Pile gripper positioning system, dynamic positioning system, monopile installation vessel, and corresponding methods

Abstract

The invention relates to a pile gripper positioning system for a pile gripper that is configured to be provided on a vessel to engage with a monopile during a monopile installation method, wherein the pile gripper positioning system comprises: —an actuator system for applying forces to the pile gripper to position the pile gripper relative to the vessel, —a measurement system for determining a position of the monopile in the pile gripper relative to the vessel, and—a pile gripper control unit for driving the actuator system in dependency of a desired position and an actual position of the monopile as measured by the measurement system, wherein the pile gripper control unit is configured to receive a signal representative for a position of the vessel, wherein, 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 at most a portion of a deviation of the position of the vessel from a desired position of the vessel, and wherein, during said 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 in dependency of a desired position and an actual position of the monopile as measured by the measurement system, and the drive signal to compensate at most a portion of a deviation of the position of the vessel from a desired position of the vessel.

1 . A pile gripper positioning system for a pile gripper that is configured to be provided on a vessel to engage with a monopile during a monopile installation method, wherein the pile gripper positioning system comprises:
 an actuator system for applying forces to the pile gripper to position the pile gripper relative to the vessel,   a measurement system for determining a position of the monopile in the pile gripper relative to the vessel, and   a pile gripper control unit for driving the actuator system in dependency of a desired position and an actual position of the monopile as measured by the measurement system,   wherein the pile gripper control unit is configured to receive a signal representative for a position of the vessel,   wherein, 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 at most a portion of a deviation of the position of the vessel from a desired position of the vessel,   and wherein, during said 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 in dependency of a desired position and an actual position of the monopile as measured by the measurement system, and the drive signal to compensate at most a portion of a deviation of the position of the vessel from a desired position of the vessel.   
     
     
         2 . A pile gripper positioning system according to  claim 1 , wherein the at least a portion of the monopile installation method includes at least a portion of the seabed penetration phase in which the monopile is suspended from a lifting crane and engaged by the pile gripper, and a lower end of the monopile has penetrated the seabed. 
     
     
         3 . A pile gripper positioning system according to  claim 1 , wherein a ratio is defined between the to be compensated portion of the deviation and the full deviation of the position of the vessel from the desired position of the vessel, and wherein the pile gripper control unit is configured such that said ratio is increasing with increasing penetration depth of the lower end of the monopile. 
     
     
         4 . A pile gripper positioning system according to  claim 3 , wherein the pile gripper control unit is configured such that said ratio has a linear relationship with the penetration depth of the lower end of the monopile. 
     
     
         5 . A pile gripper positioning system according to  claim 1 , wherein the at least a portion of the monopile installation method includes at least a portion of a lowering phase, in which the monopile is suspended from a lifting crane and engaged by the pile gripper, and a lower end of the monopile is in the water, but above the sea bottom, wherein a ratio is defined between the to be compensated portion of the deviation and the full deviation of the position of the vessel from the desired position of the vessel, and wherein the pile gripper control unit is configured such that said ratio is set to the distance between the location where the hoisting line leaves the lifting crane divided by the distance between the location where the hoisting line leaves the lifting crane and the sea bottom. 
     
     
         6 . A dynamic positioning system for a vessel, wherein the vessel comprises a pile gripper for engaging with a monopile during a monopile installation method, wherein the dynamic positioning system comprises:
 an actuator system for applying forces to the vessel to position the vessel,   a measurement system for measuring a position of the vessel, and   a dynamic positioning control unit for driving the actuator system in dependency of a desired position and an actual position of the vessel as measured by the measurement system,   wherein the dynamic positioning control unit is configured to determine a signal representative for a difference between the desired position and the actual position of the vessel,   and wherein, during at least a portion of the installation method, the dynamic positioning control unit is configured to output a signal that is representative for at most a portion of said difference.   
     
     
         7 . A dynamic positioning system according to  claim 6 , wherein the at least a portion of the monopile installation method includes at least a portion of the seabed penetration phase in which the monopile is suspended from a lifting crane and engaged by the pile gripper, and a lower end of the monopile has penetrated the seabed. 
     
     
         8 . A dynamic positioning system according to  claim 6 , wherein a ratio is defined between the outputted difference and the full difference between the desired position and the actual position of the vessel, and wherein the dynamic positioning control unit is configured such that said ratio is increasing with increasing penetration depth of the lower end of the monopile. 
     
     
         9 . A dynamic positioning system according to  claim 8 , wherein the dynamic positioning control unit is configured such that said ratio has a linear relationship with the penetration depth of the lower end of the monopile. 
     
     
         10 . A dynamic positioning system according to  claim 6 , wherein the at least a portion of the monopile installation method includes at least a portion of a lowering phase, in which the monopile is suspended from a lifting crane and engaged by the pile gripper, and a lower end of the monopile is in the water, but above the sea bottom, wherein a ratio is defined between the to be compensated portion of the deviation and the full deviation of the position of the vessel from the desired position of the vessel, and wherein the pile gripper control unit is configured such that said ratio is set to the distance between the location where the hoisting line leaves the lifting crane divided by the distance between the location where the hoisting line leaves the lifting crane and the sea bottom. 
     
     
         11 . A vessel to carry out a monopile installation method, comprising:
 a hull,   a pile gripper arranged on the hull for engaging a monopile,   a dynamic positioning system for positioning the vessel, and   a pile gripper positioning system for positioning a monopile with the pile gripper,   wherein the dynamic positioning system is configured to determine a position of the vessel,   and wherein, during at least a portion of the monopile installation method, the vessel is configured to operate the pile gripper positioning system for at most partially compensating a deviation of the determined position of the vessel from a desired position of the vessel.   
     
     
         12 . A vessel according to  claim 11 , wherein the dynamic positioning system is configured to provide the determined position of the vessel to the pile gripper positioning system, and wherein the pile gripper positioning system is a pile gripper positioning system according to  claim 1 . 
     
     
         13 . A vessel according to  claim 11 , wherein the dynamic positioning control unit is a dynamic positioning control unit according to  claim 6 , and wherein the pile gripper positioning system is configured to receive the signal that is representative for at most a portion of said difference in order to at most partially compensating a deviation of the determined position of the vessel from a desired position of the vessel. 
     
     
         14 . A vessel according to  claim 11 , wherein the vessel comprises an overall control unit, wherein the pile gripper positioning system is configured to is configured to receive a signal representative for a position of the vessel from the dynamic positioning system, to determine a drive signal for the actuator system to compensate at most a portion of a deviation of the position of the vessel from a desired position of the vessel, and to output said drive signal to the pile gripper positioning system in order to at most partially compensating a deviation of the determined position of the vessel from a desired position of the vessel. 
     
     
         15 . A method to install monopiles, wherein use is made of a vessel comprising a dynamic positioning system to position the vessel, and a pile gripper to engage with the monopile, and wherein the method comprises the following steps:
 a. lowering a monopile towards or into a seabed while engaging the monopile with the pile gripper,   b. determining a deviation of the position of the vessel from a desired position of the vessel, and   c. at most partially compensating said deviation with the pile gripper.   
     
     
         16 - 25 . (canceled)