Cable life determination method, system and device and computer readable storage medium

Abstract

The invention discloses a cable life determination method, system and device and a computer readable storage medium, and relates to the field of life estimation of vehicle parts, and the method comprises the steps: firstly, determining a torsion angle of a single-end torsion angle when a to-be-detected cable passes through a preset limit line; and determining the failure times of the to-be-tested cable based on the torsion angle and the corresponding relationship between the preset torsion angle and the failure times, thereby realizing the estimation of the service life of the cable. Visibly, the application considers that the single-end torsion angle of the cable, especially the single-end torsion angle when the cable passes through the preset limit line, has direct influence on the maximum working times, namely the failure times, of the cable, so that after the torsion angle of the single-end torsion angle when the to-be-detected cable passes through the preset limit line is determined, the maximum working times, namely the failure times, of the cable is determined. The service life of the to-be-tested cable can be estimated based on the torsion angle and the corresponding relation between the preset torsion angle and the failure frequency, and the accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of life estimation of vehicle components, and in particular to a method, system, device and computer-readable storage medium for determining the life of a cable. Background Art

[0002] Cables are usually installed between the carriages of a train. When the train passes through extreme lines such as curves, switches and ramps, the relative sway and nodding of the carriage parts will cause the spatial position and posture of the cable clamping points to change. The wire clamps drive the cables to move relative to each other. The cables will experience mechanical fatigue during long-term operation, which will affect the life of the cables. However, there is no solution for estimating the life of cables in the relevant technology. Therefore, how to estimate the life of cables is a problem that technical personnel in this field need to solve. Summary of the invention

[0003] The purpose of the present invention is to provide a method, system, device and computer-readable storage medium for determining the life of a cable. After determining the torsion angle of a single-end torsion angle of a cable to be tested when it passes through a preset limit line, the life of the cable to be tested can be estimated based on the corresponding relationship between the torsion angle and the preset torsion angle and the number of failures, with high accuracy.

[0004] In order to solve the above technical problems, the present invention provides a method for determining the life of a cable, comprising:

[0005] Determine the torsion angle of the single-end torsion angle of the cable under test when it passes through a preset limit line;

[0006] Determining the number of failures of the cable to be tested based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures;

[0007] The preset limit line is a point where the spatial position and posture of the clamping point of the cable to be tested change and the change amount is greater than a preset change amount, and the number of failures is the maximum number of times the cable can pass through the preset limit line.

[0008] Optionally, the process of determining the corresponding relationship between the preset torsion angle and the number of failures is as follows:

[0009] Determining the lengths of N cables, wherein the lengths of the N cables are different, and N is an integer not less than 2;

[0010] Converting the single-end torsion angles of the clamping points of the N cables when passing through the preset limit line into torsion angles per preset length, wherein the preset length is less than or equal to the minimum length of the N cables;

[0011] Determining the number of failures of each of the cables when passing through the preset limit line;

[0012] Determining a corresponding relationship between a preset torsion angle and a failure number based on the torsion angle of each preset length corresponding to the N cables and the failure number;

[0013] After determining the torsion angle of the single-end torsion angle of the cable under test when passing through the preset limit line, the method further includes:

[0014] The torsion angle of the single-end torsion angle of the cable to be tested is converted into a torsion angle per preset length.

[0015] Optionally, the corresponding relationship between the preset torsion angle and the number of failures is:

[0016] φ=-A*In(n)+B;

[0017] Where φ is the torsion angle per preset length, n is the number of failures, and A and B are life calculation coefficients.

[0018] Optionally, converting the torsion angle of the single-end torsion angle of the cable to be tested into a torsion angle per preset length comprises:

[0019] Determining the single-end torsion angle and design length of the cable to be tested;

[0020] The ratio of the single-end torsion angle divided by the design length is taken as the torsion angle per unit length;

[0021] The product of the torsion angle per unit length and the preset length is taken as the torsion angle per preset length.

[0022] Optionally,

[0023] Determine the torsion angle of the single-end torsion angle of the cable under test when it passes through a preset limit line, including:

[0024] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line by using the angle scale and the indicating pointer on the cable torsion angle test device;

[0025] The cable torsion angle testing device comprises:

[0026] Two longitudinal guide rails and two transverse guide rails are arranged in parallel with each other, both ends of the two transverse guide rails are slidably connected to the two longitudinal guide rails through sliders, the two transverse guide rails can rotate relative to the sliders, the two transverse guide rails are respectively provided with wire clamps, the wire clamps are provided with bearings, the cable to be tested is passed through the inner ring of the bearing, the outer ring of the bearing is fixed to the wire clamp, the inner ring can rotate relative to the outer ring, the wire clamp is provided with an angle scale, and the cable to be tested is provided with a value indicating pointer that cooperates with the angle scale;

[0027] The longitudinal guide rail is provided with a longitudinal displacement scale, and the transverse guide rail is provided with a transverse displacement scale.

[0028] Optionally, determining the torsion angle of a single-end torsion angle of the cable to be tested when passing through a preset limit line includes:

[0029] Determine the longitudinal spacing between the clamping points at both ends of the cable under test, the outlet angles of the clamping points, and the transverse spacing when the cable under test passes through a preset limit line;

[0030] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through a preset limit line based on the longitudinal spacing, the outlet angle of the clamping point and the transverse spacing;

[0031] Among them, the longitudinal spacing is the distance between the two clamping points along the vehicle length direction, the line outlet angle is the angle between the axis of the cable to be tested at the clamping point and the horizontal plane, and the lateral spacing is the displacement of the two clamping points along the horizontal lateral direction.

[0032] Optionally, determining the torsion angle of a single-end torsion angle of the cable to be tested when passing through a preset limit line based on the longitudinal spacing, the outlet angle of the clamping point and the transverse spacing includes:

[0033] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line based on the longitudinal spacing, the outlet angle of the clamping point, the transverse spacing and the preset torsion angle calculation relationship;

[0034] The preset torsion angle calculation formula is:

[0035]

[0036] Among them, α is the torsion angle of the single-end torsion angle, L is the longitudinal spacing, β is the lead-out angle of the clamping point, and W is the lateral spacing.

[0037] In order to solve the above technical problems, the present invention also provides a cable life determination system, comprising:

[0038] A torsion angle determination unit, used to determine the torsion angle of a single-end torsion angle of the cable to be tested when it passes through a preset limit line;

[0039] A life determination unit, configured to determine the number of failures of the cable to be tested based on the torsion angle and a correspondence between a preset torsion angle and the number of failures;

[0040] The preset limit line is a point where the spatial position and posture of the clamping point of the cable to be tested change and the change is greater than a preset change, and the number of failures is the maximum number of times the cable can pass through the preset limit line.

[0041] In order to solve the above technical problems, the present invention further provides a device for determining the life of a cable, comprising:

[0042] Memory for storing computer programs;

[0043] A processor is used to implement the steps of the cable life determination method as described above when executing the computer program.

[0044] In order to solve the above technical problem, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the cable life determination method as described above are implemented.

[0045] The present invention provides a method for determining the life of a cable, first determining the torsion angle of a single-end torsion angle of a cable to be tested when it passes through a preset limit circuit, and then determining the number of failures of the cable to be tested based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures, thereby realizing the estimation of the life of the cable. It can be seen that the present application takes into account that the single-end torsion angle of the cable, especially the single-end torsion angle of the cable to be tested when it passes through a preset limit circuit, has a direct impact on the number of working times of the cable. Therefore, after determining the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit circuit, the life of the cable to be tested can be estimated based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures, with high accuracy.

[0046] The present invention also provides a cable life determination system, device and computer-readable storage medium, which have the same beneficial effects as the above-mentioned cable life determination method. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0048] Figure 1 A process flow chart of a method for determining the life of a cable provided by the present invention;

[0049] Figure 2 A schematic diagram of cable layout in a workshop provided by the present invention;

[0050] Figure 3 A schematic diagram of a cable with a 90° lead-out angle provided by the present invention;

[0051] Figure 4 A schematic diagram of a cable bending and torsion coupling posture change provided by the present invention;

[0052] Figure 5 A schematic diagram of a longitudinal spacing between clamping points of a cable provided by the present invention after a posture change;

[0053] Figure 6 A schematic diagram of a vertical rotational motion of a cable according to the present invention;

[0054] Figure 7 A schematic diagram of cable movement under a horizontal limit lead-out angle state provided by the present invention;

[0055] Figure 8 A schematic diagram of the combined motion decomposition of a cable provided by the present invention;

[0056] Fig. 9 A schematic diagram of the geometric representation of cable movement through a hexahedron provided by the present invention;

[0057] Fig.10 A schematic structural diagram of a cable torsion angle testing device provided by the present invention;

[0058] Fig.11 A physical diagram of a cable torsion angle testing device provided by the present invention;

[0059] Fig.12 A schematic diagram of an angle scale and an indicating pointer provided by the present invention;

[0060] Fig.13 A schematic diagram of an angle scale and an indicating pointer provided by the present invention;

[0061] Fig.14 A schematic diagram of a wire clamp and a cable to be tested provided by the present invention;

[0062] Fig.15 A schematic diagram of the structure of a cable life determination system provided by the present invention;

[0063] Fig.16 A schematic structural diagram of a device for determining the life of a cable provided by the present invention. DETAILED DESCRIPTION

[0064] The core of the present invention is to provide a method, system, device and computer-readable storage medium for determining the life of a cable. After determining the torsion angle of the single-end torsion angle of the cable to be tested when passing through a preset limit line, the life of the cable to be tested can be estimated based on the corresponding relationship between the torsion angle and the preset torsion angle and the number of failures, with high accuracy.

[0065] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Please refer to Figure 1 , Figure 1 A process flow chart of a method for determining the life of a cable provided by the present invention, the method comprising:

[0067] S11: determining a torsion angle of a single-end torsion angle of the cable to be tested when the cable passes through a preset limit line;

[0068] It should be noted that in actual applications, the two ends of the cable are fixed at horizontally symmetrical positions of the two carriages by wire clamps (the clamping position is also called the clamping point), and there is no initial lateral misalignment. Figure 2 As shown, Figure 2 A schematic diagram of cable layout in a workshop provided by the present invention.

[0069] When the circumferential degree of freedom of the cable at the clamping point is constrained, the cable will not rotate, but due to the lateral displacement of the clamping point, the cable cross section will be subjected to torque around the axis. To measure the torsion angle, the circumferential degree of freedom of the cable at the clamping point needs to be released. The free rotation angle around its own axis generated by the root of the cable after the lateral movement of the clamping point is the torsion angle. The reference plane of the torsion angle is the normal plane passing through the root axis and perpendicular to the plane where the current cable is located. The calculation of the torsion angle under different lead-out angles can be converted into the calculation of the relative angle between the reference plane of the initial position and the position after the posture change. Based on this, the angle between the clamping point line at the initial position and the clamping point line after the posture change is defined as the single-end torsion angle.

[0070] Furthermore, when the cable passes through a straight line, the torsion angle of the single-end torsion angle is usually 0, while when passing through some extreme lines, the single-end torsion angle of the cable is usually larger. Analogous to the barrel effect, the life of the cable is most affected by the extreme line. Generally, the more extreme the line, the larger the torsion angle of the single-end torsion angle of the cable. The more times the cable is subjected to a large single-end torsion angle, the shorter the remaining life of the cable. The torsion angle of the single-end torsion angle of the cable is negatively correlated with the life of the cable. The larger the torsion angle of the single-end torsion angle when the cable passes through the line, the shorter the life of the cable. In this application, the life of the cable is characterized by the number of failures, that is, the maximum number of times the cable can pass through a preset extreme line.

[0071] In the present application, the preset limit line can be determined by the usage scenario of the cable to be tested in actual application. For example, the road conditions of some vehicle driving routes can be predetermined, and the line corresponding to the maximum torsion angle of the single-end torsion angle of the cable between the vehicle carriages can be determined from the driving route. This line can be used as the preset limit line. In actual application, the preset limit line is usually an S curve, a turnout and a ramp.

[0072] It should also be noted that the solution of the present application can be used in the design stage of the cable to be tested. The single-end torsion angle of the cable to be tested when passing through a preset limit line can be determined by the usage scenario of the vehicle in which the cable to be tested is located, so as to subsequently estimate the service life of the cable based on the torsion angle.

[0073] S12: Determine the number of failures of the cable to be tested based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures;

[0074] The preset limit line is a point where the spatial position and posture of the clamping point of the cable to be tested change and the change amount is greater than the preset change amount, and the number of failures is the maximum number of times the cable can pass through the preset limit line.

[0075] Specifically, in practical applications, the corresponding relationship between the torsion angle of the single-end torsion angle of the cable and the number of failures can be established in advance. For example, the torsion angles of the single-end torsion angles of multiple cables can be determined in advance, and then a vehicle-side six-degree-of-freedom test bench can be used to perform fatigue tests on the cables to obtain the number of failures corresponding to the multiple cables, and then the corresponding relationship between the torsion angle and the number of failures is obtained based on the torsion angles of the single-end torsion angles of the multiple cables and the corresponding number of failures.

[0076] After obtaining the correspondence between the preset torsion angle and the number of failures, if the torsion angle of the single-end torsion angle of the cable to be tested is determined, the number of failures of the cable to be tested is determined based on the torsion angle and the correspondence between the preset torsion angle and the number of failures. The number of failures here is also the life of the cable to be tested.

[0077] It can be seen that the present application takes into account that the single-ended torsion angle of the cable, especially the single-ended torsion angle of the cable to be tested when passing through the preset limit circuit, has a direct impact on the number of working times of the cable. Therefore, after determining the torsion angle of the single-ended torsion angle of the cable to be tested when passing through the preset limit circuit, the life of the cable to be tested can be estimated based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures, with high accuracy.

[0078] Based on the above embodiments:

[0079] As a preferred embodiment, the process of determining the correspondence between the preset torsion angle and the number of failures is as follows:

[0080] Determine the lengths of N cables, wherein the lengths of the N cables are different, and N is an integer not less than 2;

[0081] Convert the single-end torsion angles of the clamping points of the N cables when they pass through the preset limit line into torsion angles per preset length, wherein the preset length is less than or equal to the minimum length of the N cables;

[0082] Determine the number of failures of each cable after passing through a preset limit line;

[0083] Determine a corresponding relationship between a preset torsion angle and a failure number based on the torsion angle of each preset length corresponding to the N cables and the failure number;

[0084] After determining the torsion angle of the single-end torsion angle of the cable under test when passing through the preset limit line, the method further includes:

[0085] The twist angle of the single-end twist angle of the cable to be tested is converted into a twist angle per preset length.

[0086] Specifically, in order to obtain the corresponding relationship between the preset torsion angle and the number of failures, the lengths of N cables can be determined first, and the lengths of the N cables are different. Then, the single-end torsion angles of the N cables are calculated when the clamping point passes through the preset limit line. In order to uniformly evaluate the torsion angles of the cables, the single-end torsion angles of the cables are converted into torsion angles per preset length, that is, the single-segment torsion angles of the cables are converted into torsion angles under uniform lengths, and the preset lengths here are not greater than the minimum length of the N cables. For example, if there are cables of 1.5m, 1.2m, and 0.8m, respectively, the torsion angles of the single-end torsion angles of the cables of 1.5m, 1.2m, and 0.8m can be converted into torsion angles per 0.5m. Then, the number of failures of each cable passing through the preset limit line is determined. Finally, based on the torsion angles of each preset length of the N groups of cables and the corresponding number of failures, the corresponding relationship between the preset torsion angles and the number of failures can be determined.

[0087] Adaptively, when estimating the life of the cable to be tested, after determining the torsion angle of the single-end torsion angle of the cable to be tested when passing through a preset limit line, it is also necessary to convert the torsion angle of the single-end torsion angle of the cable to be tested into a torsion angle per preset length so as to obtain the torsion angle at a uniform length.

[0088] It can be seen that in the present application, the preset torsion angle in the corresponding relationship is the torsion angle at each preset length, that is, the uniform length. When the life of the cable to be tested is subsequently estimated, the torsion angle of the cable to be tested can be converted into the torsion angle at the uniform length, so as to estimate the life of the cable to be tested based on the torsion angle at the uniform length with high accuracy.

[0089] As a preferred embodiment, the corresponding relationship between the preset torsion angle and the number of failures is:

[0090] φ=-A*In(n)+B;

[0091] Where φ is the torsion angle per preset length, n is the number of failures, and A and B are life calculation coefficients.

[0092] It should be noted that when the corresponding relationship between the preset torsion angle and the number of failures is obtained based on the torsion angle of each preset length of N groups of cables and the corresponding number of failures, A and B in φ=-A*In(n)+B can be obtained.

[0093] After determining the torsion angle of each preset length of the cable to be tested, the torsion angle of each preset length can be substituted into the corresponding relationship between the preset torsion angle and the number of failures to obtain the number of failures of the cable to be tested, that is, the service life.

[0094] As a preferred embodiment, converting the torsion angle of a single-end torsion angle of a cable to be tested into a torsion angle per preset length includes:

[0095] Determine the single-end torsion angle and design length of the cable to be tested;

[0096] The ratio of the single-end torsion angle divided by the design length is taken as the torsion angle per unit length;

[0097] The product of the torsion angle per unit length and the preset length is taken as the torsion angle per preset length.

[0098] Specifically, after obtaining the single-end torsion angle and design length of the cable to be tested, the torsion angle per preset length can be obtained by torsion angle per unit length = single-end torsion angle / design length, and then multiplying the torsion angle per unit length by the preset length.

[0099] For example, the torsion angle of a single end with a length of 0.8 m is 30 degrees, and each preset length is 0.5 m. Then, the torsion angle of each preset length is 30 / 0.8*0.5=18.75 degrees.

[0100] It can be seen that, through this method, the torsion angle for each preset length can be determined simply and reliably.

[0101] As a preferred embodiment, the preset limit line is an S curve.

[0102] In practical applications, considering that when a vehicle passes through an S curve, the single-end torsion angle of the cable at the clamping point of the car body is usually relatively large, the preset limit line can be an S curve. Of course, it can also be other limit lines, which are specifically determined according to the actual driving route of the vehicle where the cable to be tested is located.

[0103] As a preferred embodiment, determining the torsion angle of a single-end torsion angle of a cable to be tested when it passes through a preset limit line includes:

[0104] Determine the longitudinal spacing between the clamping points at both ends of the cable under test, the lead-out angle of the clamping points, and the lateral spacing when the cable under test passes through the preset limit line;

[0105] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through a preset limit line based on the longitudinal spacing, the lead-out angle of the clamping point and the transverse spacing;

[0106] Among them, the longitudinal spacing is the distance between the two clamping points along the vehicle length direction, the cable outlet angle is the angle between the axis of the cable to be tested at the clamping point and the horizontal plane, and the transverse spacing is the displacement of the two clamping points along the horizontal transverse direction.

[0107] Specifically, both ends of the cable are fixed at horizontally symmetrical positions of the two carriages by wire clamps, with no initial lateral misalignment. During the relative movement of the clamping points, the length of the cable is sufficient to adapt to the bending and torsional deformation generated by the cable.

[0108] The geometric parameters of the cable are defined as follows:

[0109] 1) Longitudinal spacing L: the distance between two clamping points along the vehicle length;

[0110] 2) Cable outlet angle β: the angle between the cable axis at the clamping point and the horizontal plane (0-90°);

[0111] 3) Transverse spacing W: The displacement along the horizontal lateral direction caused by the movement of the workshop, that is, the displacement of the two clamping points along the horizontal lateral direction.

[0112] When the cable outlet angle β=90° (such as Figure 3 As shown, Figure 3 Schematic diagram of a cable with an outlet angle of 90° provided by the present invention), when the longitudinal spacing is L, the cross-sectional state of the cable end corresponding to the lateral displacement W of the clamping point is as follows Figure 4 As shown, Figure 4 A schematic diagram of the cable bending and torsion coupling posture change provided by the present invention, wherein the rotational freedom of the cable cross section at the clamping point is constrained during the movement.

[0113] In order to analyze the cable root torsion at the clamping point before and after the posture change, the motion process is decomposed into a combined motion of bending and rotation.

[0114] Step 1: Longitudinal bending. The longitudinal spacing between the clamping points increases from L to like Figure 5 As shown, Figure 5 A schematic diagram of a longitudinal spacing between clamping points of a cable provided by the present invention after a posture change;

[0115] Step 2: Vertical rotation. The cable rotates clockwise around the top clamping point to the final position. This rotation process is a free process without torsional deformation at the root of the cable. Figure 6 As shown, Figure 6 It is a schematic diagram of the vertical rotational motion of a cable according to the present invention.

[0116] Define the angle between the clamping point line at the initial position and the clamping point line after the posture change as α (i.e., the single-end torsion angle). Considering the torsion of the double clamping points relative to the initial position, the relative torsion angle of the cable root after the cable moves horizontally is 2α. Considering the limit of the cable outlet angle in the horizontal plane, when the outlet angle β = 0°, the axes of the clamping points at both ends of the cable are collinear. After the cable moves horizontally, the axes of the two clamping points move, but they are still parallel to each other and remain in the same plane, such as Figure 7 As shown, Figure 7 A schematic diagram of cable movement under a horizontal extreme lead-out angle state provided by the present invention. The root section does not rotate relative to the respective axis, so the relative torsion angle is 0°. According to the analysis of the root torsion characteristics of cables with extreme lead-out angles of 0° and 90°, the root torsion of any other lead-out angle is a theoretical model for calculating the torsion of the lead-out angle between 0° and 90°.

[0117] Based on the above analysis, it is not difficult to obtain that the torsion angle of the single-ended torsion angle is related to the longitudinal spacing between the clamping points at both ends of the cable to be tested when passing through the preset limit line, the outlet angle of the clamping points, and the lateral spacing. Therefore, in order to obtain the torsion angle of the single-ended torsion angle of the cable to be tested, it is necessary to first determine the longitudinal spacing between the clamping points at both ends of the cable to be tested when the cable to be tested passes through the preset limit line, the outlet angle of the clamping points, and the lateral spacing.

[0118] As a preferred embodiment, determining the torsion angle of the single-end torsion angle of the cable to be tested when passing through a preset limit line based on the longitudinal spacing, the outlet angle of the clamping point and the transverse spacing includes:

[0119] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line based on the longitudinal spacing, the outlet angle of the clamping point, the transverse spacing and the preset torsion angle calculation relationship;

[0120] The preset torsion angle calculation formula is:

[0121]

[0122] Among them, α is the torsion angle of the single-end torsion angle, L is the longitudinal spacing, β is the lead-out angle of the clamping point, and W is the lateral spacing.

[0123] The process of determining the preset torsion angle calculation relationship is:

[0124] Refer to the analysis method of the 90° posture change of the cable outlet angle to decompose the spatial movement of the cable clamping point under any cable outlet angle into longitudinal bending and vertical rotation. Please refer to Figure 8 and Fig. 9 , Figure 8 A schematic diagram of the combined motion decomposition of a cable provided by the present invention, Fig. 9 A schematic diagram of the geometric representation of cable motion through a hexahedron provided by the present invention. The top surface of the hexahedron is constructed with the initial coordinate point and the position change coordinate point of the cable clamping point as vertices (points O, C, and E); the diagonal surface of the hexahedron is constructed with the position change coordinate points C and E of the clamping point and the intersection point D of the cable axis at the rotation point and the vertical lead line at point E as the vertex.

[0125] Obviously, in the constructed hexahedron, the cable root outlet angle β = ∠COB, the longitudinal spacing L = |OC|, the lateral spacing W = |CE|, the surface OABC is the plane where the cable is located in the initial position, the surface OADE is the plane where the cable is located after rotation, and OB and OD are the axes of the cable clamping point O in the initial position and after rotation, respectively.

[0126] Obviously, to calculate the relative torsion between the initial position and the vertical rotating cable section, it is necessary to select a reference plane of each axis and determine the relative torsion of the two axes by calculating the relative rotation angle of the two reference planes.

[0127] The normal plane passing through the root axis and perpendicular to the plane where the cable is located is selected as the reference plane: in the initial position, the normal plane passing through the axis OB and perpendicular to the plane OABC is the plane OBD, which is defined as the reference plane of the initial axis OB (denoted as plane η); in the position after vertical rotation, the normal plane passing through the axis OD and perpendicular to the plane OADE is defined as the reference plane of the rotation axis OD (denoted as plane λ). It is not difficult to infer that after the vertical lead of the cable around the root O rotates without torsion as a whole, the initial reference plane η is transformed into the rotation reference plane λ, and the reference plane λ is not drawn in the hexahedron. Considering that the initial reference plane η intersects with the plane OADE where the rotating cable is located at the rotation axis OD, and the plane OADE⊥λ, the calculation of the rotation angle between the reference plane η and the reference λ can be equivalent to the calculation of the complementary angle of the angle between the reference plane η and the normal plane OADE of the reference plane λ, that is, the complementary angle between the plane OBD and the plane OADE.

[0128] In the geometric method, the angle between the normals of two faces can be calculated as the angle between the two faces. In the face OCE, draw a straight line CP⊥OE through point C; since OA⊥face OCE, CP⊥OA. Therefore, CP⊥face OADE, and CP is the normal of face OADE. In the face OCB, draw a straight line CQ⊥OB through point C; since DB⊥face OBC, CQ⊥DB. Therefore, CQ⊥face OBD, and CQ is the normal of face OBD.

[0129] In summary, the calculation of the angle between the surfaces OBD and OADE is converted into the problem of calculating the angle between the normal lines CP and CQ, that is, the problem of solving the internal angle ∠PCQ in △CPQ.

[0130] In a hexahedron, the height of the hexahedron is defined by the outgoing line angle:

[0131] H=|CB|=tanβ·L (1)

[0132] In △OCE and △OCB, the equal area method gives:

[0133]

[0134]

[0135] The side length |PQ| can be calculated indirectly by the cosine theorem of △OED and △OPQ. In △OED, the cosine theorem gives:

[0136]

[0137] In △OCE and △OCB, the triangles are similar:

[0138]

[0139]

[0140] In △OPQ, since ∠POQ=∠EOD, according to the cosine theorem:

[0141]

[0142] In △PCQ, the cosine theorem gives:

[0143]

[0144] Substituting formula (1) into formula (6), we get:

[0145]

[0146] By definition, the single-ended torsion angle at the cable clamping point is the complementary angle of ∠PCQ:

[0147]

[0148] Equation (8) gives the calculation model of the single-end torsion angle of the cable clamping point. Obviously, when the lead-out angle β = 0°, the single-end torsion angle α = 0°; when the lead-out angle β = 90°, the single-end torsion angle α = tan -1 (W / L), which is consistent with the analysis conclusion of the limit lead-out angle in the previous article.

[0149] As a preferred embodiment, determining the torsion angle of a single-end torsion angle of a cable to be tested when it passes through a preset limit line includes:

[0150] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line by using the angle scale and the indicating pointer on the cable torsion angle test device;

[0151] The cable torsion angle test device includes:

[0152] Two longitudinal guide rails and two transverse guide rails are arranged in parallel with each other, both ends of the two transverse guide rails are slidably connected to the two longitudinal guide rails through sliders, the two transverse guide rails can rotate relative to the sliders, the two transverse guide rails are respectively provided with wire clamps, bearings are arranged in the wire clamps, the cable to be tested is passed through the inner ring of the bearing, the outer ring of the bearing is fixed to the wire clamp, the inner ring can rotate relative to the outer ring, the wire clamp is provided with an angle scale, and the cable to be tested is provided with a value indicating pointer that cooperates with the angle scale;

[0153] A longitudinal displacement scale is arranged on the longitudinal guide rail, and a transverse displacement scale is arranged on the transverse guide rail.

[0154] For details, please refer to Figures 10 to 14 ,in, Fig.10 A schematic diagram of the structure of a cable torsion angle testing device provided by the present invention. Fig.11 A physical diagram of a cable torsion angle testing device provided by the present invention, Fig.12 A schematic diagram of an angle scale and an indicating pointer provided by the present invention; Fig.13 A schematic diagram of an angle scale and an indicating pointer provided by the present invention, Fig.14 A schematic diagram of a wire clamp and a cable to be tested provided by the present invention.

[0155] Specifically, the cable to be tested is connected to the transverse guide rail through a wire clamp. The user can adjust the rotation angle of the transverse guide rail and the distance between the two transverse guide rails to simulate the posture change of the cable to be tested when it passes through the preset limit line, and determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line through the angle scale and the indicating pointer.

[0156] The cable torsion angle test device is designed as a "mesh" type frame structure. The frame can be processed with 40mm×40mm aluminum alloy profiles. A sliding guide groove is opened on the profile. A displacement scale and an alignment line are installed next to the guide groove for indication, so as to realize the longitudinal movement of the entire transverse guide along the longitudinal guide and the horizontal transverse movement of the cable clamp along the transverse guide. The transverse guide and the longitudinal guide matching pair are designed as a combined translation and rotation matching pair. The translation pair realizes the above-mentioned longitudinal displacement simulation function, and the rotation pair realizes the simulation of different lead-out angles through the angle scale and the indicating pointer.

[0157] In order to measure the root torsion under the motion posture of the cable, the wire clamp and the cable are designed to be matched with rolling bearings. The outer ring of the bearing and the wire clamp have an interference fit, and the inner ring of the bearing and the cable have an interference fit. The purpose of using rolling bearings is to simulate the wire clamp to the actual cable state, and to simulate the cable to be in a state of free rotation without torsion as a whole. An angle scale is installed on the wire clamp, and a value indicating pointer is installed on the cable to be tested. By reading the pointer indication after the posture of the cable to be tested occurs, the torsion angle of a single end can be measured.

[0158] Please refer to Fig.15 , Fig.15 A schematic diagram of the structure of a cable life determination system provided by the present invention, the system comprising:

[0159] A torsion angle determination unit, used to determine the torsion angle of a single-end torsion angle of the cable to be tested when it passes through a preset limit line;

[0160] A life determination unit, used to determine the number of failures of the cable to be tested based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures;

[0161] The preset limit line is a point where the spatial position and posture of the clamping point of the cable to be tested change and the change amount is greater than the preset change amount, and the number of failures is the maximum number of times the cable can pass through the preset limit line.

[0162] As a preferred embodiment, the process of determining the correspondence between the preset torsion angle and the number of failures is as follows:

[0163] Determine the lengths of N cables, wherein the lengths of the N cables are different, and N is an integer not less than 2;

[0164] Convert the single-end torsion angles of the clamping points of the N cables when they pass through the preset limit line into torsion angles per preset length, wherein the preset length is less than or equal to the minimum length of the N cables;

[0165] Determine the number of failures of each cable after passing through a preset limit line;

[0166] Determine a corresponding relationship between a preset torsion angle and a failure number based on the torsion angle of each preset length corresponding to the N cables and the failure number;

[0167] The system also includes:

[0168] The conversion unit is used to convert the torsion angle of the single-end torsion angle of the cable to be tested into a torsion angle per preset length after determining the torsion angle of the single-end torsion angle of the cable to be tested when the cable passes through a preset limit line.

[0169] As a preferred embodiment, the corresponding relationship between the preset torsion angle and the number of failures is:

[0170] φ=-A*In(n)+B;

[0171] Where φ is the torsion angle per preset length, n is the number of failures, and A and B are life calculation coefficients.

[0172] As a preferred embodiment, the conversion unit includes:

[0173] A first parameter determination unit, used to determine a single-end torsion angle and a design length of the cable to be tested;

[0174] A ratio determination unit, used for taking the ratio of the design length divided by the single-end torsion angle as the torsion angle per unit length;

[0175] The first calculation unit is used to take the product of the torsion angle per unit length and the preset length as the torsion angle per preset length.

[0176] As a preferred embodiment, the preset limit line is an S curve.

[0177] As a preferred embodiment, the torsion angle determination unit includes:

[0178] The second parameter determination unit is used to determine the longitudinal spacing between the clamping points at both ends of the cable under test, the outlet angle of the clamping points, and the transverse spacing when the cable under test passes through a preset limit line;

[0179] A second calculation unit is used to determine the torsion angle of the single-end torsion angle of the cable to be tested when passing through a preset limit line based on the longitudinal spacing, the outlet angle of the clamping point and the transverse spacing;

[0180] Among them, the longitudinal spacing is the distance between the two clamping points along the vehicle length direction, the cable outlet angle is the angle between the axis of the cable to be tested at the clamping point and the horizontal plane, and the transverse spacing is the displacement of the two clamping points along the horizontal transverse direction.

[0181] As a preferred embodiment, the second computing unit is specifically used for:

[0182] Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line based on the longitudinal spacing, the outlet angle of the clamping point, the transverse spacing and the preset torsion angle calculation relationship;

[0183] The preset torsion angle calculation formula is:

[0184]

[0185] Among them, α is the torsion angle of the single-end torsion angle, L is the longitudinal spacing, β is the lead-out angle of the clamping point, and W is the lateral spacing.

[0186] For an introduction to the cable life determination system provided by the present invention, please refer to the above method embodiment, and the present invention will not be described in detail here.

[0187] Please refer to Fig.16 , Fig.16 A schematic diagram of a device for determining the life of a cable provided by the present invention, the device comprising:

[0188] Specifically, it may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, and the computer program is loaded and executed by the processor 21 to implement the relevant steps in the method for determining the life of a cable disclosed in any of the above embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0189] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0190] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon can include an operating system 221, a computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0191] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the DC voltage control of the inverter performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include computer programs that can be used to complete other specific tasks.

[0192] For an introduction to the device for determining the life of a cable provided by the present invention, please refer to the above method embodiment, and the present invention will not be described in detail here.

[0193] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the cable life determination method as described above are implemented.

[0194] For an introduction to the computer-readable storage medium provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here.

[0195] It should be noted that, in this specification, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0196] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the life of a cable, characterized in that: include: Determine the torsion angle of the single-end torsion angle of the cable under test when it passes through a preset limit line; Determining the number of failures of the cable to be tested based on the torsion angle and the corresponding relationship between the preset torsion angle and the number of failures; The preset limit line is a point where the spatial position and posture of the clamping point of the cable to be tested change and the change amount is greater than a preset change amount, and the number of failures is the maximum number of times the cable can pass through the preset limit line.

2. The method for determining the life of a cable according to claim 1, characterized in that: The process of determining the corresponding relationship between the preset torsion angle and the number of failures is as follows: Determining the lengths of N cables, wherein the lengths of the N cables are different, and N is an integer not less than 2; Converting the single-end torsion angles of the clamping points of the N cables when passing through the preset limit line into torsion angles per preset length, wherein the preset length is less than or equal to the minimum length of the N cables; Determining the number of failures of each of the cables when passing through the preset limit line; Determining a corresponding relationship between a preset torsion angle and a number of failures based on the torsion angle of each preset length corresponding to the N cables and the number of failures; After determining the torsion angle of the single-end torsion angle of the cable under test when passing through the preset limit line, the method further includes: The single-end torsion angle of the cable to be tested is converted into a torsion angle per preset length.

3. The method for determining the life of a cable according to claim 2, characterized in that: The corresponding relationship between the preset torsion angle and the number of failures is: φ=-A*In(n)+B; Where φ is the torsion angle per preset length, n is the number of failures, and A and B are life calculation coefficients.

4. The method for determining the life of a cable according to claim 2, characterized in that: Converting the torsion angle of the single-end torsion angle of the cable to be tested into a torsion angle per preset length includes: Determining the single-end torsion angle and design length of the cable to be tested; The ratio of the single-end torsion angle divided by the design length is taken as the torsion angle per unit length; The product of the torsion angle per unit length and the preset length is taken as the torsion angle per preset length.

5. The method for determining the life of a cable according to any one of claims 1 to 4, characterized in that: Determine the torsion angle of the single-end torsion angle of the cable under test when it passes through a preset limit line, including: Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line by using the angle scale and the indicating pointer on the cable torsion angle test device; The cable torsion angle testing device comprises: Two longitudinal guide rails and two transverse guide rails are arranged in parallel with each other, both ends of the two transverse guide rails are slidably connected to the two longitudinal guide rails through sliders, the two transverse guide rails can rotate relative to the sliders, the two transverse guide rails are respectively provided with wire clamps, the wire clamps are provided with bearings, the cable to be tested is passed through the inner ring of the bearing, the outer ring of the bearing is fixed to the wire clamp, the inner ring can rotate relative to the outer ring, the wire clamp is provided with an angle scale, and the cable to be tested is provided with a value indicating pointer that cooperates with the angle scale; The longitudinal guide rail is provided with a longitudinal displacement scale, and the transverse guide rail is provided with a transverse displacement scale.

6. The method for determining the life of a cable according to any one of claims 1 to 4, characterized in that: Determine the torsion angle of the single-end torsion angle of the cable under test when it passes through a preset limit line, including: Determine the longitudinal spacing between the clamping points at both ends of the cable under test, the outlet angles of the clamping points, and the transverse spacing when the cable under test passes through a preset limit line; Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through a preset limit line based on the longitudinal spacing, the outlet angle of the clamping point and the transverse spacing; Among them, the longitudinal spacing is the distance between the two clamping points along the vehicle length direction, the line outlet angle is the angle between the axis of the cable to be tested at the clamping point and the horizontal plane, and the lateral spacing is the displacement of the two clamping points along the horizontal lateral direction.

7. The method for determining the life of a cable according to claim 6, characterized in that: Determining the torsion angle of a single-end torsion angle of the cable to be tested when passing through a preset limit line based on the longitudinal spacing, the outlet angle of the clamping point and the transverse spacing includes: Determine the torsion angle of the single-end torsion angle of the cable to be tested when it passes through the preset limit line based on the longitudinal spacing, the outlet angle of the clamping point, the transverse spacing and the preset torsion angle calculation relationship; The preset torsion angle calculation formula is: Among them, α is the torsion angle of the single-end torsion angle, L is the longitudinal spacing, β is the lead-out angle of the clamping point, and W is the lateral spacing.

8. A cable life determination system, characterized in that: include: A torsion angle determination unit, used to determine the torsion angle of a single-end torsion angle of the cable to be tested when it passes through a preset limit line; A life determination unit, configured to determine the number of failures of the cable to be tested based on the torsion angle and a correspondence between a preset torsion angle and the number of failures; The preset limit line is a point where the spatial position and posture of the clamping point of the cable to be tested change and the change amount is greater than a preset change amount, and the number of failures is the maximum number of times the cable can pass through the preset limit line.

9. A device for determining the life of a cable, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the method for determining the life of a cable as claimed in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for determining the life of a cable according to any one of claims 1 to 7 are implemented.

Images