, and significantly improves the detection efficiency of defect detection in cable armor layers based on terahertz waves and other detection waves.

[0131] Step 404: Based on the target reflected echo, determine the defect detection results of each target detection point on the surface of the armor layer.

[0132] Imaging is achieved based on the reflected echo from the target to determine whether there are defects in the armor layer.

[0133] In some embodiments, determining the defect detection results of each target detection point on the surface of the armor layer based on the target reflected echo includes: parsing the target reflected echo to obtain distance information; constructing a three-dimensional image of the armor layer based on the distance information; and performing defect identification based on the three-dimensional image to obtain the defect detection results of each target detection point.

[0134] In addition, a three-dimensional image of the outer coating can be constructed based on the target's reflected echo, and then the presence of defects in the outer coating can be determined based on the three-dimensional image of the outer coating.

[0135] This application utilizes the geometric characteristics of cables and the penetrability of terahertz waves and other detection waves to materials, as well as the total reflection at the armor layer surface, to obtain the target reflected echo. Analysis based on this echo enables a more comprehensive and accurate reconstruction imaging of the armor layer surface, allowing for timely detection of armor layer defects and significantly improving cable defect detection efficiency. Simultaneously, based on the armor layer defect detection results, water ingress channels in the buffer layer can be promptly screened to determine if ablation defects exist, reducing the likelihood of ablation failures and accidents in the buffer layer and effectively ensuring equipment and personnel safety.

[0136] This application achieves the goal of defect detection in non-planar structures such as cables, broadening the application scope of terahertz wave and other detection wave imaging. It enhances the safety and stability of cables by detecting and evaluating their condition.

[0137] In this embodiment, the incident coordinates and incident angle of the detection wave to be emitted for each target detection point are calculated using cable parameters, detection wave emitting device parameters, and the detection point coordinates of each target detection point on the armor layer surface. Subsequently, the detection wave is emitted according to the calculated incident coordinates and incident angle. This method ensures the detection wave illuminates the target detection point at an optimal angle and position, improving the receptivity of the reflected echo. After receiving the reflected echo from the target detection point, defects on the armor layer surface are accurately detected by analyzing the reflected echo. This application, through precise calculation and positioning, effectively solves the problem of difficulty in receiving reflected echoes when using non-destructive testing techniques based on terahertz waves and other detection waves to detect defects in non-planar structures such as cables. It achieves the goal of detecting defects in cable armor layers using terahertz waves and other detection waves, and improves the efficiency and accuracy of the detection.

[0138] See Figure 8 , Figure 8 This is a structural diagram of a cable defect detection device provided in an embodiment of this application. For ease of explanation, only the parts related to the embodiment of this application are shown.

[0139] The cable defect detection device 800 includes: a coordinate determination module 801, a calculation module 802, a transmission module 803, and a defect detection module 804.

[0140] The coordinate determination module 801 is used to determine the coordinates of at least one target detection point located on the surface of the armor layer of the cable.

[0141] The calculation module 802 is used to calculate the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point based on the cable parameters, the detection wave transmitting device parameters, and the detection point coordinates of each target detection point.

[0142] The transmitting module 803 is used to transmit a detection wave based on the incident coordinates and the incident angle corresponding to each of the target detection points, so as to obtain the target reflected echo of each of the target detection points.

[0143] The defect detection module 804 is used to determine the defect detection results of each target detection point on the surface of the armor layer based on the target reflected echo.

[0144] In some embodiments, the cable parameters include a first shape function of the armor layer and a second shape function of the cable's outer sheath. The apparatus further includes a shape function determination module for:

[0145] A reference coordinate system is constructed using the axial centerline of the cable as the first coordinate axis and the predetermined radial line of the cable as the second coordinate axis, resulting in a reference two-dimensional plane; the target detection point may be located within or outside the reference two-dimensional plane.

[0146] Based on the reference coordinate system, the outer diameter at the peaks and troughs of the armor layer surface, and the distance between two adjacent peaks / troughs, the first shape function of the armor layer is determined.

[0147] The second shape function of the outer layer is determined based on the reference coordinate system, the outer diameter at the crests and troughs of the outer layer surface, and the distance between two adjacent crests / troughs.

[0148] In some embodiments, the coordinate determination module is specifically used for:

[0149] Obtain the first coordinate value and target rotation angle of each target detection point; the first coordinate value is the coordinate value of the target detection point on the first coordinate axis, and the target rotation angle is the angle between the target two-dimensional plane formed by the target detection point and the first coordinate axis and the plane of the reference two-dimensional plane along a set rotation direction;

[0150] Based on the first shape function and the first coordinate value of each target detection point, the second coordinate value of each target detection point is calculated;

[0151] The first coordinate value, the second coordinate value, and the target rotation angle of each target detection point constitute the detection point coordinates of the target detection point.

[0152] In some embodiments, the outer sheath surface has detection association points that correspond one-to-one with the target detection points. The detection association line segment formed by each target detection point and its corresponding detection association point is perpendicular to the tangent at the target detection point. The cable parameters include the refractive index of the outer sheath, and the detection wave emitting device parameters include the focal length of the emitting lens. The calculation module is specifically used for:

[0153] Based on the detection point coordinates of each target detection point and the first shape function, the third shape function of the detected associated line segment is calculated;

[0154] Intersection points are calculated based on the second shape function and the third shape function to obtain the third coordinate value and the fourth coordinate value of the detection associated point. The third coordinate value, the fourth coordinate value, and the target rotation angle constitute the coordinates of the detection associated point.

[0155] Calculate the first derivative of the first shape function at the target detection point, and the second derivative of the second shape function at the detection association point;

[0156] Based on the coordinates of the detection point, the coordinates of the detection associated point, the first derivative, the second derivative, the refractive index of the outer coating, and the focal length of the emitting lens, the incident coordinates and the incident angle of the detection wave to be emitted corresponding to the target detection point are calculated; the incident coordinates, the detection point coordinates, and the coordinates of the detection associated point corresponding to each target detection point are all located in the same target two-dimensional plane.

[0157] In some embodiments, the transmitting module is specifically used for:

[0158] According to the incident coordinates and incident angle corresponding to each target detection point, a detection wave is emitted to obtain multiple first reflected echoes;

[0159] Based on multiple first reflected echoes, band filtering is performed to obtain the target reflected echo of the target detection point.

[0160] If the target reflected echo is not present among the multiple first reflected echoes, the incident angle is adjusted based on the correction parameters to obtain the correction angle;

[0161] A detection wave is emitted according to the incident coordinates and the correction angle to obtain multiple second reflected echoes;

[0162] Band selection is performed based on multiple second reflected echoes;

[0163] If the target reflection echo is present among the multiple second reflection echoes, then the step of determining the defect detection result of each target detection point on the surface of the armor layer based on the target reflection echo is performed;

[0164] If the target reflected echo is not present among the multiple second reflected echoes, then return to the step of adjusting the incident angle based on the correction parameters to obtain the correction angle.

[0165] In some embodiments, the defect detection module is specifically used for:

[0166] Analyze the reflected echo from the target to obtain distance information;

[0167] Based on the distance information, a three-dimensional image of the armor layer is constructed;

[0168] Defect identification is performed based on the three-dimensional image to obtain the defect detection results for each of the target detection points.

[0169] The cable defect detection device provided in this application embodiment can realize all the processes of the above-described cable defect detection method embodiment and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0170] Figure 9 This is a structural diagram of an electronic device provided in an embodiment of this application. As shown in the figure, the electronic device 9 of this embodiment includes: at least one processor 90 ( Figure 9 (Only one is shown in the diagram), memory 91, and computer program 92 stored in said memory 91 and executable on said at least one processor 90, which, when executed, implements the steps in any of the above method embodiments.

[0171] The electronic device 9 can be a desktop computer, laptop, handheld computer, or cloud server, etc. The electronic device 9 may include, but is not limited to, a processor 90 and a memory 91. Those skilled in the art will understand that... Figure 9 This is merely an example of electronic device 9 and does not constitute a limitation on electronic device 9. It may include more or fewer components than shown, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0172] The processor 90 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0173] The memory 91 can be an internal storage unit of the electronic device 9, such as a hard disk or memory. The memory 91 can also be an external storage device of the electronic device 9, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory 91 can include both internal and external storage units of the electronic device 9. The memory 91 is used to store the computer program and other programs and data required by the electronic device. The memory 91 can also be used to temporarily store data that has been output or will be output.

[0174] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0175] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0176] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0177] In the embodiments provided in this application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0178] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0179] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0180] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0181] The processes in the above-described embodiments can be implemented by a computer program product. When the computer program product is run on an electronic device, the electronic device executes the steps in the above-described method embodiments.

[0182] The above-described 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, and should all be included within the protection scope of this application.

Claims

1. A method for detecting defects in cables, characterized in that, include: Determine the coordinates of at least one target detection point located on the surface of the cable's armor layer; Based on the cable parameters, the parameters of the detection wave transmitting device, and the detection point coordinates of each target detection point, the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point are calculated. Based on the incident coordinates and incident angle corresponding to each target detection point, a detection wave is emitted to obtain the target reflected echo of each target detection point. Based on the reflected echo from the target, the defect detection results of each target detection point on the surface of the armor layer are determined; The cable parameters include a first shape function of the armor layer and a second shape function of the outer sheath of the cable. Before determining the coordinates of at least one target detection point located on the surface of the armor layer of the cable, the method further includes: constructing a reference coordinate system using the axial centerline of the cable as the first coordinate axis and a predetermined radial line of the cable as the second coordinate axis to obtain a reference two-dimensional plane; the target detection point is either inside or outside the reference two-dimensional plane; based on the reference coordinate system, the outer diameter at the crests and troughs of the armor layer surface, and the distance between two adjacent crests / troughs, the first shape function of the armor layer is determined, wherein the first shape function is: Based on the reference coordinate system, the outer diameters at the crests and troughs of the outer coating surface, and the distance between two adjacent crests / troughs, the second shape function of the outer coating is determined. The second shape function is: ;in, and These are surface shape functions for the armor layer and the outer layer, respectively. and These are the outer diameters at the crests and troughs of the armor layer surface, respectively. and These are the outer diameters at the crests and troughs of the outer coating surface, respectively. D The distance between two adjacent peaks / troughs; The step of determining the detection point coordinates of at least one target detection point located on the surface of the cable armor layer includes: acquiring a first coordinate value and a target rotation angle for each target detection point; the first coordinate value is the coordinate value of the target detection point on the first coordinate axis, and the target rotation angle is the angle between the target two-dimensional plane formed by the target detection point and the first coordinate axis and the reference two-dimensional plane along a set rotation direction; calculating a second coordinate value for each target detection point based on the first shape function and the first coordinate value of each target detection point; the first coordinate value, the second coordinate value, and the target rotation angle of each target detection point constitute the detection point coordinates of the target detection point; The outer sheath surface has detection association points that correspond one-to-one with the target detection points. The detection association line segment formed by each target detection point and the corresponding detection association point is perpendicular to the tangent at the target detection point. The cable parameters include the refractive index of the outer sheath, and the detection wave emitting device parameters include the focal length of the emitting lens. The calculation of the incident coordinates and incident angle of the detection wave corresponding to each target detection point, based on cable parameters, detection wave transmitting device parameters, and the detection point coordinates of each target detection point, includes: calculating the third shape function of the detection-related line segment based on the detection point coordinates of each target detection point and the first shape function. The incident coordinates, detection point coordinates, and detection-related point coordinates of each target detection point are all located on the same target two-dimensional plane. In the calculation, the target rotation angle is omitted, and only the x and y values ​​are represented. The third shape function is... Wherein, the target detection point is a point. P ,point P Coordinates are ( x p , f 1( x p The detection association point is a point. Q ,point Q Coordinates are ( x q , f 2( x q Based on the second shape function and the third shape function, the intersection point is calculated to obtain the third coordinate value and the fourth coordinate value of the detection associated point. The third coordinate value, the fourth coordinate value, and the target rotation angle constitute the coordinates of the detection associated point. The first derivative of the first shape function at the target detection point and the second derivative of the second shape function at the detection associated point are calculated. Based on the coordinates of the detection point, the coordinates of the detection associated point, the first derivative, the second derivative, the refractive index of the outer coating, and the focal length of the emitting lens, the incident coordinates and the incident angle of the detection wave to be emitted corresponding to the target detection point are calculated. The calculation specifically includes: , , ,in, The focal length of the transmitting lens, The relative refractive index of the outer coating of the exit medium and the incident medium air is given by ( ). x s , y s The incident angle is .

2. The method according to claim 1, characterized in that, The step of transmitting a detection wave based on the incident coordinates and incident angle corresponding to each target detection point to obtain the target reflected echo at each target detection point includes: According to the incident coordinates and incident angle corresponding to each target detection point, a detection wave is emitted to obtain multiple first reflected echoes; Based on multiple first reflected echoes, band filtering is performed to obtain the target reflected echo of the target detection point.

3. The method according to claim 2, characterized in that, After performing band filtering based on multiple first reflected echoes, the method further includes: If the target reflected echo is not present among the multiple first reflected echoes, the incident angle is adjusted based on the correction parameters to obtain the correction angle; A detection wave is emitted according to the incident coordinates and the correction angle to obtain multiple second reflected echoes; Band selection is performed based on multiple second reflected echoes; If the target reflection echo is present among the plurality of second reflection echoes, then the step of determining the defect detection result of each target detection point on the surface of the armor layer based on the target reflection echo is executed; if the target reflection echo is not present among the plurality of second reflection echoes, then the step of adjusting the incident angle based on the correction parameter to obtain the correction angle is returned to be executed.

4. The method according to claim 1, characterized in that, The step of determining the defect detection results of each target detection point on the surface of the armor layer based on the target reflected echo includes: Analyze the reflected echo from the target to obtain distance information; Based on the distance information, a three-dimensional image of the armor layer is constructed; Defect identification is performed based on the three-dimensional image to obtain the defect detection results for each of the target detection points.

5. A cable defect detection device, said device being used to perform the method as described in any one of claims 1-4, characterized in that, include: A coordinate determination module is used to determine the coordinates of at least one target detection point located on the surface of the cable's armor layer. The calculation module is used to calculate the incident coordinates and incident angle of the detection wave to be emitted corresponding to each target detection point based on cable parameters, detection wave transmitting device parameters, and the detection point coordinates of each target detection point. The transmitting module is used to transmit a detection wave based on the incident coordinates and the incident angle corresponding to each target detection point, so as to obtain the target reflected echo of each target detection point. The defect detection module is used to determine the defect detection results of each target detection point on the surface of the armor layer based on the target reflected echo.

6. An electronic device, characterized in that, The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the computer program, it causes the electronic device to perform the method as described in any one of claims 1 to 4.

7. A computer program product, characterized in that, Includes a computer program, which, when run, causes the method as described in any one of claims 1 to 4 to be performed.

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