Control method for submarine cable output speed of carrier turntable

Abstract

Disclosed in the present invention is a control method for a submarine cable output speed of a carrier turntable. Several single-point range finders are arranged on a turntable center cylinder of a carrier turntable, and when the carrier turntable rotates, each single-point range finder records a measured distance M and a time t; a horizontal distance Wi-1 swept by an i-th single-point range finder, that detects a submarine cable, from the detection by a first single-point range finder is calculated; on the basis of parameters Hi-1, Li-1 and Wi-1, fitting is performed to obtain a submarine cable profile; and the fitted submarine cable profile is compared with a preset allowable submarine cable profile, and accordingly, the angular velocity ω at which the carrier turntable rotates is adjusted, such that a plotted submarine cable profile matches the allowable submarine cable profile. The control method provided in the present invention can achieve the effect of controlling the tension of submarine cables, thereby preventing the submarine cables from being broken by the tension or damaged by compression; the matching accuracy between a submarine cable output speed of a carrier turntable and a submarine cable output speed of a cable-laying machine can also be improved; and when the submarine cable output speed is abnormal, warning information is sent, thereby improving the safety of submarine cable laying.

Description

A method for controlling the output speed of a bearing carousel submarine cable TECHNICAL FIELD

[0001] The present application relates to a method for controlling the output speed of a bearing carousel submarine cable, and belongs to the field of submarine cable laying. BACKGROUND

[0002] A submarine cable is a cable wrapped with insulating material and laid on the seabed. In submarine cable laying construction, in order to ensure the safety of the submarine cable under stress, the unification of the speeds of the construction ship, the cable laying machine and the laying plow needs to be considered, especially the influence on the tension of the submarine cable, to prevent the submarine cable from being damaged due to excessive tension and the submarine cable from being twisted and knotted due to insufficient tension. Therefore, the output speed of the submarine cable at the cable laying machine needs to be controlled in the construction.

[0003] However, the output speed of the submarine cable of the bearing carousel also needs to match the output speed of the submarine cable of the cable laying machine, to prevent the output speed of the submarine cable of the bearing carousel from being less than the output speed of the submarine cable of the cable laying machine, which may cause the submarine cable to be damaged due to excessive tension, and to prevent the output speed of the submarine cable of the bearing carousel from being greater than the output speed of the submarine cable of the cable laying machine, which may cause the submarine cable to be damaged due to insufficient bending radius.

[0004] Since the submarine cable is layered and wound on the center cylinder of the bearing carousel turn by turn, the length of each turn of the submarine cable is different, and it is difficult to match the output speed of the submarine cable of the bearing carousel with the output speed of the submarine cable of the cable laying machine. Therefore, how to prevent the submarine cable between the bearing carousel and the cable laying machine from being damaged becomes a technical problem to be solved.

[0005] SUMMARY

[0006] In view of the problem that the tension of the submarine cable between the bearing carousel and the cable laying machine is difficult to control in the existing submarine cable laying construction, the present application provides a method for controlling the output speed of a bearing carousel submarine cable, which fits the submarine cable profile and matches the drawn submarine cable profile with the allowed submarine cable profile, thereby solving the technical problem that the tension of the submarine cable is difficult to control.

[0007] To solve the above technical problems, the present application includes the following technical solutions:

[0008] A method for controlling the output speed of a bearing carousel submarine cable, the submarine cable is layered and wound on the center cylinder of the bearing carousel turn by turn, and the submarine cable between the lifting end at the bottom and the output end at the top forms a curve; N layers of s columns of single-point range finders are arranged on the center cylinder of the bearing carousel, and the single-point range finders are numbered from top to bottom; the radius of the submarine cable is denoted as R, and the radius of the center cylinder of the bearing carousel is denoted as D;

[0009] The control method includes the following steps:

[0010] Step 1: As the turntable rotates, the single-point distance measuring instrument records the measured distance M and time t; M is the distance between the single-point distance measuring instrument and the submarine cable; there are n layers of single-point distance measuring instruments that measure a distance greater than the preset value to the submarine cable, n≤N; the distance measured by one single-point distance measuring instrument on the first layer is M0, and the time is t0. i-2 The distance measured by the single-point distance measuring instrument at the first point of the submarine cable, i-th layer, is M. i-1 Time is denoted as t i-1 , i = 2, 3, ..., n; M i-1 The corresponding distance from the center of the submarine cable to the center of the turntable is L. i-1 , where L i-1 =R+M i-1 +D;

[0011] Step 2: Calculate t i-1 The horizontal distance W swept by the single-point rangefinder during the time interval t0. i-1 W i-1 =(t i-1 -t0)×ω×L i-1 Where ω is the angular velocity of the rotating disk;

[0012] Step 3, based on H i-1 L i-1 and W i-1 The shape of the submarine cable was fitted; where H i-1 Let be the height of the single-point rangefinder at the i-th layer;

[0013] Step 4: Compare the fitted submarine cable profile with the preset allowable submarine cable profile, and adjust the angular velocity ω of the rotating bearing turntable accordingly to match the drawn submarine cable profile with the allowable submarine cable profile.

[0014] Furthermore, the control method also includes:

[0015] Determine the distance L between the cable lifting end and the center of the carrier turntable, and calculate the cable output speed V at the cable lifting end of the carrier turntable. S V S =ω×L;

[0016] Obtain the submarine cable output speed V of the cable laying machine T ;

[0017] Compare V S With V T The size of the two values ​​will be used to issue a warning message when the deviation exceeds the allowable value.

[0018] Furthermore, the single-point rangefinders are arranged in four equal parts along the central cylinder of the turntable, and the distance between the upper and lower single-point rangefinders is d, where d = 30cm ± 10cm.

[0019] Compared with the prior art, the application has the following advantages and positive effects: the application provides a bearing turntable submarine cable output speed control method, a plurality of single-point range finders are arranged on a turntable center column of the bearing turntable, the ranging and the measured time of the submarine cable are recorded when the bearing turntable rotates, then the fitting submarine cable line shape is obtained according to parameters H i and L i , W i , the fitting submarine cable line shape is compared with a preset submarine cable allowable line shape, the angular velocity ω of the bearing turntable is adjusted according to the comparison, the drawn submarine cable line shape is matched with the submarine cable allowable line shape, the effect of controlling the submarine cable tension is achieved, the submarine cable is prevented from being damaged by the tension or being squeezed, the matching precision of the submarine cable output speed of the bearing turntable and the submarine cable output speed of the cable laying machine is improved, the warning information is sent when the submarine cable output speed is abnormal, and the safety of the submarine cable laying is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a flow chart of the bearing turntable submarine cable output speed control method in the embodiment of the application;

[0021] Fig. 2 is a schematic view of the bearing turntable and the submarine cable provided by the embodiment of the application;

[0022] Fig. 3 is a sectional view along A-A in Fig. 2;

[0023] Fig. 4 is a schematic view of the bearing turntable, the submarine cable and the single-point range finder provided by the embodiment of the application;

[0024] Fig. 5 is a schematic view of the submarine cable radius R, the distance M between the submarine cable and the single-point range finder, and the turntable center column radius D provided by the embodiment of the application;

[0025] Fig. 6 is a schematic view of the submarine cable line shape fitting provided by the embodiment of the application.

[0026] Reference signs in the drawings are as follows:

[0027] 1-bearin turntable; 2-turntable center column; 3-submarine cable; 4-single-point range finder. DETAILED DESCRIPTION

[0028] The bearing turntable submarine cable output speed control method provided by the application is further described in detail below in combination with the drawings and specific embodiments. The advantages and features of the application will be clearer in combination with the following description. It should be noted that the drawings are very simplified and use non-precise proportions, and are only used to facilitate and clarify the purpose of assisting the description of the embodiments of the application.

[0029] With reference to Figs. 2 and 3, the submarine cable on the bearing turntable is layered and wound on the center column of the turntable. For example, the submarine cable on the lowest layer is wound on the center column of the turntable, and the submarine cable is wound in a spiral manner with the radius changing from small to large. When the lowest layer is full, the second to last layer is set, and the submarine cable is wound in a spiral manner with the radius changing from large to small. The submarine cable is transported in turns, and the lifting position of the submarine cable changes with respect to the center of the turntable. If the bearing turntable rotates at a constant speed, the lifting position of the submarine cable changes from far to near with respect to the center of the turntable, and the output speed of the submarine cable also changes from large to small. If the lifting position of the submarine cable changes from near to far with respect to the center of the turntable, the output speed of the submarine cable also changes from small to large. The submarine cable is output from the bearing turntable to the input end of the cable laying machine, and then is driven to the output end of the cable laying machine. The output speed of the submarine cable of the cable laying machine also needs to be matched with the speed of the construction ship to prevent the submarine cable at the output end of the cable laying machine from being pulled too hard or too weak. Therefore, the output speed of the submarine cable of the cable laying machine is also not fixed. How to match the output speed of the submarine cable of the bearing turntable with the output speed of the submarine cable of the cable laying machine becomes a difficult problem in submarine cable laying construction.

[0030] The embodiment provides a bearing turntable submarine cable output speed control method, and the main innovation lies in that a plurality of single-point range finders are arranged, the submarine cable line shape between the bearing turntable and the input end of the cable laying machine is calculated, the rotating speed of the bearing turntable is controlled according to the change of the bending radius of the submarine cable line shape, the submarine cable line shape is kept within the allowable range, and the effect of controlling the submarine cable tension is achieved. The control method is further described below with reference to Figs. 1 to 6.

[0031] As shown in Fig. 4, the lifting position of the submarine cable is referred to as the lifting end, the top of the submarine cable is referred to as the output end, the submarine cable between the lifting end and the output end is in a curve, and the present application is used to solve the tension problem between the lifting end and the output end of the submarine cable. N layers of s columns of single-point range finders are arranged on the center column of the bearing turntable, and each layer is provided with s single-point range finders, for example, s = 1, s = 2 or s = 4, and of course other values can also be taken according to needs. Taking s = 4 as an example, the single-point range finders are arranged at an equal interval of 90° along the center column of the turntable, and each column of single-point range finders is sequentially numbered from top to bottom. The single-point range finder has a distance measuring and measuring time recording function, and the time accuracy can reach milliseconds. As an example, the number of layers of single-point range finders is determined according to the height of the turntable and the diameter of the submarine cable, and the distance between the upper and lower layers can be set as d, where d = 30 cm ± 10 cm. The radius of the submarine cable is denoted as R, and the radius of the center column of the turntable is denoted as D.

[0032] As shown in Fig. 1, the control method comprises the following steps:

[0033] Step 1: As the turntable rotates, the single-point rangefinder records the measured distance M and time t; M is the distance between the single-point rangefinder and the submarine cable. Because the bottom few layers of single-point rangefinders are covered by the coiled submarine cable, that is, single-point rangefinders below the height of the cable's lifting end are covered, it is necessary to discard the measurement data of these single-point rangefinders. A preset value can be set to only consider measurement data with a distance greater than the preset value, for example, the preset value is 20cm. Assume that there are n layers of single-point rangefinders that measure a distance greater than the preset value between themselves and the submarine cable, n≤N; the distance measured by a single-point rangefinder in the first layer is M0, and the time is t0. Subsequently, the distance measured by the single-point rangefinder in the i-th layer of the same column is M0. i-1 Time is denoted as t i-1 , i = 2, 3, ..., n; M i-1 The corresponding distance from the center of the submarine cable to the center of the turntable is L. i-1 , where L i-1 =R+M i-1 +D;

[0034] Step 2: Calculate t i-1 The horizontal distance W swept by the single-point rangefinder during the time interval t0. i-1 W i-1 =(t i-1 -t0)×ω×L i-1 Where ω is the angular velocity of the rotating disk;

[0035] Step 3, based on H i-1 L i-1 and W i-1 The shape of the submarine cable was fitted; where H i-1 Let be the height of the single-point rangefinder at the i-th layer;

[0036] Step 4: Compare the fitted submarine cable profile with the preset allowable submarine cable profile, and adjust the angular velocity ω of the rotating bearing turntable accordingly to match the drawn submarine cable profile with the allowable submarine cable profile.

[0037] Referring to Figures 4 and 5, let M be the distance between the submarine cable and the central cylinder of the turntable, and L be the distance from the center of the submarine cable to the center of the turntable. Then, L = R + M + D, where R and D are constants, and M is an indeterminate value. Let ω be the angular velocity of the turntable's rotation, and v be the output velocity of the submarine cable supporting the turntable. Then, v = ω × (R + M + D), therefore v is related to ω and M.

[0038] The bearing carousel releases the submarine cable by rotating, and the top output end of the submarine cable is substantially unchanged relative to the ground position. During the rotation of the bearing carousel, the single-point range finders arranged in an array can scan the submarine cable once every certain time interval. The distance M between the single-point range finder and the submarine cable can be measured through the blocking of the submarine cable, and the measured time t is recorded. When the single-point range finder scans the submarine cable, the single-point range finder is vertically arranged, and the submarine cable is delivered in a curve, so that the single-point range finder scans the submarine cable at different times.

[0039] As shown in FIG. 6, 10 layers of single-point range finders are vertically displayed. Taking the single-point range finders in one column as an example, the measurement time of the single-point range finder measuring the first layer of the submarine cable is t0, and the measurement times of the remaining single-point range finders are t1, t2, …, t9 in sequence. The distances between the single-point range finders and the submarine cable are M1, M2, …, M9, respectively. The distances between the center of the submarine cable and the center of the bearing carousel are L1, L2, …, L9, respectively. i-1 The horizontal distance W scanned by the single-point range finder in the time period from t0 to t1 i-1 , i = 2, 3, …, 10. According to H i-1 , L i-1 and W i-1 , the submarine cable line shape is fitted; wherein H i-1 is the height of the single-point range finder in the i-th layer.

[0040] In one specific embodiment, the bearing carousel submarine cable output speed control method further comprises:

[0041] The distance l between the submarine cable lifting end and the center of the bearing carousel is determined, and the submarine cable output speed V S of the submarine cable lifting end of the bearing carousel is calculated S = ω × l;

[0042] The submarine cable output speed V T of the cable laying machine is obtained.

[0043] The sizes of V S and V T are compared, and when the deviation between them exceeds the allowable value, a warning information is issued.

[0044] It should be noted that the application only uses the result of comparing the submarine cable output speed of the bearing carousel with the submarine cable output speed of the cable laying machine as an auxiliary means, because it is difficult to accurately match the submarine cable output speed with the submarine cable output speed of the cable laying machine, and the error will accumulate. There is a possibility that the submarine cable output speed and the submarine cable output speed of the cable laying machine are not much different, but due to the accumulation of errors, the line shape of the submarine cable has changed a lot. Therefore, the application takes the submarine cable line shape as the basis for adjusting the rotation speed of the bearing carousel, and takes the result of comparing the submarine cable output speed of the bearing carousel with the submarine cable output speed of the cable laying machine as an auxiliary judgment factor for whether an abnormality occurs.

[0045] It should be noted that the calculation of data and the fitting of the shape of the submarine cable can be automatically completed by a controller or a computer, such as the data collected by the single-point range finder is transmitted to the computer, the corresponding data is automatically calculated by the pre-designed calculation formula in the calculation module of the computer, the three-dimensional curve of the submarine cable is fitted by establishing a three-dimensional coordinate system, and the rotation angular velocity of the bearing turntable is automatically controlled by automatically comparing with the set allowable curve according to the comparison result.

[0046] It should be noted that the shape of the submarine cable can also be fitted by setting 1 column of single-point range finders, which can be fitted once per rotation, but when multiple columns are set, the shape of the submarine cable can be fitted in each column, which can reduce the interval time of fitting of two submarine cable shapes and improve the control accuracy.

[0047] The technical features of the above-described embodiments can be combined arbitrarily, and to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0048] The above-described embodiments only express several embodiments of the present application, which are described in detail and in detail, but should not be construed as limiting the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A load bearing carousel cable output speed control method, characterized in that, The cable is layered and coiled on the carousel center column of the load bearing carousel, and the cable bottom lifting end and the top output end form a curve; N layers of s column single point range finders are arranged on the carousel center column of the load bearing carousel, and the single point range finders are numbered from top to bottom; the cable radius is denoted as R, and the carousel center column radius is denoted as D; The control method comprises the following steps: Step one, when the bearing turntable rotates, the single-point distance meter records the measured distance M and time t; M is the distance between the single-point distance meter and the submarine cable; there are n layers of single-point distance meters measuring the distance between them and the submarine cable greater than the preset value, n≤N; the distance measured by a single-point distance meter in the first layer is M0, the time is t0, and the distance measured by the single-point distance meter in the i layer of the column is M i-1 , the time is recorded as t i-1 , i = 2, 3, …, n; M i-1 The distance between the corresponding submarine cable center and the bearing turntable center is L i-1 , wherein L i-1 = R + M i-1 + D; Step two, calculate t i-1 The horizontal distance W swept by the single-point distance meter in the time period to t0 i-1 , W i-1 = (t i-1 -t0) x ω x L i-1 Wherein, ω is the angular velocity of the rotating bearing turntable; Step three, according to H i-1 , L i-1 and W i-1 , the cable shape is fitted; wherein H i-1 is the height of the i-th layer of single-point range finder. Step four, comparing the fitted cable line shape with the preset cable allowable line shape, and adjusting the angular velocity ω of the load bearing carousel rotation to make the drawn cable line shape match the cable allowable line shape.

2. The load bearing carousel cable output speed control method according to claim 1, characterized in that, The control method further comprises: The distance l between the cable lifting end and the center of the load bearing turntable is determined, and the cable output speed V of the cable lifting end of the load bearing turntable is calculated S , V S = ω × l; Obtaining a cable output speed V of a cable laying machine T ; Comparison V S With V T The size of the deviation when both exceed the allowable value, the alert information is issued.

3. The load bearing carousel cable output speed control method according to claim 1 or 2, characterized in that, The single point range finders are arranged in four equal parts along the carousel center column, and the spacing between the upper and lower two layers of single point range finders is d, d = 30 cm ± 10 cm.

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