An optical fiber twist testing device and method

Abstract

This invention relates to the field of fiber optic measurement technology, and more particularly to a fiber optic twist testing device, comprising: a test platform and, along the length of the test platform, an automatic cable feeding mechanism, a cable feeding control mechanism, a fiber pressing mechanism, a fiber twist identification mechanism, and a fiber rotation clamping mechanism, all sequentially arranged on the same side of the test platform. The fiber under test is drawn from a fiber optic reel and passes sequentially through the cable feeding control mechanism, the fiber pressing mechanism, and the fiber rotation clamping mechanism. The fiber rotation clamping mechanism moves the fiber under test along the length of the test platform. The naturally drooping fiber under test passes through the detection area of ​​the fiber twist identification mechanism, and, based on the twist direction detected by the fiber twist identification mechanism, performs a fiber untwisting action. This invention achieves automatic mechanical control, reducing errors caused by human operation. Simultaneously, the fiber twist identification mechanism detects the twist direction and degree of twist of the fiber, ensuring the accuracy of the fiber twist test. This invention also discloses a corresponding testing method.

Description

Technical Field

[0001] This invention relates to the field of optical fiber measurement technology, and in particular to an optical fiber twist testing device and method. Background Technology

[0002] In practical applications, standard single-mode fiber will inevitably deviate from perfect circular symmetry, even if the deviation is very small. Due to this deviation, the two orthogonal polarization planes are no longer arbitrarily chosen, and a time difference will occur when the two polarization modes propagate along the fiber, resulting in polarization mode dispersion (PMD).

[0003] Polarization mode dispersion (PMD) in optical fibers is a major factor limiting the development of long-distance, high-speed optical transmission network systems. There are two main methods to improve PMD. The first is to increase the refractive index and stress symmetry of the fiber. The key to this method is to control existing fiber manufacturing processes to ensure that the produced fibers have good geometric symmetry and reduce the stress on the fibers. The second method is to use a twisting process in the fiber drawing process, which can effectively reduce the stress and elliptic birefringence of the fiber. The twisting condition of the fiber can be checked by recording the twisting on the take-up reel.

[0004] A published patent, application number CN201710613594.7, discloses an optical fiber twist measurement device and method. Specifically, it discloses a test platform, an optical fiber holder mounted on the test platform, and a fiber unwinding reel. The fiber unwinding reel has a twisted optical fiber to be tested wound on it. After unwinding from the reel, the optical fiber is inserted into the optical fiber holder and clamped. The test platform has a horizontally extending slide rail. Two optical fiber holders, each capable of sliding within the slide rail, are used. One of the holders has a rotary actuator that drives it to rotate around its own axis. After both holders simultaneously clamp the optical fiber, the rotation of one holder causes the fiber to untwist. The rotating holder has a rotation angle acquisition device. By manually operating the holders and the rotary actuator, the twist direction of the optical fiber is observed, and the degree of twist is recorded.

[0005] The technical solution of the above patent can test the fiber twist degree relatively accurately. However, the test of the above patent requires human judgment of the fiber twist direction and whether the fiber has been untwisted, which is very easy to cause measurement error and result in inaccurate fiber twist degree measurement. Summary of the Invention

[0006] To address at least one of the aforementioned technical problems, this invention proposes an optical fiber twist test device and method, which solves the problem of inaccurate detection results caused by human factors in the detection of the twist direction and twist degree of the optical fiber under test in the prior art, thereby improving the accuracy of optical fiber twist measurement.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides an optical fiber twist testing device, comprising:

[0009] Test bench;

[0010] A wire feeding control mechanism is fixedly mounted on the test bench and is used to detect the tension of the optical fiber under test.

[0011] An automatic fiber feeding mechanism is used to place the fiber optic reel and control the fiber feeding speed according to the tension of the fiber to be tested.

[0012] An optical fiber pressing and releasing mechanism is fixedly mounted on the test bench. The optical fiber pressing and releasing mechanism is used to fix the optical fiber under test to form a fixed end of the optical fiber under test.

[0013] An optical fiber twist identification mechanism is fixedly installed on the test platform to detect the twist direction of the optical fiber under test.

[0014] An optical fiber rotating clamping mechanism is moved along the length of the test platform and is disposed on the test platform. The optical fiber rotating clamping mechanism is used to clamp and rotate the free end of the optical fiber under test around its own axis, and is used to perform a retraction action on the optical fiber under test. The optical fiber rotating clamping mechanism rotates relative to the test platform so that the optical fiber under test is in a relatively free drooping state during the test.

[0015] The automatic wire feeding mechanism, the wire feeding control mechanism, the optical fiber pressing mechanism, the optical fiber twisting identification mechanism, and the optical fiber rotating clamping mechanism are sequentially arranged on the same side of the test bench along the length direction of the test bench;

[0016] The optical fiber under test is led out from the optical fiber reel and passes sequentially through the fiber release control mechanism, the optical fiber pressing mechanism, and the optical fiber rotating clamping mechanism. The optical fiber rotating clamping mechanism drives the optical fiber under test to move along the length of the test platform. The naturally drooping optical fiber under test passes through the detection area of ​​the optical fiber twist recognition mechanism, and performs an optical fiber untwisting action according to the twist direction of the optical fiber under test detected by the optical fiber twist recognition mechanism.

[0017] Preferably, the automatic wire feeding mechanism includes:

[0018] Cable tray, used to hold fiber optic reels;

[0019] The first driving device is fixedly installed on one side of the wire feeding bracket and is used to drive the optical fiber reel to rotate.

[0020] The disc shaft is connected at one end to the output end of the first drive device and at the other end to the optical fiber disc. The disc shaft is rotatably mounted on the wire feeding bracket via a bearing assembly.

[0021] Preferably, the wire feeding control mechanism includes:

[0022] A support is fixedly disposed at one end of the test bench. The end of the support away from the test bench is provided with a mounting hole. A connecting shaft is rotatably disposed in the mounting hole, and both ends of the connecting shaft extend out of the mounting hole.

[0023] A disc-shaped cam, one side of which is fixedly connected to one end of the connecting shaft;

[0024] A slide bar has at least one adjustment hole along its length, and the end of the connecting shaft away from the disc cam is movably fixed to the adjustment hole;

[0025] A spring, one end of which is connected to the slide rod, and the other end of which is connected to the test platform;

[0026] The first guide wheel is rotatably disposed at the end of the slide rod away from the spring and is located on the opposite side of the slide rod from the disc cam. The outer periphery of the first guide wheel is provided with a first fiber groove to facilitate the placement of the fiber to be tested.

[0027] A distance sensor is disposed directly below the disc-shaped cam and is installed at a distance from the disc-shaped cam;

[0028] When the tension of the optical fiber under test changes, the first guide wheel presses down or lifts up, causing the slide bar to rotate around the connecting shaft, which in turn causes the disc cam to rotate, changing the distance between the disc cam and the distance sensor. The automatic wire feeding mechanism controls the wire feeding speed according to the detection result of the distance sensor.

[0029] Preferably, the fiber optic compression mechanism includes:

[0030] The second guide wheel is set on the test platform. The rotation center axis of the second guide wheel is parallel to the rotation center axis of the first guide wheel. The outer periphery of the second guide wheel is provided with a second fiber groove to facilitate the placement of the fiber to be tested. The second fiber groove and the first fiber groove are located in the same plane.

[0031] The pressure roller, in cooperation with the second guide roller, presses or releases the optical fiber under test when the pressure roller is pressed into or lifted out of the second optical fiber groove;

[0032] A pressing and releasing assembly is used to drive the pressure roller to press into or lift out of the second fiber groove. The pressing and releasing assembly includes:

[0033] The mounting part is fixed to the test bench;

[0034] The second driving device is fixed to the mounting part;

[0035] One end of the guide rod is fixedly connected to the pressure roller, and the other end is connected to the output end of the second drive device;

[0036] The second driving device drives the guide rod to extend and retract along its length, thereby causing the pressure roller to press into or lift away from the second optical fiber groove.

[0037] Preferably, the optical fiber rotating clamping mechanism is a rotating pneumatic gripper, which includes:

[0038] Servo motor;

[0039] A rotating shaft is connected to the output end of the servo motor;

[0040] Several pneumatic gripper fingers are rotatably fixed to one end of the rotating shaft away from the servo motor, and the several pneumatic gripper fingers are evenly distributed around the central axis of the rotating shaft.

[0041] A piston cylinder is connected to several of the aforementioned gripper fingers, the piston cylinder being used to drive the several gripper fingers to open or close in order to grasp or release the optical fiber to be tested.

[0042] Preferably, the fiber optic twist identification mechanism includes:

[0043] A detection plate is movably disposed under the test stage. The detection plate has a rectangular array of several detection holes, which form the detection area of ​​the detection plate. The naturally drooping optical fiber to be tested is located in the detection area.

[0044] Several sets of fiber optic position sensors are used to determine the direction of fiber twist by detecting the vertical distance between the fiber under test and the detection plate in a naturally drooping state between each set of fiber optic position sensors. The several sets of fiber optic position sensors are movably fixed in the detection hole by limiting components.

[0045] Preferably, the fiber optic twist testing device further includes a moving mechanism, the moving mechanism comprising:

[0046] A slide rail is fixed to the test platform along the length of the test platform.

[0047] The first slider is slidably disposed on the slide rail, and the fiber pressing mechanism is fixed to the first slider;

[0048] The second slider is slidably disposed on the slide rail, and the optical fiber rotation clamping mechanism is fixed to the second slider;

[0049] A third driving device is used to drive the second slider to slide along the slide rail. The third driving device includes a rack parallel to the slide rail and fixed to the test platform, a gear cooperating with the rack, and a mobile motor whose output end is fixed to the gear for driving the gear to rotate.

[0050] Preferably, the fiber twisting test device further includes a fiber cleaving mechanism for cutting the fixed end of the fiber under test. The fiber cleaving mechanism is fixed to the mounting part on the side near the fiber rotation clamping mechanism. The fiber cleaving mechanism is a parallel opening and closing pneumatic gripper. The parallel opening and closing pneumatic gripper includes a cylinder fixed to the mounting part, two gripping fingers that move in opposite directions or towards each other to form an opening and closing action, and a cutting element disposed between the two gripping fingers. When the gripping fingers move towards each other, the cutting element contacts and cuts the fiber under test located between the cutting elements.

[0051] A second aspect of the present invention provides a method for testing the twist of an optical fiber, implemented based on the optical fiber twist testing device described in the first aspect, comprising the following steps:

[0052] S1, install the fiber optic reel on the cable feeding bracket, take the fiber to be tested and pass it through the first guide wheel and the second guide wheel in sequence, start the first drive device to unwind the untwisted fiber on the fiber optic reel.

[0053] S2, start the third drive device and move the rotating gripper toward the second guide wheel. After the rotating gripper clamps the free end of the optical fiber to be tested, start the third drive device and the first drive device and move the rotating gripper away from the second guide wheel to the set position. Then, turn off the third drive device and the first drive device. During the movement, keep the optical fiber to be tested in a horizontal and straight state.

[0054] S3, start the second drive device, drive the pressure roller to press down into the second fiber groove and fix the fiber under test located in the second fiber groove;

[0055] S4, start the third drive device to move the rotating gripper towards the second guide wheel, so that the optical fiber under test located between the second guide wheel and the rotating gripper hangs down naturally. At the same time, the twisting direction of the optical fiber under test is determined by the optical fiber position sensor, and the servo motor is started to drive the gripper fingers to perform a rotational untwisting action opposite to the twisting direction of the optical fiber under test until the optical fiber under test is untwisted; the rotation angle of the servo motor is the twisting degree of the optical fiber under test.

[0056] S5, activate the parallel opening and closing gripper to cut the optical fiber under test;

[0057] S6. Repeat S2-S5 above to perform multiple unwinding tests and calculate the average twist of the optical fiber under test.

[0058] Preferably, step S4 includes the following steps:

[0059] S41, based on the parabolic path of the naturally drooping optical fiber under test, with the axis of symmetry of the parabola as the center of symmetry, the optical fiber under test is divided into a symmetrical first optical fiber segment and a second optical fiber segment under test. The first optical fiber segment under test is connected to a rotating pneumatic gripper, and the second optical fiber segment under test is connected to a pressure roller and a second guide roller. Multiple sets of optical fiber position sensors are set on the dynamically changing parabolic path of the first and second optical fiber segments under test to measure the torsion of the optical fiber under test at different time points.

[0060] S42, the vertical distance between the first and second fiber segments to be tested and the detection plate is detected by the fiber position sensor, i.e., moving away from or closer to the detection plate, to determine the twisting direction of the fiber segment to be tested, and the pneumatic gripper fingers are driven by the servo motor to perform a rotational untwisting action opposite to the twisting direction of the fiber segment to be tested.

[0061] S43, when the lowest point of the natural droop of the optical fiber under test is parallel to the center line of the detection hole at the same height on the detection plate; and / or, when the optical fiber position sensor detects that the distance between the first optical fiber segment under test and the second optical fiber segment under test and the detection plate remains unchanged, the servo motor is turned off, the rotating gripper stops working, and the untwisting of the optical fiber under test is completed.

[0062] Compared with the prior art, the fiber optic twist testing device and method provided by the present invention have the following advantages:

[0063] 1. This invention, by incorporating an automatic fiber feeding mechanism, a fiber feeding control mechanism, an optical fiber pressing mechanism, and an optical fiber rotation clamping mechanism on the test bench, achieves automated mechanical control of the optical fiber's feeding, clamping, fixing, and movement, reducing errors caused by human operation. Simultaneously, the fiber twist recognition mechanism detects the twist direction and degree of the optical fiber, further ensuring the accuracy of the fiber twist test, so that the measured fiber twist accurately reflects the overall twist degree of the optical fibers on the fiber optic reel.

[0064] 2. The fiber feeding control mechanism in this invention controls the fiber feeding speed by detecting the tension of the fiber under test. The slide rod rotates around the axis of the connecting shaft, and the end of the slide rod connected to the spring forms an elastic end. When the tension of the fiber under test, which is threaded through the first fiber slot, changes, the first guide wheel located at the other end of the slide rod will rotate downwards due to increased pressure or upwards due to decreased pressure. Furthermore, by detecting changes in the distance between the distance sensor and the disc cam, the tension change of the fiber under test on the first guide wheel is reflected. This achieves precise control of the fiber tension.

[0065] 3. The moving mechanism in this invention, by setting a first slider and a second slider that cooperate with the slide rail, enables the fiber pressing mechanism to move to an appropriate position on the slide rail and be fixed as needed. The fiber rotation clamping mechanism can perform high-precision linear motion under the drive of the rack and pinion transmission mechanism, thereby improving the stability of the movement of the fiber under test and reducing the impact of inaccurate measurement caused by the unstable movement of the fiber under test in the fiber twist identification mechanism.

[0066] 4. This invention utilizes a second guide wheel in conjunction with a pressure wheel, and controls the lifting and lowering of the pressure wheel through a pressing and releasing assembly. This allows for the pressing or releasing of the optical fiber under test according to testing needs, improving the flexibility of fiber control. Simultaneously, the second guide wheel and pressure wheel form a relatively compact structure, reducing the space required for the fiber pressing and releasing mechanism within the testing device.

[0067] 5. This invention employs a fiber optic rotating clamping mechanism to clamp and rotate the free end of the fiber under test. Simultaneously, based on the sag of the free end, the control system controls the rotating clamping mechanism to rotate downwards, thereby adjusting the axis of the rotating gripper to align with the sag angle of the fiber's free end. This ensures the fiber is in a natural sag state during testing, minimizing external forces and improving the accuracy of fiber torsion measurement.

[0068] 6. This invention uses an optical fiber twist identification mechanism to quantify the twist direction and degree of optical fiber, reducing errors caused by human judgment. This improves the accuracy of optical fiber twist testing, ensuring that the measured twist accurately reflects the overall twist of the optical fibers on the fiber optic reel. Attached Figure Description

[0069] Figure 1 A three-dimensional view of a fiber optic twist testing device;

[0070] Figure 2 This is a front view of an optical fiber twist testing device;

[0071] Figure 3 This is a perspective view of the automatic wire feeding mechanism in this invention;

[0072] Figure 4 This is a side view of the automatic wire feeding mechanism in this invention;

[0073] Figure 5 This is a front view of the wire-laying control mechanism in this invention;

[0074] Figure 6 This is a perspective view of the wire feeding control mechanism in this invention;

[0075] Figure 7 A perspective view of the moving mechanism in this invention;

[0076] Figure 8 A perspective view of the fiber optic compression mechanism in this invention;

[0077] Figure 9 Side view of the fiber optic compression mechanism in this invention;

[0078] Figure 10 A front view of the fiber optic compression and amplification mechanism in this invention;

[0079] Figure 11 Schematic diagram of the optical fiber rotation clamping mechanism in this invention;

[0080] Figure 12 A perspective view of the optical fiber rotation clamping mechanism in this invention;

[0081] Figure 13 A front view of the optical fiber rotating clamping mechanism in this invention;

[0082] Figure 14 A schematic diagram of the fiber optic twist identification mechanism (with some detection holes omitted) in this invention;

[0083] Figure 15 Flowchart of the fiber optic twist test method in this invention;

[0084] The main reference numerals in the figure are as follows:

[0085] 10. Test stand; 101. Rectangular frame; 102. Support legs;

[0086] 20. Line feeding control mechanism; 201. Support part; 202. Connecting shaft; 203. Disc cam; 204. Slide rod; 205. Adjustment hole; 206. Spring; 207. First guide wheel; 2071. First fiber optic groove; 208. Distance sensor;

[0087] 30. Automatic wire feeding mechanism; 301. Wire feeding bracket; 302. First drive device; 303. Reel; 304. Fiber optic reel; 305. Bearing assembly;

[0088] 40. Fiber optic compression mechanism; 401. Second guide wheel; 4011. Second fiber optic slot; 402. Pressure wheel; 403. Compression assembly; 4031. Mounting part; 4032. Second drive device; 4033. Guide rod;

[0089] 50. Fiber optic twist recognition mechanism; 501. Detection plate; 5011. Detection hole; 502. Fiber optic position sensor;

[0090] 60. Fiber optic rotary clamping mechanism; 601. Servo motor; 602. Rotary shaft; 603. Pneumatic gripper fingers; 604. First mounting plate; 605. Second mounting plate; 606. Rotating shaft;

[0091] 70. Moving mechanism; 701. Slide rail; 702. First slider; 703. Second slider; 704. Third drive device; 7041. Rack; 7042. Gear; 7043. Moving motor;

[0092] 80. Fiber optic cutting mechanism; 801. Cylinder; 802. Gripper finger;

[0093] 90. Fiber optic cable to be tested. Detailed Implementation

[0094] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments of the present invention.

[0095] Example 1

[0096] Please refer to Figure 1 and Figure 2 As shown, an optical fiber twist testing device includes: a test platform 10 and an automatic wire feeding mechanism 30, a wire feeding control mechanism 20, an optical fiber pressing and feeding mechanism 40, an optical fiber twist identification mechanism 50, and an optical fiber rotation clamping mechanism 60, which are sequentially arranged on the same side of the test platform 10 along the length direction of the test platform 10.

[0097] The fiber under test 90 is led out from the fiber reel 304 and passes through the cable release control mechanism 20, the fiber pressing mechanism 40 and the fiber rotation clamping mechanism 60 in sequence. The fiber rotation clamping mechanism 60 drives the fiber under test 90 to move along the length of the test table 10. The naturally drooping fiber under test 90 passes through the detection area of ​​the fiber twist recognition mechanism 50 and performs fiber untwisting action according to the twist direction of the fiber under test 90 detected by the fiber twist recognition mechanism 50.

[0098] It should be noted that the test platform 10 in this embodiment serves to provide an installation platform for the aforementioned automatic cable laying mechanism, cable laying control mechanism 20, fiber optic pressing mechanism 40, fiber optic twist identification structure, and fiber optic rotating clamping mechanism 60. Therefore, the structural form of the test platform 10 is not limited in this embodiment. Figure 7 As shown in this embodiment, the test platform 10 includes a rectangular frame 101 and legs 102 supporting both sides of the rectangular frame 101.

[0099] The following description, using test bench 10 as a reference, details the specific installation locations and structures of the other mechanisms mentioned above.

[0100] 1. Automatic wire feeding mechanism 30

[0101] Please refer to Figures 1-4As shown, in this embodiment, the automatic wire feeding mechanism 30 is placed next to the test bench 10. Its purpose is to maintain a certain height difference between the automatic wire feeding mechanism 30 and the wire feeding control mechanism 20 for the fiber 90 under test, so that the wire feeding control mechanism 20 can accurately control the wire feeding speed of the fiber 90 under test by the tension.

[0102] In this embodiment, the automatic cable delivery mechanism 30 includes a cable delivery bracket 301 for placing the fiber optic reel 304, a first driving device 302 for driving the fiber optic reel 304 to rotate, and a shaft 303 for connecting the cable delivery bracket 301 and the fiber optic reel 304. The axis of the shaft 303 coincides with the axis of the fiber optic reel 304 to improve the stability of the rotation of the fiber optic reel 304. The shaft 303 is rotatably mounted on the upper part of the cable delivery bracket 301 via a vertical bearing seat assembly, and the output end of the first driving device 302 is connected to one end of the shaft 303.

[0103] To facilitate automatic control of the wire feeding speed, the first drive device 302 in this embodiment uses a motor as the drive source. Specifically, the first drive device 302 can be a servo motor 601, a DC motor, or a stepper motor, etc. Of course, to improve the accuracy and stability of wire feeding, and to provide sufficient torque output and adjustable speed when necessary, the above-mentioned motors can be used in conjunction with a speed reducer to achieve the aforementioned objectives. The working principle of the motor and its use in conjunction with the speed reducer are existing technologies and will not be elaborated upon here.

[0104] 2. Wire laying control mechanism 20

[0105] Please refer to Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, in this embodiment, the wire feeding control mechanism 20 controls the wire feeding speed of the fiber 90 under test by detecting the tension of the fiber 90 under test.

[0106] Considering that the optical fiber 90 to be tested requires a certain tension, in this embodiment, the wire feeding control mechanism 20 and the above-mentioned automatic wire feeding mechanism 30 have a certain height difference.

[0107] Specifically, the wire feeding control mechanism 20 includes: a support part 201, which is fixedly disposed at one end of the test bench 10, specifically the upper part of the support leg 102 near the automatic wire feeding mechanism 30. The end of the support part 201 away from the test bench 10 is provided with a mounting hole, and a connecting shaft 202 is rotatably disposed within the mounting hole, with both ends of the connecting shaft 202 extending out of the mounting hole;

[0108] The disc-shaped cam 203 is fixedly connected to one end of the connecting shaft 202;

[0109] The slide bar 204 has at least one adjustment hole 205 along its length, and the end of the connecting shaft 202 away from the disc cam 203 is movably fixed to the adjustment hole 205.

[0110] Spring 206 is connected at one end to slide bar 204 and at the other end to test bench 10;

[0111] The first guide wheel 207 is rotatably disposed at the end of the slide bar 204 away from the spring 206, and is located on the opposite side of the slide bar 204 from the disc cam 203. The outer periphery of the first guide wheel 207 is provided with a first fiber groove 2071 to facilitate the placement of the fiber optic cable 90 to be tested.

[0112] The distance sensor 208 is located directly below the disc cam 203 and is at a distance from the disc cam 203.

[0113] Understandably, the slide bar 204 rotates around the axis of the connecting shaft 202, at which point the end of the slide bar 204 connected to the spring 206 forms an elastic end. When the tension of the optical fiber 90 to be tested, which is inserted into the first optical fiber groove 2071, changes, the first guide wheel 207 located at the other end of the slide bar 204 will rotate downwards due to increased pressure or rotate upwards due to decreased pressure.

[0114] Since the disc cam 203 is connected to the first guide wheel 207 via the connecting shaft 202, when the first guide wheel 207 rotates downward or upward as described above, this rotation downward and rotation upward are manifested in the disc cam 203 as counterclockwise or clockwise rotation (the positioning angle is from the first guide wheel 207 to the disc cam 203).

[0115] In this embodiment, the tension change of the optical fiber 90 to be tested on the first guide wheel 207 is reflected by detecting the distance change between the distance sensor 208 and the disc cam 203.

[0116] Specifically, in this embodiment, the distance sensor 208 can be a laser distance sensor 208, which calculates the distance by utilizing the time it takes for the laser to travel from emission to reflection. Because lasers have high directionality and high brightness, high measurement accuracy can be achieved. Of course, this application does not limit the type of distance sensor 208.

[0117] Generally, the disc cam 203 can be a flat circular or elliptical shape, with a raised profile. In this embodiment, a circular disc cam 203 is used, and the overall structure can be regarded as a smooth arc connection between the outer periphery of the disc and an arc-shaped protrusion.

[0118] When the disc cam 203 rotates around the axis of the connecting shaft 202, the distance between the disc cam 203 and the distance sensor 208 changes.

[0119] Specifically, in this embodiment, when the disc cam 203 rotates clockwise, the distance between the disc cam 203 and the distance sensor 208 increases, indicating that the first guide wheel 207 rotates and rises, and the pressure exerted by the fiber optic cable 90 on the first guide wheel 207 decreases, thus reducing the tension of the fiber optic cable 90. When the disc cam 203 rotates counterclockwise, the distance between the disc cam 203 and the distance sensor 208 decreases, indicating that the first guide wheel 207 rotates and presses down, and the pressure exerted by the fiber optic cable 90 on the first guide wheel 207 increases, thus increasing the tension of the fiber optic cable 90.

[0120] To facilitate automatic control of the fiber optic cable laying speed, in this embodiment, the first drive device 302, the distance sensor 208, and the second drive device 4032, the third drive device 704, and the servo motor 601 described below are all connected to the control system.

[0121] Understandably, in this embodiment, the distance between the distance sensor 208 and the disc cam 203 can be set to a certain value or a range. When the distance detected by the distance sensor 208 exceeds this certain value or range, the wire feeding speed of the first drive device 302 can be adjusted by the control system to adjust the tension of the optical fiber 90 to be tested.

[0122] It should be noted that the pressure applied to the first guide wheel 207 varies depending on the type of optical fiber 90 under test. To improve the detection sensitivity of the cable feeding control mechanism 20, i.e., to ensure that the first guide wheel 207 can rotate significantly downwards or upwards when the tension of the optical fiber 90 under test changes significantly, in this embodiment, a spring 206 with a suitable stiffness coefficient can be selected according to the magnitude of the pressure applied to the first guide wheel 207 by the optical fiber 90 under test. This ensures appropriate deformation while improving detection sensitivity. Specifically, when the applied pressure is large, a spring 206 with a larger stiffness coefficient is selected; when the applied pressure is small, a spring 206 with a smaller stiffness coefficient is selected.

[0123] Please refer to Figure 5 and Figure 6 As shown, the slide bar 204 in this embodiment is provided with several adjustment holes 205. Its function is to adjust the length of the lever arm of the slide bar 204 on both sides of the adjustment hole 205 through different adjustment holes 205, thereby adjusting the rotation lifting or rotation pressing amount of the first guide wheel 207 under the same pressure, and thus adjusting the distance change of the disc cam 203.

[0124] It should be noted that in this embodiment, the fixing between the connecting shaft 202 and the slide rod 204 can be achieved by setting corresponding through holes on the slide rod 204 and the connecting shaft 202, and by using pins or bolts and nuts that are compatible with the through holes to achieve a movable and detachable fixing.

[0125] 3. Mobile mechanism 70

[0126] Please refer to Figure 7 As shown, to facilitate adjustment of the fiber pressing mechanism 40 and the fiber rotation clamping mechanism 60, the fiber twisting test device in this embodiment further includes a moving mechanism 70, which includes:

[0127] The slide rail 701 is fixed on the test platform 10 along the length of the test platform 10;

[0128] The first slider 702 is slidably mounted on the slide rail 701, and the fiber optic pressing mechanism 40 is fixed to the first slider 702.

[0129] The second slider 703 is slidably mounted on the slide rail 701, and the fiber optic rotation clamping mechanism 60 is fixed to the second slider 703.

[0130] The third driving device 704 is used to drive the second slider 703 to slide along the slide rail 701. The third driving device 704 includes a rack 7041 parallel to the slide rail 701 and fixed to the test platform 10, a gear 7042 that cooperates with the rack 7041, and a moving motor 7043 whose output end is fixed to the gear 7042 for driving the gear 7042 to rotate.

[0131] Specifically, in this embodiment, the slide rail 701 is fixed to one side of the rectangular frame 101. To facilitate adjustment of the length of the slide rail 701, it is designed as a multi-segment assembly. Users can add or remove the number of slide rail 701 segments as needed to meet testing requirements.

[0132] Considering that the fiber optic compression mechanism 40 serves as the fixing point for the fixed end of the fiber optic cable 90 under test during the testing process, it needs to be relatively fixed to the slide rail 701 after the test begins. In this embodiment, a limiting component is provided between the first slider 702 and the slide rail 701. This limiting component can be a bolt or a pin, etc. Similarly, if the second slider 703 needs to be fixed, the same fixing method can be used to achieve relative fixation with the slide rail 701.

[0133] Please refer to Figure 7 and Figure 12As shown, in this embodiment, the third driving device 704 employs a rack and pinion 7041 and a gear 7042 meshing structure. Specifically, a first mounting plate 604 is fixed on the second slider 703, wherein a moving motor 7043 is fixed to the upper part of the first mounting plate 604, and the output end of the moving motor 7043 extends to the lower part of the first mounting plate 604, connecting with the gear 7042 at the lower part of the first mounting plate 604. The rack 7041 is fixed at a relative height to the gear 7042, and the teeth of the rack 7041 face the gear 7042. It should be noted that the aforementioned third driving device 704 can also employ other types of linear drive mechanisms, such as screw drive mechanisms, pneumatic drive mechanisms, hydraulic drive mechanisms, and linear motors.

[0134] In this embodiment, the moving mechanism 70, by setting a first slider 702 and a second slider 703 that cooperate with the slide rail 701, enables the fiber pressing mechanism 40 to move to an appropriate position on the slide rail 701 and be fixed as needed. The fiber rotation clamping mechanism 60 can perform high-precision linear motion under the drive of the rack and pinion 7041 and gear 7042 transmission mechanism, thereby improving the stability of the movement of the fiber under test 90 and reducing the impact of the fiber twist identification mechanism 50 on inaccurate measurement caused by the unstable movement of the fiber under test 90.

[0135] 4. Fiber optic compression mechanism 40

[0136] Please refer to Figures 8-10 As shown, in this embodiment, the fiber compression mechanism 40 is fixedly installed on the test bench 10 to fix the fiber under test 90 to form a fixed end of the fiber under test 90.

[0137] The second guide wheel 401 is set on the test bench 10. The rotation center axis of the second guide wheel 401 is parallel to the rotation center axis of the first guide wheel 207. The outer periphery of the second guide wheel 401 is provided with a second fiber groove 4011 to facilitate the placement of the fiber 90 to be tested. The second fiber groove 4011 and the first fiber groove 2071 are located in the same plane.

[0138] The pressure roller 402 cooperates with the second guide roller 401. When the pressure roller 402 is pressed into or lifted out of the second optical fiber groove 4011, it presses or releases the optical fiber 90 to be tested.

[0139] Pressing and releasing assembly 403 is used to drive pressure roller 402 to press into or lift out of second fiber groove 4011. Pressing and releasing assembly 403 includes:

[0140] Mounting part 4031 is fixed to test stand 10;

[0141] The second drive unit 4032 is fixed to the mounting part 4031;

[0142] The guide rod 4033 is fixedly connected at one end to the pressure roller 402 and at the other end to the output end of the second drive device 4032;

[0143] The second driving device 4032 drives the guide rod 4033 to extend and retract along its length, thereby driving the pressure roller 402 to press into or lift away from the second optical fiber groove 4011.

[0144] In this embodiment, the second guide wheel 401 cooperates with the pressure wheel 402, and the lifting and lowering of the pressure wheel 402 is controlled by the pressure release assembly 403. This allows for the compression or release of the fiber optic cable 90 under test according to testing needs, improving the flexibility of controlling the fiber optic cable 90. Simultaneously, the second guide wheel 401 and the pressure wheel 402 form a relatively compact structure, reducing the space required for the fiber optic cable compression and release mechanism 40 within the testing device.

[0145] The first fiber slot 2071 and the second fiber slot 4011 are located in the same plane, which can ensure that the path of the fiber under test 90 is in the same plane during the cable laying and transmission process, reducing the twist and offset of the fiber under test 90, and improving the accuracy of the twist measurement of the fiber under test 90 to a certain extent.

[0146] It should be noted that, in order to facilitate the installation of the second guide wheel 401 and the pressing and releasing assembly 403, an installation part 4031 is provided in this embodiment. Specifically, the installation part 4031 is an L-shaped plate, and the second guide wheel 401 is rotatably fixed on the side of the L-shaped plate away from the slider through a fixed shaft.

[0147] Please refer to Figures 8-10 As shown, the second driving device 4032 can be a pneumatic cylinder or a hydraulic cylinder (not shown in the figure). Meanwhile, the guide rod 4033 is a parallel double guide rod 4033. The lower part of the double guide rod 4033 is connected by a fixing plate. The pressure roller 402 is fixed to the fixing plate by a fixing shaft. The upper part of the double guide rod 4033 is connected by a connecting plate. The connecting plate is connected to the output end of the pneumatic cylinder or the hydraulic cylinder.

[0148] Understandably, the use of dual guide rods 4033 can guide the lifting and lowering of the pressure roller 402 from two directions, ensuring that the pressure roller 402 can smoothly press into or lift out of the second fiber optic groove 4011 in a straight line. At the same time, by adjusting parameters such as the air intake and pressure of the cylinder, the movement speed and pressure of the pressure roller 402 can be accurately controlled.

[0149] 5. Fiber optic cutting mechanism 80

[0150] Please refer to Figures 8-10 As shown, in order to facilitate the automatic cutting of optical fibers, the optical fiber twist test device in this embodiment also includes an optical fiber cutting mechanism 80 for cutting off the fixed end of the optical fiber 90 to be tested.

[0151] Specifically, in this embodiment, the fiber optic cleaving mechanism 80 is a parallel opening and closing gripper. To facilitate the installation of the parallel opening and closing gripper, a suspension plate is vertically connected downwards to one end of the L-shaped plate near the fiber optic rotating clamping mechanism 60. Specifically, the parallel opening and closing gripper includes a cylinder 801 fixed to the suspension plate, two gripping fingers 802 that move in opposite directions or towards each other to form an opening and closing action, and a cutting element disposed between the two gripping fingers 802. When the gripping fingers 802 move towards each other, the cutting element contacts and cuts the fiber optic cable 90 to be tested located between the cutting elements.

[0152] It is understandable that the cylinder 801 mentioned above can be a pneumatic cylinder or a hydraulic cylinder. The cutting part can be made of diamond material, which has the advantages of having a sharp cutting edge, enabling high-precision cutting, ensuring the flatness and smoothness of the cut surface, and generating less heat during the cutting process, thus reducing damage to the internal structure of the optical fiber.

[0153] 6. Fiber optic rotating clamping mechanism 60

[0154] Please refer to Figures 11-13 As shown, in this embodiment, the optical fiber rotating clamping mechanism 60 is moved and disposed on the test table 10 along the length direction of the test table 10. The optical fiber rotating clamping mechanism 60 is used to clamp and rotate the free end of the optical fiber 90 under test around its own axis, and is used to perform a retraction action on the optical fiber 90 under test. The optical fiber rotating clamping mechanism 60 rotates relative to the test table 10 so that the optical fiber 90 under test is in a relatively free drooping state during the test.

[0155] Specifically, in this embodiment, the optical fiber rotating clamping mechanism 60 is a rotating pneumatic gripper. To facilitate the installation of the rotating pneumatic gripper, in this embodiment, a second mounting plate 605 is rotatably connected to one end of the first mounting plate 604 near the optical fiber pressing mechanism 40 via a rotating shaft 606. The axis of the rotating shaft 606 of the second mounting plate 605 is parallel to the rotation center line of the first guide wheel 207 or the second guide wheel 401. To facilitate automatic control of the rotation of the second mounting plate 605, the aforementioned rotating shaft 606 can be connected to a motor, and the rotation of the motor can be controlled by a control system, ensuring that the free end of the optical fiber 90 under test is collinear with the rotating shaft 606 of the rotating pneumatic gripper, thereby ensuring that the optical fiber 90 under test is in a naturally drooping state during the measurement process.

[0156] In this embodiment, the rotary gripper includes a servo motor 601 and a rotating shaft 602 respectively disposed on both sides of the second mounting plate 605. The servo motor 601 is fixed to the second mounting plate 605, and the rotating shaft 602 is connected to the output end of the servo motor 601. A plurality of gripper fingers 603 are rotatably disposed at the end of the rotating shaft 602 away from the servo motor 601, and the plurality of gripper fingers 603 are evenly distributed about the central axis of the rotating shaft 602.

[0157] A piston cylinder is connected to several pneumatic gripper fingers 603. The piston cylinder is used to drive the several pneumatic gripper fingers 603 to open or close in order to grasp or release the optical fiber 90 to be tested.

[0158] It should be noted that in this embodiment, the number of pneumatic gripper fingers 603 is three. Of course, in actual operation, the number of pneumatic gripper fingers 603 can be selected according to the clamping requirements of the optical fiber 90 to be tested, so as to ensure that the rotating pneumatic gripper has a stable clamping effect.

[0159] Furthermore, to improve the gripping stability of the pneumatic gripper fingers 603, in this embodiment, the surface of the pneumatic gripper fingers 603 in contact with the optical fiber 90 under test is treated with a special anti-slip treatment, such as adding a coating of a material with high friction, like rubber or silicone. This better prevents the optical fiber from slipping when gripping it, improving gripping stability. For example, a silicone material with high frictional properties can be selected and attached to the surface of the pneumatic gripper fingers 603 by bonding or embedding. When the pneumatic gripper fingers 603 close to grip the optical fiber 90 under test, the silicone is in close contact with the surface of the optical fiber 90, increasing friction and thus improving the gripping stability of the pneumatic gripper fingers 603.

[0160] Meanwhile, the shape of the gripper fingers 603 can be designed according to the shape of the optical fiber 90 under test, so that the gripper fingers 603 fit better with the optical fiber 90 under test. For example, the end of the gripper fingers 603 can be set to a concave shape, so that it can better wrap around the optical fiber when closed and prevent it from moving radially.

[0161] For ease of automatic control, the aforementioned servo motor 601 and piston cylinder are both connected to the control system. Their connection methods and control principles are existing technologies and will not be elaborated upon here.

[0162] 7. Fiber optic twist identification mechanism 50

[0163] Please refer to Figure 1 , Figure 2 and Figure 14 As shown, in this embodiment, when the fiber under test 90 is subjected to a torsion test, the fiber torsion identification mechanism 50 is used to detect the torsion direction of the fiber under test 90 during the process from the straightened state to the naturally drooping state, so that the fiber rotation clamping mechanism 60 can determine the rotation direction of the detwisting.

[0164] In this embodiment, the fiber optic twist identification mechanism 50 includes:

[0165] The detection plate 501 is movably set at the lower part of the test stage 10. The rectangular array of the detection plate 501 has a number of detection holes 5011, and the number of detection holes 5011 forms the detection area of ​​the detection plate 501. The naturally hanging optical fiber 90 to be tested is located in the detection area.

[0166] Several sets of fiber optic position sensors 502 are used to determine the direction of fiber twist by detecting the vertical distance between the fiber under test 90, which is naturally drooping between each set of fiber optic position sensors 502, and the detection plate 501. Several sets of fiber optic position sensors 502 are movably fixed in the detection hole 5011.

[0167] Specifically, in this embodiment, the detection plate 501 is a rectangular plate. The movable detection plate 501 can be adjusted in a timely manner according to the drooping position of the fiber optic cable 90 under test and the area of ​​movement, so as to ensure that the fiber optic position sensor 502 can detect the torsion of the fiber optic cable 90 under test throughout the process and ensure the accuracy of the detection.

[0168] Meanwhile, the fiber optic position sensor 502 should be positioned to cover as much of the downward movement path of the fiber optic cable 90 under test as possible. The specific arrangement of the fiber optic position sensor 502 will be described in detail in the test methods section below.

[0169] To ensure the stability of the fiber optic position sensor 502 installation and improve its measurement accuracy, a limiting component (not shown in the figure) is provided between the detection hole 5011 and the fiber optic position sensor 502 in this embodiment.

[0170] Specifically, the limit component can adopt the following structural form:

[0171] Positioning Structure: A positioning protrusion or groove is provided inside the detection hole 5011, which cooperates with the corresponding groove or protrusion on the fiber optic position sensor 502 to achieve more precise positioning. For example, a small positioning protrusion is provided around the inner wall of the detection hole 5011 along the circumferential direction, and a corresponding groove is provided on the outer shell of the fiber optic position sensor 502. When the fiber optic position sensor 502 is inserted into the detection hole 5011, the protrusion is embedded in the groove, restricting the rotation and displacement of the fiber optic position sensor 502 and improving its fixed stability.

[0172] Elastic fixing structure: An elastic fixing component, such as a spring clip 206 or a rubber pad, is installed inside the detection hole 5011. When the fiber optic position sensor 502 is inserted into the detection hole 5011, the elastic fixing component applies a certain pressure to the fiber optic position sensor 502, making it tightly fixed inside the hole. For example, using a rubber pad as a fixing component, it is pasted to the inner wall of the detection hole 5011. The rubber pad has a certain elastic deformation capacity. When the fiber optic position sensor 502 is inserted, the rubber pad is compressed, and the resulting reaction force clamps the fiber optic position sensor 502, which can both ensure the fixing effect and prevent damage to the sensor.

[0173] Threaded fixing structure: Where the housing structure of the fiber optic position sensor 502 allows, internal and external threads can be provided on the detection hole 5011 and the fiber optic position sensor 502 respectively, and the sensor can be fixed in the detection hole 5011 by threaded connection. This method of fixing is firm and not easy to loosen, which can significantly improve the stability of the fiber optic position sensor 502.

[0174] To ensure that the fiber optic position sensors 502 extend from the detection plate 501 at a consistent length after installation, a positioning plate is provided in this embodiment. The positioning plate is parallel to the detection plate 501 and located in front of it. The positioning plate can be slidably mounted on the rectangular frame 101 of the test bench 10. When installing the fiber optic position sensors 502, the sensor is considered properly installed when it contacts the positioning plate. After installation, the lengths of the installed fiber optic position sensors 502 extending from the detection plate 501 are consistent. This ensures the consistency of the measurement reference when measuring the vertical distance between the fiber optic cable 90 and the detection plate 501. Especially when measuring the same group of fibers, it allows for a direct determination of whether the fiber optic cable 90 is closer to or further from the detection plate 501, thus identifying fiber twisting during cable laying.

[0175] The fiber optic twist testing device in this embodiment, by setting an automatic cable feeding mechanism 30, a cable feeding control mechanism 20, a fiber optic pressing mechanism 40, and a fiber optic rotation clamping mechanism 60 on the test bench 10, enables automatic mechanical control of the fiber optic cable feeding, clamping, fixing, and movement, reducing errors caused by human operation. Simultaneously, the fiber optic twist identification mechanism 50 detects the twist direction and degree of the fiber optic cable, further ensuring the accuracy of the fiber optic twist test, so that the measured fiber optic twist accurately reflects the overall twist of the fiber optic cable on the fiber optic reel 304.

[0176] Example 2

[0177] Please refer to Figure 15 As shown, a fiber optic twist test method, implemented based on the fiber optic twist test device of Embodiment 1, includes the following steps:

[0178] S1, install the fiber optic reel 304 on the cable laying bracket 301, take the fiber optic cable 90 to be tested and pass it through the first guide wheel 207 and the second guide wheel 401 in sequence, start the first drive device 302, and unwind the fiber optic cable on the fiber optic reel 304.

[0179] It should be noted that the purpose of unwinding the fiber on the fiber optic reel 304 is to remove interference factors. Specifically, since the fiber under test 90 at the head end of the fiber optic reel 304 is a free end, it may have been partially unwound. This will have a certain impact on the accuracy of the subsequent measurement of the twist of the fiber under test 90.

[0180] S2, start the third drive device 704, move the rotating gripper toward the second guide wheel 401, after the rotating gripper clamps the free end of the optical fiber 90 to be tested, start the third drive device 704 and the first drive device 302, move the rotating gripper away from the second guide wheel 401 to the set position, and then turn off the third drive device 704 and the first drive device 302. During the movement, keep the optical fiber 90 to be tested in a horizontal and straight state.

[0181] It should be noted that, generally speaking, the test length of the optical fiber 90 to be tested is 1 meter. In this embodiment, a positioning block that slides relative to the slide rail 701 is set on the slide rail 701. According to the length of the optical fiber 90 to be tested, the sliding position of the second slider 703 is limited by the positioning block to ensure the consistency of the optical fiber measurement length each time.

[0182] Understandably, when the measured length of the optical fiber 90 is inconsistent with the conventional measured length, it can be adjusted accordingly by changing the relative position of the positioning block on the slide rail 701. Clearly, the positioning block can be fixed to the slide rail 701 using positioning pins or positioning bolts.

[0183] S3, start the second drive device 4032, drive the pressure roller 402 to press down into the second optical fiber groove 4011 and fix the optical fiber 90 under test located in the second optical fiber groove 4011.

[0184] It should be noted that the function of the pressure roller 402 and the second fiber groove 4011 is to press the second fiber into the second fiber groove 4011, thereby forming a fixed end of the fiber under test 90, ensuring that the fixed end of the fiber under test 90 will not twist during the torsion test, thus ensuring the accuracy of the torsion test of the fiber under test 90.

[0185] S4, the third drive device 704 is activated, and the rotating gripper is moved towards the second guide wheel 401, so that the optical fiber 90 to be tested, located between the second guide wheel 401 and the rotating gripper, hangs down naturally. At the same time, the optical fiber position sensor 502 determines the twisting direction of the optical fiber 90 to be tested, and the servo motor 601 is activated to drive the gripper finger 603 to perform a rotational untwisting action opposite to the twisting direction of the optical fiber 90 to be tested, until the untwisting of the optical fiber 90 to be tested is completed; the rotation angle of the servo motor 601 is the twisting degree of the optical fiber 90 to be tested.

[0186] It should be noted that, as described in Embodiment 1, in order to ensure that the fiber optic cable 90 under test is in a natural drooping state during testing and is not affected by other external forces as much as possible, in this embodiment, the rotating shaft 606 is driven by a motor to rotate, thereby driving the second mounting plate 605 to rotate, and thus adjusting the axis of the rotating gripper to be collinear with the free end of the fiber optic cable 90 under test, so that the fiber optic cable 90 under test is in a free drooping state.

[0187] Specifically, S4 above includes the following steps:

[0188] S41, based on the parabolic path of the naturally drooping optical fiber 90 under test, with the axis of symmetry of the parabola as the center of symmetry, the optical fiber 90 under test is divided into a first segment and a second segment. The first segment is connected to the rotating pneumatic gripper, and the second segment is connected to the pressure roller 402 and the second guide roller 401. Multiple sets of optical fiber position sensors 502 are respectively set on the dynamically changing parabolic path of the first and second segments to measure the torsion of the optical fiber 90 under test at different time points.

[0189] It should be noted that in this embodiment, each group of fiber optic position sensors 502 includes two fiber optic position sensors 502 disposed within the detection holes 5011 at the same height. The positions of each group of fiber optic position sensors 502 measuring the first and second fiber optic segments under test at the same time point are symmetrical with respect to the parabolic axis of symmetry at that time point.

[0190] S42, the fiber optic position sensor 502 detects the change in the vertical distance between the first and second fiber optic segments 90 and the detection plate 501, i.e., moving away from or closer to the detection plate 501, to determine the twisting direction of the fiber optic segment 90, and drives the pneumatic gripper finger 603 to perform a rotational untwisting action opposite to the twisting direction of the fiber optic segment 90 through the servo motor 601.

[0191] Specifically, in this embodiment, clockwise rotation or twisting direction can be set as positive, and counterclockwise rotation or twisting direction can be set as negative. The clockwise and counterclockwise observation directions are those from the servo motor 601 looking at the pneumatic gripper finger 603, that is, from the top of the pneumatic gripper finger 603.

[0192] Generally, when the untwisted fiber optic segments 90 are close to each other, the distance between the first and second fiber optic segments 90 and the detection plate 501 should remain unchanged. When the fiber optic segments 90 are twisted, due to the torsional stress inside the fiber, the first and second fiber optic segments 90 will move away from (closer to) or closer to (far away from) the detection plate 501, respectively.

[0193] Specifically, when the fiber optic sensor detects that the first fiber optic segment 90 under test is moving away from the detection plate 501 and the second fiber optic segment 90 under test is moving closer to the detection plate 501, the servo motor 601 drives the pneumatic gripper finger 603 to rotate counterclockwise; when the fiber optic sensor detects that the first fiber optic segment 90 under test is moving closer to the detection plate 501 and the second fiber optic segment 90 under test is moving away from the detection plate 501, the servo motor 601 drives the pneumatic gripper finger 603 to rotate clockwise.

[0194] S43, when the lowest point of the natural droop of the fiber under test 90 is parallel to the center line of the detection hole 5011 at the same height on the detection plate 501; and or, when the fiber position sensor 502 detects that the distance between the first fiber under test 90 segment and the second fiber under test 90 segment and the detection plate 501 remains unchanged, the servo motor 601 is turned off, the rotating gripper stops working, and the untwisting of the fiber under test 90 is completed.

[0195] S5, start the parallel opening and closing air gripper to cut the optical fiber under test by 90;

[0196] S6. Repeat S2-S5 above to perform multiple untwist tests and calculate the average twist of the fiber under test.

[0197] Specifically, in this embodiment, it is assumed that the twisting period of the fiber 90 under test is n, and the test is performed 2n times. The twisting degree from the first to the 2nth test is recorded as D1...D2n respectively. Then the twisting degree per meter of fiber 90 under test is (D1+D2+...D2n) / 2n.

[0198] In this embodiment, the fiber optic twist test method involves fixing one end of the fiber optic cable 90 under test and bringing the other end closer together while gripped by a rotating pneumatic gripper. Multiple fiber optic position sensors 502 on the detection plate 501 identify the twist direction of the fiber optic cable 90. The rotating pneumatic gripper rotates in the opposite direction to the twist, performing a de-twisting action on the fiber optic cable 90. The de-twisting of the fiber optic cable 90 is determined to be complete when the lowest point of its natural droop is horizontal and / or the vertical distance between the fiber optic cable 90 and the detection plate 501 remains constant. This test method achieves near-automatic control throughout the entire testing process, reducing detection errors and uncertainties that may be caused by human operation, and improving testing efficiency and accuracy. Furthermore, the twist determination employs dynamic multi-point testing, quantifiable criteria for de-twisting completion, and averaging of multiple measurements, ensuring that the entire determination process does not rely on subjective human judgment, thus improving the accuracy of the determination and further enhancing the accuracy of the detection.

[0199] It should be noted that all the motors, cylinders, hydraulic cylinders, etc., used for driving in this application are connected to the control system to maximize the automation control of the fiber optic twist test device. The connection methods and control principles are existing technologies and will not be elaborated upon here.

[0200] The above description is a specific implementation of the embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An optical fiber twist test apparatus, characterized by, The application relates to a fiber optic cable testing device. The device comprises a testing table (10), a fiber optic cable tension control mechanism (20) fixedly arranged on the testing table (10) and used for detecting the tension of a fiber optic cable (90) to be tested, an automatic fiber optic cable unwinding mechanism (30) used for placing a fiber optic cable reel (304) and controlling the unwinding speed of the fiber optic cable reel (304) according to the tension of the fiber optic cable (90) to be tested, a fiber optic cable pressing mechanism (40) fixedly arranged on the testing table (10) and used for fixing the fiber optic cable (90) to be tested to form a fixed end of the fiber optic cable (90) to be tested, a fiber optic cable twist recognition mechanism (50) fixedly arranged on the testing table (10) and used for detecting the twist direction of the fiber optic cable (90) to be tested, and a fiber optic cable rotating clamping mechanism (60) movably arranged on the testing table (10) along the length direction of the testing table (10) and used for clamping and rotating the free end of the fiber optic cable (90) to be tested around the axis of the fiber optic cable rotating clamping mechanism (60) to perform a fiber optic cable untwisting operation, wherein the fiber optic cable rotating clamping mechanism (60) rotates relative to the testing table (10) to make the fiber optic cable (90) to be tested in a relatively free and drooping state during the testing process. The automatic fiber optic cable unwinding mechanism (30), the fiber optic cable tension control mechanism (20), the fiber optic cable pressing mechanism (40), the fiber optic cable twist recognition mechanism (50) and the fiber optic cable rotating clamping mechanism (60) are sequentially arranged on the same side of the testing table (10) along the length direction of the testing table (10). The fiber optic cable (90) to be tested is sequentially arranged through the fiber optic cable tension control mechanism (20), the fiber optic cable pressing mechanism (40) and the fiber optic cable rotating clamping mechanism (60) from the fiber optic cable reel (304), the fiber optic cable rotating clamping mechanism (60) drives the fiber optic cable (90) to move along the length direction of the testing table (10), the naturally drooping fiber optic cable (90) to be tested passes through the detection area of the fiber optic cable twist recognition mechanism (50), and the fiber optic cable untwisting operation is performed according to the twist direction of the fiber optic cable (90) to be tested detected by the fiber optic cable twist recognition mechanism (50). The fiber optic cable twist recognition mechanism (50) comprises a detection plate (501) movably arranged on the lower part of the testing table (10), a plurality of detection holes (5011) arranged in a rectangular array on the detection plate (501), a plurality of detection areas formed by the detection holes (5011) on the detection plate (501), and the naturally drooping fiber optic cable (90) to be tested located in the detection areas. A plurality of groups of fiber optic position sensors (502) are used for judging the twist direction of the fiber optic cable (90) to be tested by detecting the vertical distance between the naturally drooping fiber optic cable (90) to be tested and the detection plate (501) in each group of fiber optic position sensors (502), and the fiber optic position sensors (502) are movably fixed in the detection holes (5011) through a limiting assembly. The automatic fiber optic cable unwinding mechanism (30) comprises an unwinding support (301) used for placing the fiber optic cable reel (304), and a first driving device (302) fixedly arranged on one side of the unwinding support (301) and used for driving the fiber optic cable reel (304) to rotate. ​ ​ ​ ​ ​ 2. The fiber twist test apparatus of claim 1, wherein, ​ ​ ​ A disc shaft (303) is connected with the output end of the first driving device (302) at one end and fixedly connected with the fiber disc (304) at the other end. The disc shaft (303) is rotatably arranged on the pay-off support (301) through a bearing assembly (305).

3. The fiber twist test apparatus of claim 2, wherein, The pay-off control mechanism (20) comprises: A support part (201) is fixedly arranged at one end of the test table (10). An installation hole is arranged at the end of the support part (201) away from the test table (10). A connecting shaft (202) is rotatably arranged in the installation hole. The connecting shaft (202) extends out of the installation hole at both ends. A disc-shaped cam (203) is fixedly connected with one end of the connecting shaft (202). A slide rod (204) is provided with at least one adjusting hole (205) along the length direction of the slide rod (204). One end of the connecting shaft (202) away from the disc-shaped cam (203) is movably fixed with the adjusting hole (205). A spring (206) is connected with the slide rod (204) at one end and connected with the test table (10) at the other end. A first guide wheel (207) is rotatably arranged at the end of the slide rod (204) away from the spring (206) and located at the opposite side of the disc-shaped cam (203) along the slide rod (204). The outer circumferential side of the first guide wheel (207) is provided with a first fiber slot (2071) for placing the to-be-tested optical fiber (90). A distance sensor (208) is arranged below the disc-shaped cam (203) and has an installation distance with the disc-shaped cam (203). When the tension of the to-be-tested optical fiber (90) changes, the first guide wheel (207) drives the slide rod (204) to rotate around the connecting shaft (202) and further drives the disc-shaped cam (203) to rotate, so that the distance between the disc-shaped cam (203) and the distance sensor (208) changes. The automatic pay-off mechanism (30) controls the pay-off speed according to the detection result of the distance sensor (208).

4. The fiber twist test apparatus of claim 3, wherein, The optical fiber pressure pay-off mechanism (40) comprises: A second guide wheel (401) is arranged on the test table (10). The rotation center axis of the second guide wheel (401) is parallel to the rotation center axis of the first guide wheel (207). The outer circumferential side of the second guide wheel (401) is provided with a second fiber slot (4011) for placing the to-be-tested optical fiber (90). The second fiber slot (4011) is located in the same plane as the first fiber slot (2071). A pressure roller (402) cooperates with the second guide wheel (401). When the pressure roller (402) is pressed into or lifted away from the second fiber slot (4011), the to-be-tested optical fiber (90) is compressed or released. A pressure pay-off assembly (403) is used to drive the pressure roller (402) to press into or lift away from the second fiber slot (4011). The pressure pay-off assembly (403) comprises: An installation part (4031) is fixed with the test table (10). A second driving device (4032) is fixed with the installation part (4031). A guide rod (4033) is fixedly connected with the pressing wheel (402) at one end and connected with the output end of the second driving device (4032) at the other end; The second driving device (4032) drives the guide rod (4033) to stretch or contract along the length direction of the guide rod (4033), thereby driving the pressing wheel (402) to press into or lift away from the second fiber slot (4011).

5. The fiber twist test apparatus of claim 4, wherein, The fiber rotating clamping mechanism (60) is a rotary air claw, and the rotary air claw comprises: A servo motor (601); A rotating shaft (602) connected with the output end of the servo motor (601); A plurality of air claw fingers (603) rotatably fixed to one end of the rotating shaft (602) away from the servo motor (601), and the plurality of air claw fingers (603) are uniformly distributed around the central axis of the rotating shaft (602); A piston cylinder connected with the plurality of air claw fingers (603), the piston cylinder being used to drive the plurality of air claw fingers (603) to open or close to grasp or release the fiber to be tested (90).

6. The fiber twist test apparatus of claim 5, wherein, The fiber twist test device further comprises a moving mechanism (70), and the moving mechanism (70) comprises: A slide rail (701) fixed to the test table (10) along the length direction of the test table (10); A first sliding block (702) slidingly arranged on the slide rail (701), the fiber pressing mechanism (40) being fixed with the first sliding block (702); A second sliding block (703) slidingly arranged on the slide rail (701), the fiber rotating clamping mechanism (60) being fixed with the second sliding block (703); A third driving device (704) for driving the second sliding block (703) to slide along the slide rail (701), the third driving device (704) comprising a rack (7041) parallel to the slide rail (701) and fixed with the test table (10), a gear (7042) matched with the rack (7041), and a moving motor (7043) having an output end fixed with the gear (7042) and used to drive the gear (7042) to rotate.

7. The fiber twist test apparatus of claim 6, wherein, The fiber twist test device further comprises a fiber cutting mechanism (80) for cutting the fixed end of the fiber to be tested (90), the fiber cutting mechanism (80) being fixed to the mounting portion (4031) near the fiber rotating clamping mechanism (60), the fiber cutting mechanism (80) being a parallel opening and closing air claw, and the parallel opening and closing air claw comprising a cylinder body (801) fixed with the mounting portion (4031), two clamping fingers (802) moving away from or towards each other to form an opening and closing action, and a cutting piece arranged between the two clamping fingers (802); when the two clamping fingers (802) move towards each other, the cutting piece touches and cuts the fiber to be tested (90) located between the cutting piece.

8. A method for testing fiber twist based on the fiber twist testing device according to claim 7, characterized in that, The method comprises the following steps: S1, install the fiber disc (304) on the paying-off support (301), take the fiber to be tested (90) to pass through the first guide wheel (207) and the second guide wheel (401) in sequence, start the first driving device (302), and wind off the fiber twisted off from the fiber disc (304); S2, start the third driving device (704) to move the rotating claw to the second guide wheel (401), after the rotating claw clamps the free end of the measured optical fiber (90), start the third driving device (704) and the first driving device (302) to move the rotating claw to the set position away from the second guide wheel (401), and then close the third driving device (704) and the first driving device (302), and keep the measured optical fiber (90) in a horizontal straight state during the movement; S3, start the second driving device (4032) to drive the pressure roller (402) to press into the second optical fiber groove (4011) and fix the measured optical fiber (90) in the second optical fiber groove (4011); S4, start the third driving device (704) to move the rotating claw to the second guide wheel (401), so that the measured optical fiber (90) between the second guide wheel (401) and the rotating claw naturally droops, and the direction of the measured optical fiber (90) is determined according to the optical fiber position sensor (502), and the servo motor (601) is started to drive the claw finger (603) to rotate in the opposite direction of the measured optical fiber (90) to perform the untwisting action until the measured optical fiber (90) is untwisted; the rotation angle of the servo motor (601) is the torsion degree of the measured optical fiber (90); S5, start the parallel opening and closing claw to cut off the measured optical fiber (90); S6, repeat S2-S5 above to perform multiple untwisting tests and obtain the average torsion degree of the measured optical fiber (90).

9. The method of claim 8, wherein the step of determining the fiber twist comprises the step of: The S4 includes the following steps: ​ S41, according to the parabolic path of the natural droop of the measured optical fiber (90), taking the symmetry axis of the parabola as the symmetric center, the measured optical fiber (90) is divided into symmetric first measured optical fiber (90) section and second measured optical fiber (90) section, the first measured optical fiber (90) section is connected with the rotating claw, and the second measured optical fiber (90) section is connected with the pressure roller (402) and the second guide wheel (401); a plurality of groups of optical fiber position sensors (502) are arranged on the dynamic parabolic paths of the first measured optical fiber (90) section and the second measured optical fiber (90) section respectively to measure the torsion degree of the measured optical fiber (90) at different time nodes; S42, according to the vertical distance change between the first measured optical fiber (90) section and the second measured optical fiber (90) section and the detection plate (501) detected by the optical fiber position sensor (502), that is, away from or close to the detection plate (501), the direction of the measured optical fiber (90) is judged, and the claw finger (603) is driven by the servo motor (601) to rotate in the opposite direction of the measured optical fiber (90) to perform the untwisting action; S43, when the lowest part of the natural droop of the to-be-tested optical fiber (90) is parallel to the center line of the detection hole (5011) on the detection plate (501) at the same height; and / or, when the optical fiber position sensor (502) detects that the distance between the first to-be-tested optical fiber (90) segment and the second to-be-tested optical fiber (90) segment and the detection plate (501) remains unchanged, the servo motor (601) is turned off, the rotating gas claw stops working, and the to-be-tested optical fiber (90) is untwisted.

Images