A method of measuring a cable pitch ratio and a pitch ratio measuring device

Abstract

The application discloses a kind of cable pitch ratio measurement method and pitch ratio measuring device.Method includes successively collecting the magnetic field intensity value of multiple transverse detection points in the extension direction of multicore cable and generating first magnetic field intensity curve, and determining the two first curve peak points of adjacent on it, and determining the pitch value of multicore cable based on the distance value between the two;Along the direction of the circumference around multicore cable, successively collect the magnetic field intensity value of multiple ring detection points and generate second magnetic field intensity curve;Determine the second curve peak point on the second magnetic field intensity curve, and determine the straight line distance value of ring detection point from target wire core when the corresponding magnetic field intensity value is collected;Obtain the cable outer diameter value of multicore cable, determine the wire core outer diameter value of target wire core based on outer diameter value and straight line distance value, and determine the pitch ratio of multicore cable based on wire core outer diameter value and pitch value.The above scheme can improve the measurement accuracy of the pitch ratio of multicore cable.

Description

Technical Field

[0001] This invention relates to the field of cable testing technology, and in particular to a method and device for measuring cable pitch ratio. Background Technology

[0002] In many engineering fields such as modern power transmission and communication transmission, cables are the core carriers of electrical energy and signal transmission. Among them, the cable pitch ratio is a key parameter characterizing the structure of multi-core stranded cables, directly determining the cable's electrical insulation performance, bending mechanical strength, and signal transmission stability. Therefore, accurately obtaining the cable pitch ratio has significant engineering value for cable factory testing and on-site operation and maintenance assessment.

[0003] Currently, the industry-standard method for detecting cable pitch ratio is direct manual measurement. This method requires laying the cable to be tested flat and using measuring tools such as tape measures and rulers to manually measure the axial distance between adjacent points with the same twisting characteristics on the cable core. This distance is the cable pitch. The ratio of the cable pitch to the outer diameter is determined by measuring the outer diameter of the core.

[0004] However, this traditional measurement method has obvious drawbacks. It relies entirely on manual reading and positioning marks, and the random errors introduced by human operation are relatively large, which will ultimately significantly reduce the measurement accuracy of the pitch ratio. At the same time, manual measurement requires the identification of the external stranding pattern of the cable, which is cumbersome and has low detection efficiency, making it difficult to meet the needs of large-scale, high-precision non-destructive testing. Summary of the Invention

[0005] In view of this, this application provides a method and device for measuring the pitch ratio of cables, the main purpose of which is to solve the technical problem of low accuracy in measuring the pitch ratio of multi-core cables.

[0006] According to a first aspect of the present invention, a method for measuring cable pitch ratio is provided, the method comprising: AC power is connected to the target core of the multi-core cable to be measured. Magnetic field strength values ​​at multiple lateral detection points are sequentially collected along the extension direction of the multi-core cable using a magnetic field strength sensor. A first magnetic field strength curve is generated based on the magnetic field strength value at each of the lateral detection points. On the first magnetic field strength curve, two adjacent peaks of the first curve are identified, and the pitch value of the multi-core cable is determined based on the distance between the two adjacent peaks of the first curve. Along the direction surrounding the central axis of the multi-core cable, magnetic field strength values ​​at multiple circumferential detection points are sequentially collected by a magnetic field strength sensor, and a second magnetic field strength curve is generated based on the magnetic field strength value at each of the circumferential detection points. The peak point of the second curve is determined on the second magnetic field strength curve, and the straight-line distance between the magnetic field strength sensor and the target wire core is determined when the magnetic field strength sensor collects the magnetic field strength value corresponding to the peak point of the second curve. Obtain the outer diameter value of the multi-core cable, determine the outer diameter value of the target core based on the outer diameter value and the straight distance value, and determine the pitch ratio of the multi-core cable based on the outer diameter value and the pitch value.

[0007] In an optional embodiment, the vertical coordinate of the first coordinate system in which the first magnetic field strength curve is located is the magnetic field strength value, and the horizontal coordinate of the first coordinate system is the distance from the first end of the multi-core cable along the extension direction of the lateral detection point; determining the pitch value of the multi-core cable based on the distance between two adjacent first curve peaks includes: determining the difference between the horizontal coordinates corresponding to the two adjacent first curve peaks, and determining the difference between the horizontal coordinates as the pitch value.

[0008] In an optional embodiment, before determining the peak point of the second curve on the second magnetic field strength curve, the method further includes: determining whether the second magnetic field strength curve includes peaks and troughs belonging to the same waveform period; if the second magnetic field strength curve does not include peaks and troughs belonging to the same waveform period, performing the step of sequentially collecting magnetic field strength values ​​at multiple circumferential detection points along the direction surrounding the central axis of the multi-core cable using a magnetic field strength sensor, and generating a second magnetic field strength curve based on the magnetic field strength value at each of the circumferential detection points, to generate the second magnetic field strength curve again, until the second magnetic field strength curve includes peaks and troughs belonging to the same waveform period.

[0009] In an optional embodiment, determining the outer diameter of the target conductor based on the cable outer diameter and the straight-line distance includes: determining the outer diameter of the conductor based on the following first formula:

[0010] Where R is the cable outer diameter, D is the conductor outer diameter, and L1 is the straight-line distance; Determining the pitch ratio of the multi-core cable based on the outer diameter of the conductor and the pitch value includes: determining the pitch ratio of the multi-core cable based on the following second formula:

[0011] Where K is the pitch ratio of the multi-core cable, P is the pitch value, and D is the outer diameter of the conductor.

[0012] According to a second aspect of the present invention, a pitch ratio measuring device is provided, the device comprising a measuring controller, a magnetic field strength sensor, a sensor slide rail, a first clamping component, and a second clamping component, wherein the measuring controller is used to perform the cable pitch ratio measuring method as described above; The first clamping component is used to clamp the first end of the multi-core cable, and the second clamping component is used to clamp the second end of the multi-core cable, so that the multi-core cable is in a straight state; The sensor slide rail is parallel to the multi-core cable clamped between the first clamping component and the second clamping component, and can rotate around the central axis of the multi-core cable. The magnetic field strength sensor is communicatively connected to the measurement controller and is used to collect the magnetic field strength value at its location and send the magnetic field strength value to the measurement controller. The magnetic field strength sensor can move along the sensor slide rail.

[0013] In an optional embodiment, the transmission end of the measurement controller is communicatively connected to a remote host computer to transmit the calculated pitch ratio to the host computer.

[0014] In an optional embodiment, the sensor slide rail is made of a non-magnetic material; the non-magnetic material includes one of epoxy resin, nylon, polytetrafluoroethylene, polyvinyl chloride resin plastic, and fiberglass.

[0015] In an optional embodiment, the magnetic field strength sensor is disposed on the walking unit, the walking unit is slidably mounted on the sensor slide rail, and the walking unit is used to move on the sensor slide rail; the output terminal of the measurement controller is communicatively connected to the control terminal of the walking unit, and the measurement controller is used to output control signals to the walking unit to adjust the moving speed and moving direction of the walking unit on the sensor slide rail.

[0016] In an optional embodiment, the pitch ratio measuring device further includes a first rotating disk and a second rotating disk; a first rotating axis of the first rotating disk is connected to the first clamping component, a second rotating axis of the second rotating disk is connected to the second clamping component, and the line connecting the first rotating axis and the second rotating axis coincides with the straight line containing the multi-core cable, so that the first rotating disk and the second rotating disk can rotate about the central axis of the multi-core cable respectively; a first end of the sensor slide rail is connected to a first connection point on the disk surface of the first rotating disk, and a second end of the sensor slide rail is connected to a second connection point on the disk surface of the second rotating disk, and the line connecting the first connection point and the second connection point is parallel to the central axis of the multi-core cable, so that the sensor slide rail is parallel to the multi-core cable.

[0017] In an optional embodiment, the pitch ratio measuring device further includes a servo motor, the drive end of which is connected to the first rotating shaft of the first rotating disk to drive the first rotating shaft to rotate; the output end of the measuring controller is also connected to the control end of the servo motor, and the measuring controller is used to output control signals to the servo motor to adjust the start / stop state, rotation speed and rotation direction of the servo motor.

[0018] The present invention provides a method and device for measuring cable pitch ratio, which adopts a non-contact magnetic field detection scheme, eliminating the need for manual marking and ruler measurement, thus eliminating measurement errors caused by manual positioning and reading, and effectively improving the measurement accuracy of pitch ratio.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A flowchart illustrating a method for measuring cable pitch ratio provided by an embodiment of the present invention is shown. Figure 2 A schematic diagram of a first magnetic field strength curve provided by an embodiment of the present invention is shown; Figure 3 This diagram illustrates the distribution of circumferential detection points according to an embodiment of the present invention. Figure 4 This figure shows one of the structural schematic diagrams of a pitch ratio measuring device provided in an embodiment of the present invention; Figure 5 This is a second schematic diagram of the structure of a pitch ratio measuring device provided in an embodiment of the present invention; Figure 6 A schematic diagram of a first rotating disk provided in an embodiment of the present invention is shown; Figure 7 A schematic diagram of a second rotating disk provided in an embodiment of the present invention is shown; Figure 8 This diagram illustrates the measurement effect of a pitch ratio measuring device provided in an embodiment of the present invention. Detailed Implementation

[0021] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0022] In many engineering fields such as modern power transmission and communication transmission, cables are the core carriers of electrical energy and signal transmission. Among these, the cable pitch ratio is a key parameter characterizing the structure of multi-core stranded cables, directly determining the cable's electrical insulation performance, bending mechanical strength, and signal transmission stability. Therefore, accurately obtaining the cable pitch ratio has significant engineering value for cable factory testing and on-site operation and maintenance assessment. Currently, the industry-standard method for detecting cable pitch ratio is direct manual measurement. This method requires the cable to be laid flat, and using measuring tools such as tape measures and rulers, the axial distance between adjacent points with the same stranding characteristics on the cable cores is manually measured. This distance is the cable pitch, and the ratio of the cable pitch to the outer diameter of the core is determined as the cable pitch ratio. However, this traditional measurement method has significant drawbacks. It relies entirely on manual reading and positioning marks, and the random errors introduced by human operation are substantial, ultimately significantly reducing the accuracy of the pitch ratio measurement. Furthermore, manual measurement requires identifying the external stranding patterns of the cable, making the operation cumbersome and inefficient, and failing to meet the needs of large-scale, high-precision non-destructive testing.

[0023] To address the above problems, in one embodiment, such as Figure 1 As shown, a method for measuring cable pitch ratio is provided. Taking the application of this method to computer equipment as an example, the method is used to measure the pitch ratio of a multi-core cable, which is a conventional symmetrical stranded power cable. The method includes the following steps: 101. Connect AC power to the target core of the multi-core cable to be measured, and sequentially collect the magnetic field strength values ​​at multiple lateral detection points along the extension direction of the multi-core cable using a magnetic field strength sensor, and generate a first magnetic field strength curve based on the magnetic field strength value at each of the lateral detection points.

[0024] Here, one core of a multi-core cable can be selected as the target core. An alternating current of a specific frequency is input to it, causing it to emit a magnetic field, which is then used to measure the pitch ratio. Alternatively, alternating currents of different frequencies can be input to multiple cores in the multi-core cable, causing each core to generate a magnetic field of a different frequency, allowing for individual pitch ratio measurements. This embodiment uses the measurement of a target core in a multi-core cable as an example; the measurement methods for other cores in the cable can refer to the target core measurement method and will not be elaborated here.

[0025] Specifically, a multi-core cable can be laid straight on a horizontal surface, and the target core of the cable can be connected to an external AC power source to supply AC power of a specific frequency to the target core. Furthermore, a magnetic field strength sensor can be moved from one end of the multi-core cable to the other, at a preset distance from the center of the cable's cross-section, along a direction parallel to the cable's extension. During this movement, it will pass through multiple preset lateral detection points, each equidistant from the center of the cable's cross-section. The magnetic field strength sensor can then sequentially collect the magnetic field strength value at each lateral detection point. The more lateral detection points there are, the more accurate the resulting first magnetic field strength curve will be. Alternatively, the magnetic field strength value at the sensor's location can be collected in real time during its movement, and multiple locations can be selected to generate the first magnetic field strength curve.

[0026] Here, the vertical axis of the first coordinate system containing the first magnetic field strength curve represents the magnetic field strength value, and the horizontal axis represents the distance from the lateral detection point to the first end of the multi-core cable along the direction parallel to the cable's extension. Here, the left end of the multi-core cable can be considered the first end. Specifically, for each lateral detection point, it can be projected onto the multi-core cable along the direction perpendicular to its extension, and the straight-line distance from the projection point to the first end of the cable can be determined. This straight-line distance is then defined as the horizontal axis value of the lateral detection point in the first coordinate system. Through this method, the horizontal axis value of each lateral detection point in the first coordinate system can be determined.

[0027] Furthermore, when the magnetic field strength sensor is moved along the extension direction of the multi-core cable, when the magnetic field strength sensor is at a lateral detection point, the magnetic field strength value at the lateral detection point is collected, the magnetic field strength value at the lateral detection point is used as the vertical coordinate value, and the horizontal coordinate value corresponding to the lateral detection point is determined. Based on the horizontal coordinate value and the vertical coordinate value of the lateral detection point, the coordinate point corresponding to the lateral detection point is determined on the first coordinate system.

[0028] Furthermore, as the magnetic field strength sensor moves to each lateral detection point, the coordinates corresponding to that lateral detection point are determined on the first coordinate system using the method described above, thus obtaining the coordinates of each lateral detection point on the first coordinate system. Further, according to the chronological order in which the magnetic field strength sensor moves to each lateral detection point, the coordinates on the first coordinate system are connected sequentially to obtain the first magnetic field strength curve. Here, the form of the first magnetic field strength curve is as follows: Figure 2 As shown.

[0029] 102. On the first magnetic field strength curve, determine two adjacent peaks of the first curve, and based on the distance between the two adjacent peaks of the first curve, determine the pitch value of the multi-core cable.

[0030] Specifically, iterate through the coordinates of all transverse detection points corresponding to the first magnetic field strength curve, such as... Figure 2 As shown, a point on the first magnetic field strength curve with a local maximum magnetic field strength value can be selected as the first curve peak point and determined as the initial curve peak point P1. Then, from the coordinates of all the aforementioned lateral detection points, a first curve peak point whose abscissa is adjacent to the initial curve peak point P1 can be selected and determined as the adjacent curve peak point P2. The adjacent curve peak point P2 can be either to the left or to the right of the initial curve peak point P1. Here, the initial curve peak point P1 and the adjacent curve peak point P2 are the peak points of two waveforms with adjacent waveform periods. Further, the abscissa values ​​corresponding to the two peak points in the first coordinate system are read, and the difference between the two abscissa values ​​is calculated. This difference is the distance between the two adjacent peak points, i.e., the pitch value of the multi-core cable. If there are no two peak points in the first magnetic field strength curve, the length of the multi-core cable to be measured can be increased, and the first magnetic field strength curve can be generated again until there are two peak points in the first magnetic field strength curve.

[0031] 103. Along the direction surrounding the central axis of the multi-core cable, the magnetic field strength values ​​at multiple circumferential detection points are collected sequentially by a magnetic field strength sensor, and a second magnetic field strength curve is generated based on the magnetic field strength value at each of the circumferential detection points.

[0032] Here, as Figure 3 As shown, after determining the pitch value of the multi-core cable, the magnetic field strength sensor 200 is fixed at a specific lateral detection point along the direction of the multi-core cable's extension. It is then rotated clockwise or counterclockwise around the multi-core cable in a plane perpendicular to its extension direction, with the geometric center P3 of the cable's cross-section as the center. Multiple circumferential detection points P4 can be preset on the rotation trajectory of the magnetic field strength sensor 200. The more circumferential detection points P4, the more accurate the subsequent second magnetic field strength curve. The number and position of the circumferential detection points P4 can be predetermined. Using the geometric center P3 of the multi-core cable as a reference, several circumferential detection points P4 are arranged at circumferential positions forming different angles with the geometric center P3, and the angle mapping between each circumferential detection point P4 and the geometric center P3 is stored locally.

[0033] Furthermore, as the magnetic field strength sensor 200 rotates clockwise or counterclockwise around the multi-core cable, it can collect the magnetic field strength value at each circumferential detection point P4 it reaches, and then associate the collected magnetic field strength value with the circumferential detection point P4.

[0034] Furthermore, a second magnetic field strength curve can be generated based on the magnetic field strength value of each circumferential detection point P4 and the relative angle between each circumferential detection point P4 and the geometric center P3. Here, the vertical axis of the second coordinate system containing the second magnetic field strength curve represents the magnetic field strength value, and the horizontal axis represents the angle value. When the magnetic field strength value of a circumferential detection point P4 is obtained, the horizontal axis of the circumferential detection point P4 is determined in the second coordinate system based on the relative angle between the circumferential detection point P4 and the geometric center P3, and the vertical axis of the circumferential detection point P4 is determined in the second coordinate system based on the magnetic field strength value of the circumferential detection point P4, so as to obtain the coordinate point of the circumferential detection point P4 in the second coordinate system. Based on the above method, the coordinate points corresponding to all circumferential detection points P4 can be determined in the second coordinate system, and the coordinate points of each circumferential detection point P4 in the second coordinate system can be connected sequentially according to the time order of the acquisition of the corresponding magnetic field strength values ​​to obtain the second magnetic field strength curve.

[0035] 104. Determine the peak point of the second curve on the second magnetic field strength curve, and determine the straight-line distance between the magnetic field strength sensor and the target wire core when the magnetic field strength sensor collects the magnetic field strength value corresponding to the peak point of the second curve.

[0036] Specifically, the coordinates of all circumferential detection points on the second magnetic field strength curve can be traversed, and a point where the magnetic field strength value is locally maximized on the second magnetic field strength curve can be selected as the peak point of the second curve. Here, the second magnetic field strength curve needs to have a trough point adjacent to the peak point of the second curve; to do this, it can be determined whether the second magnetic field strength curve includes peaks and troughs belonging to the same waveform period. If the peak point of the second curve does not include peaks and troughs belonging to the same waveform period, step 103 is executed again to generate the second magnetic field strength curve again, until the second magnetic field strength curve includes peaks and troughs belonging to the same waveform period.

[0037] Furthermore, when the magnetic field strength sensor moves to the circumferential detection point corresponding to the peak of the second curve, the straight-line distance between the geometric center of the magnetic field strength sensor and the target wire core is determined. Here, the projection point of the geometric center on the target wire core along the direction perpendicular to the extension of the multi-core cable can be determined, and the distance between the geometric center and the projection point is defined as the straight-line distance. Further, because the target wire core is intertwined with other wire cores in the multi-core cable, it is not on a straight line. Even if the distance between the magnetic field strength sensor and the geometric center of the multi-core cable remains equal during the movement of the magnetic field strength sensor around the multi-core cable, the distance between the magnetic field strength sensor and the target wire core at different angles of the multi-core cable will not be the same. Therefore, calibration measurements can be performed in advance. The magnetic field strength sensor is fixed to a designated position along the extension direction of the multi-core cable, and the magnetic field strength sensor is rotated around the geometric center of the multi-core cable in a plane perpendicular to the extension direction. The distance values ​​between the sensor and the target wire core corresponding to each rotation angle are recorded, establishing a mapping relationship between angle and distance values ​​and storing it locally.

[0038] In the actual measurement process, after determining the coordinate point of the second curve peak in the second coordinate system, the abscissa of the coordinate point is determined, i.e., the angle value, and the distance value mapped and stored with the angle value is obtained. This distance value is then determined as the straight-line distance value.

[0039] Alternatively, when the magnetic field strength sensor acquires the magnetic field strength value corresponding to the peak of the second curve, i.e., when the relative angle between the magnetic field strength sensor and the geometric center of the multi-core cable is the angle recorded by the abscissa of the peak of the second curve in the second coordinate system, the straight-line distance from the geometric center of the magnetic field strength sensor to the target core can be measured to obtain the straight-line distance value. This angle value can then be determined as the first angle value.

[0040] Here, a trough point adjacent to the peak of the second magnetic field strength curve can also be determined in the second magnetic field strength curve, and the abscissa of this trough point in the second coordinate system can be determined. The angle value corresponding to this abscissa can then be determined as the second angle value. Further, when the relative angle between the magnetic field strength sensor and the geometric center of the multi-core cable is measured to be the second angle value, the second distance value between the magnetic field strength sensor and the target wire core can be measured. At this time, the relationship between the first angle value, the second angle value, the straight-line distance value, and the second distance value is as shown in Formula 1: L1 / L2=B(θ2) / B(θ1)(1) Where L1 is the straight-line distance value, L2 is the second distance value, B(θ1) is the first angle value, and B(θ2) is the second angle value. Furthermore, the pre-measured outer diameter value of the multi-core cable can be obtained, which is equal to the sum of the straight-line distance value and the second distance value.

[0041] 105. Obtain the outer diameter value of the multi-core cable, determine the outer diameter value of the target core based on the outer diameter value and the straight distance value, and determine the pitch ratio of the multi-core cable based on the outer diameter value and the pitch value.

[0042] Specifically, the outer diameter of the target wire core can be determined based on the following formula 2, i.e., the first formula: (2) Where R is the cable outer diameter, D is the conductor outer diameter, and L1 is the straight-line distance; Furthermore, based on the following formula 3, i.e., the second formula, the pitch ratio of the multi-core cable is determined: (3) Where K is the pitch ratio of the multi-core cable, P is the pitch value, and D is the outer diameter of the conductor.

[0043] The cable pitch ratio measurement method provided in this embodiment adopts a magnetic field non-contact detection scheme, which eliminates the need for manual marking and ruler measurement process, thereby eliminating measurement errors caused by manual positioning and reading, and effectively improving the measurement accuracy of pitch ratio.

[0044] Furthermore, embodiments of this application also provide a pitch ratio measuring device, such as... Figure 4 As shown, the device includes a measurement controller 100, a magnetic field strength sensor 200, a sensor slide rail 300, a first clamping component 400, and a second clamping component 500. The measurement controller 100 can be a computer device such as a microcontroller, used to execute the cable pitch ratio measurement method described above. The transmission end of the measurement controller 100 is communicatively connected to a remote host computer (not shown in the figure) to transmit the calculated pitch ratio to the host computer. Here, the host computer can be a computer terminal used by relevant personnel.

[0045] Specifically, the first clamping component 400 is used to clamp the first end of the multi-core cable 600, and the second clamping component 500 is used to clamp the second end of the multi-core cable 600. The first clamping component 400 and the second clamping component 500 can be positioned far apart to keep the multi-core cable 600 in a straight line. The first clamping component 400 and the second clamping component 500 can be any one of an electric clamp, a manual clamp, or a fixed clamping base, and both are used to clamp both ends of the multi-core cable 600, keeping the multi-core cable 600 in a horizontal position. Simultaneously, the first clamping component 400 and the second clamping component 500 only clamp the outer sheath end of the multi-core cable 600, allowing the cores in the multi-core cable 600 to be connected to an external AC power source (not shown in the figure) to allow AC current to flow through the cores.

[0046] Furthermore, the sensor slide rail 300 is parallel to the multi-core cable 600 clamped between the first clamping component 400 and the second clamping component 500. That is, the line connecting the first clamping component 400 and the second clamping component 500 and the sensor slide rail 300 are parallel to the horizontal plane. The line connecting the first clamping component 400 and the second clamping component 500 does not intersect with the sensor slide rail 300 and is not on the same plane. They are coplanar straight lines.

[0047] Furthermore, the sensor slide rail 300 is made of a non-magnetic material; the non-magnetic material includes one of epoxy resin, nylon, polytetrafluoroethylene, polyvinyl chloride resin plastic, and fiberglass. Furthermore, the sensor slide rail 300 can rotate in a circular motion around the geometric center axis of the clamped multi-core cable 600. Furthermore, the magnetic field strength sensor 200 is communicatively connected to the measurement controller 100, and is used to collect the magnetic field strength value at the location of the magnetic field strength sensor 200 and send the magnetic field strength value to the measurement controller 100. The magnetic field strength sensor 200 can move along the sensor slide rail 300.

[0048] Here, the magnetic field strength sensor 200 can be fixedly mounted on the walking unit (not shown in the figure), and the walking unit is slidably mounted on the sensor slide rail 300 for moving on the sensor slide rail 300; wherein, the walking unit can be an electric slide table, which can be controlled to move on the sensor slide rail 300.

[0049] Furthermore, the output terminal of the measurement controller 100 is communicatively connected to the control terminal of the walking unit. The measurement controller 100 is used to output control signals to the walking unit to adjust the moving speed and moving direction of the walking unit on the sensor slide rail 300.

[0050] In the actual working process, the staff first clamps and straightens the two ends of the multi-core cable 600 to be tested through the first clamping component 400 and the second clamping component 500 respectively, and keeps them in a straight state. The target core is connected to an external AC power supply to supply AC power. The measurement controller 100 controls the walking unit to drive the magnetic field strength sensor 200 to move along the sensor slide rail 300 parallel to the cable axis to collect magnetic field strength data at each point and generate a first magnetic field strength curve. Further, the measurement controller 100 identifies the distance between two adjacent peaks on the curve to obtain the cable pitch value. Then, the magnetic field strength sensor 200 is kept stationary on the sensor slide rail 300, and the sensor slide rail 300 is driven to rotate around the geometric center axis of the cable. The magnetic field strength sensor 200 collects magnetic field data in the circumferential direction to generate a second magnetic field strength curve, and locates the straight distance between the sensor and the target core corresponding to the peak of the second magnetic field strength curve. Combined with the known cable outer diameter, the outer diameter of the core is calculated, and finally, the pitch ratio of the multi-core cable is calculated based on the pitch value and the outer diameter of the core.

[0051] Furthermore, such as Figure 5 As shown, the pitch ratio measuring device further includes a first rotating disk 700 and a second rotating disk 800 that are parallel to each other; the first rotating disk 700 and the second rotating disk 800 can be annular discs.

[0052] Specifically, the first rotating shaft 710 of the first rotating disk 700 is fixedly connected to the first clamping component 400, and the second rotating shaft 810 of the second rotating disk 800 is fixedly connected to the second clamping component 500. The first rotating disk 700 can rotate around the first rotating shaft 710 as its axis, and the second rotating disk 800 can rotate around the second rotating shaft 810 as its axis. The line connecting the first rotating shaft 710 and the second rotating shaft 810 coincides with the straight line containing the multi-core cable 600, so that the first rotating disk 700 and the second rotating disk 800 can rotate about the geometric center axis of the multi-core cable 600 in a plane perpendicular to the extension direction of the multi-core cable 600.

[0053] Furthermore, such as Figure 6 As shown, the first end of the sensor slide rail is fixedly connected to the first connection point 720 on the surface of the first rotating disk 700; as Figure 7 As shown, the second end of the sensor slide rail is connected to the second connection point 820 on the surface of the second rotating disk 800; when the first rotating disk 700 and the second rotating disk 800 rotate synchronously to any angle, the first connection point 720 covers the second connection point 820 along the projection perpendicular to the direction of the second rotating disk 800.

[0054] Furthermore, the line connecting the first connection point 720 and the second connection point 820 is parallel to the central axis of the multi-core cable, so that the sensor slide rail disposed between the first rotating disk 700 and the second rotating disk 800 is parallel to the multi-core cable. The sensor slide rail can be rotated around the multi-core cable simply by rotating the first rotating disk 700 or the second rotating disk 800.

[0055] Furthermore, the pitch ratio measuring device also includes a servo motor, the drive end of which is connected to the first rotating shaft of the first rotating disk to drive the first rotating shaft to rotate; at the same time, the rotation of the first rotating shaft will drive the first rotating disk to rotate, and then the second rotating disk will rotate synchronously through the sensor slide rail.

[0056] Furthermore, the output terminal of the measurement controller is also connected to the control terminal of the servo motor. The measurement controller is used to output control signals to the servo motor to adjust the start / stop state, rotation speed, and number of rotations of the servo motor.

[0057] Furthermore, to directly verify the detection accuracy and reliability of this device and its corresponding measurement method, a physical prototype test was conducted. In the experiment, a three-core stranded cable was used as the test sample. The center position of the three-core cable was set as the reference center of the test platform. The total length of the cable was 15m, and the actual stranding pitch of the three conductive cores was 5m. The outer radius of the cable was measured to be 5cm by vernier calipers. The test system was built based on the aforementioned pitch ratio measurement device to carry out the test. During the experiment, alternating currents with amplitudes of 1A and frequencies of 10Hz, 30Hz, and 50Hz were respectively applied to the three conductive cores of the three-core cable. Alternating magnetic fields of different frequencies were used to decouple the signals of each individual core. During the experiment, a magnetic field strength sensor, starting from the 0m position of the cable, moved along the cable axis at a uniform speed of 10cm / s to collect magnetic field strength data at each point. The first magnetic field strength curve was plotted with the sensor's axial position as the abscissa and the magnetic field strength as the ordinate. Subsequently, the walking unit carrying the sensor was fixed at the peak magnetic field strength point, and a servo motor drove a double rotating disk to rotate a slide rail around the cable's central axis at an angular velocity of 10rad / s, completing the circumferential magnetic field sampling and plotting the data as shown in the figure. Figure 8 The second magnetic field strength curve is shown. The experimental curve shows that the distance between the peak points of adjacent axial magnetic field strengths is 5m, which is completely consistent with the actual cable pitch. The pitch ratio obtained by substituting the values ​​into the preset calculation formula matches the actual cable pitch ratio, fully demonstrating that the hardware device and its supporting testing scheme have high measurement accuracy and that the method is feasible and reliable.

[0058] The pitch ratio measuring device provided in this application can non-contactly acquire alternating magnetic field signals based on a magnetic field sensor to calculate the core pitch ratio, eliminating the need for traditional manual measurement methods and effectively improving measurement accuracy. Furthermore, it features a high degree of automation, is easy to operate, and is suitable for batch testing of multi-specification, multi-core cables.

[0059] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A method for measuring the cable pitch ratio, characterized in that, The method includes: AC power is connected to the target core of the multi-core cable to be measured. Magnetic field strength values ​​at multiple lateral detection points are sequentially collected along the extension direction of the multi-core cable using a magnetic field strength sensor. A first magnetic field strength curve is generated based on the magnetic field strength value at each of the lateral detection points. On the first magnetic field strength curve, two adjacent peaks of the first curve are identified, and the pitch value of the multi-core cable is determined based on the distance between the two adjacent peaks of the first curve. Along the direction surrounding the central axis of the multi-core cable, magnetic field strength values ​​at multiple circumferential detection points are sequentially collected by a magnetic field strength sensor, and a second magnetic field strength curve is generated based on the magnetic field strength value at each of the circumferential detection points. The peak point of the second curve is determined on the second magnetic field strength curve, and the straight-line distance between the magnetic field strength sensor and the target wire core is determined when the magnetic field strength sensor collects the magnetic field strength value corresponding to the peak point of the second curve. Obtain the outer diameter value of the multi-core cable, determine the outer diameter value of the target core based on the outer diameter value and the straight distance value, and determine the pitch ratio of the multi-core cable based on the outer diameter value and the pitch value.

2. The method according to claim 1, characterized in that, The vertical axis of the first coordinate system in which the first magnetic field strength curve is located is the magnetic field strength value, and the horizontal axis of the first coordinate system is the distance from the first end of the multi-core cable along the extension direction of the lateral detection point. Determining the pitch value of the multi-core cable based on the distance between two adjacent peaks of the first curve includes: Determine the difference in abscissa between the abscissas of two adjacent peaks of the first curve, and define the difference in abscissa as the pitch value.

3. The method according to claim 1, characterized in that, Before determining the peak point of the second curve on the second magnetic field strength curve, the method further includes: Determine whether the second magnetic field strength curve contains peaks and troughs belonging to the same waveform period. If the second magnetic field strength curve does not contain peaks and troughs belonging to the same waveform period, repeat the step of sequentially collecting magnetic field strength values ​​at multiple circumferential detection points along the direction surrounding the central axis of the multi-core cable using a magnetic field strength sensor, and generating a second magnetic field strength curve based on the magnetic field strength value at each circumferential detection point, to generate the second magnetic field strength curve again, until the second magnetic field strength curve contains peaks and troughs belonging to the same waveform period.

4. The method according to claim 1, characterized in that, Determining the outer diameter of the target conductor based on the cable outer diameter and the straight-line distance includes: The outer diameter of the wire core is determined based on the following first formula: Where R is the cable outer diameter, D is the conductor outer diameter, and L1 is the straight-line distance; Determining the pitch ratio of the multi-core cable based on the outer diameter of the conductor and the pitch value includes: The pitch ratio of the multi-core cable is determined based on the following second formula: Where K is the pitch ratio of the multi-core cable, P is the pitch value, and D is the outer diameter of the conductor.

5. A pitch ratio measuring device, characterized in that, The device includes a measurement controller, a magnetic field strength sensor, a sensor slide rail, a first clamping component, and a second clamping component, wherein the measurement controller is used to perform the cable pitch ratio measurement method as described in any one of claims 1 to 4; The first clamping component is used to clamp the first end of the multi-core cable, and the second clamping component is used to clamp the second end of the multi-core cable, so that the multi-core cable is in a straight state; The sensor slide rail is parallel to the multi-core cable clamped between the first clamping component and the second clamping component, and can rotate around the central axis of the multi-core cable. The magnetic field strength sensor is communicatively connected to the measurement controller and is used to collect the magnetic field strength value at its location and send the magnetic field strength value to the measurement controller. The magnetic field strength sensor can move along the sensor slide rail.

6. The pitch ratio measuring device according to claim 5, characterized in that, The transmission end of the measurement controller is connected to a remote host computer to transmit the calculated pitch ratio to the host computer.

7. The pitch ratio measuring device according to claim 5, characterized in that, The magnetic field strength sensor is mounted on the walking unit, which is slidably mounted on the sensor slide rail. The walking unit is used to move on the sensor slide rail. The output terminal of the measurement controller is communicatively connected to the control terminal of the walking unit. The measurement controller is used to output control signals to the walking unit to adjust the moving speed and direction of the walking unit on the sensor slide rail.

8. The pitch ratio measuring device according to claim 5, characterized in that, The sensor slide rail is made of non-magnetic material; The non-magnetic material includes one of epoxy resin, nylon, polytetrafluoroethylene, polyvinyl chloride resin plastic, and fiberglass.

9. The pitch ratio measuring device according to claim 5, characterized in that, The pitch ratio measuring device further includes a first rotating disk and a second rotating disk; The first rotating axis of the first rotating disk is connected to the first clamping component, and the second rotating axis of the second rotating disk is connected to the second clamping component. The line connecting the first rotating axis and the second rotating axis coincides with the straight line where the multi-core cable is located, so that the first rotating disk and the second rotating disk can rotate about the central axis of the multi-core cable as the axis of rotation. The first end of the sensor slide rail is connected to a first connection point on the surface of the first rotating disk, and the second end of the sensor slide rail is connected to a second connection point on the surface of the second rotating disk. The line connecting the first connection point and the second connection point is parallel to the central axis of the multi-core cable, so that the sensor slide rail is parallel to the multi-core cable.

10. The pitch ratio measuring device according to claim 9, characterized in that, The pitch ratio measuring device also includes a servo motor, the drive end of which is connected to the first rotating shaft of the first rotating disk to drive the first rotating shaft to rotate. The output terminal of the measurement controller is also connected to the control terminal of the servo motor. The measurement controller is used to output control signals to the servo motor to adjust the start / stop state, rotation speed and rotation direction of the servo motor.

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