Method and system for installing underwater structures

Abstract

This system enables the safe remote operation of installing underwater structures at target locations and in target orientations. [Solution] A method for installing an underwater structure 50 at a target position in a target orientation, comprising: attaching a long handle member 52 extending laterally to the underwater structure; a suspension step of suspending the underwater structure above the target position by a crane; a connection step of connecting a remotely operated underwater vehicle (ROV) 30 to the handle member; an adjustment step of adjusting the orientation of the underwater structure toward the target orientation by remotely operating and moving the ROV while the ROV is connected to the handle member; and a lowering step of lowering the underwater structure, whose orientation has been adjusted, to the height of the target position by the crane.

Description

Technical Field

[0001] The present invention relates to a method and a system for installing an underwater structure at a target position in a target attitude.

Background Art

[0002] Conventionally, for example, a TLP (Tension Leg Platform) is known in which a floating structure is connected to and moored to an anchor fixed to the bottom of the water using tendons such as steel pipes and mooring cables. For example, Patent Document 1 discloses a wind power generation facility that employs this TLP method.

[0003] The wind power generation facility of Patent Document 1 connects an underwater beam provided at the base portion of the wind power generation device and a sinker fixed to the bottom of the water with a mooring cable. When such a TLP method is adopted, since a strong force in the vertical direction always acts on the wind power generation facility via the mooring cable, vertical movement, pitching, and rolling can be suppressed to a small extent. In addition, since the sinker can be arranged directly below the wind power generation, the occupied area under the sea surface can be significantly suppressed compared to other mooring methods.

Prior Art Documents

[0006] However, when performing installation work in deep-sea areas, none of the above methods are feasible for adjusting the anchor's posture near the seabed. Specifically, with the method using ropes for guidance, the rope angle becomes closer to vertical at greater depths, making it difficult to adjust the anchor's posture. Furthermore, there are limits to the depths to which divers can work, making deep-sea operations difficult.

[0007] This invention has been made in view of the above problems, and aims to enable the safe remote operation of setting up an underwater structure at a target location and in a target orientation. [Means for solving the problem]

[0008] To achieve this objective, the present invention provides a method for installing an underwater structure at a target position in a target orientation, comprising: attaching a long handle member extending laterally to the underwater structure; a suspension step of suspending the underwater structure above the target position by a crane; a connection step of connecting a remotely operable underwater mobile body to the handle member; an adjustment step of adjusting the orientation of the underwater structure toward the target orientation by remotely operating and moving the underwater mobile body while it is connected to the handle member; and a lowering step of lowering the underwater structure, whose orientation has been adjusted, to the height of the target position by the crane.

[0009] According to the present invention, an underwater structure is suspended above the target position, and its attitude is adjusted by a remotely operated underwater mobile body. This allows an operator to install the underwater structure at the target position and in the target attitude from a location away from the underwater structure. Therefore, the installation of structures can be carried out remotely and safely, whether underwater or in the air.

[0010] Furthermore, by connecting an underwater moving body to a long handle member attached to the underwater structure, the attitude of the underwater structure can be adjusted, thus reducing the power required for the underwater moving body to adjust the attitude of the underwater structure by the length of the handle member.

[0011] In the present invention, the handle member is configured to be retractable, and the suspension step may be performed with the handle member retracted, while the adjustment step may be performed with the handle member extended.

[0012] In this way, the handle member contracts when the structural member is suspended in water, thus reducing the resistance force that the handle member experiences from the water.

[0013] Furthermore, in the present invention, the underwater moving body may be equipped with a gripping mechanism capable of gripping the handle member, and in the connection step, the underwater moving body may be connected to the handle member by gripping the handle member with the gripping mechanism. In this way, the gripping mechanism grips the handle member attached to the underwater structure, allowing the moving body to reliably apply force to the underwater structure and adjust its posture with high precision.

[0014] Furthermore, in the present invention, the underwater mobile body is capable of traveling on the seabed, the underwater mobile body is equipped with a winch capable of unwinding and winding up the rope, the connection step is the step of connecting the rope to the handle member before submerging the underwater structure in water, and in the adjustment step, the underwater mobile body may be lowered to the seabed before the underwater structure, and the underwater structure may be pulled and its posture adjusted by running the underwater mobile body on the seabed with the rope wound up and taut by the winch.

[0015] In this way, a moving object traveling over the seabed can adjust its posture by taking a reaction force from the seabed surface and pulling on an underwater structure, thereby reducing the driving force required for the underwater moving object.

[0016] Furthermore, in the present invention, the wire for suspending the underwater structure and the underwater structure are connected via a connecting member, and the suspension process is performed. The connecting member is switchable between a state in which the wire and the underwater structure are connected and a state in which the connection is released. After the lowering process, the connection between the wire and the underwater structure may be released by operating the connecting member with an underwater moving body that can operate the connecting member.

[0017] In this way, after the underwater structure has been installed, the process of detaching the underwater structure from the wires suspending it can also be carried out remotely.

[0018] Furthermore, the present invention relates to an installation system for installing an underwater structure, to which a laterally extending handle member is attached, at a target position and in a target orientation, comprising: a crane for suspending the underwater structure; a remotely operated underwater mobile body, which, while connected to the handle member, can adjust the orientation of the suspended underwater structure by moving it by remote operation; a first measuring unit for measuring the position and orientation of the underwater structure; a second measuring unit for measuring the position of the underwater mobile body; a monitoring unit for displaying the measurement results from the first and second measuring units; and a remote control unit for transmitting remote operation commands to the underwater mobile body. [Effects of the Invention]

[0019] According to the present invention, the operation of installing an underwater structure at a target position and in a target orientation can be safely performed by remote control. Furthermore, since force is applied to the underwater structure via a long member attached to the underwater structure to adjust its orientation, the power required for the underwater moving body can be reduced.

Brief Description of the Drawings

[0020] [Figure 1] It is a figure (part 1) showing a method for installing a structure in the first embodiment of the present invention. [Figure 2] It is a figure (part 2) showing a method for installing a structure in this embodiment. [Figure 3] It is a figure (part 3) showing a method for installing a structure in this embodiment. [Figure 4] It is a figure (part 4) showing a method for installing a structure in this embodiment. [Figure 5] It is a figure (part 5) showing a method for installing a structure in this embodiment. [Figure 6] It is a figure (part 6) showing a method for installing a structure in this embodiment. [Figure 7] It is a side view of the handle member in this embodiment. [Figure 8] It is a perspective view of the lock portion provided on the handle member, where (a) shows the state where the lock is released and (b) shows the locked state. [Figure 9] It is a figure showing an example of the display screen of the monitoring device in this embodiment. [Figure 10] It is a flowchart showing the procedure of the method for installing a structure in this embodiment. [Figure 11] It is a figure showing an example of the snap hook in this embodiment. [Figure 12] It is a figure showing the configuration of the attachment portion to the structure where the handle member is removable, where (a) is a perspective view, (b) is a cross-sectional view in the axial direction of the handle member, (c) is a perspective view seen from the back side of the paper surface of (a), and (d) is a perspective view showing the single holding member. [Figure 13] It is a side view showing another configuration example of the handle member. [Figure 14] It is a figure (part 1) showing a method for installing a structure in the second embodiment of the present invention. [Figure 15] It is a figure (part 2) showing a method for installing a structure in this embodiment. [Figure 16]This is a diagram (part 3) showing the method of installing the structure in this embodiment. [Figure 17] This is a flowchart showing the procedure for installing the structure in this embodiment. [Modes for carrying out the invention]

[0021] The following describes a first embodiment of the present invention. In this embodiment, the present invention will be described in a case where it is applied to construction work for installing an underwater structure on the seabed.

[0022] Figures 1 to 6 show a method for installing an underwater structure according to the first embodiment of the present invention. As shown in Figures 1 to 6, in this embodiment, a crane 22 equipped on a workboat 20 and a remotely operated vehicle (ROV) 30 (see Figures 2 to 6) are used to install a structure 50 at a target position and in a target orientation on the seabed 100. The ROV 30 is sometimes called an underwater drone. Furthermore, this method is not limited to ROVs; any remotely operated underwater vehicle is applicable. Structure 50 could, for example, be a reinforced concrete anchor body used to moor wind power generation equipment.

[0023] ROV30 is a remotely operated unmanned underwater vehicle equipped with a camera 31 and a manipulator 32, and moves in response to external command signals. It also has the function of performing tasks using the manipulator 32 via remote control and transmitting video signals from the camera 31 in real time. The manipulator 32 corresponds to the "gripping mechanism" of the present invention.

[0024] The ROV30's propulsion power source is a thruster (underwater propeller). In this embodiment, a high-power ROV30, such as the one sold by Argus Remote Systems (Norway), is used to adjust the position and attitude of the heavy structure 50, but it is not limited to this. Furthermore, if the thruster originally equipped with the ROV30 is insufficient, an aftermarket thruster may be added to increase the power.

[0025] Prior to the installation of the structure 50 on the seabed 100, a laterally extending handle member 52 is attached to the structure 50, and a sensor unit 54 equipped with sensors for detecting the position and orientation of the structure 50 is detachably attached. The handle member 52 is a member that the ROV 30 grips with the manipulator 32 in order to adjust the orientation of the structure 50.

[0026] The handle member 52 is a long, extendable member, and in this embodiment, it is a rod-shaped member. In this embodiment, two handle members 52 are provided, but the number of handle members 52 is not limited to this, and for example, three or more may be provided.

[0027] Figure 7 is a side view showing an example of the configuration of the handle member 52. As shown in the figure, the handle member 52 comprises a wide cylindrical portion 52a, a narrow cylindrical portion 52b, a spring 52c, a locking portion 52d, and a gripping portion 52e. The gripping portion 52e is provided at the tip of the narrow cylindrical portion 52b (right end in Figure 7).

[0028] The narrow cylindrical portion 52b is provided inside the thick cylindrical portion 52a so as to be movable in the axial direction. The spring 52c is provided on the base end (left end in Figure 7) side of the narrow cylindrical portion 52b inside the thick cylindrical portion 52a and biases the narrow cylindrical portion 52b in a direction that causes it to retract from the thick cylindrical portion 52a. Engaging portions (not shown) are provided on the inner circumferential surface near the tip of the thick cylindrical portion 52a and on the outer circumferential surface near the base end of the narrow cylindrical portion 52b, respectively. These engaging portions engage with each other, preventing the narrow cylindrical portion 52b from coming out of the thick cylindrical portion 52a.

[0029] A mounting plate 80 is fixed to the base end of the thick cylindrical portion 52a. The handle member 52 is attached to the structure 50 by fixing the mounting plate 80 to the side surface of the structure 50 with bolts 82.

[0030] The locking portion 52d is provided on the outer circumference near the tip of the thicker cylindrical portion 52a. The locking portion 52d is a mechanism for locking the movement of the thinner cylindrical portion 52b relative to the thicker cylindrical portion 52a, and a known locking mechanism can be used.

[0031] Figures 8(a) and 8(b) are perspective views showing an example of the locking mechanism 52d. The locking mechanism 52d illustrated in the figure includes a locking operating member 52f that is rotatably mounted. When the locking operating member 52f is oriented as shown in Figure 8(a), the mechanism is unlocked. In the unlocked state, the narrow cylindrical portion 52b can move relative to the wide cylindrical portion 52a, and the handle member 52 extends as the narrow cylindrical portion 52b retracts from the wide cylindrical portion 52a due to the biasing force of the spring 52c. On the other hand, as shown in Figure 8(b), when the locking operating member 52f is rotated from the state shown in (a), the mechanism enters a locked state. In the locked state, the movement of the narrow cylindrical portion 52b relative to the wide cylindrical portion 52a is locked, and the length of the handle member 52 is fixed.

[0032] To retract the handle member 52 from its extended state, the locking operating member 52f is set to the unlocked state shown in Figure 8(a), and the narrow cylindrical portion 52b is pushed into the wider cylindrical portion 52a. When the narrow cylindrical portion 52b is pushed in to the predetermined position, a latch mechanism (not shown) inside the locking portion 52d is activated, causing the handle member 52 to rotate to the locked state shown in Figure 8(b), and the locking portion 52d becomes locked. As a result, the handle member 52 is held in the retracted state. Furthermore, in the retracted state, the locking operating member 52f can be rotated to the state shown in Figure 8(a) to release the lock on the narrow cylindrical portion 52b, and the handle member 52 can be extended by the biasing force of the spring 52c.

[0033] The locking mechanism 52d is not limited to the one shown in Figure 8. For example, a mechanism similar to the opening and closing button on an automatic umbrella may be used, where pressing a push button releases the lock and extends the handle member 52, and when the handle member 52 is retracted, it automatically locks. Other known locking mechanisms applicable to telescopic members can also be used.

[0034] As shown in Figures 1 to 6, a lifting hook 26 is connected to the lower end of the crane wire 24 that descends from the tip of the crane 22. A lifting wire 28 is connected to the lower side of the lifting hook 26, and a structure 50 is connected to the lower end of the lifting wire 28 and suspended. Therefore, the structure 50 can be lowered by operating the crane 22 and extending the crane wire 24. Furthermore, after the lifting removal operation described later is completed, the lifting hook 26 can be recovered on the water surface by winding up the crane wire 24. The lifting hook 26 corresponds to the "connecting member" of the present invention.

[0035] ROV30 can communicate with a remote control device 34 installed on the workboat 20. When the operator operates the remote control device 34, a corresponding remote control command signal is sent to ROV30, allowing ROV30 to be remotely controlled. ROV30 can operate in both travel mode and hold mode, and the remote control device 34 can instruct which mode to operate in. In travel mode, ROV30 can be moved in any direction by instructing it to move forward, backward, rotate left and right, etc. In hold mode, ROV30 can be kept in a stationary state by compensating for the effects of disturbances such as water currents.

[0036] Similarly, the manipulator 32 can also be remotely controlled by an operator via the remote control device 34. Specifically, the manipulator 32 has a robot arm 32a and a grip 32b provided at its tip, and the movement of the grip 32b by the robot arm 32a, as well as the opening and closing operation of the grip 32b, can be instructed from the remote control device 34.

[0037] Then, with the grip 32b of the manipulator 32 gripping the gripping portion 52e of the handle member 52, the ROV 30 moves, thereby applying force to the structure 50, which can be used to adjust the attitude and fine-tune the position of the structure 50, as will be described later.

[0038] Although the remote control device 34 and the ROV 30 are connected by a wire, they may also be connected wirelessly using a wireless method that enables underwater communication (for example, sonar communication). Furthermore, the imaging signal from the camera 31 installed on the ROV30 is transmitted to the monitoring device 70, which will be described later, and displayed on the screen of the monitoring device 70, which will also be described later.

[0039] The sensor unit 54 attached to the structure 50 is equipped with a compass sensor 56 that measures the orientation (three-dimensional orientation) of the structure 50. For example, a geomagnetic compass sensor or a gyroscope can be used as the compass sensor 56. The sensor unit 54 is also equipped with a buoyancy device so that, as will be described later, if it is removed from the structure 50 underwater, it will float to the water surface due to buoyancy.

[0040] Furthermore, in this embodiment, a USBL (Ultra Short Base Line) type underwater direction / distance detection device is used as a positioning device for measuring the position of the structure 50, which can determine the position of an underwater object by combining position information from GNSS and underwater sound wave information.

[0041] The underwater direction / distance finding device is configured by installing a transceiver 60 on a sensor unit 54 and a transponder 62 on the underwater portion of the workboat 20. When an acoustic signal is transmitted from the transceiver 60, the transponder 62 transmits acoustic information in response. Based on this acoustic information, the relative position between the transponder 62 and the transceiver 60 can be obtained. Note that the underwater direction / distance finding device is not limited to a USBL (Ultra Short Base Line) type underwater direction / distance finding device; any device capable of measuring relative distance and direction underwater is acceptable.

[0042] A GPS receiver 64 is installed on the workboat 20, and the GPS receiver 64 can acquire the position information of the workboat 20. Since the relative positions of the installation locations of the GPS receiver 64 and the transponder 62 on the workboat 20 are known in advance, the position information of the transceiver 60 can be determined from the position information acquired by the GPS receiver 64 and the relative positions of the transponder 62 and the transceiver 60 measured by the underwater direction / distance finding device. Furthermore, since the mounting position of the transceiver 60 on the structure 50 is also known in advance, the position information of a predetermined position on the structure 50 (for example, one of the vertices on the bottom surface, or the center of gravity on the bottom surface) can be determined from the position information of the transceiver 60.

[0043] In this embodiment, the target location for installing the structure 50 is determined by the position of a specific vertex on the bottom surface of the structure 50. Therefore, the position information of the specific vertex is obtained from the position information of the transponder 62 as the position information of the structure 50.

[0044] The positional information of the structure 50 obtained as described above, along with the attitude information of the structure 50 measured by the orientation sensor 56, is transmitted to the monitoring device 70 on the workboat. The output signal of the orientation sensor 56 may be transmitted to the monitoring device 70 by wire, or by wireless communication capable of underwater communication.

[0045] Furthermore, ROV30 is equipped with a function to measure its own position and orientation using the same method as described above for measuring the position and orientation of structure 50. The measurement results of ROV30's position and orientation are also transmitted to the monitoring device 70.

[0046] Figure 9 shows an example of the display screen of the monitoring device 70. As shown in the figure, the screen of the monitoring device 70 includes a camera image display area 701, a coordinate display area 702, and a graphic display area 703 that graphically displays the positional relationship between the structure 50 and the ROV 30.

[0047] The camera image display area 701 displays images transmitted in real time from the cameras 31 of the two ROVs 30. In the illustrated example, ROV1 on the left shows the state before the handle member 52 is extended, while ROV2 on the right shows the state after the handle member 52 has been extended.

[0048] The coordinate display area 702 displays the measured values, i.e., the current values, of the position and orientation information (X, Y, Z coordinates and inclination angles α, β, γ in the three directions) of the structure 50 in real time, along with the respective target values ​​and the deviation of the current values ​​from the target values.

[0049] The inclination angle α represents the direction in the horizontal plane (for example, the angle clockwise from the north direction). The inclination angles β and γ are the angles of inclination in two directions from the vertical direction. Since the structure 50 is suspended and installed vertically, the target values ​​for inclination angles β and γ are zero. Therefore, the posture of the structure 50 is represented by the inclination angle α, i.e., the direction. While the current values ​​of inclination angles β and γ are approximately zero, they fluctuate around zero due to swaying caused by water flow, etc.

[0050] The graphic display area 703 displays the current positions of the structure 50 and ROV30 in real time, along with the target position and target orientation of the structure 50, shown as dashed lines. The current position of the structure 50 is drawn based on the current position and orientation values ​​displayed in the coordinate display area 702. The current position of the ROV30 is drawn based on the position and orientation information transmitted from each ROV30.

[0051] In this embodiment, the target position of the structure 50 is specified as a single point, but a target range may also be specified (i.e., an acceptable range is set based on the center value of the target range).

[0052] Furthermore, among the X, Y, and Z coordinates, the Z coordinate (vertical coordinate) is the depth of the seabed 100 relative to the water surface, and the depth of the seabed 100 measured by a depth sensor installed on the bottom of the workboat 20 is set as the target value. However, in the case of installation on the seabed 100 as in this embodiment, the Z coordinate may be excluded from the coordinates of the target position.

[0053] The operator remotely controls the ROV 30 while monitoring the monitoring device 70 so that the orientation of the structure 50 (specifically, the inclination angle α in the horizontal plane, i.e., the direction) approaches the target orientation (i.e., so that the deviation approaches zero). In addition, for adjusting the position of the structure 50, rough adjustments are made by operating the crane 22, and fine adjustments are made with the ROV 30 once it approaches the target position. It is preferable that the ROV operator who operates the ROV 30 and the crane operator who operates the crane 22 are separate workers, and that they communicate with each other while performing their respective operations.

[0054] The following describes the procedure for installing structure 50 on the seabed 100, using the flowchart in Figure 10 and referring to Figures 1 to 6.

[0055] Prior to the installation of the structure 50, the handle member 52 attached to the structure 50 is retracted. That is, the handle member 52 is retracted and locked by pushing the narrow cylindrical portion 52b into the wide cylindrical portion 52a from the unlocked state.

[0056] First, in step S10, the crane operator operates the crane 22 and performs a lifting process in which the structure 50 is lowered to a depth near the seabed 100 so that it is above the target position, as shown in Figure 1. When this suspension process is carried out, as described above, the handle member 52 is contracted, so the water resistance force acting on the handle member 52 is reduced as the structure 50 settles.

[0057] Next, in step S12, the ROV operator sets the ROV 30 to travel mode and remotely controls the two ROV 30s to approach the structure 50 while checking the display screen of the monitoring device 70 (particularly the graphic display area 703). Then, as shown in Figure 2, the operator grasps the locking operation member 52f of the locking portion 52d of the handle member 52 with the grip 32b of the manipulator 32 and rotates it to release the lock and extend the handle member 52.

[0058] Next, in step S14, similar to step S12, the two ROVs 30 are remotely operated while checking the display screen of the monitoring device 70, and as shown in Figure 3, the manipulator 32 is moved to a position where the grip 32b of the manipulator 32 can grasp the gripping portion 52e of the handle member 52, and a connection process is performed in which the grip 32b grasps the gripping portion 52e of the handle member 52.

[0059] Next, in step S16, an adjustment process is performed to adjust the position and orientation of the structure 50. Specifically, the ROV operator checks the position and orientation information, particularly the inclination angle α, displayed in the coordinate display area 702 of the monitoring device 70, and remotely moves the ROV 30 to adjust the orientation of the ROV 30 to the target value by applying force to the structure 50, as shown by the arrows in Figure 4. If the position (X,Y coordinates) of the structure 50 displayed in the coordinate display area 702 is outside the target position, the operator contacts the crane operator and makes a rough adjustment to the position using the crane 22. Once the deviation from the target position is small, the ROV operator makes a fine adjustment to the position using the ROV 30, similar to the orientation adjustment.

[0060] In step S16, when adjusting the posture of the structure 50, it is necessary to apply a large load (moment) to the structure 50 because of its heavy weight. In this embodiment, a long handle member 52 is attached to the structure 50, and the ROV 30 applies force to the gripping portion 52e at the tip of the handle member 52 to adjust the posture of the structure 50. This allows a large moment corresponding to the length of the handle member 52 to be applied to the structure 50 by the lever principle. As a result, the power required for the ROV 30 can be reduced, making it possible to use a relatively small ROV 30.

[0061] By the way, in this embodiment, in order to adjust the attitude of the structure 50 using two ROV30s, it is necessary to operate these two ROV30s in coordination. However, in order to remotely control two ROV30s individually and operate them in coordination, a high level of operational skill is required of the ROV operator.

[0062] Therefore, in order to facilitate the adjustment of the attitude of the structure 50 by remotely controlling two ROV30s, in this embodiment, the remote control device 34 and the monitoring device 70 are linked, and when adjusting the position and attitude of the structure 50, the remote control device 34 is equipped with an automatic operation function that automatically remotely controls each ROV30 so that the deviation between the current position and attitude of the structure 50 and the target value becomes zero.

[0063] Specifically, the automated operation function calculates the direction and amount of movement each ROV 30 should move based on the position of the gripping portion 52e when the gripping member 52 is extended and held by the grip 32b of each ROV 30, and the deviation of the structure 50's attitude (inclination angle α) from the target attitude. It then automatically generates and transmits a command signal to each ROV 30 to move in the calculated direction by the calculated amount. This automates the adjustment of the structure 50's attitude, significantly reducing the burden on the ROV operator.

[0064] Alternatively, instead of completely automating the operation of the ROV30 as described above, the system may be configured so that when an ROV operator remotely controls one ROV30, the other ROV30 is automatically controlled in accordance with its movement. In this case as well, the ROV operator only needs to remotely control one ROV30, thus reducing the operator's burden when adjusting the posture of the structure 50.

[0065] Once the position and orientation of the structure 50 have been adjusted to the target values ​​as described above, in step S18, the orientation of the structure 50 is maintained by setting the ROV 30's operating mode to hold mode, and the crane 22 is operated to lower the structure 50 together with the ROV 30, performing a descent process in which the structure 50 lands on the seabed 100.

[0066] The landing of ROV30 on the seabed 100 can be confirmed, for example, by the Z coordinate of the current position of structure 50 reaching the target value (water depth value), or by a sudden decrease in the load on crane 22 that suspends structure 50. However, confirmation is not limited to these methods; confirmation may also be made based on the video footage from ROV30's camera 31 displayed on the monitoring device 70, or by installing a sensor on the bottom surface of structure 50 to detect landing, or by combining two or more of these methods to more reliably confirm landing on the seabed 100.

[0067] As described above, in this embodiment, in step S10, the structure 50 is sunk to a depth close to the seabed 100, and then in step S16, its position and orientation are adjusted. In step S18, the structure 50 is sunk further to land on the seabed 100. Therefore, the amount of sunk after the adjustment of position and orientation until landing is small. As a result, the structure 50 can be installed on the seabed 100 while maintaining the position and orientation adjusted in step S16.

[0068] In step S18, once it is confirmed that the structure 50 has landed on the seabed 100, a command signal is sent to the ROV 30 to open the grip 32b of the manipulator 32, and the gripping member 52 releases its grip.

[0069] Next, in step S20, the ROV 30 retracts the handle member 52. Specifically, the manipulator 32 grips the gripping portion 52e of the handle member 52 with its grip 32b, and the manipulator 32 pushes the narrow cylindrical portion 52b into the wider cylindrical portion 52a, thereby locking the handle member 52 in a retracted state. Furthermore, as will be described later, if the handle member 52 is detachably attached to the structure 50, instead of retracting the handle member 52, the handle member 52 may be removed and recovered by the ROV 30.

[0070] Next, in step S22, the lifting operation is performed by one of the ROV30. The lifting operation involves removing the lifting wire 28 that suspends the structure 50 from the lifting hook 26, and is performed by releasing the lock on the lifting hook 26 with the manipulator 32 of one of the ROV30s. The ROV30 not used for the lifting operation is floated to the surface and recovered.

[0071] Here, we will explain an example of the ball removal process. Figure 11 shows an example of a lifting hook 26. In this embodiment, Nautilus Rigging's SubseaHooks product is used as the lifting hook, and the figure is quoted from the product's introduction website (https: / / www.nautilusrigging.com / products / subsearov-hooks).

[0072] As shown in Figure 11, the lifting hook 26 comprises a ring portion 262 and a fixing hook portion 263 integrally formed at both ends of the main body portion 261. The crane wire 24 is hooked onto the inside of the ring portion 262.

[0073] The base of the movable hook portion 264 is rotatably connected to the base of the fixed hook portion 263. Normally, as shown by the solid line in Figure 6, the tip of the movable hook portion 264 engages with the tip of the fixed hook portion 263, forming a closed open / closed hook portion 265, to which the lifting wire 28 is hooked.

[0074] The movable hook portion 264 is provided with a locking portion 266, to which an operating rope 267 is connected. Under normal circumstances, the locking portion 266 locks the rotation of the movable hook portion 264, preventing the lifting wire 28 from detaching from the opening / closing hook portion 265.

[0075] During the lifting operation, the ROV30 is remotely operated to grasp the operating rope 267 with the grip 32b of the manipulator 32 and lift it upward. This releases the lock by the locking part 266, and as shown by the dashed line, the movable hook part 264 rotates upward (counterclockwise in the diagram), opening the opening / closing hook part 265, thereby allowing the lifting wire 28 to be detached from the lifting hook 26.

[0076] In step S22, the sensor unit 54 attached to the structure 50 is also removed by the ROV30's manipulator 32. Specifically, for example, the sensor unit 54 is fixed to the structure 50 with a wire, and the wire and the sensor unit 54 are connected with a mechanism equipped with a locking function, such as the lifting hook 26 described above. By releasing the lock on this mechanism, the sensor unit 54 can be removed. Then, the ROV30's manipulator 32 can release the lock in the same manner as in the lifting hook removal operation, and the sensor unit 54 can be removed.

[0077] Since the sensor unit 54 is equipped with a buoyancy device, when it is removed from the structure 50, it will float to the surface of the water due to its buoyancy, allowing it to be recovered and reused. Alternatively, instead of providing a buoyancy device to the sensor unit 54, a wire or rope extending to the workboat 20 may be connected to it, and when the sensor unit 54 is removed from the structure 50, it may be lifted up by that wire or rope.

[0078] Once the ball removal and sensor unit 54 removal operations in step S22 are completed, the ROV30 is then brought to the surface of the sea in step S24, recovered, and the series of operations is completed.

[0079] As described in step S20 of Figure 10, the handle member 52 may be detachably attached to the structure 50, and the ROV 30 may be used to remove the handle member 52 from the structure 50.

[0080] Figures 12(a) to (d) show the configuration of the attachment part 81 to the structure 50, which makes the handle member 52 removable. (a) is a perspective view, (b) is a side view, (c) is a perspective view of (a) from below, and (d) is a perspective view showing the retaining member 86, which will be described later.

[0081] As shown in Figures 12(a) to (d), the mounting portion 81 includes a mounting cylinder portion 84 fixed to the surface of the mounting plate 80, and a holding member 86 for holding the handle member 52 (thick cylinder portion 52a) in the mounting cylinder portion 84. Similar to the configuration shown in Figure 7, the mounting plate 80 is fixed to the structure 50 by bolts 82.

[0082] The retaining member 86 includes a locking pin 86a, a fall prevention part 86b, a retaining member gripping part 86c, and a fall prevention wire 86d. The fall prevention wire 86d connects an appropriate part of the holding member 86 to the thick cylindrical portion 52a of the handle member 52, preventing it from falling when the holding member 86 is removed.

[0083] As shown in Figure 12(d), the fall prevention portion 86b consists of an Ω-shaped bent strip plate comprising a circular curved portion 861a and bent portions 861b at both ends. A lock pin 86a is fixed to the inside of the central part of the circular curved portion 861a. The retaining member gripping portion 86c is fixed to the outside of the central part of the circular curved portion 861a.

[0084] The mounting cylinder portion 84 is configured such that its inner diameter is slightly larger than the outer diameter of the thick cylinder portion 52a of the handle member 52, and the base end of the thick cylinder portion 52a is inserted into the inside of the mounting cylinder portion 84. A through hole 87 is formed in both the mounting cylinder portion 84 and the thick cylinder portion 52a of the handle member 52, passing through them radially.

[0085] Furthermore, the circular curved portion 861a is configured such that its inner diameter is slightly smaller than the outer diameter of the mounting cylinder portion 84. By spreading the pair of bent portions 861b, the circular curved portion 861a is attached to the outer circumference of the mounting cylinder portion 84 so that the lock pin 86a passes through the through hole 87, and the holding member 86 is held in a state where it embraces the outer circumference of the mounting cylinder portion 84. This prevents the lock pin 86a fixed to the fall prevention portion 86b from falling out, so that the handle member 52 can be reliably held attached to the structure 50.

[0086] When the handle member 52 is attached using the mounting portion 81 described above, in step S20 of Figure 10, the ROV 30 grips the holding member gripping portion 86c with its grip 32b and moves it in a direction that pulls the lock pin 86a out of the mounting cylinder portion 84. As a result, the holding member 86 is removed from the mounting cylinder portion 84 by the bending portion 861b of the fall prevention portion 86b being pushed open by the outer surface of the mounting cylinder portion 84, and the lock pin 86a is also removed.

[0087] In this state, the handle member 52 can be removed from the structure 50 by gripping the gripping portion 52e of the handle member 52 with the grip 32b and pulling it out. The removed handle member 52 can be recovered by raising the ROV 30 while the grip 32b is still gripping the gripping portion 52e. At the same time, the holding member 86 connected to the handle member 52 by the fall prevention wire 86d can also be recovered.

[0088] The configuration for detachably attaching the handle member 52 to the structure 50 is not limited to the configuration shown in Figure 12. For example, a screw hole may be provided in the structure 50, and a threaded portion may be provided at the base end of the handle member 52 so that it can be screwed into the screw hole in the structure 50. Other suitable configurations that can be detached by the ROV 30 can also be used.

[0089] By the way, the handle member is not limited to the configuration shown in Figure 7. Figure 13 is a side view showing a handle member 252, which is a different form from the handle member 52. In the configuration illustrated in the figure, the handle member 252 has a structure similar to, for example, a household tension rod. That is, a narrow cylindrical portion 252b is provided inside a wide cylindrical portion 252a so as to be able to move back and forth, and a grip portion 252c is provided spanning the outer circumference of the wide cylindrical portion 252a and the narrow cylindrical portion 252b. A length fixing screw 252d is provided on the grip portion 252c, and the narrow cylindrical portion 252b is fixed by rotating the fixing operation part 252e on the head of the length fixing screw 252d clockwise to tighten the length fixing screw 252d to the narrow cylindrical portion 252b, and the fixing of the narrow cylindrical portion 252b is released by rotating the fixing operation part 252e counterclockwise to loosen the length fixing screw 252d, making the handle member 252 extendable and retractable.

[0090] When using the handle member 252 with the configuration shown in Figure 13, when extending the handle member 252 in step S12 of Figure 10, first, the manipulator 32 grips the fixing operation part 252e with the grip 32b and rotates it to loosen the length fixing screw 252d, then the gripping part 52e is gripped and the thin cylindrical part 52b is pulled out from the thick cylindrical part 52a, and then the length fixing screw 252d is tightened again to fix it in place.

[0091] Furthermore, when retracting the handle member 252 in step S20 of Figure 10, the manipulator 32 grips the fixing operation part 252e of the length fixing screw 252d with the grip 32b to loosen the screw, then the handle member 52 grips the gripping part 52e to push the narrow cylindrical part 252b into the wide cylindrical part 252a, and then the length fixing screw 252d is tightened again to fix it in place.

[0092] As described above, according to this embodiment, in the installation work of the structure 50 on the seabed 100, a series of operations including adjusting the position and orientation of the structure 50, installing it on the seabed 100, and removing the balls can be performed by remote control.

[0093] This eliminates the need for divers to perform the work, making it possible to efficiently and safely adjust the position and orientation of the structure 50 underwater and install it on the seabed 100, even when the installation location of the structure 50 is in a deep water area where divers cannot perform the work. Furthermore, since the ROV30 can be remotely controlled while monitoring the position and orientation of the structure 50 with the monitoring device 70, the structure 50 can be installed at the target position and in the target orientation with high precision.

[0094] Furthermore, as described above, when performing the adjustment process to adjust the posture of the structure 50, the handle member 52, which is a long member, is attached to the structure 50, and the gripping portion 52e at the tip of the handle member 52 is gripped to adjust the posture of the structure 50. Therefore, due to the lever principle, a large moment corresponding to the length of the handle member 52 can be applied to the structure 50. This reduces the power required for the posture ROV 30 to adjust the posture of the structure 50, making it possible to use a relatively small ROV 30. As a result, the cost of the equipment can be reduced, the range of usable ROV 30s expands, and the procurement of ROV 30s becomes easier.

[0095] Furthermore, by making the handle member 52 extendable and retractable, when submerging it in water in step S10 of Figure 10, the water resistance force on the handle member 52 can be reduced by retracting the handle member 52. Furthermore, if the handle member 52 is detachably attached to the structure 50, the handle member 52 can be reused by removing it in step S20 and recovering it with the ROV 30.

[0096] Next, a second embodiment of the present invention will be described. In this embodiment, the description of components common to the first embodiment will be omitted or simplified. Figures 14 to 16 show the installation method of the underwater structure in this embodiment, and Figure 17 is a flowchart showing the procedure of this installation method.

[0097] In this embodiment, the ROV130 is used to perform the installation work of the structure 50, instead of the ROV30 in the first embodiment described above. As shown in Figures 14 to 16, ROV130 is equipped with crawler tracks 140 and can travel over the seabed 100. ROV130 is also equipped with a winch 132 around which a wire 134 is wound. The movement of ROV130 using the crawler tracks 140, and the unwinding and rewinding of the wire 134 using the winch 132, can be remotely controlled from the remote control device 34. In this embodiment, the wire 134 corresponds to the "rod" of the present invention.

[0098] In the installation work of this embodiment, first, in step S110 of Figure 17, the structure 50 is suspended by the crane 22 to a target position above the water surface, and with the ROV 130 floating on the water surface, the wire 134 is connected to the gripping portion 52e of the handle member 52. The handle member 52 is kept in a retracted state. Furthermore, the wire 134 and the gripping portion 52e are connected, for example, via a hook 142 having the same configuration as the lifting hook 26 described in the first embodiment, so that the wire 134 can be detached from the handle member 52.

[0099] Next, in step S112, the crane 22 is operated to sink the structure 50 into the water, as shown in Figure 14, and the ROV 130 is also sunk in conjunction with it. In this embodiment, a handle member 52 is provided at the lower part of the structure 50. This is to allow the ROV 130, which has landed on the seabed 100, to stably perform adjustment work on the structure 50 from below, as will be described later.

[0100] Next, in step S114, the crane 22 is used to lower the structure 50 to near the seabed 100, and the ROV 130 is remotely controlled to land on the seabed 100 before the structure 50, as shown in Figure 15.

[0101] Once ROV130 lands on the seabed 100, in step S116, the sinking of the structure 50 is stopped, and the handle member 52 is extended in the same manner as in the first embodiment (step S12 in Figure 11). This extension operation is performed by lowering ROV30, which is equipped with a manipulator, into the water, as in the first embodiment described above.

[0102] Next, in step S118, as shown in Figure 15, the wire 134 is tensioned by remotely operating the winch 132 to wind up the wire 134.

[0103] Next, in step S120, the ROV 30 is moved on the seabed 100 by remotely driving the crawler 140 of the ROV 130, and the structure 50 is pulled and rotated via the handle member 52 using the wire 134, thereby adjusting the posture (tilt angle α) of the structure 50 toward the target value. The position of the structure 50 is adjusted by rough adjustment using the crane 22 and fine adjustment using the ROV 130, similar to the first embodiment (step S16 in Figure 10).

[0104] Once the position and orientation of the structure 50 reach the target values, in step S122, as shown in Figure 16, the crane 22 is used to further lower the structure 50 and bring it to rest on the seabed 100.

[0105] In this embodiment as well, in step S114, the structure 50 is sunk to a depth close to the seabed 100, and then in step S120, its position and orientation are adjusted. In step S122, the structure 50 is brought down to the seabed 100. As a result, the amount of sunk before landing is reduced, and the structure 50 can be placed on the seabed 100 while maintaining the position and orientation adjusted in step S120.

[0106] Next, in step S124, the ROV 30 equipped with a manipulator, as in the first embodiment, is lowered into the water, and the wire 134 is removed from the handle member 52 by operating the hook 142 connecting the wire 134 and the handle member 52 in the same manner as the ball removal operation in the first embodiment. The ball removal operation from the lifting hook 26 and the removal of the sensor unit 54 are also performed using the same ROV 30 in the same manner as in the first embodiment. Furthermore, in step S124, using the same ROV 30, the handle member 52 is retracted, or removed if the handle member 52 is removable, similar to step S20 in the first embodiment (Figure 11).

[0107] Next, in step S126, ROV130 and ROV30, which was used to remove the wire 134, are floated to the surface and recovered, completing the operation. In this embodiment, ROV30 is used to remove the wire 134, etc., in addition to ROV130 which adjusts the posture. However, by providing ROV130 with a manipulator 32 similar to that of ROV30, ROV130 can perform the removal of the wire 134, etc., and ROV30 may be made unnecessary.

[0108] In this embodiment, the ROV 130 equipped with crawler tracks 140 is driven on the seabed 100 to pull the wire 134 and adjust the attitude of the structure 50. Therefore, a reaction force can be taken from the seabed 100 to apply force to the structure 50, which reduces the driving force required for the ROV 30, and allows the ROV 130, which has relatively little power, to perform the position and attitude adjustment work of the structure 50.

[0109] Furthermore, similar to the first embodiment described above, the posture of the structure 50 is adjusted by a wire 134 connected to the gripping portion 52e at the tip of the elongated handle member 52. This allows the moment acting on the ROV 130 to be increased by the lever principle, thereby further reducing the power required for the ROV 130.

[0110] In the embodiments described above, two ROV30s and 130s were used, but the system is not limited to this. For example, three or more ROV30s and 130s may be used depending on the number of handle members 52 attached to the structure 50.

[0111] Furthermore, although the above embodiments described the case in which an anchor body is installed on the seabed as the structure 50, the present invention is not limited to this and can be applied to cases in which structures other than anchor bodies are installed on the seabed.

[0112] Furthermore, this method is applicable not only when the structure 50 is installed on the seabed 100, but also when it is installed in an underwater position above the seabed 100. For example, when constructing a structure underwater, it is conceivable that the structural components of the structure will be installed at a target position higher than the seabed, and this method is applicable in such cases as well. [Explanation of Symbols]

[0113] 20 Workboats 22 Cranes 24 Crane wire 26 Lifting hooks 261 Main body 262 Ring section 263 Fixing hook section 264 Movable hook section 265 Opening / closing hook section 266 Lock section 28 Lifting wire 30 ROV 31 Camera 32 Manipulators 32a Robot Arm 32b Grip 34 Remote control device 50 Structures 52 Handle member 52a Thick tube part 52b Narrow tube part 52c spring 52d Locking part 52e Grip 52f Locking operating member 54 Sensor Unit 56 Directional Sensor 60 transceivers 62 Transponders 64 GPS receiver 70 Monitoring equipment 701 Camera image display area 702 Coordinate display area 703 Graphics display area 80 Mounting plate 81 Mounting part 82 volts 83 Mounting bolts 84 Mounting cylinder section 86 Retaining member 86a Locking pin 86b Falling prevention part 86c Holding member grip part 86d Fall prevention wire 861a Circular curved section 861b Bent part 87 Through hole 100 underwater 130 ROV 132 Winch 134 wires 140 Crawler 142 hooks 252 Handle member 252a Thick tube part 252b Narrow tube part 252c Grip section 252d Length fixing screw 252e Fixed operation part

Claims

1. A method for installing an underwater structure at a target location and in a target orientation, A long handle member extending laterally is attached to the aforementioned underwater structure. A lifting step in which the underwater structure is suspended above the target position by a crane, A connection step of connecting a remotely operated underwater mobile body to the handle member, An adjustment step is to adjust the posture of the underwater structure toward the target posture by remotely controlling and moving the underwater moving body while it is connected to the handle member, A lowering step involves lowering the underwater structure, whose posture has been adjusted, to the height of the target position using the crane. A method for installing an underwater structure equipped with [a specific feature / feature].

2. A method for installing an underwater structure according to claim 1, The aforementioned handle member is configured to be extendable and retractable. The aforementioned suspension process is performed with the handle member in a retracted state. The adjustment step is performed with the handle member extended. Methods for installing underwater structures.

3. A method for installing an underwater structure according to claim 1 or 2, The underwater moving body is equipped with a gripping mechanism capable of gripping the handle member, In the connection step, the gripping mechanism grips the handle member, thereby connecting the underwater moving body to the handle member. Methods for installing underwater structures.

4. A method for installing an underwater structure according to claim 1 or 2, The aforementioned underwater mobile body is capable of traveling on the seabed. The underwater mobile body is equipped with a winch capable of unwinding and winding up the rope, The aforementioned connection step is the step of connecting the rope to the handle member before submerging the underwater structure in water. In the adjustment process, the underwater mobile body is brought to the bottom of the sea before the underwater structure, and the rope is wound up with the winch and taut, and then moved over the bottom of the sea, thereby pulling the underwater structure and adjusting its posture. Methods for installing underwater structures.

5. A method for installing an underwater structure according to claim 1 or 2, After connecting the wire that suspends the underwater structure to the underwater structure via a connecting member, the suspension process is performed. The connecting member is switchable between a state in which the wire and the underwater structure are connected and a state in which the connection is released. After the aforementioned descent process, the connection between the wire and the underwater structure is released by operating the connecting member with an underwater mobile body capable of manipulating the connecting member. Methods for installing underwater structures.

6. An installation system for setting an underwater structure, to which a long, laterally extending handle member is attached, to a target position and in a target orientation, A crane for suspending the aforementioned underwater structure, A remotely operated underwater mobile body, which, while connected to the handle member, can adjust the posture of the suspended underwater structure by moving it remotely. A first measuring unit for measuring the position and orientation of the underwater structure, A second measuring unit for measuring the position of the underwater moving body, A monitoring unit that displays the measurement results from the first measurement unit and the second measurement unit, A remote control unit that transmits remote control commands to the underwater moving body, An installation system for underwater structures equipped with [specific features / features].

Images