Pile gripper positioning system, automatic ship position holding system, monopile installation ship, and corresponding method

Abstract

The present invention relates to a pile gripper positioning system for a pile gripper configured to be provided on a ship for engaging a monopile during a monopile installation method. The pile gripper positioning system comprises an actuator system for applying a force to the pile gripper to position the pile gripper relative to the ship, a measurement system for determining the position of the monopile within the pile gripper relative to the ship, and a pile gripper control unit for driving the actuator system depending on a desired position and an actual position of the monopile measured by the measurement system. The pile gripper control unit is configured to receive a signal representing the position of the ship, and during at least a part of the monopile installation method, the pile gripper control unit is configured to determine a drive signal for the actuator system to compensate for at least a part of a deviation of the position of the ship from a desired position of the ship. During the at least a part of the monopile installation method, the pile gripper control unit for driving the actuator system is configured to drive the actuator system depending on the desired position and the actual position of the monopile measured by the measurement system and the drive signal to compensate for at least a part of a deviation of the position of the ship from a desired position of the ship.

Description

Technical Field

[0001] The present invention relates to the installation of monopiles as part of the installation process of wind turbines, particularly offshore wind turbines.

Background Art

[0002] In known methods for installing offshore wind turbines, a foundation in the form of a monopile is first installed by driving the monopile into the seabed, and then the wind turbine is installed on the monopile either by installing the wind turbine as a whole at once or by assembling the disassembled wind turbine on the monopile.

[0003] There is a tendency towards larger wind turbines, and it is required to install offshore wind turbines in locations with greater water depths than currently seen. Both result in larger and heavier foundations. Thus, it is expected that it will soon be necessary to install monopiles exceeding 100 meters, and in some cases over 120 meters. The weight of such monopiles can be greater than 1000 mt and in some cases can exceed 1300 mt.

[0004] To save time during the installation process, the use of floating vessels is preferred over jack-up vessels. Such floating vessels typically include a lifting crane for suspending the monopile and a pile gripper for engaging the monopile, and the lifting crane and the pile gripper cooperate to lower the monopile into the sea, particularly using a pile gripper positioning system. Generally, the vessel further includes an automatic position-keeping system for positioning the vessel during the lowering of the monopile.

[0005] When the automatic position-keeping system and the pile gripper positioning system function independently of each other, there can be a stability problem where the automatic position-keeping system becomes unstable.

[0006] To solve the above other problems, International Patent Publication No. 2020 / 145825 proposes interconnecting control systems of different actuators of a ship, such as an automatic ship position holding system and a pile gripper positioning system. One of the disclosed interconnections uses commands for motive action, i.e., signals directly or indirectly transmitted to an actuator by a pile gripper positioning system, to determine the force intended to be applied to the ship, and subsequently determines a compensating action and controls the automatic ship position holding system to apply the compensating action. This is also known as feed-forward control.

[0007] However, the applicant of the present application has found that this type of feed-forward control is insufficient to provide stability in all desired operating situations.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of the above, an object of the present invention is to improve the stability of a monopile installation method using a floating ship having an automatic ship position holding system and a pile gripper positioning system.

Means for Solving the Problems

[0010] According to a first aspect of the present invention, there is provided a pile gripper positioning system for a pile gripper configured to be provided on a ship for engaging a monopile during a monopile installation method, the pile gripper positioning system comprising: an actuator system for applying a force to the pile gripper to position the pile gripper relative to the ship; and A measurement system for determining the position of a monopile within a pile gripper relative to a ship, and a pile gripper control unit for driving an actuator system depending on a desired position and an actual position of the monopile measured by the measurement system comprising, the pile gripper control unit being configured to receive a signal representing the position of the ship, during at least a part of the monopile installation method, the pile gripper control unit being configured to determine a drive signal for the actuator system to compensate for at least a part of the deviation of the position of the ship from the desired position of the ship, during said at least a part of the monopile installation method, the pile gripper control unit for driving the actuator system drives the actuator system depending on the desired position and the actual position of the monopile measured by the measurement system and the drive signal to compensate for at least a part of the deviation of the position of the ship from the desired position of the ship.

[0011] According to a first aspect of the present invention, when the pile gripper and the corresponding pile gripper positioning system are configured to fully compensate for the movement of the ship, full compensation is likely to apply a relatively large force to the ship to urge it away from its desired position, thereby requiring more compensation and potentially causing stability problems. During at least some parts of the monopile installation method, this can cause unstable behavior. By only partially compensating for the movement of the ship and thus allowing a deviation of the position of the monopile from its desired position, the force applied to the ship by the pile gripper can be limited to prevent unstable behavior.

[0012] Accordingly, by only partially compensating for the movement of the ship, the setpoint of the pile gripper (and thus the monopile) is intentionally changed from the desired position to an adjusted position, and the pile gripper control unit is then configured to control the actuator system using this changed setpoint. However, there is always some setpoint, and the pile gripper control unit always acts to make the actual position the same as the position represented by the setpoint, regardless of whether this position is the desired position or a position intentionally selected to be different from the desired position. Those skilled in the art will recognize that this intentional change in the setpoint is not associated with any undesirable offsets or tolerances that may inherently exist in the control system, nor with means for reducing the applied force and preventing damage. These means may be applied as an addition to the present invention, but the control system having different setpoints for the position of the pile gripper and attempting to satisfy this setpoint within a range that could have been set by a force limitation loop instead of the original desired setpoint does not change. The present invention is further not related to the lack of control when the pile gripper is within a specific desired position range.

[0013] It is explicitly noted that the position of the monopile within the pile gripper may alternatively or additionally refer to the position of a part of the monopile and / or the orientation of the monopile or a part thereof.

[0014] It is further noted that the position of the ship may alternatively or additionally refer to the position of a part of the ship and / or the orientation of the ship or a part thereof.

[0015] It is also explicitly noted that determining a drive signal for the actuator system to compensate for at least a part, even the maximum, of the deviation of the ship's position from the desired position of the ship means that at least a non-zero part of the deviation of the ship's position from the desired position is directly or indirectly ignored or discarded by multiplication by a factor less than 1 or by subtraction of a non-zero value.

[0016] The above monopile installation method may include a plurality of steps including, but not limited to, the following: A lifting step in which the monopile is lifted above the water level from a lifting crane and engaged by a pile gripper, A lowering step in which the monopile is lowered from the lifting crane, engaged by a pile gripper, and the lower end of the monopile is underwater but above the seabed, A seabed penetration step in which the monopile is lowered from the lifting crane, engaged by a pile gripper, and the lower end of the monopile penetrates the seabed, A driving step in which the monopile is engaged by a pile gripper and driven into the seabed using a hammer or the like.

[0017] In one embodiment, at least a part of the monopile installation method includes at least a part of the seabed penetration step.

[0018] In one embodiment, at least a part of the monopile installation method includes at least a part of the lowering step, for example, the part of the lowering step immediately before the seabed penetration step, and the lower end of the monopile is directly above the seabed so as to penetrate the seabed.

[0019] In one embodiment, a part to be compensated for the displacement of the ship's position from the desired position of the ship and the ratio of the displacement of the ship's position from the desired position of the ship, that is, the total displacement of the ship's position from the desired position of the ship are defined.

[0020] In one embodiment, the ratio or the non-zero value to be subtracted depends on one or more of the following parameters: The weight of the monopile, The length of the monopile, The inclination of the monopile with respect to the vertical, The length of the hoisting wire between the lifting crane and the monopile, The direction of the hoisting wire between the lifting crane and the monopile, The length of the monopile below the pile gripper, The length of the monopile above the pile gripper, and The length of the monopile between the pile gripper and the seabed, the water depth, i.e., the distance between the seabed and the water surface, the distance between the position where the lifting line leaves the lifting crane and the pile gripper, the distance between the lower end of the monopile and the seabed, the distance between the position where the lifting line leaves the lifting crane and the seabed, the distance between the pile gripper and the seabed, the ratio of the length of the monopile below the pile gripper to the length of the monopile above the pile gripper, the ratio of the length of the monopile above the pile gripper to the length of the monopile between the pile gripper and the seabed, the position of the center of gravity of the monopile, and the tension of the lifting wire between the lifting crane and the monopile.

[0021] In one embodiment, during at least a portion of the seabed penetration phase, the pile gripper control unit is configured such that the ratio increases with an increase in the penetration depth of the lower end of the monopile or a non-zero value to be subtracted decreases with an increase in the penetration depth of the lower end of the monopile.

[0022] In one embodiment, during at least a portion of the seabed penetration phase, the pile gripper control unit is configured such that the ratio has a linear relationship with the penetration depth of the lower end of the monopile.

[0023] In one embodiment, during at least a portion of the lowering phase, the pile gripper control unit is configured such that the ratio is set to be the distance between the position where the lifting line leaves the lifting crane divided by the distance between the position where the lifting line leaves the lifting crane and the seabed.

[0024] According to a second aspect of the present invention, there is provided an automatic ship position holding system for a ship, the ship comprising a pile gripper for engaging with a monopile during a monopile installation method, and the automatic ship position holding system An actuator system for applying a force to a ship to position the ship, A measurement system for measuring the position of the ship, An automatic ship position holding control unit for driving the actuator system depending on a desired position and an actual position of the ship measured by the measurement system comprising, The automatic ship position holding control unit is configured to determine a signal representing a difference between a desired position and an actual position of the ship, During at least a part of the installation method, the automatic ship position holding control unit is configured to output a signal representing at most a part of said difference.

[0025] It is explicitly noted here that the difference between the desired position and the actual position of the ship may alternatively be referred to as the deviation of the position of the ship from the desired position.

[0026] It is further noted that the position of the ship may alternatively or additionally refer to the position of a part of the ship and / or the orientation of the ship or a part thereof.

[0027] It is also explicitly noted that a part of the difference between the desired position and the actual position of the ship means that at least a non-zero part of said difference is directly or indirectly ignored or discarded by multiplication by a coefficient less than 1 or by subtraction of a non-zero value.

[0028] The monopile installation method described above may include a plurality of steps including but not limited to the following: A lifting step in which the monopile is lifted above the water level from a lifting crane and engaged by a pile gripper, A lowering step in which the monopile is lowered from a lifting crane, engaged by a pile gripper, and the lower end of the monopile is in the water but above the seabed, A seabed penetration step in which the monopile is lowered from a lifting crane, engaged by a pile gripper, and the lower end of the monopile penetrates the seabed, The driving step in which the monopile is engaged by a pile gripper and driven into the seabed using a hammer or the like.

[0029] In one embodiment, at least a part of the monopile installation method includes at least a part of the seabed penetration step.

[0030] In one embodiment, at least a part of the monopile installation method includes at least a part of the lowering step, for example, the part of the lowering step immediately before the seabed penetration step, and the lower end of the monopile is directly above the seabed so as to penetrate the seabed.

[0031] In one embodiment, a ratio of the output difference to the total difference between the desired position and the actual position of the ship is defined.

[0032] In one embodiment, the ratio or the non-zero value to be subtracted depends on one or more of the following parameters: The weight of the monopile, The length of the monopile, The inclination of the monopile with respect to the vertical, The length of the hoisting wire between the hoisting crane and the monopile, The direction of the hoisting wire between the hoisting crane and the monopile, The length of the monopile below the pile gripper, The length of the monopile above the pile gripper, and The length of the monopile between the pile gripper and the seabed, The water depth, that is, the distance between the seabed and the water surface, The distance between the position where the hoisting line leaves the hoisting crane and the pile gripper, The distance between the lower end of the monopile and the seabed, The distance between the position where the hoisting line leaves the hoisting crane and the seabed, The distance between the pile gripper and the seabed, The ratio of the length of the monopile below the pile gripper to the length of the monopile above the pile gripper, The length of the monopile above the pile gripper and the ratio of the length of the monopile between the pile gripper and the seabed, the position of the center of gravity of the monopile, and the tension of the hoisting wire between the hoisting crane and the monopile.

[0033] In one embodiment, during at least a portion of the seabed penetration phase, the automatic ship position holding control unit is configured such that the ratio increases with an increase in the penetration depth of the lower end of the monopile or a non-zero value to be subtracted decreases with an increase in the penetration depth of the lower end of the monopile.

[0034] In one embodiment, during at least a portion of the seabed penetration phase, the automatic ship position holding control unit is configured such that the ratio has a linear relationship with the penetration depth of the lower end of the monopile.

[0035] In one embodiment, during at least a portion of the lowering phase, the automatic ship position holding control unit is configured such that the ratio is set to be the distance between the position where the hoisting line leaves the hoisting crane divided by the distance between the position where the hoisting line leaves the hoisting crane and the seabed.

[0036] According to a third aspect of the present invention, a ship for performing a monopile installation method is provided, the ship comprising a hull, a pile gripper arranged on the hull for engaging with the monopile, an automatic ship position holding system for positioning the ship, a pile gripper positioning system for positioning the monopile together with the pile gripper and is provided with the automatic ship position holding system is configured to determine the position of the ship, during at least a portion of the monopile installation method, the ship is configured to operate the pile gripper positioning system to at least partially compensate for the deviation of the determined position of the ship from the desired position of the ship.

[0037] In one embodiment, the automatic ship position holding system is configured to provide the determined position of the ship to the pile gripper positioning system, and the pile gripper positioning system is a pile gripper positioning system according to the first aspect of the present invention.

[0038] In one embodiment, the automatic ship position holding control unit is an automatic ship position holding control unit according to the second aspect of the present invention, and the pile gripper positioning system is configured to receive a signal representing at most a part of the difference in order to at least partially compensate for the deviation of the determined position of the ship from the desired position of the ship.

[0039] In one embodiment, the ship includes an overall control unit, and the pile gripper positioning system receives a signal representing the position of the ship from the automatic ship position holding system, and the actuator system determines a drive signal for compensating for at most a part of the deviation of the position of the ship from the desired position of the ship, and is configured to output the drive signal to the pile gripper positioning system to at least partially compensate for the deviation of the determined position of the ship from the desired position of the ship.

[0040] According to a fourth aspect of the present invention, a method for installing a monopile is provided, and a ship having an automatic ship position holding system for positioning the ship and a pile gripper for engaging with the monopile is used. The method includes: a. Lowering the monopile towards or into the seabed while engaging the monopile with the pile gripper; b. Determining the deviation of the position of the ship from the desired position of the ship; c. At least partially compensating for the deviation with the pile gripper. Including.

[0041] In one embodiment, the ship includes a lifting crane for lifting the monopile.

[0042] In one embodiment, the method is performed while the monopile is suspended by a lifting crane.

[0043] In one embodiment, the method is performed during a portion of a monopile installation method.

[0044] In one embodiment, the method is performed during at least a portion of a seabed penetration stage in which the monopile is suspended from a lifting crane, engaged by a pile gripper, and the lower end of the monopile penetrates the seabed.

[0045] In one embodiment, the method is a carry-out during at least a portion of a lowering stage in which the monopile is suspended from a lifting crane, engaged by a pile gripper, and the lower end of the monopile is in the water but above the seabed.

[0046] According to a fifth aspect of the present invention, an automatic ship position holding system for a ship is provided. The ship includes a lifting crane for lifting a monopile and a pile gripper for engaging the monopile. The lifting crane and the pile gripper cooperate to lower the monopile into the sea. The automatic ship position holding system includes an actuator system for applying a force to the ship to position the ship, a measurement system for measuring the position of the ship, an automatic ship position holding control unit for driving the actuator system depending on a desired position and an actual position of the ship measured by the measurement system and the automatic ship position holding control unit is configured to receive a signal representing a force applied to the ship by the pile gripper, the automatic ship position holding control unit is configured to use a portion of the signal as a feed-forward signal for driving the actuator system.

[0047] The obvious improvement compared to WO 2020 / 145825 by using the actual force applied to the ship by the pile gripper instead of the desired force to be applied by the pile gripper is insufficient to improve stability in all situations, but is based on the insight that stability is improved by using a portion of the actual force applied by the pile gripper as a feedforward signal.

[0048] It is explicitly noted here that the position of the ship may alternatively or additionally refer to the position of a part of the ship and / or the orientation of the ship or a part thereof.

[0049] It is further explicitly noted that using a portion of the signal representing the force applied to the ship by the pile gripper means that at least a non-zero portion of the signal is ignored or discarded by multiplication by a factor less than 1 or by subtraction of a non-zero value.

[0050] In one embodiment, the ratio of the portion of the signal used as the feedforward signal to the total signal received is from 0.4 to 0.9, preferably from 0.5 to 0.7, for example 0.6.

[0051] The monopile installation method may include a plurality of steps including but not limited to the following: A lifting step in which the monopile is lifted above the water level from a lifting crane and engaged by a pile gripper, A lowering step in which the monopile is lowered from the lifting crane, engaged by a pile gripper, and the lower end of the monopile is in the water but above the seabed, A seabed penetration step in which the monopile is lowered from the lifting crane, engaged by a pile gripper, and the lower end of the monopile penetrates the seabed, A driving step in which the monopile is engaged by a pile gripper and driven into the seabed using a hammer or the like.

[0052] In one embodiment, the ratio of the used portion of the signal as the feedforward signal to the total received signal or the non-zero value to be subtracted depends on the stage of the monopile installation method.

[0053] In one embodiment, using only a portion of the signal representing the force applied to the ship by the pile gripper, such as a ratio less than 1 or a non-zero value to be subtracted, is applicable only during the lowering stage and / or the seabed penetration stage.

[0054] In one embodiment, the ratio of the used portion of the signal as the feedforward signal to the total received signal or the non-zero value to be subtracted depends on one or more of the following parameters: The weight of the monopile, The length of the monopile, The inclination of the monopile with respect to the vertical, The length of the hoisting wire between the hoisting crane and the monopile, The direction of the hoisting wire between the hoisting crane and the monopile, The length of the monopile below the pile gripper, The length of the monopile above the pile gripper, The length of the monopile between the pile gripper and the seabed, The ratio of the length of the monopile below the pile gripper to the length of the monopile above the pile gripper, The ratio of the length of the monopile above the pile gripper to the length of the monopile between the pile gripper and the seabed, The position of the center of gravity of the monopile, and The tension of the hoisting wire between the hoisting crane and the monopile.

[0055] In one embodiment, the ratio of the used portion of the signal as the feedforward signal to the total received signal depends on the length of the monopile below the pile gripper or the length of the monopile between the pile gripper and the seabed, and the length of the monopile above the pile gripper. In one embodiment, this dependency may be applicable only during the seabed penetration stage.

[0056] In one embodiment, during the seabed penetration phase, the automatic ship position holding system is configured to determine the ratio α between the used portion of the signal as the feedforward signal and the total received signal using the following formula: α = a / (a + b) where a is the length of the monopile above the pile gripper, and b is the length of the monopile below the pile gripper or the length of the monopile between the pile gripper and the seabed.

[0057] In one embodiment, the automatic ship position holding system is configured to receive an input that enables determination of the parameters a and b. This input may include one or more of the following information: a measurement signal representing the parameter a, a measurement signal representing the parameter b, the total length of the monopile being processed, a measurement signal representing the (vertical) position of the lifting hook from which the monopile is suspended, and (average) water depth.

[0058] According to a sixth aspect of the present invention, there is provided a pile gripper positioning system configured to be provided on a ship for engaging a monopile suspended by a ship's lifting crane. The pile gripper positioning system includes an actuator system for applying a force to the pile gripper to position the pile gripper relative to the ship, and a measurement system for determining the position of the monopile within the pile gripper, and a pile gripper control unit for driving the actuator system depending on the desired position and the actual position of the monopile measured by the measurement system and the measurement system is further configured to determine the force applied to the ship by the pile gripper. The pile gripper control unit is configured to output a signal representing a part of the force applied to the ship by the pile gripper measured by the measurement system.

[0059] Here, it is explicitly noted that the position of the pile gripper may alternatively or additionally refer to the position of a part of the pile gripper and / or the orientation of the pile gripper or a part thereof. Further, the position of the monopile within the pile gripper may alternatively or additionally refer to the position of a part of the monopile and / or the orientation of the monopile or a part thereof.

[0060] It is further explicitly noted that outputting a part of the signal representing the force applied to the ship by the pile gripper means that at least the non - zero part of the said signal is ignored or discarded by multiplication by a coefficient less than 1 or by subtraction of a non - zero value.

[0061] In one embodiment, the ratio of the output signal to the signal representing the force applied to the ship by the pile gripper measured by the measurement system is 0.4 to 0.9, preferably 0.5 to 0.7, for example 0.6.

[0062] In one embodiment, the ratio of the output signal to the signal representing the force applied to the ship by the pile gripper measured by the measurement system, or the non - zero value to be subtracted, depends on the steps of the monopile installation method as described above for the fifth aspect of the present invention.

[0063] In one embodiment, outputting only a part of the signal representing the force applied to the ship by the pile gripper measured by the measurement system, for example a ratio less than 1 or a non - zero value to be subtracted, is applicable only during the lowering stage and / or the seabed penetration stage.

[0064] In one embodiment, the ratio of the output signal to the signal representing the force applied to the vessel by the pile gripper measured by the measurement system, or the non-zero value to be subtracted, depends on one or more of the following parameters: The weight of the monopile, The length of the monopile, The inclination of the monopile with respect to the vertical, The length of the lifting wire between the lifting crane and the monopile, The direction of the lifting wire between the lifting crane and the monopile, The length of the monopile below the pile gripper, The length of the monopile above the pile gripper, The length of the monopile between the pile gripper and the seabed, The ratio of the length of the monopile below the pile gripper to the length of the monopile above the pile gripper, The ratio of the length of the monopile above the pile gripper to the length of the monopile between the pile gripper and the seabed, The position of the center of gravity of the monopile, and The tension in the lifting wire between the lifting crane and the monopile.

[0065] In one embodiment, the ratio of the output signal to the signal representing the force applied to the vessel by the pile gripper measured by the measurement system, or the non-zero value to be subtracted, depends on the length of the monopile below the pile gripper, the length of the monopile between the pile gripper and the seabed, and the length of the monopile above the pile gripper. In one embodiment, this dependency may only apply during the seabed penetration phase.

[0066] In one embodiment, during the seabed penetration phase, the automatic ship position holding system is configured to determine the ratio α of the output signal to the signal representing the force applied to the vessel by the pile gripper measured by the measurement system using the following equation: α = a / (a + b) a is the length of the monopile above the pile gripper, and b is the length of the monopile below the pile gripper or the length of the monopile between the pile gripper and the seabed.

[0067] In one embodiment, the automatic ship position holding system is configured to receive an input that enables determination of parameters a and b. This input may include one or more of the following information: A measurement signal representing parameter a, A measurement signal representing parameter b, The total length of the monopile to be processed, A measurement signal representing the (vertical) position of the lifting hook from which the monopile is suspended, and (Average) water depth.

[0068] According to a seventh aspect of the present invention, a ship for installing a monopile is provided, the ship comprising: A hull, A lifting crane provided on the hull for suspending the monopile, A pile gripper for engaging with the monopile, An automatic ship position holding system for positioning the ship, A pile gripper positioning system for positioning the monopile together with the pile gripper and The pile gripper positioning system is configured to determine the force applied to the ship by the pile gripper, and the ship is configured to use a portion of the determined force as a feedforward signal to the automatic ship position holding system to position the ship.

[0069] Here, it is explicitly noted that the position of the ship may alternatively or additionally refer to the position of a part of the ship and / or the orientation of the ship or a part thereof. Further, the position of the monopile may alternatively or additionally refer to the position of a part of the monopile and / or the orientation of the monopile or a part thereof.

[0070] In one embodiment, the pile gripper positioning system is configured to provide a signal representing the force applied to the ship by the pile gripper to the automatic ship position holding system, and the automatic ship position holding system is the automatic ship position holding system according to the fifth aspect of the present invention.

[0071] In one embodiment, the pile gripper positioning system is the pile gripper positioning system according to the sixth aspect of the present invention, and the pile gripper positioning system provides a signal representing a part of the force applied to the ship by the pile gripper determined by the pile gripper positioning system to the automatic ship position holding system.

[0072] In one embodiment, the ship includes an overall control unit, the pile gripper positioning system is configured to provide a signal representing the force applied to the ship by the pile gripper to the overall control unit, and the overall control unit uses a part of the signal received from the pile gripper positioning system to determine a feedforward signal to be provided to the automatic ship position holding system by the overall control unit.

[0073] Explicitly note that using a part of the signal representing the force applied to the ship by the pile gripper means that the overall control unit ignores or discards at least the non-zero part of the signal by multiplying it by a coefficient less than 1 or subtracting a non-zero value.

[0074] According to the eighth aspect of the present invention, a method for installing a monopile is provided. A ship is used, which includes an automatic ship position holding system for positioning the ship, a lifting crane for suspending the monopile, and a pile gripper for engaging with the monopile during the lowering of the monopile. The method includes: a. Lowering the monopile towards or into the seabed while engaging the monopile with the pile gripper; b. Determining the force applied to the ship by the pile gripper during the lowering; c. using a portion of the determined force as a feed - forward signal to an automatic ship - position - holding system to position the ship including.

[0075] In one embodiment, the method is performed when the monopile is being lifted by a lifting crane.

[0076] It is explicitly mentioned here that the embodiments and / or features described in connection with one aspect of the present invention can be readily applied to other aspects of the present invention where appropriate.

[0077] As an example, a pile gripper positioning system according to a first aspect of the present invention may be combined with a pile gripper positioning system according to a sixth aspect of the present invention as follows: A pile gripper positioning system configured to be provided on a ship for engaging a monopile during a monopile installation method, the pile gripper positioning system comprising: an actuator system for applying a force to the pile gripper to position the pile gripper relative to the ship; a measurement system for determining the position of the monopile within the pile gripper relative to the ship; a pile gripper control unit for driving the actuator system depending on a desired position and the actual position of the monopile measured by the measurement system; and the pile gripper control unit is configured to receive a signal representing the position of the ship; during at least a portion of the monopile installation method, the pile gripper control unit is configured to determine a drive signal for the actuator system to compensate for at most a portion of the deviation of the position of the ship from the desired position of the ship; Between at least a part of the methods for installing monopiles, a pile gripper control unit for driving an actuator system is configured to drive the actuator system depending on a desired position and an actual position of the monopile measured by a measurement system and a drive signal, so as to compensate for at least a part of the deviation of the position of the ship from the desired position of the ship. The measurement system is further configured to determine a force applied to the ship by the pile gripper. The pile gripper control unit is configured to output a signal representing at least a part of the force applied to the ship by the pile gripper measured by the measurement system.

[0078] As a further example, an automatic ship position holding system according to a second aspect of the present invention may be combined with an automatic ship position holding system according to a fifth aspect of the present invention as follows: An automatic ship position holding system for a ship, wherein the ship comprises a lifting crane for lifting a monopile and a pile gripper for engaging with the monopile, and the lifting crane and the pile gripper are configured to cooperate during a monopile installation method to lower the monopile into the sea. The automatic ship position holding system comprises: an actuator system for applying a force to the ship to position the ship; a measurement system for measuring the position of the ship; an automatic ship position holding control unit for driving the actuator system depending on a desired position and an actual position of the ship measured by the measurement system; and the automatic ship position holding control unit is configured to determine a signal representing a difference between the desired position and the actual position of the ship; During at least a part of the installation method, the automatic ship position holding control unit is configured to output a signal representing at least a part of the maximum of the difference. The automatic ship position holding control unit is configured to receive a signal representing a force applied to the ship by the pile gripper. The automatic ship position holding control unit is configured to use a portion of the signal as a feed-forward signal for driving the actuator system.

[0079] As another example, a ship according to a third aspect of the present invention may be combined with a ship according to a seventh aspect of the present invention as follows: A ship for performing a monopile installation method, a hull, a pile gripper disposed on the hull for engaging with the monopile, an automatic ship position holding system for positioning the ship, a pile gripper positioning system for positioning the monopile together with the pile gripper and, the pile gripper positioning system is configured to determine the force applied to the ship by the pile gripper, the ship is configured to use a portion of the determined force as a feed-forward signal to the automatic ship position holding system to position the ship, the automatic ship position holding system is configured to determine the position of the ship, during at least a portion of the monopile installation method, the ship is configured to operate the pile gripper positioning system to at least partially compensate for the deviation of the determined position of the ship from the desired position of the ship by up to a maximum.

[0080] Alternatively, the ship may be described as follows: A ship for performing a monopile installation method, a hull, a pile gripper disposed on the hull for engaging with the monopile, an automatic ship position holding system for positioning the ship, a pile gripper positioning system for positioning the monopile together with the pile gripper and, The automatic ship position holding system is an automatic ship position holding system according to the second aspect of the present invention, the pile gripper positioning system is a pile gripper positioning system according to the sixth aspect of the present invention, and / or The automatic ship position holding system is an automatic ship position holding system according to the fifth aspect of the present invention, and the pile gripper positioning system is a pile gripper positioning system according to the first aspect of the present invention.

[0081] As a further example, the method according to the fourth aspect of the present invention may be combined with the method according to the eighth aspect of the present invention as follows: A method for installing a monopile, wherein a ship is used, the ship comprising an automatic ship position holding system for positioning the ship and a pile gripper for engaging with the monopile, the method comprising: a. lowering the monopile towards or into the seabed while engaging the monopile with the pile gripper; b. determining a deviation of the position of the ship from a desired position of the ship; c. at least partially compensating for said deviation with the pile gripper; d. determining a force applied to the ship by the pile gripper during lowering; e. using a portion of said determined force as a feed-forward signal to the automatic ship position holding system to position the ship. Including.

[0082] Throughout this specification, it is explicitly stated that a signal may refer to its signal value where appropriate. Thus, the term "signal" may be replaced throughout this specification by the term "signal value".

Brief Description of the Drawings

[0083] Next, the present invention will be described non-limitingly with reference to the accompanying drawings, in which like parts are designated by like reference numerals.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0084] FIGS. 1 and 2 schematically illustrate a ship 200 according to an embodiment of the present invention. The ship 200 includes a deck 201. The deck 201 provides sufficient space to store five monopiles 202 in a horizontal orientation in this case. The monopiles 202 are stored such that their longitudinal axes are parallel to the longitudinal axis of the ship 200.

[0085] In this embodiment, the ship 200 is a single-hull ship, but alternatively, the ship can also be semi-submersible.

[0086] At the stern of the ship 200, a lifting crane 203 is provided. The lifting crane 203 is arranged at the center of the deck 201 when viewed in the lateral direction of the ship 200 so as to coincide with the center of gravity of the ship 200. On one side of the lifting crane, a pile gripper 1 is arranged, and on the opposite side of the lifting crane 203, a pile driving mechanism 205, which is also alternatively called a pile hammer, is arranged at a corresponding storage location.

[0087] When the ship 200 sails to an offshore installation location where the monopile 202 needs to be installed on the seabed, the monopile 202 is positioned within the pile holder 50 of the pile gripper 1. In this embodiment, the pile holder 50 is rotatable between a vertical orientation capable of receiving a horizontally oriented monopile and a horizontal orientation as shown in FIG. 1 that can guide the lowering of the monopile into the sea or into the seabed towards the seabed. In this embodiment, the monopile is positioned in the pile holder 50 of the pile gripper 1 while the pile holder 50 is in the vertical position.

[0088] The arms 57, 58 of the pile holder 50 are movable between an open position that allows the monopile 202 to pass through the arms 57, 58, thus enabling the reception of the monopile, and a closed position where the pile holder 50 (and thus the pile gripper 1) engages with the monopile 202 to restrict movement in a direction perpendicular to the longitudinal axis of the monopile 202.

[0089] The pile holder 50 may be provided with a pile support portion 77 configured to engage with the lower end of the monopile 202. The monopile 202 can be engaged by first positioning the pile support portion 77 at a desired position and then translating the monopile along its longitudinal axis until the lower end of the monopile engages with the pile support portion 77. The pile support portion 77 is used to restrict movement of the monopile 202 in a direction parallel to the longitudinal axis of the monopile 202, which is advantageous when standing the monopile 202 upside down.

[0090] Next, with the lower side of the monopile 202 within the pile holder 50, the upper end of the monopile 202 is lifted using the lifting crane 203, thereby rotating the monopile 202 from a horizontal orientation to a vertical orientation. FIG. 2 shows the monopile in an intermediate diagonal orientation between the horizontal and vertical orientations.

[0091] After rotation, the pile holder 50 is in a horizontal position, which may alternatively be referred to as the lowering position, and the monopile 202 is positioned outside the contour of the ship 202, i.e., outside the ship as viewed from above, in order to be lowered into the water as seen in FIG. 1.

[0092] Before lowering the monopile 202 into the water, the lower end of the monopile 202 needs to be disengaged from the pile support 77. The monopile 202 can then first be lifted using the lifting crane 203 and then moved so as not to interfere with the pile support 77. The monopile 202 can then be lowered into the water.

[0093] During the above operations, the ship 200 is in a floating state, and the pile holder 50 compensates for the wave motion of the ship 200 to maintain a predetermined X - Y position independent of the wave motion of the ship 200 by operating the pile gripper positioning system of the pile gripper 1 in wave motion compensation mode, which will be described in more detail below with reference to FIGS. 3 - 10.

[0094] In order to enable the pile gripper 1 to maintain a predetermined X - Y position, the ship 200 must maintain its position within the working range of the pile gripper 1. Accordingly, the ship 200 is provided with an automatic position - holding system for positioning the ship 200, including maintaining or adjusting the position or orientation of the ship 200. The automatic position - holding system includes, for example, an actuator system including a number of propulsion modules 220 for applying force to the ship 200, and preferably enables at least translation of the ship 200 within a horizontal X - Y plane and rotation of the ship 200 about the Z - axis.

[0095] When the monopile 202 is lowered into the water and suspended from the lifting crane 203, the lifting crane 203 can be operated in a wave motion compensation mode so that the monopile 202 is compensated for the wave motion of the ship 200 to maintain a predetermined Z position regardless of the wave motion of the ship 200. This may also be referred to as heave correction.

[0096] To lift the upper end of the monopile 202 and rotate the monopile 202 from a horizontal orientation to a vertical orientation, the lifting crane 203 may include a pile clamping device 210 having a clamping portion 211 that clamps the upper end of the monopile 202 and a connecting portion 212 that enables the pile clamping device to be connected to the load connector 213 of the lifting crane 203. The connecting portion 212 can rotate freely relative to the clamping portion 211 during the lifting of the upper end, that is, during the rotation of the monopile 202.

[0097] FIG. 3 schematically illustrates a control method of the ship 200 according to an embodiment of the present invention. The control method of FIG. 3 can be used to control the ship 200 of FIG. 1.

[0098] FIG. 3 schematically illustrates the ship 200, an automatic ship position holding system 100 for positioning the ship 200, and a pile gripper 1 having a pile gripper positioning system 150 for positioning the monopile together with the pile gripper 1. Although the pile gripper 1 is shown to be part of the pile gripper positioning system 150, it is explicitly noted here that the pile gripper 1 is not part of the pile gripper positioning system 150. The pile gripper 1 includes structural elements, and the pile gripper positioning system 150 includes all other components configured to position the structural elements of the pile gripper 1.

[0099] The automatic ship position holding system 100 includes an actuator system 220 for applying a force F1 to the ship 200 to position the ship 200. The automatic ship position holding system 100 further includes a measurement system 105 for measuring the position of the ship 200, and an automatic ship position holding control unit 110 for driving the actuator system 220 depending on a desired position 111 and an actual position 112 measured by the measurement system 105.

[0100] The pile gripper positioning system 150 includes an actuator system 170 for applying a force F2 to the pile gripper 1 to position the pile gripper 1 relative to the ship 200. The pile gripper positioning system 150 further includes a measurement system 155 for determining the position of the monopile within the pile gripper 1, and a pile gripper control unit 160 for driving the actuator system 170 using a drive signal 164 depending on a desired position 161 and an actual position 162 of the monopile measured by the measurement system 155.

[0101] The automatic ship position holding system 100 is configured to output a signal 112a representing the position of the ship 200. This signal 112a is supplied to the pile gripper positioning system 150, where the pile gripper control unit 160 is configured to receive the signal 112a representing the position of the ship 200.

[0102] In this embodiment, during at least part of the monopile installation method, the pile gripper control unit 160 is configured to determine a drive signal 163 for the actuator system 170 to compensate for at least part of the deviation of the position of the ship 200 from the desired position of the ship 200.

[0103] The signal 112a output by the automatic ship position holding system 100 may be equal to the actual position 112 measured by the measurement system 105. Subsequently, the deviation of the position of the ship 200 from the desired position of the ship 200 is determined by providing the desired position 111 of the ship 200 via the dashed line 111b, which may enable the pile gripper control unit 160 to compare the actual position 112 with the desired position 111.

[0104] Alternatively, the deviation of the position of the ship 200 from the desired position 111 of the ship 200 may be determined in the automatic ship position holding system, for example, by comparing the signal 112 with the signal 111a and outputting this comparison as the signal 112a, where the signal 112a represents here the deviation of the position of the ship 200 from the desired position 111 of the ship.

[0105] Alternatively, the position output by the measurement system 105 may already be a relative measurement value indicating the deviation of the position of the ship 200 from the desired position 111 of the ship, so there is no need to provide the desired position further. Since there are many possible ways, the signals 111a and 111b are shown using dashed lines.

[0106] The pile gripper control unit 160 drives the actuator system 170 using a drive signal 164 that depends on the desired position 161, the actual position 162 of the monopile measured by the measurement system 155, and the drive signal 163, at least between the said parts of the monopile installation method, and is further configured to compensate for at least a part of the deviation of the position of the ship from the desired position of the ship.

[0107] In this embodiment, compensating for at least a part of the deviation of the ship 200 from the desired position of the ship is implemented by applying a coefficient α, where α < 1, to the received signal 112a and possibly also to the received signal 11b if it exists. Alternatively, a non-zero value can also be subtracted from the (one or more) received signals.

[0108] Figure 4 schematically illustrates a control method for a ship 200 according to another embodiment of the present invention. The control method of Figure 4 can be used to control the ship 200 of Figure 1.

[0109] Figure 4 schematically illustrates the ship 200, an automatic position-keeping system 100 for positioning the ship 200, and a pile gripper 1 having a pile gripper positioning system 150 for positioning a monopile together with the pile gripper 1. Although the pile gripper 1 is shown as being part of the pile gripper positioning system 150, it is expressly noted here that the pile gripper 1 is not part of the pile gripper positioning system 150. The pile gripper 1 includes structural elements, and the pile gripper positioning system 150 includes all other components configured to position the structural elements of the pile gripper 1.

[0110] The automatic position-keeping system 100 includes an actuator system 220 for applying a force F1 to the ship 200 to position the ship 200. The automatic position-keeping system 100 further includes a measurement system 105 for measuring the position of the ship 200, and an automatic position-keeping control unit 110 for driving the actuator system 220 depending on a desired position 111 and an actual position 112 measured by the measurement system 105.

[0111] The pile gripper positioning system 150 includes an actuator system 170 for applying a force F2 to the pile gripper 1 to position the pile gripper 1 relative to the ship 200. The pile gripper positioning system 150 further includes a measurement system 155 for determining the position of the monopile within the pile gripper 1, and a pile gripper control unit 160 for driving the actuator system 170 using a drive signal 164 depending on a desired position 161 and an actual position 162 of the monopile measured by the measurement system 155.

[0112] The automatic ship position holding system 100 is configured to output a signal 112a representing the position of the ship 200. This signal 112a is supplied to the pile gripper positioning system 150, where the pile gripper control unit 160 is configured to receive the signal 112a representing the position of the ship 200.

[0113] The automatic ship position holding system 100 is configured to output a signal 112a representing at least a part of the difference between the desired position 111a and the actual position 112 of the ship 200 during at least a part of the installation method to be executed. This signal 112a is supplied to the pile gripper positioning system 150, where the pile gripper control unit 160 is configured to receive the signal 112a representing a part of the position deviation of the ship 200.

[0114] Alternatively, the signal output by the measurement system 105 may already be a relative measurement value indicating the deviation of the position of the ship 200 from the desired position 111a or 111 of the ship 202, whereby the signal 111a can be omitted.

[0115] The pile gripper control unit 160 drives the actuator system 170 using a drive signal 164 that depends on at least the desired position 161, the actual position 162 of the monopile measured by the measurement system 155, and the signal 112a representing the difference between the desired position and the actual position of the ship 200 during at least the said part of the monopile installation method, and is further configured to compensate for at least a part of the said difference.

[0116] In this embodiment, compensating for at least a part of the difference between the desired position and the actual position of the ship 200 is implemented by applying a coefficient α, where α < 1, to the said difference. Alternatively, a non-zero value can also be subtracted from the difference.

[0117] FIG. 5 schematically illustrates a control method for the ship 200 according to a further embodiment of the present invention. The control method of FIG. 5 can be used to control the ship 200 of FIG. 1.

[0118] FIG. 5 schematically illustrates a ship 200, an automatic ship position holding system 100 for positioning the ship 200, and a pile gripper 1 having a pile gripper positioning system 150 for positioning a monopile together with the pile gripper 1. Although the pile gripper 1 is shown as being part of the pile gripper positioning system 150, it is expressly noted here that the pile gripper 1 is not part of the pile gripper positioning system 150. The pile gripper 1 includes structural elements, and the pile gripper positioning system 150 includes all other components configured to position the structural elements of the pile gripper 1.

[0119] The automatic ship position holding system 100 includes an actuator system 220 for applying a force F1 to the ship 200 to position the ship 200. The automatic ship position holding system 100 further includes a measurement system 105 for measuring the position of the ship 200, and an automatic ship position holding control unit 110 for driving the actuator system 220 depending on an input signal 111 and an actual position 112 measured by the measurement system 105.

[0120] The pile gripper positioning system 150 includes an actuator system 170 for applying a force F2 to the pile gripper 1 to position the pile gripper 1 relative to the ship 200. The pile gripper positioning system 150 further includes a measurement system 155 for determining the position of the monopile within the pile gripper 1, and a pile gripper control unit 160 for driving the actuator system 170 using a drive signal 164 depending on an input signal 161 and an actual position 162 of the monopile measured by the measurement system 155.

[0121] The input signals 111 and 161 are respectively provided to the automatic position holding control unit 110 and the pile gripper control unit 160 by the overall control unit 180. The overall control unit 180 is configured to receive one or more inputs and output signals 111 and 161 that enable the use of information from different systems when driving the automatic position holding system 100 and the pile gripper positioning system 150 depending on these one or more inputs. Two examples of one or more inputs to the overall control unit 180, namely, the user input 181 and the measurement signal 112 from the measurement system 155, are shown.

[0122] Thus, the measurement signal 112 provided to the overall control unit 180 represents the actual position of the ship 200. The overall control unit 180 is configured to compare this actual position of the ship 200 with the desired position 111a of the ship 200 and determine the drive signal 163 using only a part of the comparison result within the unit 190 to at least partially compensate for the deviation of the determined position of the ship from the desired position of the ship. The drive signal 163 may, in some cases, be combined with other signals to determine the input signal 161 to be provided to the pile gripper control unit 160.

[0123] To at least partially compensate for the deviation of the determined position of the ship from the desired position of the ship, a coefficient α is applied to the signals 112 and 111a. Alternatively, a non-zero value can also be subtracted from the received signal.

[0124] With reference to FIGS. 1 to 5, a part of the monopile installation method has already been described. More specifically, the monopile installation method may include, but is not limited to, a plurality of steps including the following: After the monopile has been fully rotated to a vertical orientation, as shown, for example, in FIG. 2, a lifting step in which the monopile is lifted above the water level from the lifting crane and engaged by the pile gripper. The monopile is lifted from the lifting crane, engaged by the pile gripper, and the lower end of the monopile is in the water but above the seabed, also referred to throughout this specification as the seabed, during the lowering stage. The seabed penetration stage where the monopile is lifted from the lifting crane, engaged by the pile gripper, and the lower end of the monopile penetrates the seabed, and The driving-in stage where the monopile is engaged by the pile gripper and driven into the seabed using a hammer or the like.

[0125] Figure 6 schematically illustrates the monopile 202 during the seabed penetration stage of the monopile installation method. The monopile 202 is lifted from the lifting crane using a pile clamping device 210 comprising a clamping portion 211 that clamps the upper end of the monopile 202 and a connecting portion 212 that enables connection of the pile clamping device 210 to the load connector of the lifting crane. The connecting portion 212 can rotate freely relative to the clamping portion 211 about a rotation axis 251, thereby providing a suspension point. Alternatively, the clamping device 210 may include only the clamping portion 211 configured to be directly connected to the load connector of the lifting crane and thereby provide a suspension point 251 that allows some rotation of the clamping portion 211 relative to the load connector. The connecting portion 212 may in this case be the winch cable and the load connector, referenced using reference numeral 250 to clearly distinguish the two alternative suspension types.

[0126] During the seabed penetration stage, the lower end of the monopile 202 penetrates the seabed SB, and the monopile 202 is engaged by the pile gripper to apply a force FG to the monopile using, for example, a pile gripper positioning system as described above.

[0127] Various parameters can be defined as follows: a The length of the monopile above the pile gripper a’ The distance between the pile gripper and the suspension point The length of the monopile below the pile gripper, and The length of the monopile between the pile gripper and the seabed.

[0128] Alternatively, or additionally, the following parameters may be defined: c = a + b’, i.e., the length of the monopile above the seabed, and c’ = a’ + b’, i.e., the distance between the seabed and the suspension point.

[0129] The ratio α described above in connection with FIGS. 3 to 5 can be determined during the seabed penetration phase using the following formula or its equivalent: JPEG2025522764000002.jpg32113where L is equal to the length of the monopile, l1 is a monopile of a predetermined length above the seabed, i.e., L - l1 is the predetermined length of the monopile penetrating the seabed, also called the penetration depth, and the control of the monopile corresponds to a situation where the pile gripper positioning system is sufficiently stable to fully compensate for the deviation of the actual position of the ship from the desired position of the ship. Therefore, during the duration of the seabed penetration phase when the parameter c is between L and L - l1, at most a part of the said deviation is compensated by the pile gripper positioning system.

[0130] By compensating only a part of the deviation, the stability is improved as a compensation for the possible position loss of the monopile. However, at this stage of the monopile installation method, the position of the monopile can still be corrected, and a large compensation force due to the deviation of the position of the ship is prevented. As the penetration depth increases, the stability of the monopile improves, a greater force can be applied between the monopile and the ship, the position of the monopile can be corrected, and thus it becomes possible to fully compensate for the deviation of the position of the ship.

[0131] It is explicitly noted that although the above formula shows a linear relationship, other relationships, such as quadratic, hyperbolic, non-linear, etc., may also be used here.

[0132] FIG. 7 schematically illustrates a vessel 200 during the lowering stage of a monopile installation method as described above, for example. The vessel includes a lifting crane 203 for lowering the monopile 202 using a winch line 215. The vessel 200 further includes a pile gripper 10 for engaging with the monopile.

[0133] FIG. 7 includes a vessel 200 and a monopile 202 in solid and dashed lines. The solid-line version corresponds to a situation where the monopile 202 is in a vertical orientation above the position LO where the monopile 202 is to be installed on the seabed SB and the vessel 200 is in the desired position.

[0134] The dashed-line version corresponds to a situation where the vessel 200 is being drifted, and thus there is a displacement Δx of the position of the vessel 200 from its desired position (solid line).

[0135] Due to the displacement Δx of the position of the vessel 200, the position where the winch line 215 leaves the lifting crane 203 is also displaced, whereby, in principle, the monopile 202 is carried away with the winch line and the monopile 202 moves away from the position LO.

[0136] In one embodiment, the pile gripper 10 can be operated to compensate for only a portion α*Δx of the displacement Δx of the position of the vessel 200 from its desired position, using, for example, one of the control systems of FIGS. 3 - 5. α is defined by the ratio D1 / (D1 + D2), where D1 is the distance between the position where the winch line 215 leaves the lifting crane 203 and the pile gripper 10, and D2 is the distance between the pile gripper 10 and the seabed SB. Thus, D1 + D2 is the position where the winch line 215 leaves the lifting crane 203 and the seabed SB.

[0137] The advantage of defining α as the ratio D1 / (D1+D2) is that the monopile 202 maintains its orientation towards the intended installation position LO regardless of the movement of the ship, thereby allowing the monopile to be easily landed on the seabed SB at position LO without stability problems. After landing on the seabed, the seabed penetration stage begins, and the situation of Figure 6 may apply.

[0138] In one embodiment, the formula for α described in relation to Figure 6 can be applied to the seabed penetration stage with the difference that the minimum ratio defined by D1 / (D1+D2) is always applied according to the embodiment of Figure 7.

[0139] Figure 8 schematically illustrates a control method for a ship 200 according to an embodiment of the present invention. The control method of Figure 3 can be used to control the ship 200 of Figure 1.

[0140] Figure 8 schematically illustrates the ship 200, an automatic position-keeping system 100 for positioning the ship 200, and a pile gripper 1 having a pile gripper positioning system 150 for positioning the monopile together with the pile gripper 1. Although the pile gripper 1 is shown as being part of the pile gripper positioning system 150, it is explicitly stated here that the pile gripper 1 is not part of the pile gripper positioning system 150. The pile gripper 1 includes structural elements, and the pile gripper positioning system 150 includes all other components configured to position the structural elements of the pile gripper 1.

[0141] The automatic position-keeping system 100 includes an actuator system 220 for applying a force F1 to the ship 200 to position the ship 200. The automatic position-keeping system 100 further includes a measurement system 105 for measuring the position of the ship 200 and an automatic position-keeping control unit 110 for driving the actuator system 220 depending on the desired position 111 and the actual position 112 measured by the measurement system 105.

[0142] The pile gripper positioning system 150 includes an actuator system 170 for applying a force F2 to the pile gripper 1 to position the pile gripper 1 relative to the ship 200. The pile gripper positioning system 150 further includes a measurement system 155 for determining the position of the monopile within the pile gripper 1, and a pile gripper control unit 160 for driving the actuator system 170 depending on a desired position 161 and an actual position 162 of the monopile measured by the measurement system 155.

[0143] The measurement system 155 is further configured to determine a force F3 applied to the ship 200 by the pile gripper 1. The pile gripper positioning system 150 is further configured to output a signal representing the measured force F3 and provide the signal to the automatic ship position holding system 100.

[0144] In this embodiment, the automatic ship position holding system 100 is configured to use only a portion of the signal supplied by the pile gripper positioning system 150 as a feedforward signal to the automatic ship position holding control unit 110 by applying a coefficient α, where the coefficient α < 1, to the received signal. Alternatively, a non-zero value can be subtracted from the received signal.

[0145] FIG. 9 schematically illustrates a control method for a ship 200 according to another embodiment of the present invention. The control method of FIG. 9 can be used to control the ship 200 of FIG. 1.

[0146] FIG. 9 schematically illustrates a ship 200, an automatic ship position holding system 100 for positioning the ship 200, and a pile gripper 1 having a pile gripper positioning system 150 for positioning a monopile together with the pile gripper 1. Although the pile gripper 1 is shown as being part of the pile gripper positioning system 150, it is explicitly stated here that the pile gripper 1 is not part of the pile gripper positioning system 150. The pile gripper 1 includes structural elements, and the pile gripper positioning system 150 includes all other components configured to position the structural elements of the pile gripper 1.

[0147] The automatic ship position holding system 100 includes an actuator system 220 for applying a force F1 to the ship 200 to position the ship 200. The automatic ship position holding system 100 further includes a measurement system 105 for measuring the position of the ship 200, and an automatic ship position holding control unit 110 for driving the actuator system 220 depending on a desired position 111 and an actual position 112 measured by the measurement system 105.

[0148] The pile gripper positioning system 150 includes an actuator system 170 for applying a force F2 to the pile gripper 1 to position the pile gripper 1 relative to the ship 200. The pile gripper positioning system 150 further includes a measurement system 155 for determining the position of the monopile within the pile gripper 1, and a pile gripper control unit 160 for driving the actuator system 170 depending on a desired position 161 and an actual position 162 of the monopile measured by the measurement system 155.

[0149] The measurement system 155 is further configured to determine the force F3 applied to the ship 200 by the pile gripper 1. The pile gripper positioning system 150, in this embodiment, is further configured to output a signal representing a part of the measured force F3 by applying a coefficient α, where the coefficient α < 1, to the measurement signal, and to provide this reduced signal to the automatic ship position holding system 100. Alternatively, a non-zero value can be subtracted from the measurement signal to obtain a reduced signal.

[0150] The automatic ship position holding system 100 is configured to use the reduced signal provided by the pile gripper positioning system 150 as a feedforward signal to the automatic ship position holding control unit 110.

[0151] FIG. 10 schematically illustrates a control method for a ship 200 according to a further embodiment of the present invention. The control method of FIG. 10 can be used to control the ship 200 of FIG. 1.

[0152] FIG. 10 schematically shows the ship 200, the automatic ship position holding system 100 for positioning the ship 200, and the pile gripper 1 having a pile gripper positioning system 150 for positioning a monopile together with the pile gripper 1. Although the pile gripper 1 is shown as being part of the pile gripper positioning system 150, it is explicitly noted here that the pile gripper 1 is not part of the pile gripper positioning system 150. The pile gripper 1 includes structural elements, and the pile gripper positioning system 150 includes all other components configured to position the structural elements of the pile gripper 1.

[0153] The automatic ship position holding system 100 includes an actuator system 220 for applying a force F1 to the ship 200 to position the ship 200. The automatic ship position holding system 100 further includes a measurement system 105 for measuring the position of the ship 200, and an automatic ship position holding control unit 110 for driving the actuator system 220 depending on an input signal 111 and an actual position 112 measured by the measurement system 105.

[0154] The pile gripper positioning system 150 includes an actuator system 170 for applying a force F2 to the pile gripper 1 to position the pile gripper 1 relative to the ship 200. The pile gripper positioning system 150 further includes a measurement system 155 for determining the position of the monopile within the pile gripper 1, and a pile gripper control unit 160 for driving the actuator system 170 depending on an input signal 161 and an actual position 162 of the monopile measured by the measurement system 155.

[0155] The input signals 111 and 161 are respectively provided to the automatic ship position holding control unit 110 and the pile gripper control unit 160 by the overall control unit 180. The overall control unit 180 is configured to receive one or more inputs and output signals 111 and 161 that enable the use of information from different systems when driving the automatic ship position holding system 100 and the pile gripper positioning system 150 depending on these one or more inputs. Two examples of the one or more inputs to the overall control unit 180, namely, a user input 181 and a measurement signal from the measurement system 155, are shown.

[0156] The measurement system 155 is further configured to determine the force F3 applied to the ship 200 by the pile gripper 1. Thus, the signal provided to the overall control unit represents the force F3. The overall control unit uses only a portion of this signal to determine the corresponding drive signal within unit 190 and, optionally, combines the drive signal with other signals to determine the input signal 111 to be provided to the automatic position holding control unit 110. In this way, a portion of the force F3 can be used as a feedforward signal for driving the automatic position holding system 100. Alternatively, the drive signal used as the feedforward signal is provided as a separate input from the overall control unit 180 to the automatic position holding control unit 110 adjacent to the input signal 111. This can facilitate the separate use of the separate inputs.

[0157] To use only a portion of the determined force F3, a coefficient α, where α < 1, is applied by the overall control unit received signal. Alternatively, a non-zero value can be subtracted from the received signal.

[0158] Referring again to FIG. 6, the ratio α described above in connection with FIGS. 8-10 can be determined during the seabed penetration phase using the following equation: α = a / (a + b)

[0159] In one embodiment, a may be replaced by a' and / or b may be replaced by b'. If a (or a') is 1.5 times b (or b') to b (or b') during the seabed penetration phase, α will be between 0.5 and 0.6.

Claims

1. A pile gripper positioning system for a pile gripper configured to be installed on a ship for engaging with a monopile during a monopile installation method, wherein the pile gripper positioning system is An actuator system for applying force to the pile gripper to position the pile gripper relative to the vessel, A measuring system for determining the position of the monopile within the pile gripper relative to the vessel, A pile gripper control unit for driving the actuator system depending on the desired position and the actual position of the monopile as measured by the measuring system, Equipped with, The pile gripper control unit is configured to receive a signal representing the position of the vessel, During at least a portion of the monopile installation method, the pile gripper control unit is configured such that the actuator system determines a drive signal to compensate for at least a portion of the deviation of the vessel's position from a desired position. During at least a portion of the monopile installation method, the pile gripper control unit for driving the actuator system is configured to drive the actuator system depending on a desired position and the actual position of the monopile as measured by the measuring system and the drive signal to compensate for at least a portion of the deviation of the vessel's position from the desired position of the vessel, in a pile gripper positioning system.

2. The pile gripper positioning system according to claim 1, wherein the at least portion of the monopile installation method includes at least a portion of the seabed penetration stage in which the monopile is suspended from a lifting crane, engaged by the pile gripper, and the lower end of the monopile penetrates the seabed.

3. A ratio is defined between the portion of the displacement to be compensated and the total displacement of the position of the vessel from the desired position of the vessel, and the pile gripper control unit is configured such that the ratio increases with increasing penetration depth of the lower end of the monopile, according to claim 2.

4. The pile gripper positioning system according to claim 3, wherein the pile gripper control unit is configured such that the ratio has a linear relationship with the penetration depth of the lower end of the monopile.

5. The pile gripper positioning system according to claim 1, wherein the at least portion of the monopile installation method includes at least a portion of a lowering stage in which the monopile is suspended from a lifting crane and engaged by the pile gripper, and the lower end of the monopile is in the water but above the seabed, and a ratio is defined between the portion of the displacement to be compensated and the total displacement of the position of the vessel from the desired position of the vessel, and the pile gripper control unit is configured such that the ratio is set to the distance between the hoisting line and the position where it leaves the lifting crane divided by the distance between the hoisting line and the seabed.

6. An automatic ship positioning system for a vessel, wherein the vessel is equipped with pile grippers for engaging with monopiles during a monopile installation method, and the automatic ship positioning system is An actuator system for applying force to the vessel to position the vessel, A measuring system for measuring the position of the aforementioned vessel, An automatic ship position holding control unit for driving the actuator system depending on a desired position and the actual position of the ship as measured by the measuring system, Equipped with, The automatic ship position holding control unit is configured to determine a signal representing the difference between the desired position and the actual position of the ship. An automatic ship position holding system in which, during at least a portion of the installation method, the automatic ship position holding control unit is configured to output a signal representing at most a portion of the difference.

7. The automatic ship positioning system according to claim 6, wherein the at least portion of the monopile installation method includes at least a portion of the seabed penetration stage in which the monopile is suspended from a lifting crane, engaged by the pile gripper, and the lower end of the monopile penetrates the seabed.

8. An automatic ship positioning system according to claim 7, wherein a ratio is defined between the output difference and the total difference between the desired position of the ship and the actual position, and the automatic ship positioning control unit is configured to increase the ratio with increasing penetration depth of the lower end of the monopile.

9. The automatic ship position holding system according to claim 8, wherein the automatic ship position holding control unit is configured such that the ratio has a linear relationship with the penetration depth of the lower end of the monopile.

10. The automatic ship position holding system according to claim 6, wherein the at least portion of the monopile installation method includes at least a portion of a lowering stage in which the monopile is suspended from a lifting crane and engaged by the pile gripper, the lower end of the monopile is in the water but above the seabed, and a ratio is defined between the portion of the displacement to be compensated and the total displacement of the ship's position from the desired position of the ship, and the pile gripper control unit is configured such that the ratio is set to the distance between the hoisting line and the position where it leaves the lifting crane divided by the distance between the hoisting line and the seabed.

11. A vessel for carrying out a monopile installation method, The hull and, A pile gripper positioned on the hull to engage with the monopile, An automatic ship positioning system for positioning the aforementioned ship, A pile gripper positioning system for positioning a monopile together with the aforementioned pile gripper, Equipped with, The automatic ship position holding system is configured to determine the position of the ship, During at least a portion of the monopile installation method, the vessel is configured to operate the pile gripper positioning system to compensate, at most partially, for any deviation of the vessel from a desired position of the vessel to the determined position of the vessel.

12. The vessel according to claim 11, wherein the automatic vessel positioning system is configured to provide the pile gripper positioning system with the determined position of the vessel, and the pile gripper positioning system is the pile gripper positioning system according to claim 1.

13. The automatic ship positioning control unit is the automatic ship positioning control unit according to claim 6, and the pile gripper positioning system is configured to receive the signal representing at most a portion of the difference in order to at most partially compensate for at most a portion of the deviation of the ship from a desired position of the ship to the determined position of the ship according to claim 11.

14. The vessel according to claim 11, wherein the vessel comprises a total control unit, the pile gripper positioning system is configured to receive a signal representing the position of the vessel from the automatic position holding system, the actuator system determines a drive signal to compensate for at most a portion of the deviation of the vessel from a desired position, and outputs the drive signal to the pile gripper positioning system to compensate at most a portion of the determined deviation of the vessel from a desired position.

15. A method for installing a monopile, wherein a vessel is used, the vessel comprising an automatic positioning system for positioning the vessel and a pile gripper for engaging with the monopile, and the method is a. The steps of lowering the monopile toward or into the seabed while engaging the monopile with the pile gripper, b. A step of determining the deviation of the position of the vessel from a desired position of the vessel, c. A step of compensating for the aforementioned displacement at most partially with the pile gripper. Methods that include...

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