A kind of steel wire rope damage detection device for tensioning cable in ship DP system

Abstract

This invention discloses a damage detection device for steel wire ropes used in tensioning cables in a ship's dynamic positioning (DP) system, relating to the field of marine engineering technology. The device includes a detection probe, a signal processing module, and a control unit. The detection probe is slidably mounted on the steel wire rope of the tensioning cable. The detection probe contains a magnetization unit and a surrounding sensor array. The magnetization unit partially magnetizes the steel wire rope, and the surrounding sensor array captures leakage magnetic field signals from damaged areas of the steel wire rope. The signal processing module amplifies, filters, and performs analog-to-digital conversion on the signals acquired by the surrounding sensor array. The control unit determines the degree of wire breakage, wear, or corrosion of the steel wire rope based on the signals processed by the signal processing module and outputs an alarm signal. By using a detection probe slidably mounted on the tensioning cable, the damage status of the steel wire rope can be monitored in real time during the continuous winding and unwinding process.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a device for detecting damage to steel wire ropes used in tensioning cables in a ship's DP system. Background Technology

[0002] With the development of marine engineering and deep-sea technology, dynamic positioning systems (DP systems) are increasingly widely used in various engineering vessels, research vessels, and offshore platforms. DP systems utilize propellers to counteract the effects of wind, waves, and currents through automatic control systems, thereby maintaining the predetermined position and heading of ships or offshore structures. To ensure positioning accuracy, especially when GPS or acoustic reference signals are interfered with, the system typically relies on physical mooring methods as a low-frequency position reference.

[0003] In existing technologies, lightweight tension cables are connected between the vessel and the seabed anchorage point, used in conjunction with tensioners, and are a key component in DP systems that provides relative displacement feedback. Currently, mainstream tension cable monitoring equipment in the industry primarily focuses on monitoring the cable tension, release length, and geometric angles. This data is mainly used to calculate the vessel's displacement to assist the DP system in thrust distribution.

[0004] However, under harsh conditions of long-term high-load operation, seawater corrosion, and repeated bending, the steel wire rope in the tensioning cable is highly susceptible to damage such as wear, corrosion, wire breakage, and localized fatigue. Since existing equipment lacks wire rope damage detection capabilities, current maintenance methods heavily rely on manual visual inspection. This traditional manual inspection method has the following significant drawbacks: Visual inspection can only detect macroscopic defects on the surface of the wire rope, and is powerless to detect internal defects such as broken wires, corrosion, and hidden damage caused by metal fatigue. Unpredictable rope breakage accidents can directly lead to the loss of position references, seriously threatening the positioning security of the DP system, and even causing marine accidents. At the same time, for the sake of safety, operators often adopt an overly conservative replacement strategy, resulting in high maintenance costs.

[0005] Although there are offline flaw detectors available on the market for ordinary lifting wire ropes, ordinary handheld or clamp-on sensors cannot adapt to such high-frequency dynamic conditions because the tension cable of the DP system is under constant tension for a long time and swings dynamically with the six degrees of freedom of the ship. They are also difficult to integrate directly into the existing tension cable wheel system without changing the mechanical architecture of the original DP equipment. Summary of the Invention

[0006] The purpose of this invention is to provide a damage detection device for steel wire ropes used in tensioning cables in a ship's DP system, so as to solve the problems existing in the prior art and realize online detection of steel wire ropes used in tensioning cables in a ship's DP system.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides a damage detection device for steel wire ropes used in tensioning cables in a ship's DP system, comprising a detection probe, a signal processing module, and a control unit; The detection probe is used to slide on the steel wire rope of the tension cable; the detection probe is equipped with a magnetization unit and a surrounding sensor array. The magnetization unit is used to magnetize part of the steel wire rope, and the surrounding sensor array is used to capture the leakage magnetic field signal that overflows from the damaged part of the steel wire rope. The signal processing module is used to amplify, filter, and perform analog-to-digital conversion on the signals collected by the surround sensor array. The control unit is used to determine the degree of wire breakage, wear, or corrosion of the wire rope based on the signals processed by the signal processing module, and output an alarm signal.

[0008] Preferably, at any given time, the magnetizing unit can magnetize a length of the wire rope of 100mm to 200mm.

[0009] Preferably, the surround sensor array is a Hall sensor array or a tunnel magnetoresistive sensor array.

[0010] Preferably, the detection probe adopts an openable / closing structure so that it can be directly installed on the tension cable path of the existing ship DP system without cutting the wire rope.

[0011] Preferably, the magnetization unit is a ring-shaped permanent magnet or a ring-shaped coil sleeved on the steel wire rope.

[0012] Preferably, the annular permanent magnet includes a first semi-circular annular permanent magnet and a second semi-circular annular permanent magnet. The first semi-circular annular permanent magnet is fixed on a first magnetic yoke, and the second semi-circular annular permanent magnet is fixed on a second magnetic yoke. The first magnetic yoke and the second magnetic yoke are respectively fixedly connected to the housing of the detection probe.

[0013] Preferably, both the signal processing module and the control unit are fixedly installed in the control cabinet of the ship's DP system.

[0014] Preferably, the sensors in the surround sensor array are respectively connected to the signal processing module via signal lines.

[0015] Preferably, all sensors in the surround sensor array are distributed circumferentially along the detection probe.

[0016] Preferably, the control unit is a programmable logic controller.

[0017] The present invention achieves the following technical effects compared to the prior art: The steel wire rope damage detection device for tensioning cables in the ship DP system of the present invention, by setting a detection probe that is slidably sleeved on the tensioning cable, can monitor the damage status of the steel wire rope in real time during the continuous winding and unwinding process. This solves the industry pain point that existing DP systems cannot monitor steel wire rope damage, fundamentally eliminates the risk of rope breakage caused by hidden damage to the steel wire rope, and ensures the positioning safety of the DP system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the tension cable in which the damage detection device for tension cables in the ship DP system of the present invention is installed; Figure 2 This is a schematic diagram of the detection probe in the steel wire rope damage detection device for tensioning cables in the ship DP system of the present invention; Figure 3 This is a schematic diagram of the housing of the detection probe in the damage detection device for tension cable wire rope in the ship DP system of the present invention; In the diagram: 1. Ship DP system; 101. Fixed bracket; 102. Roller; 2. Detection probe; 21. Housing; 211. First half-shell; 212. Second half-shell; 22. Surround sensor array; 23. Ring permanent magnet; 231. First semi-circular ring permanent magnet; 232. Second semi-circular ring permanent magnet; 24. First magnetic yoke; 25. Second magnetic yoke; 3. Steel wire rope; 4. Hinge; 5. First mounting plate; 6. Second mounting plate. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The purpose of this invention is to provide a damage detection device for steel wire ropes used in tensioning cables in a ship's DP system, so as to solve the problems existing in the prior art and realize online detection of steel wire ropes used in tensioning cables in a ship's DP system.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figures 1 to 3 As shown, this embodiment provides a damage detection device for steel wire ropes used in tensioning cables in a ship's DP system, including a detection probe 2, a signal processing module, and a control unit; The detection probe 2 is used to slide on the steel wire rope 3 of the tension cable; the detection probe 2 is equipped with a magnetization unit and a surrounding sensor array 22. The magnetization unit is used to partially magnetize the steel wire rope 3, and the surrounding sensor array 22 is used to capture the leakage magnetic field signal that overflows from the damaged part of the steel wire rope 3. The signal processing module amplifies, filters, and performs analog-to-digital conversion on the signals collected by the surround sensor array 22. The control unit determines the degree of wire breakage, wear, or corrosion of the wire rope 3 based on the signals processed by the signal processing module and outputs an alarm signal. Through the amplification, filtering, and AD conversion of the signal processing module, combined with the intelligent algorithm of the control unit (PLC), this embodiment can not only sense damage but also distinguish the different characteristics of wire breakage, wear, and corrosion, and quantify the degree of damage. Compared with qualitative judgment by manual visual inspection, this embodiment provides a quantitative damage level assessment, helping maintenance personnel to formulate scientific replacement strategies, avoiding the high costs caused by overly conservative maintenance, and also preventing accidents caused by operating with damage.

[0024] In the optional schemes of this embodiment, it is more preferred that the magnetizing unit can magnetize the length of the steel wire rope 3 by 100mm to 200mm at the same time.

[0025] In the optional embodiments of this example, the more preferred option is that the surround sensor array 22 is a Hall sensor array or a tunnel magnetoresistive sensor array.

[0026] In this embodiment, a magnetization unit is used to magnetize a local section (100mm–200mm) of the wire rope 3 to near saturation, and combined with a surround sensor array 22 (Hall / TMR) to achieve 360° full circumferential coverage. Compared with single-point detection, the surround array effectively avoids missed detections caused by the rotation or eccentricity of the wire rope 3, and can accurately capture the weak leakage magnetic field changes caused by broken wires, corrosion, and wear, which greatly improves the signal-to-noise ratio in strong sea conditions.

[0027] Reference Figure 3In the optional scheme of this embodiment, it is more preferred that the housing 21 of the detection probe 2 adopts an openable structure. The housing 21 of the detection probe 2 includes a first half-shell 211 and a second half-shell 212. Both the first half-shell 211 and the second half-shell 212 are semi-cylindrical housings 21. One end of the first half-shell 211 is hinged to one end of the second half-shell 212 through a hinge 4. The other end of the first half-shell 211 is provided with a first mounting plate 5. The other end of the second half-shell 212 is respectively provided with a second mounting plate 6 corresponding to the first mounting plate 5. The first mounting plate 5 and the corresponding second mounting plate 6 can be connected by bolts and nuts. The first half-shell 211 and the second half-shell 212 can rotate relative to each other so that the detection probe 2 can open and close as a whole, so as to be directly installed on the tensioning cable path of the existing ship DP system 1 without cutting the wire rope 3. The detection probe 2 adopts an openable structure design, allowing it to directly "hug" the running wire rope 3. After the detection probe 2 is huddled on the running wire rope 3, the first mounting plate 5 and the corresponding second mounting plate 6 are fixedly connected by bolts and nuts. The housing 21 of the detection probe 2 is detachably fixed to the fixed bracket 101 in the ship's DP system 1 used for tensioning cable deployment and retraction, maintaining the stability of the detection probe 2's position. This allows the tension cable to slide relative to the detection probe 2 along its axial direction during deployment and retraction, meeting the requirement of "no modification to the original tensioner mechanical structure," greatly reducing modification costs and construction risks, and possessing high engineering practical value and promising prospects for promotion. In this embodiment, there are two hinges 4, two first mounting plates 5, and two second mounting plates 6.

[0028] In the optional schemes of this embodiment, it is more preferred that the magnetization unit adopts a ring-shaped permanent magnet 23 or a ring-shaped coil sleeved on the steel wire rope 3. In practical applications, either a permanent magnet scheme can be used to ensure long-term stable operation without power supply, or a ring-shaped coil sleeved on the steel wire rope 3 can be used to magnetize the steel wire rope 3 by energizing the ring-shaped coil to generate a magnetic field. This facilitates on-site debugging and precise control of the magnetic field strength.

[0029] In the optional scheme of this embodiment, the more preferred one is that the annular permanent magnet 23 includes a first semi-circular annular permanent magnet 231 and a second semi-circular annular permanent magnet 232. The first semi-circular annular permanent magnet 231 is fixed on the first magnetic yoke 24, and the second semi-circular annular permanent magnet 232 is fixed on the second magnetic yoke 25. The first magnetic yoke 24 and the second magnetic yoke 25 are respectively fixedly connected to the housing 21 of the detection probe 2.

[0030] In the optional schemes of this embodiment, it is more preferred that the signal processing module and the control unit are both fixedly installed in the control cabinet of the ship's DP system 1.

[0031] In the optional embodiments of this example, it is more preferred that the sensors in the surround sensor array 22 are respectively connected to the signal processing module via signal lines.

[0032] In the optional embodiments of this example, it is more preferred that all the sensors in the surround sensor array 22 are distributed along the circumference of the detection probe 2.

[0033] In the optional schemes of this embodiment, the control unit is preferably a programmable logic controller.

[0034] The specific working principle of the wire rope damage detection device for tensioning cables in the ship DP system of this embodiment is as follows: The magnetization unit in the detection probe 2 establishes a closed magnetic circuit. When the steel wire rope 3 passes through the magnetization unit, it is magnetized by the magnetization unit. In an ideal state, if the steel wire rope 3 is of uniform material and has no damage, the magnetic lines of force will mainly propagate in a closed manner along the inside of the high magnetic permeability medium of the steel wire rope 3, with very little leakage to the outside. When the wire rope 3 has defects such as wear, corrosion, broken wires or local fatigue, the effective cross-sectional area at that point decreases and the magnetic permeability changes abruptly. The magnetic lines of force that originally flowed smoothly inside the wire are forced to bypass the defect or penetrate the surface of the wire, thus generating a leakage magnetic field that radiates outward. The surrounding sensor array 22 (such as a Hall element or a TMR sensor) is evenly distributed along the inner circumference of the probe, precisely to sense this weak leakage magnetic field signal from all directions without any blind spots. As the DP system operates, the tension cable 3 is continuously released or retracted from the drum 102, and the cable 3 moves axially relative to the detection probe 2; the surround sensor array 22 continuously scans the surface of the cable 3, and converts the captured changes in the spatial leakage magnetic field into a weak analog voltage signal; this signal is then transmitted to the signal processing module, and successively undergoes low-noise amplification (to match the range of the AD conversion), bandpass filtering (to filter out high-frequency noise and power frequency interference caused by ship rolling, mechanical vibration and power frequency interference) and analog-to-digital conversion, finally forming a digital signal stream that can be processed by the digital system; The control unit receives digital data from the signal processing module and performs feature extraction and analysis. The algorithm first performs differential comparison between the current signal and the preset "intact steel wire rope 3" reference signal to identify abnormal peak characteristics. Then, based on the amplitude, width, and phase characteristics of the peak, it distinguishes the defect type (e.g., broken wire usually manifests as sharp pulses, while corrosion manifests as wide fluctuations). Finally, based on industry standards or user-defined thresholds, it determines the damage level (e.g., light corrosion, moderate wear, severe broken wire). Once the damage is determined to reach the warning threshold, the control unit immediately outputs an alarm signal to the DP control console or centralized control system, prompting operators to take measures such as reducing load, limiting speed, or stopping maintenance to effectively avoid the risk of rope breakage.

[0035] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A steel wire rope damage detection device for a tensioning cable in a marine vessel DP system, characterized by: Includes a detection probe, a signal processing module, and a control unit; The detection probe is used to slide on the steel wire rope of the tension cable; the detection probe is equipped with a magnetization unit and a surrounding sensor array. The magnetization unit is used to magnetize part of the steel wire rope, and the surrounding sensor array is used to capture the leakage magnetic field signal that overflows from the damaged part of the steel wire rope. The signal processing module is used to amplify, filter, and perform analog-to-digital conversion on the signals collected by the surround sensor array. The control unit is used to determine the degree of wire breakage, wear, or corrosion of the wire rope based on the signals processed by the signal processing module, and output an alarm signal.

2. A wire rope damage detection device for a mooring line of a marine vessel DP system according to claim 1, characterized in that: At the same time, the magnetization unit can magnetize the length of the steel wire rope from 100mm to 200mm.

3. The wire rope damage detection device for a mooring line of a marine vessel DP system according to claim 1, characterized in that: The surrounding sensor array is either a Hall sensor array or a tunnel magnetoresistive sensor array.

4. The wire rope damage detection apparatus for a mooring line of a marine vessel DP system according to claim 1, characterized in that: The detection probe adopts an openable structure so that it can be directly installed on the tensioning cable path of the existing ship DP system without cutting the steel wire rope.

5. The damage detection device for steel wire ropes used in tensioning cables in a ship DP system according to claim 1, characterized in that: The magnetization unit uses a ring-shaped permanent magnet or a ring-shaped coil wrapped around the steel wire rope.

6. The damage detection device for tension cables in a ship DP system according to claim 5, characterized in that: The annular permanent magnet includes a first semi-circular annular permanent magnet and a second semi-circular annular permanent magnet. The first semi-circular annular permanent magnet is fixed on a first magnetic yoke, and the second semi-circular annular permanent magnet is fixed on a second magnetic yoke. The first magnetic yoke and the second magnetic yoke are respectively fixedly connected to the housing of the detection probe.

7. The wire rope damage detection apparatus for a mooring line of a marine vessel DP system according to claim 1, characterized in that: Both the signal processing module and the control unit are fixedly installed in the control cabinet of the ship's DP system.

8. The wire rope damage detection apparatus for a mooring line of a marine vessel DP system according to claim 1, characterized in that: The sensors in the surround sensor array are connected to the signal processing module via signal lines.

9. The wire rope damage detection apparatus for a mooring line of a marine vessel DP system according to claim 1, characterized in that: All sensors in the surround sensor array are distributed circumferentially along the detection probe.

10. A wire rope damage detection device for a mooring line of a marine vessel DP system according to claim 1, characterized in that: The control unit is a programmable logic controller.

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