Mooring cable state monitoring system

Abstract

A mooring line state monitoring system (1A) according to one embodiment is a system for monitoring the state of a mooring line (3) wound around a spool (21) of a mooring machine (2) and unwound from the mooring machine (2), and comprises: a controller (6) for controlling the state of the mooring line (3); and a payoff radius calculation unit that calculates a payoff radius, which is the winding radius of the payoff portion of the mooring cable (3) with respect to the spool (21), on the basis of the height of the mooring cable (3) at the plurality of points from the deck (11), the horizontal distance from the center of the spool (21) to the plurality of points, and the height of the center of the spool (21) from the deck (11).

Description

Technical Field

[0001] The present disclosure relates to a mooring line status monitoring system. Background Art

[0002] Conventionally, ships are equipped with mooring machines (motor winches) including drums on which mooring cables are wound. When a ship is moored to a quay or the like using mooring cables released from the mooring machine, the tension of the mooring cables changes due to tide levels, loads, winds, and tidal currents. Therefore, it is desirable to detect the tension of the mooring cables.

[0003] For example, Patent Document 1 describes that a mooring machine includes a band brake, and the tension of the mooring cable is calculated based on the number of layers of the mooring cable on the drum and the band tension of the band brake. The number of layers of the mooring cable on the drum, for example, the rotation angle of the drum is converted into the number of layers of the mooring cable.

[0004] Prior art literature: Patent literature: Patent document 1: International Publication No. 2022 / 030533. Summary of the invention

[0005] Problems to be solved by the invention: However, when the mooring cable is wound on the drum, if the mooring cable is wound into a spiral shape without gaps for each layer, there is a correlation between the rotation angle of the drum and the number of layers of the mooring cable. However, in reality, the mooring cable is not necessarily wound on the drum in that way, and if the rotation angle of the drum is converted into the number of layers, the tension of the mooring cable may not be calculated correctly. Therefore, in order to accurately calculate the tension of the mooring cable, it is desirable to detect the winding radius of the drum relative to the paid-out portion of the mooring cable, that is, the paid-out radius.

[0006] Therefore, an object of the present disclosure is to provide a mooring line state monitoring system capable of detecting the pay-out radius of a mooring line.

[0007] Means of solving the problem: The present invention provides a mooring cable state monitoring system, which is a mooring cable state monitoring system for monitoring the state of a mooring cable wound on a drum of a mooring machine and released from the mooring machine, and comprises: a controller for calculating a winding radius of a released portion of the mooring cable relative to the drum, i.e., a release radius, based on the height of the mooring cable from a deck at multiple points, the horizontal distance from the center of the drum to the multiple points, and the height of the center of the drum from the deck.

[0008] Effect of the invention: According to the present disclosure, there is provided a mooring line state monitoring system capable of detecting a pay-out radius of a mooring line. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a perspective view of a mooring line state monitoring system according to a first embodiment; Figure 2 middle Figure 2 A is a perspective view of a portion of a height measuring instrument. Figure 2 B is a perspective view of a modified example thereof; Figure 3 is a diagram showing the positional relationship between a mooring machine, a mooring cable, and a mooring metal fitting in the first embodiment; Figure 4 is a side view of a mooring line state monitoring system according to a second embodiment; Figure 5 is a side view of a mooring line state monitoring system according to a third embodiment; Figure 6 It is along Figure 5 The graph of the VI-VI line; Figure 7 is a perspective view of a mooring line state monitoring system according to a fourth embodiment; Figure 8 is a perspective view of a mooring line state monitoring system according to a fifth embodiment; Fig. 9 is a perspective view of a mooring cable status monitoring system according to another embodiment; Fig.10 It is a perspective view of a mooring line state monitoring system according to another embodiment. DETAILED DESCRIPTION

[0010] (First embodiment) Figure 1 1A is a mooring cable state monitoring system according to a first embodiment. The mooring cable state monitoring system 1A is a system for monitoring the state of a mooring cable 3 that is wound up on a drum 21 of a mooring machine 2 and released from the mooring machine 2. Figure 1 In the embodiment, the mooring rope 3 is released from the mooring machine 2 above the drum 21, but the mooring rope 3 may be released from the mooring machine 2 below the drum 21.

[0011] Specifically, the mooring cable status monitoring system 1A, such as Figure 1 and Figure 3 As shown, it includes: two height measuring instruments 4, which measure the heights h1 and h2 of the mooring cable 3 from the deck 11 at two measuring points 71 and 72; and a controller 6, which is electrically connected to the height measuring instruments 4. Figure 3 In order to simplify the drawings, the height measuring instrument 4 is omitted. The measuring points 71 and 72 are located between the mooring metal fitting 12 closest to the mooring machine 2 among the mooring metal fittings installed by the mooring cable 3 and the mooring machine 2. In addition, the "height of the mooring cable 3" is the length of the vertical line from the center of the mooring cable 3 to the deck 11.

[0012] In this embodiment, a sliding type height measuring instrument 4A is used as the height measuring instrument 4. Each height measuring instrument 4A includes: a rod 41, which moves up and down together with the mooring cable 3; and a pair of retractable pillars 42, which support both ends of the rod 41. The rod 41 is parallel to the axial direction of the drum 21 and contacts the mooring cable 3 from below. Each pillar 42 is as shown in FIG. Figure 2 As shown in FIG. 1A , the rod 41 includes a cylindrical fixed portion 44 and a movable portion 43 slidably held in the fixed portion 44. A spring 45 for urging the movable portion 43 is disposed in the fixed portion 44. The spring 45 urges the movable portion 43, thereby maintaining the rod 41 in contact with the mooring cable 10.

[0013] In addition, the height measuring instrument 4A includes: a detector 5 that detects the displacement of the rod 41; and a calculation unit that converts the displacement of the rod 41 detected by the detector 5 into the height of the mooring cable 3. The calculation unit may also be assembled in the controller 6. In this embodiment, the stroke sensor 5A is used as the detector 5. However, if Figure 2 As shown in FIG. 2B , a photoelectric sensor 5B may be used as the detector 5 .

[0014] Regarding the controller 6, the functions of the elements disclosed in this specification can be performed using a circuit or processing circuit including a general-purpose processor, a special-purpose processor, an integrated circuit, an ASIC (Application Specific Integrated Circuits), an existing circuit, and / or a combination thereof, which is constructed or programmed to perform the disclosed functions. The processor includes transistors and other circuits, so it can be regarded as a processing circuit or circuit. In the present disclosure, a circuit, unit, or means is hardware that performs the listed functions, or hardware that is programmed to perform the exemplified functions. The hardware may be the hardware disclosed in this specification, or it may be other known hardware that is programmed or constructed to perform the listed functions. When the hardware is a processor that is considered to be a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to constitute the hardware and / or processor.

[0015] like Figure 3 As shown, the horizontal distances L1 and L2 from the center of the drum 21 to the measuring points 71 and 72 and the height H of the center of the drum 21 from the deck 11 are pre-stored in the controller 6. In addition, the heights h1 and h2 of the mooring cable 3 measured by the height measuring instrument 4A are input to the controller 6. Based on the heights h1 and h2 of the mooring cable 3, the horizontal distances L1 and L2 and the center height H of the drum 21, the controller 6 calculates the winding radius of the released portion (the portion separated from the drum 21 or the lower layer surrounding portion wound on the drum 21) of the mooring cable 3 relative to the drum 21, that is, the release radius Rr.

[0016] For example, the controller 6 calculates the release radius Rr of the mooring cable 3 using the following mathematical formula (1): [Mathematical formula 1] .

[0017] Furthermore, when the calculated pay-out radius Rr is smaller than the radius Rd of the drum 21, the controller 6 determines that rewinding due to the pulling-in of the mooring cable 3 into the lower layer has occurred in the mooring machine 2. The pulling-in of the mooring cable 3 into the lower layer means that the paid-out portion of the mooring cable 3 is embedded between the lower layer winding portions wound on the drum 21 and cannot be pulled out.

[0018] As described above, in the mooring cable state monitoring system 1A of the present embodiment, the position of the released portion of the mooring cable 3 on the vertical line passing through the center of the drum 21 can be estimated based on the heights h1 and h2 of the mooring cable 3 from the deck 11 at the measuring points 71 and 72 and the horizontal distances L1 and L2 from the center of the drum 21 to these measuring points 71 and 72. Therefore, by subtracting the center height H of the drum 21 from the position of the released portion, the released radius Rr of the mooring cable 3 can be detected.

[0019] Furthermore, in the present embodiment, when the calculated pay-out radius Rr is smaller than the radius Rd of the drum 21, it is determined that rewinding caused by the pulling-in of the mooring cable 3 toward the lower layer has occurred in the mooring machine 2, and therefore, the subsequent rotation of the drum 21 in the pay-out direction and the winding of the mooring cable 3 can be prevented.

[0020] <Modification> The number of measurement points may be three or more. In this case, the controller uses the following mathematical formula (2) and mathematical formula (3) to calculate the release radius Rr of the mooring cable 3. In this way, if the number of measurement points is increased, the release radius Rr of the mooring cable 3 can be calculated more accurately. [Mathematical formula 2] , [Mathematical formula 3] .

[0021] (Second embodiment) Figure 4 FIG. 2 shows a mooring cable state monitoring system 1B according to a second embodiment. The mooring cable state monitoring system 1B includes only one height measuring instrument 4A described in the first embodiment. Figure 4 In order to simplify the drawing, the height measuring instrument 4A is omitted. The height measuring instrument 4A measures the height h1 of the mooring cable 3 from the deck 11 at the position of the mooring metal fitting 12 closest to the mooring machine 2 among the mooring metal fittings installed by the mooring cable 3, that is, at the measuring point 73 between the fixing point 74 and the mooring machine 2.

[0022] In the present embodiment, the height h2 of the mooring cable 3 from the deck 11 at the fixed point 74, the horizontal distance L2 from the center of the drum 21 to the fixed point 74, the horizontal distance L1 from the center of the drum 21 to the measuring point 73, and the height H of the center of the drum 21 from the deck 11 are pre-stored in the controller 6. In addition, the height h1 of the mooring cable 3 measured by the height measuring instrument 4A is input to the controller 6. The controller 6 calculates the release radius Rr of the mooring cable 3 based on the heights h1 and h2 of the mooring cable 3, the horizontal distances L1 and L2, and the center height H of the drum 21. For example, the controller 6 calculates the release radius Rr using the above-mentioned mathematical formula (1).

[0023] In the mooring cable state monitoring system 1B of the present embodiment, the position of the released portion of the mooring cable 3 on the plumb line passing through the center of the drum 21 can be estimated based on the heights h1 and h2 of the mooring cable 3 from the deck 11 at the measuring point 73 and the fixing point 74 and the horizontal distances L1 and L2 from the center of the drum 21 to these measuring points 73 and the fixing point 74. Therefore, the released radius Rr of the mooring cable 3 can be detected by subtracting the center height H of the drum 21 from the position of the released portion.

[0024] Furthermore, in this embodiment, the cost can be reduced by the amount of the number of height measuring instruments 4A, compared to the first embodiment in which the release radius Rr of the mooring rope 3 is calculated based on the heights at a plurality of measurement points. In contrast, in the configuration of the first embodiment, a plurality of measurement points can be set near the mooring machine 2, so that the release radius Rr of the mooring rope 3 can be accurately calculated compared to the case in which the release radius Rr of the mooring rope 3 is calculated based on the heights at the fixed point 74 and the measurement point 73.

[0025] <Modification> Similar to the modification of the first embodiment, there may be a plurality of measurement points between the fixed point and the mooring rope 2. In this case, the controller 6 calculates the release radius Rr of the mooring rope 3 using the above-mentioned equations (2) and (3).

[0026] (Third Embodiment) Figure 5 1C of the mooring rope state monitoring system of the third embodiment is shown in FIG. In this embodiment, a photoelectric height measuring instrument 4B is used instead of the slide-type height measuring instrument 4A of the second embodiment.

[0027] Altimeter 4B, such as Figure 6As shown, it includes a light emitting unit 61 and a light receiving unit 62 disposed on both sides of the mooring cable 3. Laser beams are emitted from the light emitting unit 61 to the light receiving unit 62 in a manner arranged vertically at a predetermined pitch, and the height of the mooring cable 3 is measured by the position where the laser beam is blocked by the mooring cable 3. In addition, the facing direction of the light emitting unit 61 and the light receiving unit 62 does not necessarily have to be a horizontal direction, but may be a vertical direction.

[0028] This embodiment can also achieve the same effects as those of the second embodiment. In addition, two photoelectric height measuring instruments 4B may be used instead of the two slide-type height measuring instruments 4A of the first embodiment.

[0029] (Fourth Embodiment) Figure 7 , a mooring cable state monitoring system 1D according to a fourth embodiment is shown. In this embodiment, two sliding height measuring instruments 4C are used, similarly to the first embodiment. Each height measuring instrument 4C includes: a rod 41 parallel to the axial direction of the drum 21, which moves up and down together with the mooring cable 3; a pair of retractable pillars 42, which support both ends of the rod 41; a detector, which detects the displacement of the rod 41; and a calculation unit, which converts the displacement of the rod 41 detected by the detector into the height of the mooring cable 3.

[0030] In this embodiment, the rod 41 contacts the mooring cable 3 from above. With this structure, the rod 41 can be maintained in contact with the mooring cable 3 by gravity, so a spring for maintaining the rod 41 in contact with the mooring cable 3 is not required. That is, no spring is arranged in the support column 42.

[0031] (Fifth Embodiment) Figure 8 , a mooring cable state monitoring system 1E of a fifth embodiment is shown. In this embodiment, two swing-type height measuring instruments 4D are used. Each height measuring instrument 4D includes: a rod 41 parallel to the axial direction of the drum 21, which moves up and down together with the mooring cable 3; a pair of booms 47 connected to both ends of the rod 41; and a pair of struts 48 that swingably support the booms 47. The rod 41 contacts the mooring cable 3 from below, and the boom 47 is biased by a spring, thereby maintaining the rod 41 in a state of contact with the mooring cable 10.

[0032] Each height measuring device 4D includes a detector 5 for detecting the displacement of the rod 41 and a calculation unit for converting the displacement of the rod 41 detected by the detector 5 into the height of the mooring cable 3. In the present embodiment, the detector 5 is an encoder for detecting the swing angle of the boom 47 as the displacement of the rod 41.

[0033] The present embodiment can also achieve the same effects as those of the first embodiment. In addition, when the rod 41 contacts the mooring rope 3 from above, the spring for urging the boom 47 can be omitted.

[0034] (Other Implementations) The present disclosure is not limited to the above-described embodiments, and various modifications may be made without departing from the gist of the present disclosure.

[0035] For example, Fig. 9 As in the mooring cable state monitoring system 1F shown in FIG. 1 , when the mooring cable 3 is released from the mooring machine 2 below the drum 21, the release radius Rr of the mooring cable 3 can also be calculated using the above-mentioned mathematical formula (1). In addition, when the mooring cable 3 is released from the mooring machine 2 below the drum 21, the release radius Rr of the mooring cable 3 can also be calculated as follows: Fig. 9 As in the mooring line state monitoring system 1F shown in FIG. 1 , a height measuring instrument 4A including a spring is used, in which a rod 41 contacts the mooring line 3 from below. Fig.10 As in the mooring line state monitoring system 1G shown in the figure, a height measuring instrument 4C without a spring is used in which a rod 41 contacts the mooring line 3 from above.

[0036] When a plurality of height measuring instruments 4 are used, the types of all height measuring instruments 4 do not necessarily have to be the same, and any two or more of the above-mentioned sliding height measuring instruments 4A or 4C, photoelectric height measuring instruments 4B, and swing height measuring instruments 4D may be combined.

[0037] Alternatively, the altimeter 4 may not be used, and the controller 6 may calculate the height of the mooring cable 3 from the deck 11 at multiple points based on the image captured by the camera. In this case, the horizontal distances from the center of the drum 21 to the multiple points may be pre-stored in the controller 6 or calculated based on the image.

[0038] (Summarize) As a first aspect, the present disclosure provides a mooring cable status monitoring system, which is a mooring cable status monitoring system that monitors the status of a mooring cable wound on a drum of a mooring machine and released from the mooring machine, and comprises: a controller that calculates the winding radius of the released portion of the mooring cable relative to the drum, that is, the release radius, based on the height of the mooring cable from a deck at multiple points, the horizontal distance from the center of the drum to the multiple points, and the height of the center of the drum from the deck.

[0039] According to the above configuration, the position of the paid-out portion of the mooring cable on the plumb line passing through the center of the drum can be estimated based on the height of the mooring cable from the deck at a plurality of points and the horizontal distances from the center of the drum to these plurality of points. Therefore, the paid-out radius of the mooring cable can be detected by subtracting the center height of the drum from the position of the paid-out portion.

[0040] As a second aspect, in the first aspect, the plurality of points may include: a fixed point, which is a position of a mooring metal fitting closest to the mooring machine among the mooring metal fittings installed by the mooring cable; and at least one measuring point between the fixed point and the mooring machine, and the mooring cable state monitoring system further includes: at least one height measuring instrument, which measures the height of the mooring cable from the deck at the at least one measuring point, and the controller stores the height of the mooring cable at the fixed point, the horizontal distance from the center of the drum to the fixed point, the horizontal distance from the center of the drum to the at least one measuring point, and the center height of the drum, and inputs the height of the mooring cable measured by the at least one height measuring instrument. According to this structure, compared with calculating the release radius of the mooring cable based on the heights at a plurality of measuring points, the cost can be reduced by the amount of the number of height measuring instruments.

[0041] As a third aspect, in the first aspect, the plurality of points may include a plurality of measuring points between the mooring metal fitting closest to the mooring machine among the mooring metal fittings installed by the mooring cable and the mooring machine, and the mooring cable state monitoring system may further include: a plurality of height measuring instruments that measure the height of the mooring cable from the deck at the plurality of measuring points, and the controller stores the horizontal distance from the center of the drum to the plurality of measuring points and the center height of the drum, and inputs the height of the mooring cable measured by the plurality of height measuring instruments. According to this structure, since the plurality of measuring points are set near the mooring machine, the release radius of the mooring cable can be accurately calculated compared with the case where the release radius of the mooring cable is calculated based on the height at the fixed point and at least one measuring point.

[0042] As a fourth aspect, in the second aspect, for example, the at least one height measuring instrument may include: a rod that moves up and down together with the mooring cable; and a detector that detects a displacement of the rod.

[0043] As a fifth aspect, in the third aspect, for example, each of the plurality of height measuring instruments may include: a rod that moves up and down together with the mooring cable; and a detector that detects a displacement of the rod.

[0044] As a sixth aspect, in the fourth or fifth aspect, the rod may contact the mooring cable from above. According to this structure, the rod can be maintained in contact with the mooring cable by gravity, so a spring for maintaining the rod in contact with the mooring cable is not required.

[0045] As a seventh aspect, in any one of the first to sixth aspects, the controller may determine that a rewinding caused by the mooring cable being pulled into a lower layer has occurred in the mooring machine when the calculated pay-out radius is smaller than the radius of the drum. According to this structure, it is possible to prevent the mooring cable from being reeled in by the subsequent rotation of the drum in the pay-out direction.

Claims

1. A mooring cable status monitoring system, characterized in that: A mooring cable state monitoring system for monitoring the state of a mooring cable wound on a drum of a mooring machine and released from the mooring machine, It has: A controller calculates a winding radius of the paid-out portion of the mooring cable relative to the drum, i.e., a pay-out radius, based on the height of the mooring cable from the deck at multiple points, the horizontal distance from the center of the drum to the multiple points, and the height of the center of the drum from the deck.

2. The mooring line status monitoring system according to claim 1, characterized in that: The plurality of points include: a fixed point, which is a position of a mooring metal member of the mooring cable that is closest to the mooring machine; and at least one measuring point between the fixed point and the mooring machine. The mooring cable state monitoring system further comprises: at least one height measuring instrument, which measures the height of the mooring cable from the deck at the at least one measuring point; The controller stores the height of the mooring cable at the fixed point, the horizontal distance from the center of the drum to the fixed point, the horizontal distance from the center of the drum to the at least one measuring point, and the center height of the drum, and inputs the height of the mooring cable measured by the at least one height measuring instrument.

3. The mooring line status monitoring system according to claim 1, characterized in that: The plurality of points include a plurality of measuring points between a mooring metal member closest to the mooring machine in the mooring cable installation and the mooring machine, The mooring cable state monitoring system further comprises: a plurality of height measuring instruments, which measure the height of the mooring cable from the deck at the plurality of measuring points; The controller stores the horizontal distances from the center of the drum to the plurality of measuring points and the center height of the drum, and inputs the heights of the mooring cables measured by the plurality of height measuring instruments.

4. The mooring cable status monitoring system according to claim 2, characterized in that: The at least one height measuring instrument includes a rod that moves up and down together with the mooring cable, and a detector that detects a displacement amount of the rod.

5. The mooring line status monitoring system according to claim 3, characterized in that: The plurality of height measuring instruments respectively include: a rod that moves up and down together with the mooring cable; and a detector that detects a displacement amount of the rod.

6. The mooring line status monitoring system according to claim 4 or 5, characterized in that: The rod is in contact with the mooring line from above.

7. The mooring line status monitoring system according to any one of claims 1 to 5, characterized in that: The controller determines that rewinding due to the pulling in of the mooring rope toward the lower layer has occurred in the mooring machine when the calculated pay-out radius is smaller than the radius of the drum.

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