Leakage self-diagnosis photoelectric umbilical cord watertight cable and manufacturing method thereof

Abstract

The invention discloses a cable diagnosis technology, and aims to provide a leakage self-diagnosis photoelectric umbilical cord watertight cable and a manufacturing method thereof, and the key points of the technical scheme are that the cable comprises an optical unit used for transmitting an optical signal; an electrical unit for transmitting an electrical signal; the inner sheath is used for wrapping the optical unit and the electric unit to form a photoelectric transmission structure; the bearing layer wraps the outer layer of the inner sheath and is used for supporting the mechanical strength of the cable; the force bearing layer comprises a round woven body formed by weaving spaced windowing twisted pairs and aramid fibers according to the tension ratio of 1: 5-1: 8; the spaced windowed twisted pair comprises a silver-plated copper conductor, 5-8 windowed silver-plated copper conductors are arranged in the length of each meter, a polyimide sheath is stripped on the surface of the conductor at intervals to form an exposed interval of 1.2 mm-1. 8mm, the twisted pair pitch is controlled within the range of 4-6 times of the diameter of the conductor, and the windowing pitch error is smaller than or equal to + / -0.05 mm; the outer sheath wraps the outer layer of the force bearing layer and is used for protecting the cable from external physical damage and environmental influence and ensuring the water tightness of the cable; the method is suitable for the technical field of cable diagnosis.

Description

Technical Field

[0001] The present invention relates to a cable diagnosis technology, and more specifically, to a leakage self-diagnosing optoelectronic umbilical watertight cable and a manufacturing method thereof. Background Art

[0002] At present, there are mainly two commonly used underwater real-time monitoring technologies. One is to judge by terminal data, that is, to judge the situation of the transmission path through the transmission stability of optoelectronic signals and whether the terminal equipment and data are abnormal; the other is to use an independent monitoring route and an underwater monitoring terminal for monitoring and judgment by means such as optics and acoustics. The first method is relatively traditional and is a passive monitoring means. Once the terminal transceiver data is abnormal, it means that an accident has occurred in the transmission link, and at the same time, the fault point cannot be locked; the second method is an active monitoring means, which can accurately lock the fault point, but the cost is high and the system is relatively complex, and separate link laying and terminal interface reservation are also required. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a leakage self-diagnosing optoelectronic umbilical watertight cable and a manufacturing method thereof.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A leakage self-diagnosing optoelectronic umbilical watertight cable, comprising:

[0005] An optical unit for transmitting optical signals;

[0006] An electrical unit for transmitting electrical signals;

[0007] An inner sheath for wrapping the optical unit and the electrical unit to form an optoelectronic transmission structure;

[0008] A load-bearing layer wrapped around the outer layer of the inner sheath for supporting the mechanical strength of the cable; the load-bearing layer includes a round woven body formed by braiding spaced-apart windowed twisted pairs and aramid fibers at a tension ratio of 1:5 - 1:8;

[0009] The spaced-apart windowed twisted pair includes a silver-plated copper conductor with 5 - 8 windows arranged per meter in length, the surface of the conductor is stripped of the polyimide sheath at intervals to form an exposed interval of 1.2 mm - 1.8 mm, the twist pitch is controlled within the range of 4 - 6 times the conductor diameter, and the window spacing error ≤ ±0.05 mm;

[0010] An outer sheath wrapped around the outer layer of the load-bearing layer for protecting the cable from external physical damage and environmental influences and ensuring the watertightness of the cable;

[0011] A real-time monitoring transmission line, which is arranged at the position of the load-bearing layer and is connected to the spaced-apart windowed twisted pair for real-time monitoring of the leakage situation.

[0012] The present invention is further configured such that: the braiding angle of the aramid fiber in the load-bearing layer is 30°-45°, the wire diameter ratio of the spaced window twisted pair to the aramid fiber is 1:2.6-1:3.3, the braiding density is 85%-92%, and the distribution density of the spaced window twisted pair in the braided body is 0.8-1.2 per square centimeter.

[0013] The present invention is further configured such that: the outer sheath is made of a modified polyethylene material, and its components by weight percentage include: high-density polyethylene: 70%-80%; ethylene-vinyl acetate copolymer: 12%-15%; nano-silica: 3%-5%; antioxidant 1010: 0.6%-1%; carbon black masterbatch: 2%-5%.

[0014] A manufacturing method of a leakage self-diagnosis optoelectronic umbilical watertight cable, characterized by comprising the following steps:

[0015] S1. Conductor pretreatment: After two silver-plated copper wires are subjected to plasma cleaning, a polyimide insulating layer is coated at a speed of 0.8-1.2 m / min, and an insulated conductor is formed after curing.

[0016] S2. Spaced window preparation: A periodic 1.5-mm exposed window area is formed on the surface of the insulated conductor by using a laser ablation process, the tolerance of the window spacing is controlled within ±0.03 mm, and the deviation of the window position is ≤0.05 mm.

[0017] S3. Twisted pair forming: Two pretreated conductors are stranded with a pitch of 5-6 times the diameter, the stranding tension is controlled at 0.8-1.2 N, and the fluctuation value of the conductor resistance is monitored in real time during the stranding process and is ≤0.05 Ω / m.

[0018] S4. Load-bearing layer braiding: The spaced window twisted pair and the aramid fiber are jointly braided by a braiding machine, wherein: the tension of the twisted pair is set to 2-3 N, the tension of the aramid fiber is set to 15-18 N, the main shaft speed of the braiding machine is adjusted to 12-15 rpm, and the dynamic adjustment range of the braiding angle is 30°±2°; after braiding, it is wrapped outside the inner sheath.

[0019] S5. Outer sheath extrusion: A 45-mm single-screw extruder is used, and the temperature of each zone is set as follows: the first zone is 160-170 °C, the second zone is 170-180 °C, the third zone is 180-185 °C, the die head is 190-200 °C, the extrusion speed is controlled at 15-20 m / min, and the die head pressure is maintained at 8-10 MPa.

[0020] S6. Online monitoring: After the extrusion process, the outer sheath is wrapped outside the load-bearing layer, and a capacitive coupling detection device is set to detect the fluctuation range of the capacitance difference between the window area and the non-window area in real time and is ≤5 pF / m.

[0021] S7. Dynamic testing: The finished cable is tested 2000 times through a cyclic bending testing machine with a bending radius ≥ 8D, and the offset of the window opening position is required to be ≤ 0.1 mm.

[0022] S8. Immersion verification: The cable is placed in a simulated environment with a water depth of 100 m for 72 hours, and the insulation resistance value of the twisted pair is monitored to be ≥ 10 GΩ·km.

[0023] S9. Final inspection: X-ray tomography is used to detect the uniformity of the braid density, and the density deviation is required to be ≤ ±3%.

[0024] The present invention is further configured as: The control method for real-time monitoring of the transmission line includes the following steps:

[0025] S1-1. Under standard working conditions, measure and record the reference resistance value R of the window opening area of the twisted pair, the capacitance value C corresponding to the ambient temperature T, and the position parameter A under different bending states.

[0026] S1-2. The resistance R1, ambient temperature T1, capacitance C1, and position offset A1 of the cable are collected in real time at a frequency of 10 Hz. All the collected data are saved in chronological order and compared and analyzed with the reference data.

[0027] S1-3. Calculate the dynamic compensation for environmental interference, which are respectively:

[0028] Temperature compensation coefficient a = 1 + 0.0035×(T1 - T0);

[0029] Position correction factor b = 1 + 0.01×(A1 - A);

[0030] S1-4. Set three judgment thresholds, including:

[0031] Early warning threshold X: 15% ≤ |R1 / (a×b) - R| ≤ 25%;

[0032] Alarm threshold Y: 25% < |R1 / (a×b) - R| ≤ 40%;

[0033] Fault threshold Z: |R1 / (a×b) - R| > 40%;

[0034] If the early warning threshold X is detected, then the capacitance auxiliary detection is triggered. When |C1 / (a×b) - C| < 8%, the monitoring state is continued. Otherwise, it turns to S1-5;

[0035] If the alarm threshold Y is detected, then the Kalman filter is activated to optimize the position parameter, and A2 = A1 / (a×b) is recalculated. When A2 still exceeds the alarm threshold B, the audible and visual alarm is triggered to remind the staff;

[0036] When the fault threshold Z is detected, the main power supply is immediately cut off and the standby communication channel is activated, and the fault location coordinates are recorded for subsequent processing by the staff;

[0037] S1-5. Make a comprehensive judgment by combining the resistance change rate △R, capacitance deviation △C, and temperature gradient △T. When △R > 15% and △C > 8% and △T < 0.5°C / min, start the leakage location algorithm and record relevant data; when △R > 25% and △C < 5%, start the fault analysis program to locate the damage cause;

[0038] S1-6. The staff injects a pulse signal to accurately locate the leakage position, and the positioning error should be controlled within ±0.3m to quickly locate the fault position. Once the leakage is located and the problem is confirmed, make timely adjustments and maintenance.

[0039] The beneficial effects of the present invention are:

[0040] 1. Compared with the prior art, the leakage self-diagnosis optoelectronic umbilical watertight cable of the present invention forms a multi-layer composite structure, significantly improving the mechanical strength and environmental adaptability of the cable. The load-bearing layer is woven with spaced window twisted pairs and aramid fibers at a tension ratio of 1:5 - 1:8, enabling the cable to maintain a tensile strength of ≥150 MPa under the deep-sea high-pressure environment. At the same time, the high modulus property of aramid fibers can effectively inhibit the bending deformation of the cable; the 5 - 8 window openings per meter of the spaced window twisted pairs, through the capacitive coupling between the exposed sections and the real-time monitoring line, achieve a leakage detection sensitivity of ±5 pF / m, and the window opening spacing error ≤ ±0.05 mm, ensuring the stability of the monitoring signal; in addition, the twist pitch is controlled within the range of 4 - 6 times the conductor diameter, which can reduce the signal crosstalk to ≤ -80 dB, ensuring the transmission efficiency of the electrical unit. The modified polyethylene material of the outer sheath combined with the watertight structure enables the cable to have an insulation resistance of ≥10 GΩ·km in a 100m water depth environment, meeting the requirements of long-term deep-sea operations.

[0041] 2. The leakage self-diagnosis optoelectronic umbilical watertight cable of the present invention optimizes the mechanical properties and signal transmission stability of the cable by defining the braiding parameters of the load-bearing layer. The design of the aramid fiber braiding angle of 30° - 45° increases the axial tensile strength of the cable to 180 - 220 MPa, and at the same time, the radial compressive strength reaches 50 - 60 MPa, avoiding the structural collapse caused by deep-sea pressure. The wire diameter ratio of the spaced window twisted pairs to aramid fibers is 1:2.6 - 1:3.3, which not only ensures the uniform distribution of the twisted pairs in the braided body but also reduces the risk of concentrated stress on the twisted pairs through the buffering effect of aramid. The setting of the braiding density of 85% - 92% reduces the cable weight by 15% - 20%, and at the same time, the porosity ≤ 8%, effectively preventing the infiltration of external media. Experimental data show that this parameter combination can make the offset of the window opening position ≤ 0.1 mm after 2000 cycles of bending of the cable, significantly better than the ±0.3 mm error of the traditional braiding process.

[0042] 3. In the present invention, through the synergistic effect of 70%-80% high-density polyethylene and 12%-15% ethylene-vinyl acetate copolymer, the impact strength of the sheath reaches 50 kJ / m 2 , and at the same time, the environmental stress cracking resistance time is ≥1500 h; the addition of 3%-5% nano-silica increases the surface hardness of the sheath to Shore D 65-70, and the wear resistance is 3-5 times higher than that of pure polyethylene. The ultraviolet absorption characteristics of 2%-5% carbon black masterbatch enable the tensile strength retention rate of the cable to be ≥90% after 5000 h of outdoor exposure. The antioxidant 1010 of 0.6%-1% inhibits the rate of thermal oxygen aging, extending the material life to more than 20 years. This formulation is extruded at a die head pressure of 8-10 MPa, and the deviation of the sheath thickness uniformity is ≤±5%, effectively ensuring the water tightness.

[0043] 4. The present invention does not affect the design, structure and cabling process of the original optoelectronic umbilical water-tight cable. The added real-time monitoring unit is located in the load-bearing layer between the inner and outer sheaths of the umbilical cable. The real-time monitoring of the outer sheath leakage is carried out through the intermittently exposed conductors, and the short-circuit signal is transmitted to the terminal device through the short-circuit alarm position, and the fault point position is confirmed by calculating the field strength voltage drop. Without affecting the normal optoelectronic transmission inside the inner sheath, the leakage problem can be accurately monitored and predicted, and there is no need to set up a separate monitoring transmission route, which has good feasibility and application effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is the structural diagram of the leakage self-diagnosing optoelectronic umbilical water-tight cable of the present invention.

[0045] Figure 2 is the structural diagram of the intermittently windowed twisted pair in the leakage self-diagnosing optoelectronic umbilical water-tight cable of the present invention.

[0046] Figure 1-2 Reference numerals: 1, optical unit; 2, electrical unit; 3, inner sheath; 4, load-bearing layer; 5, intermittently windowed twisted pair; 6, outer sheath. DETAILED DESCRIPTION OF THE INVENTION

[0047] Refer to Figure 1-2 to further describe the embodiments of the leakage self-diagnosing optoelectronic umbilical water-tight cable of the present invention and its manufacturing method.

[0048] For ease of explanation, in the embodiments, spatial relative terms such as "upper", "lower", "left", "right", etc. are used to describe the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientations shown in the figure, the spatial terms are intended to include different orientations during the use or operation of the device. For example, if the device in the figure is inverted, the element described as being "lower" than other elements or features will be positioned "above" other elements or features. Therefore, the exemplary term "lower" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein can be interpreted accordingly.

[0049] Moreover, relational terms such as "first" and "second" are only used to distinguish one component with the same name from another, and do not necessarily require or imply any such actual relationship or order between these components.

[0050] Figures 1 to 2 A leak self-diagnostic optoelectronic umbilical watertight cable shown includes:

[0051] An optical unit 1 for transmitting optical signals;

[0052] An electrical unit 2 for transmitting electrical signals;

[0053] An inner sheath 3 for wrapping the optical unit 1 and the electrical unit 2 to form an optoelectronic transmission structure;

[0054] A bearing layer 4 wrapped around the outer layer of the inner sheath 3 for supporting the mechanical strength of the cable; the bearing layer 4 includes a round woven body formed by braiding spaced windowed twisted pairs 5 and aramid fibers at a tension ratio of 1:5 - 1:8;

[0055] The spaced windowed twisted pair 5 includes a silver-plated copper conductor with 5 - 8 windows arranged per meter in length, and the polyimide sheath on the surface of the conductor is stripped at intervals to form an exposed interval of 1.2 mm - 1.8 mm. The twist pitch is controlled within the range of 4 - 6 times the conductor diameter, and the window spacing error ≤ ±0.05 mm;

[0056] An outer sheath 6 wrapped around the outer layer of the bearing layer 4 for protecting the cable from external physical damage and environmental influences and ensuring the watertightness of the cable;

[0057] A real-time monitoring transmission line, which is arranged at the position of the bearing layer 4 and connected to the spaced windowed twisted pair 5 for real-time monitoring of leakage conditions;

[0058] Compared with the prior art, the leakage self-diagnosing optoelectronic umbilical watertight cable of the present invention forms a multi-layer composite structure, significantly improving the mechanical strength and environmental adaptability of the cable. The load-bearing layer 4 is woven with spaced-apart windowed twisted pairs 5 and aramid fibers at a tension ratio of 1:5 - 1:8, enabling the cable to maintain a tensile strength of ≥150 MPa under the deep-sea high-pressure environment. At the same time, the high-modulus property of the aramid fibers can effectively inhibit the bending deformation of the cable; the window design at every 5 - 8 meters of the spaced-apart windowed twisted pair 5 realizes a leakage detection sensitivity of ±5 pF / m through the capacitive coupling between the exposed section and the real-time monitoring line, and the window spacing error is ≤±0.05 mm, ensuring the stability of the monitoring signal; in addition, the twist pitch is controlled within the range of 4 - 6 times the conductor diameter, which can reduce the signal crosstalk to ≤ -80 dB, guaranteeing the transmission efficiency of the electrical unit 2. The modified polyethylene material of the outer sheath 6 combined with the watertight structure enables the cable to have an insulation resistance of ≥10 GΩ·km in a 100 m water depth environment, meeting the requirements for long-term deep-sea operations.

[0059] In the load-bearing layer 4, the braiding angle of the aramid fibers is 30° - 45°, the wire diameter ratio of the spaced-apart windowed twisted pair 5 to the aramid fibers is 1:2.6 - 1:3.3, and the braiding density is 85% - 92%. Among them, the distribution density of the spaced-apart windowed twisted pair 5 in the braided body is 0.8 - 1.2 per square centimeter;

[0060] By defining the braiding parameters of the load-bearing layer 4, the mechanical properties and signal transmission stability of the cable are optimized. The design of the aramid fiber braiding angle of 30° - 45° increases the axial tensile strength of the cable to 180 - 220 MPa, and at the same time, the radial compressive strength reaches 50 - 60 MPa, avoiding the structural collapse caused by deep-sea pressure. The wire diameter ratio of 1:2.6 - 1:3.3 between the spaced-apart windowed twisted pair 5 and the aramid fibers not only ensures the uniform distribution of the twisted pair in the braided body but also reduces the risk of stress concentration on the twisted pair through the buffering effect of the aramid. The setting of the braiding density of 85% - 92% reduces the cable weight by 15% - 20%, and at the same time, the porosity is ≤8%, effectively preventing the infiltration of external media. Experimental data show that this parameter combination can make the offset of the window position ≤0.1 mm after 2000 cycles of bending of the cable, significantly better than the ±0.3 mm error of the traditional braiding process.

[0061] The outer sheath 6 uses a modified polyethylene material, and its components by weight percentage include: high-density polyethylene: 70% - 80%; ethylene-vinyl acetate copolymer: 12% - 15%; nano-silica: 3% - 5%; antioxidant 1010: 0.6% - 1%; carbon black masterbatch: 2% - 5%;

[0062] Through the synergistic effect of 70% - 80% high-density polyethylene and 12% - 15% ethylene-vinyl acetate copolymer, the impact strength of the sheath reaches 50 kJ / m 2, meanwhile, the environmental stress cracking resistance time ≥ 1500h; the addition of 3%-5% of nano-silica increases the surface hardness of the sheath to Shore D 65-70, and the wear resistance is 3-5 times higher than that of pure polyethylene. The ultraviolet absorption characteristics of 2%-5% of carbon black masterbatch enable the tensile strength retention rate of the cable to be ≥ 90% after 5000h of outdoor exposure. 0.6%-1% of antioxidant 1010 inhibits the rate of thermal oxygen aging, extending the material life to more than 20 years. This formulation is extruded at a die head pressure of 8-10 MPa, and the deviation of the sheath thickness uniformity ≤ ±5%, effectively ensuring the water tightness.

[0063] A manufacturing method of a leak self-diagnosing optoelectronic umbilical water-tight cable, characterized by comprising the following steps:

[0064] S1. Conductor pretreatment: After two silver-plated copper wires are subjected to plasma cleaning, a polyimide insulating layer is coated at a speed of 0.8-1.2 m / min, and an insulated conductor is formed after curing.

[0065] S2. Preparation of spaced windows: Periodic 1.5 mm exposed window areas are formed on the surface of the insulated conductor by a laser ablation process, the tolerance of the window spacing is controlled within ±0.03 mm, and the deviation of the window position ≤ 0.05 mm.

[0066] S3. Twisted pair forming: Two pretreated conductors are stranded with a pitch of 5-6 times the diameter, the stranding tension is controlled within 0.8-1.2 N, and the fluctuation value of the conductor resistance is monitored in real time during the stranding process ≤ 0.05 Ω / m.

[0067] S4. Braid of the load-bearing layer 4: The spaced window twisted pair 5 and aramid fibers are jointly braided by a braiding machine, wherein: the tension of the twisted pair is set to 2-3 N, the tension of the aramid fiber is set to 15-18 N, the main shaft speed of the braiding machine is adjusted to 12-15 rpm, and the dynamic adjustment range of the braiding angle is 30° ± 2°; after braiding, it is wrapped outside the inner sheath 3.

[0068] S5. Extrusion of the outer sheath 6: A 45 mm single-screw extruder is used, and the temperatures of each zone are set as follows: the first zone is 160-170 °C, the second zone is 170-180 °C, the third zone is 180-185 °C, the die head is 190-200 °C, the extrusion speed is controlled within 15-20 m / min, and the die head pressure is maintained at 8-10 MPa.

[0069] S6. On-line monitoring: After the extrusion process, the outer sheath 6 is wrapped outside the load-bearing layer 4, and a capacitance coupling detection device is set to detect the fluctuation range of the capacitance difference between the window area and the non-window area in real time ≤ 5 pF / m.

[0070] S7. Dynamic test: The finished cable is subjected to 2000 tests by a cyclic bending test machine with a bending radius ≥ 8D, and the requirement is that the offset of the window position ≤ 0.1 mm.

[0071] S8. Immersion verification: Place the cable in a simulated environment with a water depth of 100 m for 72 hours, and monitor that the insulation resistance value of the twisted pair is ≥ 10 GΩ·km;

[0072] S9. Finished product inspection: Use X-ray tomography to detect the density uniformity of the braid, and require the density deviation to be ≤ ±3%;

[0073] Through precise control of process parameters, ensure the consistency of cable performance. For example, in step S2, the tolerance of the laser ablation window spacing is ±0.03 mm, so that the fluctuation of the capacitance monitoring signal is ≤ ±2%; in step S4 of braiding, the cooperation of the tension of the twisted pair at 2 - 3 N and the tension of the aramid fiber at 15 - 18 N avoids fiber breakage or deformation of the twisted pair. In step S5, the extrusion temperature is controlled in zones combined with a speed of 15 - 20 m / min, so that the crystallinity of the sheath reaches 70% - 75% and the tensile strength is ≥ 25 MPa; in step S6, the capacitance coupling detection device monitors the capacitance difference fluctuation between the windowed area and the non-windowed area in real time ≤ 5 pF / m, and defective products can be removed online, increasing the finished product rate to 99.5%; in step S9, the density deviation detected by X-ray tomography is ≤ ±3%, ensuring the uniform braiding of the load-bearing layer 4 and avoiding early failure caused by local stress concentration.

[0074] The control method for real-time monitoring of the transmission line includes the following steps:

[0075] S1-1. Under standard working conditions, measure and record the reference resistance value R of the windowed area of the twisted pair, the capacitance value C corresponding to the ambient temperature T, and the position parameter A under different bending states;

[0076] S1-2. Collect the resistance R1, ambient temperature T1, capacitance C1, and position offset A1 of the cable in real time at a frequency of 10 Hz. All the collected data are saved in chronological order and compared with the reference data for analysis;

[0077] S1-3. Calculate the dynamic compensation for environmental interference, which are respectively:

[0078] Temperature compensation coefficient a = 1 + 0.0035×(T1 - T0);

[0079] Position correction factor b = 1 + 0.01×(A1 - A);

[0080] S1-4. Set three judgment thresholds, including:

[0081] Early warning threshold X: 15% ≤ |R1 / (a×b) - R| ≤ 25%;

[0082] Alarm threshold Y: 25% < |R1 / (a×b) - R| ≤ 40%;

[0083] Fault threshold Z: |R1 / (a×b) - R| > 40%;

[0084] When the warning threshold X is detected, the capacitive auxiliary detection is triggered. When |C1 / (a×b)-C| < 8%, the monitoring state is continued; otherwise, it turns to S1-5.

[0085] When the alarm threshold Y is detected, the Kalman filter is activated to optimize the position parameters, and A2 = A1 / (a×b) is recalculated. When A2 still exceeds the alarm threshold B, an audible and visual alarm is triggered to alert the staff.

[0086] When the fault threshold Z is detected, the main power supply is immediately cut off and the standby communication channel is started, and the fault location coordinates are recorded for subsequent processing by the staff.

[0087] S1-5. Comprehensive judgment is made by combining the resistance change rate △R, the capacitance deviation △C, and the temperature gradient △T. When △R > 15% and △C > 8% and △T < 0.5℃ / min, the leakage location algorithm is started and relevant data are recorded; when △R > 25% and △C < 5%, the fault analysis program is started to locate the damage cause.

[0088] S1-6. The staff injects a pulse signal to accurately locate the leakage position, and the positioning error should be controlled within ±0.3m to quickly locate the fault position. Once the leakage is located and the problem is confirmed, timely adjustments and maintenance are made.

[0089] Through multi-parameter dynamic compensation and threshold grading early warning, the false alarm rate of leakage detection is ≤0.1%. The introduction of the temperature compensation coefficient and the position correction factor reduces the resistance measurement error from ±5% to ±1.2%. The three-level threshold design combined with the Kalman filter optimization can distinguish environmental interference from real leakage events, and the response time is ≤50ms; the injection pulse signal positioning technology combined with the capacitance difference analysis can accurately locate the leakage point and reduce the maintenance time by more than 60%; experiments show that the detection accuracy of this method in the simulated leakage scenario is ≥99%, and the fault analysis program can automatically classify the damage types and guide the optimization of the maintenance strategy.

[0090] The present invention does not affect the design, structure, and cabling process of the original optoelectronic umbilical waterproof cable. The added real-time monitoring unit is located in the bearing layer 4 between the inner and outer sheaths of the umbilical cable. The real-time monitoring of the leakage of the outer sheath 6 is carried out through the intermittently exposed conductors, and the short-circuit signal is transmitted to the terminal device through the short-circuit alarm position. The fault point position is confirmed by calculating the field strength voltage drop. Without affecting the normal optoelectronic transmission inside the inner sheath 3, the leakage problem can be accurately monitored and predicted, and there is no need to set up a separate monitoring transmission route, which has good feasibility and application effect.

[0091] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention shall be included within the protection scope of the present invention.

Claims

1. A leakage self-diagnosis photoelectric umbilical watertight cable, characterized by: include: An optical unit (1) for transmitting an optical signal; An electrical unit (2) for transmitting electrical signals; An inner sheath (3) is used to enclose the optical unit (1) and the electrical unit (2) to form a photoelectric transmission structure; A load-bearing layer (4) is wrapped around the outer layer of the inner sheath (3) and is used to support the mechanical strength of the cable; the load-bearing layer (4) comprises a round braided body formed by braiding the spaced-window twisted pair wires (5) and aramid fibers at a tension ratio of 1:5-1:8; The intermittent windowed twisted pair (5) comprises a silver-plated copper conductor with 5-8 windows per meter, the polyimide sheath on the conductor surface is peeled off at intervals to form an exposed area of ​​1.2mm-1.8mm, the twisted pair pitch is controlled within the range of 4-6 times the conductor diameter, and the window spacing error is ≤±0.05mm; An outer sheath (6), wrapped around the outer layer of the load-bearing layer (4), is used to protect the cable from external physical damage and environmental influences and ensure the water tightness of the cable; A real-time monitoring transmission line is arranged at the bearing layer (4) and connected to the spaced-window twisted pair (5) for real-time monitoring of leakage.

2. The leakage self-diagnosis photoelectric umbilical watertight cable according to claim 1, characterized in that: The braiding angle of the aramid fiber in the load-bearing layer (4) is 30°-45°, the wire diameter ratio of the spaced-window twisted pair (5) to the aramid fiber is 1:2.6-1:3.3, the braiding density is 85%-92%, and the distribution density of the spaced-window twisted pair (5) in the braided body is 0.8-1.2 strands per square centimeter.

3. The leakage self-diagnosis photoelectric umbilical watertight cable according to claim 1, characterized in that: The outer sheath (6) is made of modified polyethylene material, and its components by weight percentage include high-density polyethylene: 70%-80%; ethylene-vinyl acetate copolymer: 12%-15%; nano silicon dioxide: 3%-5%; antioxidant 1010: 0.6%-1%; and carbon black masterbatch: 2%-5%.

4. A method for manufacturing a watertight leakage self-diagnosis photoelectric umbilical cable applicable to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Conductor pretreatment: After two silver-plated copper wires are plasma cleaned, they are coated with a polyimide insulation layer at a speed of 0.8-1.2 m / min, and then cured to form an insulated conductor; S2. Preparation of interval windows: laser ablation is used to form periodic 1.5mm exposed window areas on the surface of the insulated conductor. The window spacing tolerance is controlled at ±0.03mm, and the window position deviation is ≤0.05mm; S3, twisted pair forming: twist two pre-treated conductors at a pitch of 5-6 times the diameter, and control the twisting tension at 0.8-1.2N. During the twisting process, the conductor resistance fluctuation value is monitored in real time and is ≤0.05Ω / m; S4, weaving of the load-bearing layer (4): weaving the spacer window twisted pair wires (5) and the aramid fiber together through a braiding machine, wherein: the tension of the twisted pair wires is set to 2-3N, the tension of the aramid fiber is set to 15-18N, the main shaft speed of the braiding machine is adjusted to 12-15rpm, and the dynamic adjustment range of the braiding angle is 30°±2°; after the braiding is completed, it is wrapped around the outside of the inner sheath (3); S5, outer sheath (6) extrusion: using a 45 mm single screw extruder, the temperature of each zone is set as follows: zone 1 160-170°C, zone 2 170-180°C, zone 3 180-185°C, die head 190-200°C, extrusion speed is controlled at 15-20 m / min, and die mouth pressure is maintained at 8-10 MPa; S6, online monitoring: after the extrusion process, the outer sheath (6) is wrapped around the outside of the bearing layer (4), and a capacitive coupling detection device is set to detect the capacitance difference between the window area and the non-window area in real time, and the fluctuation range is ≤5pF / m; S7, Dynamic test: The finished cable is tested 2000 times by a cyclic bending test machine with a bending radius of ≥8D, and the window position offset is required to be ≤0.1mm; S8, Water immersion verification: Place the cable in a simulated environment with a water depth of 100m for 72 hours, and monitor the insulation resistance of the twisted pair to be ≥10GΩ·km; S9. Finished product inspection: Use X-ray tomography to detect the uniformity of woven density, and the density deviation is required to be ≤±3%.

5. The leakage self-diagnosis photoelectric umbilical watertight cable according to claim 1, characterized in that: The control method for real-time monitoring of the transmission line comprises the following steps: S1-1. Under standard working conditions, measure and record the reference resistance value R of the twisted pair window area, the capacitance value C corresponding to the ambient temperature T, and the position parameter A under different bending states; S1-2, collect the cable resistance R1, ambient temperature T1, capacitance C1 and position offset A1 in real time at a frequency of 10 Hz. All collected data are saved in chronological order and compared with the benchmark data for analysis; S1-3, calculate the dynamic compensation of environmental interference, respectively: Temperature compensation coefficient a = 1 + 0.0035 × (T1-T0); Position correction factor b = 1 + 0.01 × (A1-A); S1-4. Set three judgment thresholds, including: Warning threshold X: 15% ≤ |R1 / (a×b)-R| ≤ 25%; Alarm threshold Y: 25%<|R1 / (a×b)-R|≤40%; Fault threshold Z: |R1 / (a×b)-R|>40%; If the warning threshold X is detected, the capacitor auxiliary detection is triggered. When |C1 / (a×b)-C| is less than 8%, the monitoring state is maintained. Otherwise, go to S1-5. If the alarm threshold Y is detected, the Kalman filter is activated to optimize the position parameters and recalculate A2 = A1 / (a×b). When A2 still exceeds the alarm threshold B, an audible and visual alarm is triggered to alert the staff; If the fault threshold Z is detected, the main power supply is immediately cut off and the backup communication channel is activated, and the coordinates of the fault location are recorded to facilitate subsequent processing by the staff; S1-5. Combine the resistance change rate △R, capacitance deviation △C, and temperature gradient △T to make a comprehensive judgment. If △R>15% and △C>8% and △T<0.5℃ / min, start the leakage location algorithm and record relevant data; if △R>25% and △C<5%, start the fault analysis program to locate the cause of the damage; S1-6. The staff will accurately locate the leakage position by injecting pulse signals, and the positioning error should be controlled within ±0.3m to facilitate rapid positioning of the fault position. Once the leakage is located and the problem is confirmed, timely adjustments and maintenance will be made.

Images