Method and system for determining the height position of a weight

Abstract

To provide a method and system for grasping the height position of a weight, capable of easily and accurately grasping the height position of the weight in a water bottom leveling operation using the weight suspended by a crane mounted on a ship. [Solution] A first pipe 2 is installed on a ship 20 equipped with a crane 21, a second pipe 3 is fixed to a weight 30, the first pipe 2 and the second pipe 3 are connected by a communicating pipe 4, a liquid L is stored inside the first pipe 2 and the second pipe 3, and the communicating pipe 4 is filled with the liquid L. A computing device 8 calculates the height position of a managed position P3 of the weight 30 based on position coordinate data of a predetermined position of the ship 20 input from a positioning means 7, measurement data of a liquid level position LP inside the first pipe 2 input from a first liquid level position measuring sensor 5 provided in the first pipe 2, and measurement data of a liquid level position LP inside the second pipe 3 input from a second liquid level position measuring sensor 6 provided in the second pipe 3.

Description

[Technical Field]

[0001] The present invention relates to a method and system for determining the height position of a weight, and more particularly to a method and system for determining the height position of a weight that can easily and accurately determine the height position of a weight when leveling the bottom of a body of water using a weight suspended by a crane mounted on a ship. [Background technology]

[0002] Various methods have been proposed for determining the height of a weight suspended by a ship-mounted crane during bottom leveling work. For example, a method has been proposed in which an optical prism is attached to the weight, and an automatic tracking total station installed on land emits light toward the optical prism, and the light reflected by the optical prism is analyzed by the automatic tracking total station to determine the height (height coordinate) of the weight. With this method, when changing the planar position of the weight, it is necessary to readjust the light irradiation direction of the automatic tracking total station to match the position of the optical prism attached to the weight. Therefore, the bottom leveling work must be temporarily interrupted when changing the planar position of the weight.

[0003] Another method for determining the height position of a weight has been proposed, which involves calculating the height at which the weight contacts the bottom of the water (a rubble mound) when dropped onto the bottom (a rubble mound) from the altitude of the tip of the crane measured by a GPS sensor attached to the tip of the crane, the amount of wire rope that has been let out from the crane, and the height (length) of the weight (see Patent Document 1). The method described in Patent Document 1 requires determining the amount of wire rope that has been let out from the crane, but it is difficult to accurately determine the amount of wire rope that has been let out. For example, one method is to determine the amount of wire rope that has been let out from the rotational speed (number of rotations) of the drum that releases the wire rope. However, because the wire rope is wound around the drum in an irregular, overlapping manner, it is difficult to accurately determine the amount of wire rope that has been let out from the rotational speed of the drum. Therefore, a new method is needed that can more easily and accurately determine the height position of a weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-161674 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method and system for determining the height position of a weight that can easily and accurately determine the height position of a weight suspended by a crane mounted on a ship during water bottom leveling work. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a method for determining the height position of a weight for determining the height position of a desired management target position of a weight suspended by a crane mounted on a ship during bottom leveling work using the weight, the method comprising the steps of: installing a first tubular body extending in a vertical direction on the ship; fixing a second tubular body extending in the vertical direction to the weight; connecting the first tubular body and the second tubular body by a communicating pipe; storing liquid inside the first tubular body and the second tubular body; and filling the communicating pipe with the liquid; calculating height coordinates of a ship-side reference position previously set for the ship based on position coordinate data of a predetermined position of the ship acquired by a positioning means; and measuring the height position of a first liquid level position meter provided on the first tubular body. a first separation distance in the vertical direction between the ship's side reference position and the liquid level position inside the first pipe based on measurement data of the liquid level position inside the first pipe obtained by a liquid level position measurement sensor; a second separation distance in the vertical direction between a weight-side reference position preset for the weight and the liquid level position inside the second pipe based on measurement data of the liquid level position inside the second pipe obtained by a second liquid level position measurement sensor provided on the second pipe; a height coordinate of the weight-side reference position calculated based on the height coordinate of the ship's side reference position, the first separation distance, and the second separation distance; and a height position of the managed position calculated based on the height coordinate of the weight-side reference position.

[0007] The height position determination system of the present invention is a weight position determination system for determining the height position of a desired management target position of a weight suspended by a crane mounted on a ship during water bottom leveling work using the weight, the system comprising: a first pipe body extending in the vertical direction installed on the ship; a second pipe body extending in the vertical direction fixed to the weight; a communicating pipe connecting the first pipe body and the second pipe body; a first liquid level position measurement sensor provided on the first pipe body; a second liquid level position measurement sensor provided on the second pipe body; positioning means for acquiring position coordinate data of a predetermined position on the ship; and a computing device communicably connected to the first liquid level position measurement sensor, the second liquid level position measurement sensor, and the positioning means, wherein liquid is stored inside the first pipe body and inside the second pipe body, and the communicating pipe is filled with the liquid, and the position coordinate data acquired by the positioning means and the position coordinate data acquired by the first liquid level position measurement sensor are and measurement data of the liquid level position inside the first pipe obtained by the second liquid level position measurement sensor are input to the arithmetic device, and the arithmetic device calculates the height coordinate of a ship-side reference position that is preset for the ship based on the input position coordinate data, calculates a first vertical separation distance between the ship-side reference position and the liquid level position inside the first pipe based on the measurement data of the liquid level position inside the first pipe, calculates a second vertical separation distance between a weight-side reference position that is preset for the weight and the liquid level position inside the second pipe based on the measurement data of the liquid level position inside the second pipe, calculates the height coordinate of the weight-side reference position based on the calculated height coordinate of the ship-side reference position, the first separation distance, and the second separation distance, and calculates the height position of the managed position based on the calculated height coordinate of the weight-side reference position. [Effects of the Invention]

[0008] According to the present invention, when position coordinate data of a predetermined position of a ship on which a crane is mounted, acquired by a positioning means, measurement data of the liquid level position inside a first tubular body installed on the ship, acquired by a first liquid level position measurement sensor, and measurement data of the liquid level position inside a second tubular body fixed to the weight, acquired by a second liquid level position measurement sensor, are input into a computing device, the computing device calculates height coordinates of a weight-side reference position that is preset for the weight.The computing device then calculates the height position of a desired management target position of the weight based on the calculated height coordinates of the weight-side reference position.This makes it possible to easily and accurately determine the height position of a weight suspended by a crane mounted on a ship during water bottom leveling work using the weight. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram illustrating a side view of a situation in which the height position of a weight suspended by a crane is determined when the weight has landed on the bottom of the water (foundation mound) using a weight height position determination system according to an embodiment of the present invention. [Figure 2] 2 is an explanatory diagram showing a schematic plan view of a situation in which the height position of a weight is determined using the weight height position determination system of FIG. 1; FIG. [Figure 3] FIG. 2 is an explanatory diagram illustrating an enlarged cross-sectional view of the first pipe body and first liquid level position measurement sensor arranged on the ship of FIG. 1, and the second pipe body and second liquid level position measurement sensor installed on the weight. [Figure 4] FIG. 2 is an explanatory diagram illustrating a side view of a situation in which the weight height position determination system of FIG. 1 is used to determine the height position of a weight suspended by a crane when the weight is positioned above the bottom of the water (foundation mound). [Figure 5] FIG. 5 is an explanatory diagram illustrating an enlarged cross-sectional view of the first pipe body and first liquid level position measurement sensor arranged on the ship of FIG. 4, and the second pipe body and second liquid level position measurement sensor installed on the weight. [Figure 6]An explanatory diagram illustrating a cross-sectional view of a first pipe body and a first liquid level position measurement sensor placed on a ship, and a second pipe body and a second liquid level position measurement sensor installed on the weight when the height position of a weight suspended by a crane is determined using a weight height position determination system of another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a method and system for determining the height position of a weight according to the present invention will be described based on the embodiments shown in the drawings.

[0011] In the height position determining method and height position determining system 1 of the present invention shown in FIGS. 1 to 5, the height position (height coordinate) of the desired management position P3 of the weight 30 is determined during leveling work of the water bottom SB using the weight 30 suspended by a crane 21 mounted on a ship 20. As shown in FIG. 1, in this embodiment, the management position P3 is set at the bottom of the weight 30. The management position P3 can be set at any position on the weight 30. This embodiment illustrates a case where the weight 30 suspended by the crane 21 is used to perform leveling work of a foundation mound M of the water bottom SB (so-called rubble leveling work). The foundation mound M is a base for installing caissons that form breakwaters and revetments. In this invention, the foundation mound M is considered to be part of the water bottom SB. In the following explanation, the water bottom SB will be described as the foundation mound M.

[0012] As shown in the example in Figure 1, in the work of forming the foundation mound M, a large amount of rubble is dropped into the water using a rubble barge or the like to form the general shape of the foundation mound M. Then, a leveling work is performed to adjust the shape and height of the foundation mound M by repeatedly dropping a weight 30 suspended by a crane 21 mounted on a ship 20 onto the foundation mound M. In the leveling work, the height positions of the top surface and slope of the foundation mound M are adjusted to the pre-planned design height. The height position of the top surface of the foundation mound M is confirmed by determining the height position of the managed position P3 of the weight 30 when it has landed on the bottom of the foundation mound M.

[0013] The crane 21 is equipped with a tiltable boom 22, and a weight 30 is connected to the lower end of a hoisting wire 23 that is suspended from the tip 22a of the boom 22. The weight 30 has a support pipe portion 31 that is connected to the lower end of the hoisting wire 23 and extends in the vertical direction, and a press portion 32 that is provided at the lower end of the support pipe portion 31 and is pressed against a foundation mound M. The support pipe portion 31 has a structure in which multiple steel pipes are connected together.

[0014] As illustrated in Figures 1 to 3, the height position detection system 1 for a weight 30 includes a first tubular body 2 that is installed on a ship 20 and extends in the vertical direction, a second tubular body 3 that is fixed to the weight 30 and extends in the vertical direction, and a communicating pipe 4 that connects the first tubular body 2 and the second tubular body 3. A first through-hole 2b provided in the lower part of the first tubular body 2 and a second through-hole 3b provided in the lower part of the second tubular body 3 are connected by the communicating pipe 4. Note that in Figure 2, only the outline of the crane 21 is shown by a dashed line, and the location of the communicating pipe 4 located below the crane 21 is visualized.

[0015] The height position detection system 1 further includes a first liquid level position measurement sensor 5 provided in the first pipe 2, a second liquid level position measurement sensor 6 provided in the second pipe 3, a positioning means 7 that acquires position coordinate data of a predetermined position of the ship 20, and a computing device 8 communicatively connected to the first liquid level position measurement sensor 5, the second liquid level position measurement sensor 6, and the positioning means 7. The height position detection system 1 of this embodiment further includes a monitor 9 communicatively connected to the computing device 8, and a cable 10 that connects the second liquid level position measurement sensor 6 and the computing device 8.

[0016] The first tube 2 and the second tube 3 are configured as elongated tubes capable of containing the liquid L inside. There are no particular limitations on the material of the tubes used for the first tube 2 and the second tube 3, but it is preferable to use metal tubes (such as steel pipes) that are highly resistant to impacts. It is preferable to use round tubes for the first tube 2 and the second tube 3, but polygonal tubes can also be used. The vertical lengths of the first tube 2 and the second tube 3 can be determined as appropriate, but it is recommended to set them to between 1 m and 3 m, for example. The cross-sectional area of ​​the hollow parts of the first tube 2 and the second tube 3 can be set as appropriate, but it is recommended to set them to between 2000 mm 2 More than 35000mm 2 The cross-sectional area of ​​the hollow portion of the first tubular body 2 is preferably set to, for example, 0.8 to 1.2 times, more preferably 0.9 to 1.1 times, and even more preferably 1.0 times, the cross-sectional area of ​​the hollow portion of the second tubular body 3. In other words, the first tubular body 2 and the second tubular body 3 are preferably configured as tubular bodies having hollow portions with the same cross-sectional area.

[0017] In this embodiment, a first through hole 2b is provided in the lower part of the side surface of the first tubular body 2, and a second through hole 3b is provided in the lower part of the side surface of the second tubular body 3. The first through hole 2b can also be provided in the lower surface (bottom surface) of the first tubular body 2, for example. The second through hole 3b can also be provided in the lower surface (bottom surface) of the second tubular body 3, for example.

[0018] In this embodiment, the first tubular body 2 is disposed on the upper deck of the ship 20, but the first tubular body 2 can be disposed at any position on the ship 20. The first tubular body 2 is preferably disposed at a position on the ship 20 that is relatively less affected by rolling. Specifically, the first tubular body 2 is preferably disposed, for example, at the center of the ship's length direction, more specifically, at a position in the ship's length direction, from the bow to the stern of the ship 20, at a distance of 30% to 70% of the ship's length. The first tubular body 2 is fixed to the ship 20.

[0019] The second tubular body 3 is preferably positioned at approximately the same height as the first tubular body 2 when the weight 30 is seated on the bottom of the foundation mound M. In other words, the second tubular body 3 is preferably positioned at a height above the water surface (a height at which the weight 30 is not submerged) when the weight 30 is seated on the bottom of the foundation mound M. In this embodiment, the second tubular body 3 is fixed to the side of the upper part of the support pipe portion 31 of the weight 30. The method of fixing the second tubular body 3 to the weight 30 is not particularly limited. For example, the second tubular body 3 may be joined to the weight 30 (support pipe portion 31) by welding or adhesive, or the second tubular body 3 may be detachably fixed to the weight 30 (support pipe portion 31) using a fixing metal fitting, a fastener, or the like.

[0020] A communicating pipe 4 extends between a first pipe 2 arranged on the ship 20 and a second pipe 3 fixed to a weight 30. The longitudinal length of the communicating pipe 4 is set to be longer than the distance between the first pipe 2 (first through hole 2b) and the second pipe 3 (second through hole 3b). A part of the communicating pipe 4 located on the first pipe 2 side is arranged on the ship 20, and the other part of the communicating pipe 4 located on the second pipe 3 side is located in the water outside the ship 20.

[0021] The cross-sectional area of ​​the hollow portion of the communicating pipe 4 can be determined appropriately. For example, 2 More than 35000mm 2 The cross-sectional area of ​​the hollow portion of the communicating pipe 4 is preferably set to, for example, 0.6 to 1.2 times, more preferably 0.8 to 1.1 times, and even more preferably 1.0 times, the cross-sectional area of ​​the hollow portion of the first pipe 2. In other words, it is preferable that the hollow portions of the first pipe 2, the second pipe 3, and the communicating pipe 4 are set to have the same cross-sectional area.

[0022] The communicating pipe 4 may be formed, for example, by a hose made of an elastic material such as rubber or resin. The weight 30 and second pipe 3 move when leveling the foundation mound M of the water bottom SB. Therefore, the portion of the communicating pipe 4 extending above the water body is formed by a flexible pipe such as a hose made of an elastic material so that it can follow the movement of the weight 30 and second pipe 3. The portion of the communicating pipe 4 extending above the ship 20 may be formed by a rigid pipe such as a metal pipe, but preferably the entire length of the communicating pipe 4 is formed by a hose made of an elastic material.

[0023] It is preferable that the communicating pipe 4 be a hose whose internal cross-sectional area changes little when bent, in other words, a hose that does not easily collapse when bent. Specifically, it is preferable to use a hose for the communicating pipe 4 that is equipped with a metal or resin spring to prevent collapse.

[0024] In this embodiment, the middle portion of the communicating pipe 4 and the middle portion of the cable 10 are bundled together with a binder 11. The binders 11 are provided at multiple locations along the length of the communicating pipe 4 and the cable 10, and the middle portion of the cable 10 is aligned with the middle portion of the communicating pipe 4. In addition, the middle portion of the communicating pipe 4 in the longitudinal direction, located above the water body, is suspended by a suspending member 12 suspended from the middle of the boom 22 of the crane 21. The suspending member 12 is formed, for example, of a string-like member or a cord-like member. In this embodiment, the lower end of the suspending member 12 is connected to a single binder 11 located above the water body, and the middle portion of the communicating pipe 4 and the cable 10 in the longitudinal direction are suspended by the suspending member 12. If the binder 11 is not provided, the lower end of the suspending member 12 can be connected directly to the communicating pipe 4 or the cable 10.

[0025] In this embodiment, a damper 13 that damps vibrations of the hanging member 12 is provided as part of the hanging member 12. The damper 13 is provided on the upper part of the hanging member 12, and the upper end of the damper 13 is rotatably connected to a position midway on the boom 22 of the crane 21. For example, the damper 13 may be provided on the lower part of the hanging member 12, and the lower end of the damper 13 may be connected to the binder 11, or the lower end of the damper 13 may be directly connected to the communicating pipe 4 or the cable 10. For example, the damper 13 may be provided midway on the hanging member 12. The communicating pipe 4 and the midway portions of the cable 10 located above the water area near the second tubular body 3 should be suspended above the water area by the hanging member 12 with some slack.

[0026] 2, the portions of the communicating pipe 4 and the cable 10 that extend onto the ship 20 may be extended to positions that avoid the crane 21 and fixed to the upper deck of the ship 20. In this embodiment, the binding devices 11 arranged on the ship 20 are each fixed to the upper deck.

[0027] 3, liquid L is stored inside the first pipe 2 and the second pipe 3, and the liquid L is filled in the communicating pipe 4. The liquid level position LP inside the first pipe 2 is set to a position lower than the upper end 2a inside the first pipe 2, and the liquid level position LP inside the second pipe 3 is set to a position lower than the upper end 3a inside the second pipe 3. In other words, the liquid L is stored inside the first pipe 2 and the second pipe 3 up to a midpoint in the vertical direction.

[0028] An air vent (through hole) is provided at the top of the first pipe 2 and the top of the second pipe 3, and air is filled in the upper part of the interior of the first pipe 2 and the upper part of the interior of the second pipe 3. The internal pressure at the top of the first pipe 2 and the internal pressure at the top of the second pipe 3 are roughly the same as the atmospheric pressure at the construction site. Because the first pipe 2 and the second pipe 3 are connected by the communicating pipe 4, even if the relative height positions of the first pipe 2 and the second pipe 3 change, the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 will be the same height, like a water mound.

[0029] As the liquid L, for example, fresh water (pure water) or seawater may be used. For example, a liquid L having a higher specific gravity than fresh water (pure water) (for example, salt water with a high salt concentration or dichloromethane) may also be used. As the liquid L, for example, an antifreeze liquid that prevents freezing may also be used. As the liquid L, for example, a solution in which antifreeze liquid is mixed with fresh water may also be used.

[0030] The first liquid level position measuring sensor 5 measures the liquid level position LP inside the first pipe 2, and the second liquid level position measuring sensor 6 measures the liquid level position LP inside the second pipe 3. The first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 can be configured with known liquid level measuring sensors (level sensors). In this embodiment, a float-type first liquid level position measuring sensor 5 and a float-type second liquid level position measuring sensor 6 are used.

[0031] 3, the float-type first liquid level position measuring sensor 5 is configured to include a float 5a that floats on the liquid surface inside the first tubular body 2, and a rod 5b that extends vertically from the upper end 2a to the lower end inside the first tubular body 2. The float 5a is loosely fitted into the rod 5b, and is configured to move vertically along the rod 5b. The first liquid level position measuring sensor 5 measures the liquid level position LP inside the first tubular body 2 by sensing the height position of the float 5a floating on the liquid surface. The first liquid level position measuring sensor 5 of this embodiment has a measurement reference position (origin) at the upper end 2a inside the first tubular body 2, and is configured to measure the vertical separation distance Y1 from the measurement reference position (upper end 2a) to the liquid level position LP.

[0032] The float-type second liquid level position measuring sensor 6 is configured to have a float 6a and a rod 6b, similar to the first liquid level position measuring sensor 5. The second liquid level position measuring sensor 6 of this embodiment has a measurement reference position (origin) at the upper end 3a inside the second tubular body 3, and is configured to measure the vertical separation distance Y2 from the measurement reference position (upper end 3a) to the liquid level position LP.

[0033] Measurements by the first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 are performed sequentially, and the measurement data of the liquid level position LP inside the first pipe 2 measured by the first liquid level position measuring sensor 5 and the measurement data of the liquid level position LP inside the second pipe 3 measured by the second liquid level position measuring sensor 6 are each sequentially input to the arithmetic unit 8. In this embodiment, the first liquid level position measuring sensor 5 and the arithmetic unit 8 are connected by a cable 10, and the measurement data of the first liquid level position measuring sensor 5 is transmitted to the arithmetic unit 8 via the cable 10 by wired communication. Similarly, the second liquid level position measuring sensor 6 and the arithmetic unit 8 are connected by a cable 10, and the measurement data of the second liquid level position measuring sensor 6 is transmitted to the arithmetic unit 8 via the cable 10 by wired communication.

[0034] In addition, in this embodiment, power is supplied from the computing device 8 to each of the first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 via the cable 10. In this embodiment, an example is shown in which the cable 10 has both a communication function and a power supply function, but for example, the cable 10 for communication and the cable 10 for power supply may be provided separately.

[0035] The method of transmitting measurement data from the first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 to the computing device 8 is not limited to wired communication using the cable 10, but can also be wireless communication. Furthermore, the method of supplying power to the first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 is not limited to the method of supplying power from the computing device 8 via the cable 10, but can also be a configuration in which power is supplied to the first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 via the cable 10 from a power generator or battery provided on the ship 20 separately from the computing device 8. For example, the first liquid level position measuring sensor 5 and the second liquid level position measuring sensor 6 can each be equipped with a battery.

[0036] The positioning means 7 is configured to sequentially acquire position coordinate data of a predetermined position of the ship 20 and sequentially input the acquired position coordinate data to the calculation device 8. The predetermined position of the ship 20 from which the positioning means 7 acquires position coordinate data can be determined as appropriate. In this embodiment, the positioning means 7 uses a positioning device (GNSS receiver) that receives absolute position coordinate data from a global positioning system (GPS). When using a positioning device as the positioning means 7, if the positioning device is placed near the crane 21, radio waves from the GPS may be blocked by the crane 21, making it difficult to receive absolute position coordinate data. Therefore, it is recommended to determine in advance an area with good reception where reception of absolute position coordinate data by the positioning device is not obstructed even when the boom 22 of the crane 21 moves, and to place the positioning device in that area with good reception. In this embodiment, the positioning device is installed as the positioning means 7 on the first liquid level position measurement sensor 5, which is located away from the crane 21. For example, it is recommended to place the positioning device at a distance of 3 m or more from the movable range of the boom 22 of the crane 21. The installation location of the positioning device is not particularly limited as long as it is a location on the ship 20 where absolute position coordinate data can be received, and it can also be installed at another location on the ship 20.

[0037] The positioning means 7 is not limited to a positioning device, and can also be configured, for example, with an automatic tracking total station and an optical prism. In this case, the optical prism is installed at a predetermined position on the ship 20, and the automatic tracking total station is placed on land or a floating structure away from the ship 20. The automatic tracking total station then emits light toward the optical prism, and the light reflected by the optical prism and returned is analyzed by the automatic tracking total station to obtain position coordinate data of the predetermined position of the ship 20. However, since the maximum distance that can be measured by an automatic tracking total station is about 1 km, it is preferable to use a positioning device as the positioning means 7 when the construction water area is far from land. The positioning means 7 may be configured to obtain position coordinate data of the predetermined position of the ship 20, and various other means may be used.

[0038] Furthermore, in this embodiment, a positioning device (GNSS receiver) is installed at the tip 22a of the boom 22 of the crane 21 as the second positioning means 14 for acquiring horizontal position coordinate data of the weight 30. The second positioning means 14 is configured to sequentially acquire horizontal position coordinate data of the weight 30 and sequentially input the acquired position coordinate data to the calculation device 8. The second positioning means 14 may be configured to acquire horizontal position coordinate data of the weight 30, and various other means may be used. The method for transmitting the position coordinate data from the positioning means 7 and the second positioning means 14 to the calculation device 8 is not particularly limited, and may be configured to transmit the data via wired communication or wireless communication.

[0039] A computer or the like is used as the arithmetic device 8. In this embodiment, the arithmetic device 8 is placed on the ship 20, but the placement of the arithmetic device 8 is not particularly limited. Although the example shows a case where the arithmetic device 8 and a separate monitor 9 are connected to each other so as to be able to communicate with each other, it is also possible to use, for example, a notebook-type personal computer in which the arithmetic device 8 and the monitor 9 are integrated.

[0040] The calculation device 8 is configured to calculate the height position of the desired management target position P3 of the weight 30 based on the position coordinate data input from the positioning means 7, the measurement data of the liquid level position LP inside the first tubular body 2 input from the first liquid level position measuring sensor 5, and the measurement data of the liquid level position LP inside the second tubular body 3 input from the second liquid level position measuring sensor 6. The specific calculation process performed by the calculation device 8 will be described later.

[0041] Next, a method for determining the height position of the weight 30 using the height position determination system 1 will be described.

[0042] As illustrated in Figures 1 to 3, when leveling work for a foundation mound M of the water bottom SB is carried out using a weight 30 suspended by a crane 21 mounted on a ship 20, as a preliminary preparation, a first pipe body 2 extending in the vertical direction is installed on the ship 20, and a second pipe body 3 extending in the vertical direction is fixed to the weight 30. Then, the first pipe body 2 (first through hole 2b) and the second pipe body 3 (second through hole 3b) are connected by a communicating pipe 4, and liquid L is stored inside the first pipe body 2 and the second pipe body 3, and the communicating pipe 4 is filled with liquid L.

[0043] A first liquid level position measuring sensor 5 is provided in the first pipe 2, and a second liquid level position measuring sensor 6 is provided in the second pipe 3. A positioning means 7, a computing device 8, and a monitor 9 are arranged on the ship 20, and the positioning means 7, the first liquid level position measuring sensor 5, and the second liquid level position measuring sensor 6 are each connected to the computing device 8 so as to be able to communicate with each other.

[0044] In this embodiment, the first liquid level position measuring sensor 5 and the computing device 8 are connected by a cable 10, and the second liquid level position measuring sensor 6 and the computing device 8 are connected by another cable 10. A midpoint of the cable 10 connected to the second liquid level position measuring sensor 6 and a midpoint of the communicating pipe 4 are bundled with a binder 11. Then, a suspending member 12 suspended from a midpoint of the boom 22 of a crane 21 holds the midpoint of the communicating pipe 4 in the longitudinal direction, located above the water area.

[0045] In this embodiment, the upper end of a hanging member 12 having a damper 13 is connected to a midpoint of the boom 22 of the crane 21, and a binding device 11 is connected to the lower end of the hanging member 12 at one location located above the water body. The communicating pipe 4 and the midpoint of the cable 10 located above the water body near the second tubular body 3 are left in a state of some slack. A second positioning means 14 is installed at the tip 22a of the boom 22 of the crane 21 as a means for determining the horizontal coordinate position of the weight 30.

[0046] In the advance preparation, a ship-side reference position P1 serving as a reference for the position of the ship 20 is set in advance, and a weight-side reference position P2 serving as a reference for the position of the weight 30 is set in advance. Furthermore, a desired management position P3 of the weight 30 is set, which manages the height position when the weight 30 is used to level the foundation mound M of the water bottom SB. As illustrated in FIG. 3 , in this embodiment, the ship-side reference position P1 is set to the measurement reference position of the first liquid level position measurement sensor 5 (the upper end 2a inside the first tubular body 2). The weight-side reference position P2 is set to a midpoint of the weight 30, which is located at the same height as the measurement reference position of the second liquid level position measurement sensor 6 (the upper end 3a inside the second tubular body 3). The management position P3 is set to the lower end of the weight 30 (the press section 32). The ship-side reference position P1 is not particularly limited as long as it is on the ship 20 (a position that moves following the ship 20), and can be set to any position on the ship 20. The weight-side reference position P2 and the management target position P3 are not particularly limited as long as they are on the weight 30 (positions that move following the weight 30), and can be set at any positions on the weight 30. The weight-side reference position P2 and the management target position P3 can also be set at the same position.

[0047] Then, the relative positional relationship between the set ship-side reference position P1 and a predetermined position (positioning position) of the ship 20 where position coordinate data is acquired by the positioning means 7 is determined in advance. The relative positional relationship in the up-down direction (height) between the set ship-side reference position P1 and the measurement reference position of the first liquid level position measuring sensor 5 (in this embodiment, the upper end 2a inside the first tubular body 2) is also determined in advance. The relative positional relationship in the up-down direction (height) between the set weight-side reference position P2 and the measurement reference position of the second liquid level position measuring sensor 6 (in this embodiment, the upper end 3a inside the second tubular body 3) is also determined in advance. If the weight-side reference position P2 and the management target position P3 are set in different positions, the relative positional relationship in the up-down direction (height) between the weight-side reference position P2 and the management target position P3 is also determined in advance. The data of the respective relative positional relationships described above is then input to and stored in the calculation device 8. This completes the advance preparations.

[0048] Next, a method for determining the height position of the weight 30 when using the weight 30 to level the water bottom SB (foundation mound M) will be specifically described. Figures 1 to 3 show an example of a state in which the weight 30 is placed on the top surface of the foundation mound M of the water bottom SB. As shown in Figure 3, the first pipe 2 and the second pipe 3 are connected by the communicating pipe 4, so that the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 are at the same height, regardless of the relative positional relationship between the first pipe 2 and the second pipe 3.

[0049] The position coordinate data acquired by the positioning means 7, the measurement data of the liquid level position LP inside the first pipe 2 acquired by the first liquid level position measuring sensor 5, and the measurement data of the liquid level position LP inside the second pipe 3 acquired by the second liquid level position measuring sensor 6 are each input to the calculation device 8. Specifically, the position coordinate data input from the positioning means 7 in this embodiment is absolute position coordinate data of a predetermined position of the ship 20 received by the positioning means 7 (positioning device). The measurement data input from the first liquid level position measuring sensor 5 is a measurement value of the vertical separation distance Y1 from the measurement reference position (upper end 2 a) of the first liquid level position measuring sensor 5 to the liquid level position LP inside the first pipe 2. The measurement data input from the second liquid level position measuring sensor 6 is a measurement value of the vertical separation distance Y2 from the measurement reference position (upper end 3 a) of the second liquid level position measuring sensor 6 to the liquid level position LP inside the second pipe 3.

[0050] 3, the arithmetic device 8 calculates the height coordinate H1 of a ship-side reference position P1 that is set in advance for the ship 20 based on the position coordinate data input from the positioning means 7. The arithmetic device 8 stores in advance data on the relative positional relationship between the ship-side reference position P1 and a predetermined position on the ship 20 from which the positioning means 7 acquires position coordinate data, and therefore the arithmetic device 8 can calculate the height coordinate H1 of the ship-side reference position P1 from the position coordinate data input from the positioning means 7.

[0051] The calculation device 8 further calculates a first vertical separation distance D1 between the ship-side reference position P1 and the liquid level position LP inside the first pipe 2, based on the measurement data of the liquid level position LP inside the first pipe 2 input from the first liquid level position measurement sensor 5. In this embodiment, the ship-side reference position P1 is set at the same height as the measurement reference position (upper end 2a) of the first liquid level position measurement sensor 5, so the vertical separation distance Y1 from the measurement reference position (upper end 2a) of the first liquid level position measurement sensor 5 to the liquid level position LP inside the first pipe 2 becomes the first vertical separation distance D1 between the ship-side reference position P1 and the liquid level position LP inside the first pipe 2.

[0052] The computing device 8 further calculates a second vertical separation distance D2 between the weight-side reference position P2 and the liquid level position LP inside the second tubular body 3, based on the measurement data of the liquid level position LP inside the second tubular body 3 input from the second liquid level position measuring sensor 6. In this embodiment, the weight-side reference position P2 is set at the same height as the measurement reference position (upper end 3 a) of the second liquid level position measuring sensor 6, so the vertical separation distance Y2 from the measurement reference position (upper end 3 a) of the second liquid level position measuring sensor 6 to the liquid level position LP inside the second tubular body 3 becomes the second vertical separation distance D2 between the weight-side reference position P2 and the liquid level position LP inside the second tubular body 3.

[0053] Next, the calculation device 8 calculates the height coordinate H2 of the weight side reference position P2 based on the calculated height coordinate H1 of the ship side reference position P1, the first vertical separation distance D1 between the ship side reference position P1 and the liquid level position LP inside the first tubular body 2, and the second vertical separation distance D2 between the weight side reference position P2 and the liquid level position LP inside the second tubular body 3.

[0054] 3, the liquid level position LP inside the first tubular body 2 and the liquid level position LP inside the second tubular body 3 are at the same height. Therefore, a third separation distance D3 in the vertical direction between the height coordinate H1 of the ship-side reference position P1 and the height coordinate H2 of the weight-side reference position P2 can be calculated as the difference between the first separation distance D1 in the vertical direction from the ship-side reference position P1 to the liquid level position LP inside the first tubular body 2 and the second separation distance D2 in the vertical direction from the weight-side reference position P2 to the liquid level position LP inside the second tubular body 3. The calculation formula is the following formula (1). D3 = D1 - D2 (1)

[0055] The height coordinate H2 of the weight-side reference position P2 can be calculated as the difference between the height coordinate H1 of the ship-side reference position P1 and the third separation distance D3. The calculation formula is the following equation (2). As shown in the example of Figure 3, when the height coordinate H2 of the weight-side reference position P2 is lower than the height coordinate H1 of the ship-side reference position P1, the third separation distance D3 is a positive value. H2 = H1 - D3 (2)

[0056] Substituting D3 on the right side of the above equation (2) with the equation on the right side of equation (1) gives the following equation (3): The calculation device 8 calculates the height coordinate H2 of the weight-side reference position P2 by substituting the height coordinate H1 of the ship-side reference position P1, the first separation distance D1, and the second separation distance D2 into the following equation (3). H2 = H1 - (D1 - D2) (3)

[0057] The computing device 8 performs calculations by substituting a positive value for the value of the first separation distance D1 in the above equation (3) when the liquid level position LP inside the first tubular body 2 is located below the ship-side reference position P1, and substituting a negative value for the value of the liquid level position LP inside the first tubular body 2 is located above the ship-side reference position P1. The computing device 8 performs calculations by substituting a positive value for the value of the second separation distance D2 in the above equation (3) when the liquid level position LP inside the second tubular body 3 is located below the weight-side reference position P2, and substituting a negative value for the value of the second separation distance D2 when the liquid level position LP inside the second tubular body 3 is located above the weight-side reference position P2.

[0058] In this embodiment, the ship-side reference position P1 is set to the measurement reference position (upper end 2a) of the first liquid level position measuring sensor 5, so the liquid level position LP inside the first tubular body 2 is always located below the ship-side reference position P1. Therefore, the value of the first separation distance D1 in the above equation (3) is substituted as a positive value. Furthermore, the weight-side reference position P2 is set to the measurement reference position (upper end 3a) of the second liquid level position measuring sensor 6, so the liquid level position LP inside the second tubular body 3 is always located below the weight-side reference position P2. Therefore, the value of the second separation distance D2 in the above equation (3) is substituted as a positive value.

[0059] Thereafter, the calculation device 8 calculates the height position of the desired management target position P3 of the weight 30 based on the calculated height coordinate H2 of the weight-side reference position P2. The calculation device 8 pre-stores data on the relative positional relationship in the up-down direction (height) between the weight-side reference position P2 and the management target position P3, so the calculation device 8 can calculate the height coordinate of the management target position P3 from the calculated height coordinate H2 of the weight-side reference position P2. In this embodiment, the height coordinate of the lower end of the weight 30 (press section 32) is calculated as the height coordinate of the management target position P3.

[0060] The height coordinate data of the managed position P3 calculated by the calculation device 8 is output to the monitor 9, and the height coordinate of the managed position P3 is displayed on the monitor 9. The manager of the leveling work can ascertain the height position of the weight 30 from the height coordinate of the managed position P3. In this embodiment, the absolute position coordinate data input to the calculation device 8 from the second positioning device 14 is further input to the monitor 9, and the horizontal coordinate position of the weight 30 is displayed on the monitor 9. Therefore, the manager of the leveling work can ascertain the three-dimensional coordinate position of the weight 30 by looking at the monitor 9.

[0061] When the weight 30 is resting on the foundation mound M, the height coordinate of the lower end of the weight 30 becomes the height coordinate of the foundation mound M. Therefore, when the management target position P3 is set to the lower end of the weight 30 as in this embodiment, the height of the foundation mound M can be determined by determining the height coordinate of the management target position P3 when the weight 30 is resting on the foundation mound M. Note that even when the management target position P3 is set at a position different from the lower end of the weight 30, it is possible to determine the height of the foundation mound M by determining in advance the relative positional relationship in the up-down direction between the management target position P3 and the lower end of the weight 30.

[0062] 4 and 5 show an example of a state in which the weight mass 30 is lifted by the crane 21 to a position higher than the upper surface of the foundation mound M. As shown in the examples of FIGS. 4 and 5, in the work of leveling the foundation mound M with the weight mass 30, the weight mass 30 is lifted approximately 300 mm to 2000 mm above the upper surface of the foundation mound M, and then dropped from the lifted position to compact the foundation mound M. In the work of leveling the foundation mound M, the crane 21 repeatedly lifts and drops the weight mass 30 while changing the horizontal position of the weight mass 30, thereby adjusting the height position of the upper surface of the foundation mound M to a pre-planned design height.

[0063] 4 and 5, when the weight 30 is being lifted above the foundation mound M, the calculation device 8 similarly calculates the height position of the desired management target position P3 of the weight 30 based on the position coordinate data input from the positioning means 7, the measurement data of the liquid level position LP inside the first pipe body 2 input from the first liquid level position measuring sensor 5, and the measurement data of the liquid level position LP inside the second pipe body 3 input from the second liquid level position measuring sensor 6. The calculation process by the calculation device 8 is the same as the calculation process when the weight 30 is set to the bottom of the foundation mound M. As shown in FIG. 5, when the height coordinate H2 of the weight-side reference position P2 is lower than the height coordinate H1 of the ship-side reference position P1, the value (D1-D2) in parentheses on the right side of the above equation (3) is a negative value.

[0064] When the management target position P3 is set at the lower end of the weight 30 as in this embodiment, the lifting height of the weight 30 relative to the foundation mound M can be determined and adjusted by comparing the height coordinate of the management target position P3 when the weight 30 is set down on the foundation mound M with the height coordinate of the management target position P3 when the weight 30 is lifted above the foundation mound M. Note that even when the management target position P3 is set at a position different from the lower end of the weight 30, it is possible to determine and adjust the lifting height of the weight 30 relative to the foundation mound M by determining in advance the relative positional relationship in the up-down direction between the management target position P3 and the lower end of the weight 30.

[0065] As described above, according to the height position determining system 1 and height position determining method for the weight 30, when the position coordinate data of a predetermined position of the ship 20 on which the crane 21 is mounted, acquired by the positioning means 7, the measurement data of the liquid level position LP inside the first tubular body 2 installed on the ship 20, acquired by the first liquid level position measuring sensor 5, and the measurement data of the liquid level position LP inside the second tubular body 3 fixed to the weight 30, acquired by the second liquid level position measuring sensor 6, are input to the computing device 8, the computing device 8 calculates the height coordinate H2 of the weight-side reference position P2 that is preset for the weight 30. Then, the height position of the desired management position P3 of the weight 30 is calculated based on the calculated height coordinate H2 of the weight-side reference position P2. Therefore, the height position of the weight 30 can be easily and accurately determined during leveling work of the water bottom SB (foundation mound M) using the weight 30 suspended by the crane 21 mounted on the ship 20.

[0066] While the weight 30 is being dropped from above the water bottom SB (foundation mound M), the relative height positions of the first pipe 2 and the second pipe 3 change, causing the liquid L to move between the first pipe 2 and the second pipe 3 through the communicating pipe 4. Therefore, while the weight 30 is being dropped, there are moments when the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 temporarily differ from each other, but within several seconds at the latest after the weight 30 hits the water bottom SB, the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 reach an equilibrium state at the same height.

[0067] Also, when lifting the weight 30 above the water bottom SB, there are moments when the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 are temporarily out of sync while the weight 30 is being moved upward, but within a few seconds at the latest after the weight 30 has come to rest above the water bottom SB, the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 will be at the same height and in equilibrium.

[0068] In the work of leveling the water bottom SB using the weight 30, it is only necessary to know the height position of the managed position P3 when the weight 30 is set down on the water bottom SB, and the height position of the managed position P3 when the weight 30 is hoisted above the water bottom SB, so this weight 30 height position determining system 1 and height position determining method can be effectively used in the work of leveling the water bottom SB. For example, in the initial stages of starting to level the foundation mound M, there may be unevenness from the rubble that has been thrown in, so the weight 30 may tilt when it is set down on the foundation mound M. In that case, however, the weight 30 can be slightly lifted up until it stands upright from its tilted state, and the height position of the managed position P3 of the weight 30 when it is upright can be determined, thereby determining the height position of the foundation mound M.

[0069] With this height position determination system 1, once advance preparation is performed, the height position of the weight 30 can be continuously determined even when the planar position of the weight 30 is changed. This is therefore advantageous in improving the work efficiency of leveling the water bottom SB using the weight 30. Even when an automatic tracking total station and an optical prism are used as the positioning means 7, the optical prism is installed on the ship 20, so when the planar position of the weight 30 is changed without moving the ship 20, there is no need to readjust the light irradiation direction of the automatic tracking total station, and the height position of the weight 30 can be continuously determined.

[0070] Furthermore, since the weight 30 vibrates violently when it hits the water bottom SB, installing a positioning device (GNNS receiver) on the weight 30 increases the risk of failure or malfunction. However, the second liquid level position measurement sensor 6 (a known liquid level measurement sensor) installed on the weight 30 in this height position determination system 1 is designed to be relatively resistant to vibration and impact. In particular, the known float-type liquid level measurement sensor used as the second liquid level position measurement sensor 6 in this embodiment is designed to withstand extremely strong vibrations of around 100 G, and has a low risk of malfunctioning even in environments with high vibrations. Therefore, the risk of failure or malfunction of each device constituting this height position determination system 1 is extremely low, and the height position of the managed position P3 of the weight 30 can be determined with high accuracy.

[0071] Furthermore, this height position determination system 1 has a relatively simple configuration and requires relatively low installation costs. Furthermore, this height position determination system 1 can be easily applied to an existing ship 20 equipped with a crane 21, and does not require any special electronic equipment or sensors. Therefore, it is very useful for those skilled in the art.

[0072] As in this embodiment, by setting the ship-side reference position P1 at the same height as the measurement reference position of the first liquid level position measurement sensor 5 and the weight-side reference position P2 at the same height as the measurement reference position of the second liquid level position measurement sensor 6, the amount of calculation by the calculation device 8 can be reduced, which is advantageous for calculating the height position of the managed position P3 of the weight 30 in a short period of time.

[0073] Setting the cross-sectional area of ​​the hollow portion of the first tube 2 to be, for example, 0.8 to 1.2 times, more preferably 0.9 to 1.1 times, and even more preferably 1.0 times, the cross-sectional area of ​​the hollow portion of the second tube 3 reduces the difference between the cross-sectional areas of the hollow portions of the first tube 2 and the second tube 3, which is advantageous in shortening the time required for the liquid level position LP inside the first tube 2 and the liquid level position LP inside the second tube 3 to equilibrate and reach the same height after a change in the relative height positions of the first tube 2 and the second tube 3. Accordingly, this is advantageous in calculating the height position of the management target position P3 of the weight 30 in a short time.

[0074] Furthermore, setting the cross-sectional area of ​​the hollow portion of the communicating tube 4 to, for example, 0.6 to 1.2 times, more preferably 0.8 to 1.1 times, and even more preferably 1.0 times, the cross-sectional area of ​​the hollow portion of the first tube 2 reduces the difference between the cross-sectional areas of the hollow portions of the first tube 2 and the second tube 3 and the cross-sectional area of ​​the hollow portion of the communicating tube 4. This makes it easier for the liquid L to move smoothly between the first tube 2 and the second tube 3 through the communicating tube 4 when the relative height positions of the first tube 2 and the second tube 3 change. This is therefore advantageous for shortening the time required for the liquid level position LP inside the first tube 2 and the liquid level position LP inside the second tube 3 to reach the same height and equilibrate after the relative height positions of the first tube 2 and the second tube 3 change. This is therefore more advantageous for calculating the height position of the management target position P3 of the weight 30 in a short time.

[0075] As the weight 30 moves, the degree of slack in the communicating pipe 4 extending between the first pipe 2 and the second pipe 3 and the direction in which the communicating pipe 4 bends change. However, if at least a portion of the communicating pipe 4 is formed from a hose made of an elastic material, the risk of the communicating pipe 4 collapsing and the cross-sectional area of ​​the hollow portion of the communicating pipe 4 becoming smaller can be reduced even if the degree of slack in the communicating pipe 4 and the direction in which the communicating pipe 4 bends change. This is advantageous for shortening the time required for the liquid level position LP inside the first pipe 2 and the liquid level position LP inside the second pipe 3 to equilibrate and reach the same height after the relative height positions of the first pipe 2 and the second pipe 3 change. Accordingly, this is advantageous for quickly calculating the height of the managed position P3 of the weight 30.

[0076] In particular, constructing the portion of the communicating pipe 4 located above the water area, where the degree of slackness and the direction in which the communicating pipe 4 bends are likely to change, with a hose made of an elastic material is advantageous in reducing the risk of the communicating pipe 4 collapsing and reducing the cross-sectional area of ​​the hollow portion of the communicating pipe 4. If the communicating pipe 4 is constructed with a hose equipped with a metal or resin spring that prevents collapse, it is advantageous in further reducing the risk of the communicating pipe 4 collapsing and reducing the cross-sectional area of ​​the hollow portion of the communicating pipe 4.

[0077] The communicating pipe 4 can have a double-pipe structure, for example, consisting of an inner pipe through which the liquid L flows and a protective pipe that covers the outside of the inner pipe. In this case, the inner pipe may be formed, for example, from a hose made of an elastic material, and the protective pipe may be formed from a corrugated pipe body made of a hard resin such as a corrugated hard polyethylene pipe. When the communicating pipe 4 has a double-pipe structure, the protective pipe prevents the inner pipe from being crushed, which is more advantageous in reducing the risk of the cross-sectional area of ​​the hollow portion of the communicating pipe 4 (inner pipe) becoming smaller.

[0078] When the hoisting member 12 suspended from the midpoint of the boom 22 of the crane 21 suspends the midpoint of the longitudinal portion of the communicating pipe 4 located above the water area, the midpoint of the communicating pipe 4 located above the water area is stably held even when the weight 30 moves, effectively preventing the communicating pipe 4 located above the water area from moving wildly. This is also advantageous in reducing the risk of the communicating pipe 4 coming into contact with the bow of the ship 20 and being damaged, or the risk of the communicating pipe 4 being crushed and reducing the cross-sectional area of ​​its hollow portion. Furthermore, even when the crane 21 is rotated to change the planar position of the weight 30 as shown by the arrow in FIG. 2 , the portion of the communicating pipe 4 located above the water area moves following the boom 22 of the crane 21, preventing significant changes in the degree of slack in the communicating pipe 4 located above the water area. This is therefore more advantageous in reducing the risk of the communicating pipe 4 being crushed and reducing the cross-sectional area of ​​its hollow portion.

[0079] Furthermore, as in this embodiment, providing the damper 13 on the hanging member 12 can attenuate the shaking and vibration of the communicating pipe 4 when the weight 30 moves, which is even more advantageous in reducing the risk of the communicating pipe 4 collapsing and reducing the cross-sectional area of ​​the inner hollow portion of the communicating pipe 4. For example, a hanger-shaped holder can be provided at the lower end of the hanging member 12 to support the communicating pipe 4 while preventing it from bending.

[0080] As in this embodiment, by installing a positioning device (GNSS receiver) at a predetermined position on the ship 20 as the positioning means 7 and using the positioning device to receive absolute position coordinate data as position coordinate data, the positioning means 7 can be configured very simply, and the effort and time required to set up the positioning means 7 can be reduced. Using a positioning device as the positioning means 7 eliminates the need to adjust the positioning means 7 when moving the ship 20, and the height position of the weight 30 can be continuously determined. This is therefore more advantageous in improving the work efficiency of leveling the water bottom SB using the weight 30.

[0081] If an area with good reception where reception of absolute position coordinate data by the positioning device is not hindered even when the boom 22 of the crane 21 moves is identified in advance and the positioning device is placed in that area with good reception, the risk of the positioning device losing reception of absolute position coordinate data during work to level the water bottom SB is reduced, which is advantageous for continuously determining the height position of the weight 30. This is therefore more advantageous for improving the work efficiency of work to level the water bottom SB using the weight 30.

[0082] As in another embodiment illustrated in Figure 6, in this height position detection system 1 and height position detection method, the ship-side reference position P1 can be set at a height position different from the measurement reference position of the first liquid level position measurement sensor 5 (the upper end 2a inside the first tubular body 2). Also, the weight-side reference position P2 can be set at a height position different from the measurement reference position of the second liquid level position measurement sensor 6 (the upper end 3a inside the second tubular body 3). In this embodiment, well-known ultrasonic liquid level measurement sensors are used as the first liquid level position measurement sensor 5 and the second liquid level position measurement sensor 6. The other configurations of the height position detection system 1 are the same as those of the embodiment illustrated in Figures 1 to 5 described above.

[0083] As illustrated in FIG. 6 , in this embodiment, the ship-side reference position P1 is set to a position higher than the measurement reference position (upper end 2 a) of the first liquid level position measurement sensor 5. Specifically, the ship-side reference position P1 is set to a predetermined position on the ship 20 where absolute position coordinate data is acquired by the positioning means 7 (positioning device). Also, in this embodiment, the weight-side reference position P2 is set to a position lower than the measurement reference position (upper end 3 a) of the second liquid level position measurement sensor 6. Even when the ship-side reference position P1 is set to a height position different from the measurement reference position (upper end 2 a) of the first liquid level position measurement sensor 5 and the weight-side reference position P2 is set to a height position different from the measurement reference position (upper end 3 a) of the second liquid level position measurement sensor 6, the calculation device 8 calculates the height coordinate H2 of the weight-side reference position P2 using the same calculation method as in the embodiment illustrated in FIGS. 1 to 5 described above, and calculates the height position of the managed position P3 of the weight 30 based on the calculated height coordinate H2 of the weight-side reference position P2.

[0084] However, in this embodiment, the calculation device 8 calculates the first vertical separation distance D1 between the ship's reference position P1 and the liquid level position LP inside the first pipe 2 based on the vertical separation distance Y3 between the measurement reference position (upper end 2a) of the first liquid level position measuring sensor 5 and the ship's reference position P1, which is known in advance, and the measurement data of the liquid level position LP inside the first pipe 2 input from the first liquid level position measuring sensor 5 (the measurement value of the vertical separation distance Y1 from the measurement reference position of the first liquid level position measuring sensor 5 to the liquid level position LP inside the first pipe 2).

[0085] As described above, the calculation device 8 substitutes a positive value for the value of the first separation distance D1 in the above equation (3) when the liquid level position LP inside the first tubular body 2 is located below the ship-side reference position P1, and substitutes a negative value when it is located above the ship-side reference position P1. In the situation illustrated in Fig. 6, the liquid level position LP inside the first tubular body 2 is located below the ship-side reference position P1, so the calculation device 8 substitutes a positive value for the value of the first separation distance D1 in the above equation (3).

[0086] Whether the liquid level position LP inside the first tubular body 2 is located below or above the ship's reference position P1 can be determined from the vertical positional relationship between the ship's reference position P1, which is pre-stored in the calculation device 8, and the measurement reference position (upper end 2a) of the first liquid level position measuring sensor 5, and the vertical separation distance Y1 from the measurement reference position (upper end 2a) of the first liquid level position measuring sensor 5, which is input to the calculation device 8 from the first liquid level position measuring sensor 5, to the liquid level position LP inside the first tubular body 2.

[0087] In addition, the calculation device 8 of this embodiment calculates the second vertical separation distance D2 between the weight side reference position P2 and the liquid level position LP inside the second tubular body 3 based on the vertical separation distance Y4 between the measurement reference position (upper end 3a) of the second liquid level position measuring sensor 6 and the weight side reference position P2, which is known in advance, and the measurement data of the liquid level position LP inside the second tubular body 3 input from the second liquid level position measuring sensor 6 (the measurement value of the vertical separation distance Y2 from the measurement reference position of the second liquid level position measuring sensor 6 to the liquid level position LP inside the second tubular body 3).

[0088] As described above, the calculation device 8 substitutes a positive value for the value of the second separation distance D2 in the above equation (3) when the liquid level position LP inside the second tubular body 3 is located below the weight-side reference position P2, and substitutes a negative value when it is located above the weight-side reference position P2. In the situation illustrated in Fig. 6, the liquid level position LP inside the second tubular body 3 is located above the weight-side reference position P2, so the calculation device 8 substitutes a negative value for the value of the second separation distance D2 in the above equation (3).

[0089] Whether the liquid level position LP inside the second tubular body 3 is located below or above the weight side reference position P2 can be determined from the vertical positional relationship between the weight side reference position P2, which is pre-stored in the calculation device 8, and the measurement reference position (upper end 3a) of the second liquid level position measuring sensor 6, and the vertical separation distance Y2 from the measurement reference position (upper end 3a) of the second liquid level position measuring sensor 6, which is input to the calculation device 8 from the second liquid level position measuring sensor 6, to the liquid level position LP inside the second tubular body 3.

[0090] In this way, even when the height positions at which the ship-side reference position P1 and the weight-side reference position P2 are set are changed, the height position determining system 1 and height position determining method allow the calculation device 8 to calculate the height coordinate H2 of the weight-side reference position P2 using the same calculation method as in the embodiment illustrated in Figures 1 to 5, and to calculate the height position of the managed position P3 of the weight 30 based on the calculated height coordinate H2 of the weight-side reference position P2. Thus, the same effects as in the embodiment illustrated in Figures 1 to 5 can be achieved.

[0091] The well-known ultrasonic liquid level measurement sensors used as the first liquid level position measurement sensor 5 and the second liquid level position measurement sensor 6 in this embodiment are designed to withstand strong vibrations of about 6G, and the risk of malfunctioning even in environments with strong vibrations is relatively low. Therefore, even when using the ultrasonic first liquid level position measurement sensor 5 and the second liquid level position measurement sensor 6, the risk of failure or malfunction of the devices constituting the height position detection system 1 is low, and the height position of the management target position P3 of the weight 30 can be detected with high accuracy. Note that the first liquid level position measurement sensor 5 and the second liquid level position measurement sensor 6 are not limited to float type or ultrasonic type, and can be configured with various other well-known liquid level measurement sensors. [Explanation of symbols]

[0092] 1. Height position detection system (for weights) 2 First pipe body 2a (Top end of the first body) 2b First through hole 3 Second pipe body 3a (Top end of the second body) 3b Second through hole 4 Communication pipe 5. First liquid level measurement sensor 5a Float 5b Rod 6 Second liquid level measurement sensor 6a Float 6b Rod 7 Positioning Methods 8 Arithmetic unit 9 Monitors 10 Cable 11 Binding device 12 Hanging members 13 Damper 14 Secondary Positioning Method 20 ships 21 Crane 22 Boom 22a Boom tip 23 Hanging wire 30 weight 31 Support pipe section 32 Press Department L liquid LP liquid level position P1 Ship side reference position P2 Weight side reference position P3 Management location H1 Height position (at ship's reference position) H2 Height position (of the weight side reference position) D1 First separation distance (in the vertical direction between the ship's reference position and the liquid level inside the first pipe) D2 Second separation distance (vertical direction between the reference position on the weight side and the liquid level inside the second tube) D3 Third separation distance (vertical direction between the ship's reference position and the weight's reference position) Y1 (vertical distance between the measurement reference position of the first liquid level measurement sensor and the liquid level inside the first pipe) Y2 (vertical distance between the measurement reference position of the second liquid level measurement sensor and the liquid level inside the second pipe) Y3 (vertical distance between the measurement reference position of the first liquid level measurement sensor and the ship's reference position) Y4 (vertical distance between the measurement reference position of the second liquid level measurement sensor and the reference position of the weight side) SB underwater M Foundation mound

Claims

1. 1. A method for determining the height position of a weight suspended by a crane mounted on a ship during a water bottom leveling operation, the method comprising: a first pipe extending in a vertical direction is installed on the ship, a second pipe extending in a vertical direction is fixed to the weight, the first pipe and the second pipe are connected by a communicating pipe, a liquid is stored inside the first pipe and the second pipe, and the communicating pipe is filled with the liquid; a first separation distance in the vertical direction between the ship-side reference position and the liquid level position inside the first pipe based on measurement data of the liquid level position inside the first pipe obtained by a first liquid level position measuring sensor provided on the first pipe; a second separation distance in the vertical direction between a weight-side reference position preset for the weight and the liquid level position inside the second pipe based on measurement data of the liquid level position inside the second pipe obtained by a second liquid level position measuring sensor provided on the second pipe; a height coordinate of the weight-side reference position based on the calculated height coordinate of the ship-side reference position, the first separation distance, and the second separation distance; and a height coordinate of the managed position based on the calculated height coordinate of the weight-side reference position.

2. A method for determining the height position of a weight as described in claim 1, wherein the ship-side reference position is set at the same height position as the measurement reference position of the first liquid level position measurement sensor, and the weight-side reference position is set at the same height position as the measurement reference position of the second liquid level position measurement sensor.

3. 3. The method for determining the height position of a weight according to claim 1, wherein a positioning device is installed at a predetermined position of the ship as the positioning means, and absolute position coordinate data is received as the position coordinate data by the positioning device.

4. 4. The method for determining the height position of a weight according to claim 3, further comprising: determining in advance an area of ​​good reception in which reception of the absolute position coordinate data by the positioning device is not hindered even when the boom of the crane moves; and locating the positioning device in the area of ​​good reception.

5. A method for determining the height position of a weight as described in claim 1 or 2, in which a hanging member is hung from a midpoint of the boom of the crane to hang and hold the midpoint of the longitudinal direction of the connecting pipe located above the water area.

6. 3. A method for determining the height position of a weight according to claim 1, wherein at least a part of the communication pipe is constituted by a hose made of an elastic material.

7. 1. A weight height position detection system for detecting a height position of a desired management target position of a weight suspended by a crane mounted on a ship during a water bottom leveling operation using the weight, a first pipe body extending in a vertical direction and installed on the ship; a second pipe body extending in a vertical direction and fixed to the weight; a connecting pipe connecting the first pipe body and the second pipe body; a first liquid level position measuring sensor provided on the first pipe body; a second liquid level position measuring sensor provided on the second pipe body; positioning means for acquiring position coordinate data of a predetermined position of the ship; and a computing device communicably connected to the first liquid level position measuring sensor, the second liquid level position measuring sensor, and the positioning means, wherein liquid is stored inside the first pipe body and the second pipe body, and the connecting pipe is filled with the liquid, the position coordinate data acquired by the positioning means, the measurement data of the liquid level position inside the first pipe acquired by the first liquid level position measuring sensor, and the measurement data of the liquid level position inside the second pipe acquired by the second liquid level position measuring sensor are each input to the arithmetic device; the calculation device calculates the height coordinate of a ship-side reference position that is preset for the ship based on the input position coordinate data; calculates a first vertical separation distance between the ship-side reference position and the liquid level position inside the first pipe based on measurement data of the liquid level position inside the first pipe; calculates a second vertical separation distance between a weight-side reference position that is preset for the weight and the liquid level position inside the second pipe based on measurement data of the liquid level position inside the second pipe; calculates the height coordinate of the weight-side reference position based on the calculated height coordinate of the ship-side reference position, the first separation distance, and the second separation distance; and calculates the height position of the managed position based on the calculated height coordinate of the weight-side reference position.

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