Submarine cable water entry angle detection device and method based on strain gauge bending sensor

Abstract

This invention relates to the field of submarine cable entry angle detection technology, specifically disclosing a submarine cable entry angle detection device and method based on strain gauge bending sensors. A spring steel cable guide rail is fabricated using spring steel sheets, leveraging the elastic strain characteristics of spring steel sheets. This guide rail bends with the cable, without affecting normal cable laying, and simultaneously provides guidance, preventing the cable from easily bending or twisting during the entry section. Based on the high-precision, distributed sensing measurement characteristics of strain gauge bending sensors for material structure strain, strain gauge bending sensors are evenly and spaced on the spring steel cable guide rail. The degree of bending of the cable guide rail is detected using these sensors, thereby obtaining the entry angle information during cable laying. This method is simple in structure and calculation, with high detection accuracy. Furthermore, the spring steel cable guide rail not only does not affect cable laying but also assists in the process.

Description

Technical Field

[0001] This invention relates to the field of submarine cable entry angle detection technology, and in particular to a submarine cable entry angle detection device and method based on a strain gauge bending sensor. Background Technology

[0002] Submarine cables are prone to excessive bending and twisting during laying, which can damage the cable structure, rendering it inoperable and seriously jeopardizing the safety and reliability of the laying process. The traditional solution is to use cable guide cages, but these are limited to shallow waters and are too bulky, significantly increasing the workload. Currently, the main method used is the catenary laying method. This involves measuring parameters such as the cable's entry angle and plowing angle, importing them into a model to obtain the catenary, and then using this model to guide the laying operation.

[0003] In submarine cable laying operations, obtaining the cable's entry angle into the water in real time is crucial. However, in many cases, this is done solely based on the experience of the personnel, which is inaccurate and labor-intensive. Currently, another method involves using image recognition to reconstruct the cable's attitude in three dimensions at the entry point and then estimating the entry angle. This method places high demands on the camera's installation location and image quality. Due to the unique underwater and above-water environment at the cable entry point, deploying multi-dimensional high-definition cameras that do not interfere with cable laying is not only difficult but also costly. Furthermore, the three-dimensional reconstruction requires the real-time transmission of large-capacity images, which places high demands on the communication link and consumes significant computing power for image processing. Summary of the Invention

[0004] This invention provides a device and method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor. The technical problem it solves is: how to measure the water entry angle of a submarine cable in a relatively simple and accurate manner.

[0005] To solve the above technical problems, the present invention provides a submarine cable entry angle detection device based on strain gauge bending sensors, including a spring steel sheet submarine cable guide rail made of spring steel sheet, and a plurality of strain gauge bending sensors evenly arranged at equal intervals along the length direction of the spring steel sheet submarine cable guide rail, one end of the spring steel sheet submarine cable guide rail being fixed to the cable laying vessel.

[0006] Preferably, the spring steel sheet submarine cable guide is configured as a long conduit structure with a small semi-circular ring cross-section, and the inner radius of the small semi-circular ring is greater than or equal to the radius of the submarine cable.

[0007] Preferably, when the spring steel sheet submarine cable guide is placed horizontally, with the tangent of the long conduit structure to the horizontal plane as the line of symmetry, the strain gauge bending sensor is symmetrically attached to the bottom of the outer arc surface of the long conduit structure.

[0008] Preferably, the distance between two adjacent strain gauge bending sensors on the spring steel sheet submarine cable guide rail is greater than or equal to 1 meter and less than or equal to 2 meters.

[0009] Preferably, the length of the spring steel sheet submarine cable guide rail is between the minimum water entry angle and the length of the submarine cable section entering the water at the maximum water entry angle during safe cable laying.

[0010] Preferably, the strain gauge bending sensor is equipped with an alarm module, which will sound an alarm when the bending angle value measured by the strain gauge bending sensor exceeds its preset range.

[0011] This invention also provides a method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor, the key of which includes the following steps:

[0012] S1. Install the cable entry angle detection device based on strain gauge bending sensor on the cable laying vessel.

[0013] S2. Place the submarine cable on the spring steel sheet submarine cable guide rail and begin laying the cable in the water;

[0014] S3. Multiple strain gauge bending sensors arranged on the spring steel sheet submarine cable guide rail output the bending angle values ​​they measure.

[0015] S4. Obtain the current configuration of the submarine cable on the spring steel sheet submarine cable guide rail based on multiple bending angle values ​​at the current moment.

[0016] S5. Calculate the current angle of entry into the water of the submarine cable based on the obtained cable configuration.

[0017] Further, step S4 includes the following steps:

[0018] S41. Match the multiple bending angle values ​​at the current moment with the bending angle value standard library, and determine whether there is a combination of bending angle preset values ​​with similarity at a preset threshold in the bending angle value standard library. If so, proceed to the next step; otherwise, issue an alarm. The bending angle value standard library consists of the bending angle values ​​of the first strain gauge bending sensor, the second strain gauge bending sensor to the nth strain gauge bending sensor under each allowable submarine cable entry angle.

[0019] S42. Output the cable configuration corresponding to the preset combination of bending angles with the highest similarity.

[0020] Furthermore, in step S41, the similarity D between the multiple bending angle values ​​at the current moment and the i-th set of preset bending angle values ​​in the bending angle value standard library is calculated. i Calculated using the following formula:

[0021]

[0022] Where a1, a2, ..., an represent the bending angle values ​​of the first, second to nth strain gauge bending sensors at the current moment, and bi1, bi2, ..., bin represent the bending angle values ​​of the first, second to nth strain gauge bending sensors in the i-th set of preset bending angle values.

[0023] Furthermore, in step S3, when the bending angle value measured by the strain gauge bending sensor exceeds its preset range, an alarm is triggered, and then cable laying is stopped.

[0024] This invention provides a device and method for detecting the entry angle of a submarine cable based on a strain gauge bending sensor. Utilizing the elastic strain characteristics of spring steel sheets, a spring steel sheet submarine cable guide is fabricated. This guide bends with the cable, without affecting normal cable laying, and simultaneously provides guidance, preventing the cable from bending or twisting during the entry section. Based on the high-precision, distributed sensing measurement characteristics of strain gauge bending sensors for material structure strain, strain gauge bending sensors are evenly and at equal intervals attached to the spring steel sheet submarine cable guide. The degree of bending of the guide is detected using these sensors, thereby obtaining the entry angle information during cable laying. This method is simple in structure and calculation, with high detection accuracy. Furthermore, the spring steel sheet submarine cable guide not only does not affect cable laying but also assists in the process. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the submarine cable entry angle detection device based on a strain gauge bending sensor provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the measurement principle of the strain gauge bending sensor provided in an embodiment of the present invention;

[0027] Figure 3 This is a cross-sectional view of the submarine cable entry angle detection device based on a strain gauge bending sensor provided in an embodiment of the present invention;

[0028] Figure 4 This is a perspective view of the spring steel sheet submarine cable guide provided in an embodiment of the present invention;

[0029] Figure 5 This is a flowchart of a method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor, provided in an embodiment of the present invention.

[0030] Figure reference numerals: 1-Spring steel sheet submarine cable guide rail, 2-Strain gauge bending sensor. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the present invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0032] This invention provides a device for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor, such as... Figure 1 As shown in the structural diagram, the device includes:

[0033] The cable guide 1 is made of spring steel sheet, and multiple strain gauge bending sensors 2 are evenly arranged at equal intervals along the length of the cable guide 1. One end of the cable guide 1 is fixed on the cable laying vessel.

[0034] Spring steel sheets are steel specifically used to manufacture springs and elastic elements due to their elasticity in the quenched and tempered state. The elasticity of steel depends on its ability to undergo elastic deformation; that is, within a specified range, its ability to deform elastically allows it to withstand a certain load without permanent deformation after the load is removed. Based on the characteristics of submarine cables during cable laying, a spring steel sheet submarine cable guide 1 capable of withstanding specific loads is manufactured using spring steel sheets. The submarine cable enters the sea through the spring steel sheet submarine cable guide 1. The spring steel sheet submarine cable guide 1 bends and deforms due to the force of the submarine cable, but it returns to its original shape after the cable is removed.

[0035] The phenomenon that the resistance of a metallic conductor changes when it undergoes mechanical deformation under external force is called the resistance strain effect. The resistance strain effect is the physical basis for the operation of strain gauge sensors. A resistance strain gauge sensor typically consists of an elastic body (element), a resistance strain gauge and strain adhesive, and a bridge circuit. When the strain gauge is attached to a spring plate, and a cable acts on the spring plate, causing the spring plate to bend, the strain gauge will expand and contract along with the spring plate's strain. This causes the internal metal foil to stretch or shorten with the strain. Figure 2 As shown in the schematic diagram, its resistance changes accordingly, and after being processed by the conversion module, the corresponding output voltage also changes, thus measuring the bending angle of the spring sheet based on the voltage value. Generally, the sensitive grid of the strain gauge is made of copper-chromium alloy, whose resistance change rate is constant and directly proportional to the degree of strain (bending angle).

[0036] like Figure 3As shown in the cross-sectional view, the spring steel sheet submarine cable guide 1 is configured as a long conduit structure with a small semi-circular ring (or semi-circular ring) cross-section. To ensure the submarine cable completely falls into the spring steel sheet submarine cable guide 1, the inner radius of the small semi-circular ring is greater than or equal to the radius of the submarine cable. To ensure that the curvature measured by the strain gauge bending sensor 2 is the same as that of the spring steel sheet submarine cable guide 1 (i.e., the same as the completeness of the submarine cable), the contact position of the strain gauge bending sensor 2 satisfies the following condition: when the spring steel sheet submarine cable guide 1 is placed horizontally, with the tangent of the long conduit structure to the horizontal plane as the line of symmetry, the strain gauge bending sensor 2 is symmetrically attached to the bottom of the outer arc surface of the long conduit structure. Simultaneously, to avoid wasting resources by setting too many strain gauge bending sensors 2 and affecting detection accuracy by setting too few, the distance between two adjacent strain gauge bending sensors 2 on the spring steel sheet submarine cable guide 1 is greater than or equal to 1 meter and less than or equal to 2 meters; in this embodiment, it is set to 1.2 meters.

[0037] Based on parameters such as cable weight, cable radius, and laying requirements, a spring steel sheet guide rail structure is designed. Specifically, the length of the spring steel sheet cable guide rail 1 is located between the minimum and maximum entry angles of the cable during safe laying. This structure allows the cable to enter the water from the laying vessel within a reasonable speed range. Furthermore, because the spring steel sheets counteract the cable's weight, the bending of the cable section from the water surface to the laying vessel during normal laying remains within a reasonable range, which can be continuously measured and displayed using strain gauges. If abnormal laying occurs, the bending of the cable section from the water surface to the laying vessel will exceed the reasonable range, triggering an alarm module on the strain gauge bending sensor 2, allowing the operator to make adjustments.

[0038] like Figure 4 The perspective view of the spring steel sheet submarine cable guide 1 is shown. One end of the spring steel sheet submarine cable guide 1 is equipped with a support for fixing it to the hull of the cable-laying vessel (near the point where the submarine cable enters the water). Since the guide rail only operates on the distance from the cable-laying vessel to the water surface, the length of the spring steel sheet submarine cable guide 1 is in the tens of meters range. Because the radius of the submarine cable is usually around 300 mm, the radius of the guide rail also fluctuates around this standard.

[0039] This invention also provides a method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor, such as... Figure 5 As shown in the flowchart, the method includes the following steps:

[0040] S1. Install the above-mentioned cable entry angle detection device based on strain gauge bending sensor on the cable laying vessel.

[0041] S2. Place the submarine cable on the spring steel sheet submarine cable guide rail 1 and begin laying the cable in the water;

[0042] S3. Multiple strain gauge bending sensors 2 arranged on the spring steel sheet submarine cable guide rail 1 output the bending angle value they measure.

[0043] S4. Obtain the current configuration of the submarine cable on the spring steel sheet submarine cable guide rail 1 based on multiple bending angle values ​​at the current moment.

[0044] S5. Calculate the current angle of entry into the water of the submarine cable based on the obtained cable configuration.

[0045] Specifically, in order to obtain the submarine cable configuration more quickly and accurately, this invention adopts a method of pre-calibration followed by comparison. Specifically, step S4 includes the following steps:

[0046] S41. Match the multiple bending angle values ​​at the current moment with the bending angle value standard library, and determine whether there is a combination of bending angle preset values ​​with similarity at a preset threshold in the bending angle value standard library. If so, proceed to the next step; otherwise, issue an alarm. The bending angle value standard library consists of the bending angle values ​​of the first strain gauge bending sensor 2, the second strain gauge bending sensor 2 to the nth strain gauge bending sensor 2 under various allowable submarine cable entry angles.

[0047] S42. Output the cable configuration corresponding to the preset combination of bending angles with the highest similarity.

[0048] Simply record the measured values ​​of the strain gauge bending sensor 2 corresponding to each cable configuration at various entry angles in advance (to avoid loss of generality, the sensor measured values ​​at each entry angle can be obtained by averaging multiple records). Then, through simple similarity calculation, the calibration value that is closest to the sensor measured value at the current moment (must be no less than the preset similarity threshold) can be found. If the closest value cannot be found, it must be that the entry angle is too large or too small, and an alarm will be triggered. In step S5, the entry angle corresponding to the preset combination of the closest bending angles is directly used as the entry angle of the cable at the current moment.

[0049] Specifically, in step S41, the similarity D between the multiple bending angle values ​​at the current moment and the i-th set of preset bending angle values ​​in the bending angle value standard library is calculated. i Calculated using the following formula:

[0050]

[0051] Where a1, a2, ..., an represent the bending angle values ​​of the first strain gauge bending sensor 2, the second strain gauge bending sensor 2 to the nth strain gauge bending sensor 2 at the current moment, and bi1, bi2, ..., bin represent the bending angle values ​​of the first strain gauge bending sensor 2, the second strain gauge bending sensor 2 to the nth strain gauge bending sensor 2 in the i-th set of preset bending angle values.

[0052] This method also includes a step S3, in which, during the process of the strain gauge bending sensor 2 measuring the bending angle value, if the measured value of any strain gauge bending sensor 2 is not within its reasonable range (the reasonable range of each strain gauge bending sensor 2 is different due to different installation positions), an alarm will be triggered, and the cable will be re-laid after the relevant personnel make adjustments, and the water entry angle will be measured in real time again.

[0053] In summary, the submarine cable entry angle detection device and method based on strain gauge bending sensors provided in this invention utilizes the elastic strain characteristics of spring steel sheets to create a spring steel sheet submarine cable guide 1. This guide 1 bends with the submarine cable, without affecting its normal laying, and provides guidance, preventing the cable from bending or twisting during the entry section. Based on the high-precision, distributed sensing measurement characteristics of strain gauge bending sensors 2 for material structure strain, the sensors are evenly and at equal intervals attached to the spring steel sheet submarine cable guide 1. The degree of bending of the guide 2 is detected to obtain the entry angle information during the cable laying process. This method is simple in structure and calculation, with high detection accuracy. Furthermore, the spring steel sheet submarine cable guide 1 not only does not affect cable laying but also assists in the process.

[0054] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor, characterized in that, Including the following steps: S1. Install the cable entry angle detection device based on strain gauge bending sensor on the cable laying vessel; the cable entry angle detection device includes a spring steel sheet cable guide (1) made of spring steel sheet, and multiple strain gauge bending sensors (2) evenly arranged at equal intervals on the spring steel sheet cable guide (1) along the length direction of the spring steel sheet cable guide (1), one end of the spring steel sheet cable guide (1) is fixed on the cable laying vessel. S2. Place the submarine cable on the spring steel sheet submarine cable guide rail (1) and begin laying the cable in the water; S3. Multiple strain gauge bending sensors (2) arranged on the spring steel sheet submarine cable guide (1) output the bending angle values ​​they measure. S4. Obtain the configuration of the submarine cable on the spring steel sheet submarine cable guide (1) at the current moment based on multiple bending angle values ​​at the current moment; S5. Calculate the current angle of entry of the submarine cable into the water based on the obtained configuration of the submarine cable; Step S4 includes the following steps: S41. Match the multiple bending angle values ​​at the current moment with the bending angle value standard library, and determine whether there is a combination of bending angle preset values ​​with similarity above a preset threshold in the bending angle value standard library. If so, proceed to the next step; otherwise, issue an alarm. The bending angle value standard library consists of the first strain gauge bending sensor (2), the second strain gauge bending sensor (2), and so on, pre-calibrated under various allowable submarine cable entry angles. The bending angle value of a strain gauge bending sensor (2); S42. Output the cable configuration corresponding to the preset combination of bending angles with the highest similarity.

2. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 1, characterized in that, In step S41, the similarity D between the multiple bending angle values ​​at the current moment and the i-th set of preset bending angle values ​​in the bending angle value standard library is calculated. i Calculated using the following formula: ， in, This indicates the current time of the first strain gauge bending sensor (2), the second strain gauge bending sensor (2), and so on up to the first strain gauge bending sensor (2). The bending angle value of the strain gauge bending sensor (2), This indicates the first strain gauge bending sensor (2), the second strain gauge bending sensor (2), and so on, in the i-th group of preset bending angle values. The bending angle value of the strain gauge bending sensor (2).

3. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 2, characterized in that, In step S3, when the bending angle value measured by the strain gauge bending sensor (2) exceeds its preset range, an alarm is triggered, and then the cable laying is stopped.

4. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 1, characterized in that: The spring steel sheet submarine cable guide (1) is configured as a long conduit structure with a cross-section of a small semi-circular ring, the inner radius of which is greater than or equal to the radius of the submarine cable.

5. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 4, characterized in that: When the spring steel sheet submarine cable guide (1) is placed horizontally, with the tangent of the long conduit structure to the horizontal plane as the line of symmetry, the strain gauge bending sensor (2) is symmetrically attached to the bottom of the outer arc surface of the long conduit structure.

6. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 4, characterized in that: The distance between two adjacent strain gauge bending sensors (2) on the spring steel sheet submarine cable guide (1) is greater than or equal to 1 meter and less than or equal to 2 meters.

7. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 4, characterized in that: The length of the spring steel sheet submarine cable guide (1) is between the minimum water entry angle and the length of the submarine cable section entering the water at the maximum water entry angle during safe cable laying.

8. The method for detecting the water entry angle of a submarine cable based on a strain gauge bending sensor according to claim 1, characterized in that: An alarm module is provided on the strain gauge bending sensor (2). When the bending angle value measured by the strain gauge bending sensor (2) exceeds its preset range, the alarm module will sound an alarm.

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