Patent ID: 11970370
Assignee: ITREC B.V.
Field: Handling (Mechanical engineering)
Classification: CPC B  Y | IPC B

Claim 19:
20. A method of hoisting a load by means of a crane, wherein the crane comprises:
a main boom pivotally connected at an inner end thereof about a substantially horizontal boom pivot axis, said main boom having a tip end remote from said inner end;
a main boom luffing assembly adapted to set an angle of the main boom within a main boom working angle range,
wherein the main boom has a length and a main boom working angle range such that the tip end thereof is positionable in a position wherein the tip end is at least 100 meters above the design waterline of the hull of the vessel,
a mobile hoist cable suspension member,
a hoist winch and a hoist cable driven by said hoist winch, which hoist cable depends from said mobile hoist cable suspension member, wherein an object suspension device is suspended from said hoist cable,
wherein the mobile hoist cable suspension member is supported by a motion compensating support device, which motion compensating support device comprises one or
more motor powered motion displacement actuator assemblies and a motion compensating support device controller,
wherein the method comprises:
by means of a motion compensating support device, providing motion compensation in one or more directions,
providing, by means of a first inertial measurement device, mounted on or in proximity of the nacelle, one or more first reference signals representative of actual motion of the wind turbine nacelle or in proximity thereof, and
providing, by means of a second inertial measurement device, mounted on the crane in proximity of a tip end of a main boom of the crane, one or more second reference signals representative of actual motion of the crane,
wherein the motion compensating support device controller is linked to both said first and second inertial measurement devices, the method further comprising:
computing and providing, by means of the motion compensating support device controller, control signals for said one or more motor powered motion displacement actuator assemblies on the basis of said first and second reference signals.