Arrangement and method for hoisting and compensating motion of a suspended object

Abstract

Hoisting arrangement including an upper carrier (32), a lower carrier (34), hoisting lines (38) and a line reconfiguration member (58). The upper carrier (32) is attachable or forms part of a jib (24) or boom (22) of a crane (16), the lower carrier (34) is selectively connectable (37) to a load (36) and is jointly suspended from the upper carrier, and the lines (38) interconnect corresponding pairs of upper and lower line connections on the upper and lower carriers, respectively. The line reconfiguration member is repositionable between the upper and lower carriers to change an operational configuration between a first mode wherein the lines are independently extendable and retractable in oblique directions to operate as positioning mechanism with at least four degrees of freedom, and a second mode wherein the lines extend predominantly parallel and are jointly extendable and retractable in vertical direction to operate as heavy load hoisting mechanism.

Description

Arrangement and Method for Hoisting and Compensating Motion of a Suspended ObjectTechnical Field

[0001] The invention relates to a hoisting arrangement for controlling the position and motion of a suspended object, and to a method of controlling the position and motion of an object using such hoisting arrangement.Background Art

[0002] Installing offshore wind turbines is a complicated matter. Components such as the nacelle and the turbine blades have to be lifted from the deck of an installation vessel by a crane up to large heights, for example up to 150 metres or higher. Furthermore, the components must be assembled at that height with high precision whilst being suspended from the crane. The installation task may be made even more difficult by environmental conditions applicable offshore, such as winds and waves, which may exert perturbing motions on the installation vessel, on the structure that is to be installed, and / or on the components that are suspended in the air while being lifted by the crane.

[0003] Patent document W02021 / 002749A1 describes a hoisting system for lifting and positioning components such as offshore wind turbine blades in a motion-compensated manner. This known system is adapted to hoist and position a component within a certain workspace and at a relatively light load, for instance in the order of about 250 to 500 metric tonnes. The known system includes a hoisting arrangement with multiple (for instance six) hoist cables that can be independently actuated to provide motion compensation, and for which the geometry is optimized to perform accurate positioning within the limited working space. However, outside this working point, the arrangement of cables causes a degradation in lifting performance and thereby limits the maximum load that the known arrangement can lift when no or little motion compensation is required.

[0004] It would be desirable to provide a hoisting arrangement with an improved versatility.Summary of Invention

[0005] Therefore, according to a first aspect, there is provided a hoisting arrangement that includes an upper carrier, a lower carrier, a plurality of lines, and a line reconfiguration member. The upper carrier is adapted to be fixed to or forms part of a crane jib or a crane boom, and the lower carrier is adapted to be releasably connected to a load and to be suspended together with the load from the upper carrier. The lines interconnect the upper and lower carriers. The line reconfiguration member is adapted to be repositioned between the upper carrier and the and lower carrier to change an operational configuration of the hoisting arrangement between a first mode and a second mode of operation. In the first mode, the lines are extendable and / or retractable in oblique directions to operate as a positioningmechanism for the lower carrier and the load connected thereto with at least three degrees of freedom (DOF). In the second mode, the lines are extendable and / or retractable in vertical direction to operate as a heavy hoisting mechanism for the lower carrier and the load connected thereto.

[0006] The proposed hoisting arrangement allows an efficient stabilization against undesired motions of the suspended load, in at least three DOF, but possibly in four DOF or in five DOF, and preferably in all six DOF. The term “six DOF” refers herein to a set of three independent translational directions and three independent rotational directions in three- dimensional space. Three translational motions may for instance be described by surge, sway, and heave, whereas the three rotational motions may be described by roll, pitch, and yaw. Providing a hoisting arrangement that is reconfigurable between a motion compensation mode and a heavy hoisting mode avoids the need to add a separate (at least 3DOF or 4DOF, and preferably 6DOF) motion compensation arrangement to an existing heavy hoist arrangement (e.g. a crane), and thus allows keeping the mass and complexity - relating to the required number of hoisting structures, actuators, lines, and control logic - to a minimum.

[0007] The proposed hoisting arrangement includes a line reconfiguration member, which is adapted to be moved up and down between the upper and lower carriers and along the hoisting lines. The orientations of the lines are reconfigurable by moving the line configuration member between different vertical positions relative to the upper and lower carriers, to allow the same set of lines to have increased motion compensation accuracy in the first mode, or to have increased lifting capacity in the second mode. This vertical change in position and resulting reconfiguration of the lines may be implemented in such a way that portions of the suspended lines extend in oblique directions downwards from the upper carrier to the lower carrier in the first mode to increase horizontal controllability, but extend in substantially vertical and mutually parallel fashion directly downwards in the second mode to maximize vertical hoisting capacity. The line configuration member may for instance be adapted to be positioned on, in, or near the lower carrier in the first mode, and to be positioned on, in, or near the upper carrier in the second mode, and to be translatable in generally vertical direction between these two positions to effectuate the transition between the first and second modes.

[0008] The term "line" (e.g. as in "hoist line" but not as in “centreline” or “midline") is used herein to refer generally to any kind of elongated connection like a wire, chain, rope, cord, etc (or any plurality or combination thereof) and is assumed to be sufficiently strong to lift a load connected thereto and / or for controlling the pose of that load. The line may be structurally composed of a single continuous line, a group of parallel lines, and / or a series of interconnected line segments. The lines are flexible regarding off-axis bending deformations. The term "flexible" refers herein to a line material and structure that is sufficiently deformable to allow the line to be bent by an external force from its linear rest state into a temporary curved shape with a radius of curvature comparable to a fraction of the dimensions of the winches, line guides, and connection structures (e.g. a range of centimetres to meters) withoutbreaking. Preferably, the lines also have a low off-axis elasticity (i.e. low bending stiffness) so that temporarily bending the line does not create internal restoring forces that - in comparison to the applied bending forces - are sufficiently large to urge the line back towards its linear state.

[0009] In embodiments, the lower carrier may be formed as a gripper platform, which may for instance include a main body formed as a substantially triangular prism, a substantially quadrilateral prism, a substantially hexagonal prism, or other polygonal prism or polyhedron shape. The lower carrier may for instance be formed as a gripper attachment arranged to be connected to a gripper for carrying a component or load as described in document W02021 / 002749A1.

[0010] In an embodiment, the hoisting arrangement is (part of) a crane. The crane may include a base and a jib that is directly or indirectly rotatably connected to the base. In this case, the body of the upper carrier may form an integral part of the jib.

[0011] The proposed hoisting arrangement may for instance be implemented in a crane that allows hoisting and installing different offshore wind turbine components. A crane with the proposed hoisting arrangement may transition relatively fast between the two operational modes, which allows installing various parts of the turbine in an efficient and cost-effective manner, and without requiring large mechanical reconfigurations that require the crane to be taken offline. Other components that may be installed with the proposed hoisting arrangement are for instance sub-sea stations, pipes of pipelines, spare parts, gearboxes, rotor’s, motors, components of hydrogen generators, electrolysis plants, etc.

[0012] The term “jib” is used herein to refer to a secondary arm or structure that extends from the end of a boom, or a further arm structure that extends from the end of a preceding jib of the crane. The term “boom” is used herein to refer to a relatively long arm that extends off a crane’s main body. The boom may be solid and / or lattice-shaped, and may have a fixed length or an adjustable length (e.g. telescopic), or may be articulated. However, in certain crane implementations with a main arm that is slew-rotatable about a fixed base - referred to as "slewing jib cranes” - the terms “boom” and “(main) jib” may be equivalent.

[0013] Integrating the upper carrier into the crane jib minimizes the amount of additional structure and mass needed to implement the hoisting arrangement in the crane, as compared to a hoisting arrangement module that is selectively attachable to the crane. In a hoisting arrangement with at least three independently actuatable hoisting lines (e.g. six independently actuatable lines), the jib may for instance be formed as a concave triangular star structure (e.g. resembling a concave isotoxal hexagon), which has three legs protruding from a centre region of the body from which the lines may be suspended downwards in groups. This shape requires relatively little material to span and support the distributed groups of line suspension points. In alternative embodiments, the shape of the jib body may be different, for instance other polygonal shapes, either concave or convex.

[0014] In an embodiment, the crane further includes a boom that is rotatably connected to the base. The boom may be repositionable into different luff angles relative to a reference plane associated with the base. The crane may further include a linkage that interconnects the base, the boom, and the jib. The linkage is configured to maintain the jib at a fixed elevation plane relative to the reference plane, irrespective of a momentary luff angle of the boom relative to the reference plane.

[0015] A line-based motion compensation system includes several (e.g. six) lines that are suspended and controlled from spatially distributed line exit points (e.g. pulleys) on the jib. Typically, the constellation of the upper and lower line connections and the lines extending inbetween is optimized for a certain working-space and allows a determined range of translations and rotations for the suspended load. The motion compensation performance will depend on the geometry and relative distances between the upper line connections, the lower line connections, and on the geometric projection of the upper connections onto the horizontal plane of the lower connections. When the luffing angle of the crane boom is adjusted, the projection of the line exit points from the upper carrier onto the lower carrier may deviate in shape and size relative to the expected distribution of line connections on the lower carrier. Such deviation may potentially lower performance of the motion compensation system. Using a jib-linkage that maintains a steady jib tilt under varying boom luffing angles ensures that the projection of the line exit points on the upper carrier (jib) onto the lower carrier line connection points remains the same.

[0016] Preferably, the jib is held in an orientation that allows the exit points of the line connections on the upper carrier to have maximum spread in a horizontal plane (i.e. a plane perpendicular to gravity) to allow an optimal working space for the lines to compensate motions and / or rotations of the lower carrier and load with any horizontal component. However, other situations are conceivable in which the jib plane may be oriented at non-zero angles relative to the horizontal, which the jib-linkage may also keep constant under varying boom luffing angles.

[0017] According to embodiments, the upper carrier includes upper line connections, the lower carrier includes lower line connections, and the line reconfiguration member includes a plurality of line guides. Each respective line extends between a corresponding set of three, formed by an upper line connection, a line guide and a lower line connection. Each respective line guide provides passage to a corresponding line, thereby dividing the line into a first (e.g. upper) line portion and a second (e.g. lower) line portion with a length ratio that changes when the line reconfiguration member is moved upwards or downwards between the upper and lower carriers. The first and second line portions extend in mutually different directions away from the line guide. Moving the line reconfiguration member upwards or downwards between the upper and lower carrier may change the relative orientations of the first and second line portions, and change the position of the partitioning and corresponding length ratio for the first and second line portions. For instance, when transitioning towards / into the first mode, therelative lengths of the first line portions may increase, whereas the relative lengths of the second line portions may reduce. In the first mode, each respective first line portion may extend in an oblique direction from an upper line connection to a corresponding line guide. Such oblique directions imply relatively large non-zero components in the vertical direction as well as in at least one of the transverse directions. For instance, when transitioning towards / into the second mode, the relative lengths of the first line portions may reduce, whereas the relative lengths of the second line portions may increase. In the second mode, each respective second line portion may extend predominantly in a vertical direction between a respective line guide and a lower line connection.

[0018] The term “line connection” does not necessarily mean that the line is rigidly fixed to the connection point. The line may alternatively be passed in a sliding or supported manner through a coupling point, to be directed further to its original or another connection point, such as by a connection formed as a pulley mechanism. The term “pulley mechanism” refers herein to a mechanism for redirecting the course of the line while allowing the line to slide / move along the pulley. Such mechanism may comprise one or more wheels or sheaves for guiding the line, as well as one or more joint and / or other suspension components to connect the wheel in a moveable manner to an external structure. The term “sheave” refers herein in strict sense to a rotatable wheel-like structure having a peripheral surface adapted for receiving and guiding a line. Such a sheave may be part of a pulley mechanism, or provided elsewhere. The passing of a line through multiple sheaves that may all be arranged on similar or different common axes is referred to here as “reeving” of the line and is a technique used to increase the load bearing capacity of a hoist line at the cost of speed of motion. The term "winch" is used to refer to any machine or instrument for hauling or pulling a line, and includes a drum or spool from which a line may be reeled in or out by means of an actuator, possibly powered e.g. by an electric, pneumatic, hydraulic, or combustion drive.

[0019] The oblique configuration of lines in the first mode of operation ensures that the line reconfiguration member is automatically pressed down (or released down) onto the lower carrier when the lower carrier bears a load, whereas the vertical configuration of lines in the second mode ensures that a maximum hoisting capacity becomes available.

[0020] Embodiments involving geometric / kinematic inversions of the line arrangements - wherein positions of the upper and lower carriers relative to the line reconfiguration member and / or wherein oblique and / or parallel directed portions of the interconnecting hoisting lines are vertically reversed - also fall within the presently claimed scope.

[0021] According to embodiments, the hoisting arrangement further includes a plurality of winches and a controller unit. Each of the winches may be individually actuatable to adjust a respective length of a corresponding one of the lines between the upper and lower carriers. The controller unit may be configured to coordinate separate actuation of the winches in the first mode, to individually extend or retract the corresponding lines to counteract translations and rotations of the lower carrier and the connected hoisting load in at least 3DOF - andpreferably in all 6DOF - relative to an external frame of reference. The controller unit may further be configured to coordinate synchronized actuation of the winches in the second mode, to substantially simultaneously extend or retract the lines to translate the lower carrier and the hoisting load upwards or downwards and / or to counteract vertical translations of the lower carrier and the hoisting load relative to the external reference system.

[0022] The controller unit may further be configured to coordinate individual and / or grouped actuation of the winches in the second mode, to extend or retract individual and / or groups of lines to counteract pitch and / or roll rotations of the lower carrier and the connected hoisting load. It should be noted, however, that the first mode involves motion compensation capabilities that rely at least in part on linear translations in one or more horizontal directions and / or rotations of the lower carrier and load about a vertical axis, by exploiting the oblique configuration of the hoist lines. By contrast, the second mode involves vertical hoisting and possibly also motion compensation capabilities that rely only on vertical translations and / or rotations of the lower carrier and load about horizontal axes, due to the vertical configuration of the hoist lines.

[0023] Preferably, the line reconfiguration member is held fixed in or near the upper carrier when the hoisting arrangement is in the second mode. In embodiments, the line reconfiguration member and the upper carrier are provided with a locking / unlocking mechanism that is adapted to temporarily fix a body of the line reconfiguration member to a body of the upper carrier in the second mode, and to release the locking to allow the line reconfiguration member to move towards the lower carrier and to transition towards the first mode. The locking mechanism ensures that the reconfiguration member will be held firmly in place at or near the upper carrier, when the hoisting arrangement is in the second mode. This locking mechanism is sufficiently strong to bear a combined downwards force exerted by the line reconfiguration member, the lower carrier, and the connected load, and the first and second portions of the lines, in the second mode.

[0024] The (un)locking mechanism may for instance include one or more repositionable pins (e.g. cylindrical or prismatic structures) provided in / on the body of the upper carrier, which mutually align and are insertable into one or more corresponding bore holes provided in the body of the reconfiguration member in the second mode. The pins may for instance be repositionable automatically by a mechanical, electromagnetic, or hydraulic drive.

[0025] The hoisting arrangement may include a reconfiguration actuator for repositioning the line reconfiguration member between the upper and lower carriers. This actuator may for instance include a reconfiguration wire that is fixed to the line reconfiguration member and is movably coupled to the upper carrier, and a reconfiguration winch for extending and retracting the reconfiguration wire to reposition the line reconfiguration member up- and downwards between the upper and lower carriers. This allows a relatively simple and robust mechanism for raising and lowering the reconfiguration member.

[0026] Providing a low power reconfiguration actuator may suffice in case the locking mechanism is present. The reconfiguration actuator only needs to bear the gravitational pull from the line reconfiguration member, and does not require a high lifting capacity for bearing all the other loads exerted in the second mode. The term “reconfiguration wire” is used here merely to distinguish from the hoisting lines. It should be understood that the reconfiguration wire may also be formed by a cable, a rope, a chain, etc.

[0027] According to embodiments, at least one of the hoisting lines and corresponding upper and lower connections and corresponding upper and lower line connections are formed as a multiple-reeved hoisting line arrangement, for instance a double-reeved hoisting line arrangement or a triple-reeved hoisting line arrangement. In a double-reeved arrangement, a line is coupled with one distal end to a corresponding winch, extends via one or more rolling or sliding connections (e.g. sheaves) and back to a fixed or releasable connection on one of the preceding bodies.

[0028] Providing double- or multiple-reeved hoisting line arrangements increases achievable motion compensation accuracy and / or hoisting capacity, at the expense of an increased amount of winch rotations needed to reel the line in or out to a certain extent. Any number of reeving loops may be selected to achieve a particular accuracy or capacity.

[0029] In embodiments, each respective upper line connection is formed as a pulley that is connected to a respective distal end of the carrier body. This pulley may include a wheel and a roll-pivot joint. The wheel is rotatable about a wheel axis extending through a centre of mass of the wheel. The roll-pivot joint defines a nominal roll axis that extends with a component in a plane and allows the wheel and its wheel axis to tilt upwards / downwards relative to this horizontal plane.

[0030] The upper line connection formed as a pulley with rotatable wheel and passive swivel joint allows the line sufficient (off-lead and side-lead) fleet-angle to adjust to different oblique orientations required by the desired position of the lower carrier and attached load as set by the controller unit. The amount of momentary rotation of the roll-pivot joint and / or the wheel may optionally be recorded by means of rotation sensors, such as position encoders or potentiometers, and serve as sensory input for the positioning algorithm used by the controller.

[0031] The pulley may further define a passageway, which extends along the roll axis through the roll-pivot joint, and which allows a corresponding line to extend, from an inner region of the upper carrier, into a proximal side of the roll-pivot joint, through the roll-pivot joint, and then to exit the roll-pivot joint from a distal side and via the wheel downwards towards the line reconfiguration member. By letting the line exit points substantially coincide with the pulley roll axis, the upper line connection points remain accurately defined in space even when the line orientations change, thus safeguarding accuracy of the positioning algorithm.

[0032] Alternatively or in addition, the pulley wheel is positioned at a non-zero offset substantially downwards from the roll axis, and the pulley further comprises a counterweight positioned substantially upwards of the roll axis. The weight counterbalances the pulley cageand wheel, to position the combined centre of mass at or reasonably close to the roll axis, to reduce (e.g. minimize) a net torque exerted by the wheel and the counterweight relative to the roll axis. This allows the pulley to roll effortlessly in response to deflections from the downwards line portion with minimal opposing torque.

[0033] In embodiments, each respective line guide on the line reconfiguration member is formed as a further pulley that is connected to the body. This further pulley may include a further wheel and a yaw-pivot joint. The wheel is rotatable about a further wheel axis extending substantially in a further horizontal plane and through a centre of mass of the wheel. The yaw-pivot joint has a nominal swivel axis that extends with a component in a vertical direction and allows the wheel with the further wheel axis to yaw in the further horizontal plane and about this swivel axis.

[0034] The panning and rotating capability of the pulleys allows passive minimization of shear forces exerted by the lines on the distribution of line guides on the reconfiguration member when the line orientations change due to positional adjustments to the lower carrier and load as enforced by the controller unit. The amount of momentary rotation of the yaw-pivot joint and / or the wheel may optionally be recorded by means of rotation sensors, such as position encoders, and serve as sensory input for the positioning algorithm used by the controller.

[0035] Also this pulley may define a passageway, which extends along the swivel axis through the yaw-pivot joint, and which allows a corresponding line to extend, from the upper carrier, via the further wheel, into an upper or lateral side of the yaw-pivot joint (wherein “lateral” refers to a component directed along the further horizontal plane), through the yawpivotjoint, and then to exit the yaw-pivot joint from a lower side and towards the lower carrier. By letting the line exit points substantially coincide with the pulley yaw axis, the line guide points may be maintained accurately aligned with the connection points on the lower carrier even when the line orientations change, thus preserving accuracy of the positioning algorithm.

[0036] In embodiments of the present proposal, the lines may include three, four, five, or six hoist lines, each hoist line connecting a respective upper line connection on the upper carrier, via a respective line guide on the line reconfiguration member, with a respective lower line connection on the lower carrier. In the first mode, the lines may then be extendable and retractable in oblique directions to operate as a positioning mechanism for the lower carrier and the load with three DOF, or with four DOF, or with five DOF, or with six DOF. Using six separate hoist lines ensures that enough linearly independent lines with actuators are available to allow controlling and compensating movement of the lower carrier (and connected load) in all 6DOF. Reducing the number of independently actuatable hoist lines to five, four or even three is contemplated, but is expected to reduce the number of DOF and to increase the coupling between distinct rotational and translational directions in which the hoisting arrangement will be able to control the position of the suspended lower carrier and load in a motion-compensated manner. Each of the lines may individually be single-reeved or multiple-reeved. The (three, four, five, or six) hoist lines and connection points corresponding to the line connections and line guides may span a first polyhedron in the first mode and a different polyhedron in the second mode. The transition between the first and second polyhedron shapes may take place in a gradual and continuous manner during the transition between the first and second modes, and may involve the presence of both polyhedron shapes with varying height ratios and with the member in-between.

[0037] In an embodiment including six hoist lines, the hoist lines are coupled to the upper carrier, the lower carrier, and the reconfiguration member, thereby forming three groups of six coupling points. Preferably, each one of the three groups of six coupling points is distributed across the corresponding body in a non-collinear arrangement (implying that no possible point-triplet of the six points arranged on the same body lie on a single line). The hoisting arrangement may for instance include exactly six independently actuatable hoist lines, either single-reeved or multiple-reeved. This forms a minimum number of independent lines and actuators needed for achieving full 6DOF motion compensation in the first mode, without having redundant lines and actuators that may unnecessarily complicate the line constellation and motion compensation decision logic.

[0038] In an embodiment, the upper line connections are arranged in or on the upper carrier in an upper point distribution that spans and forms the vertices of an upper polygon in an upper plane, and the line guides are arranged in or on the line reconfiguration member in an intermediate point distribution that spans and forms the vertices of an intermediate polygon in an intermediate plane. In this case, the upper polygon, the intermediate polygon, and the first line portions interconnecting the vertices of the first and intermediate polygons may jointly span a polygonal antiprism or a polygonal antiprism with truncated (i.e. “chamfered) corners, the truncation yielding another polygon with a doubled number of vertices. The upper and lower polygonal surfaces of the antiprisms are rotated relative to each other, thus ensuring that the lines interconnecting these surfaces extend with sufficient lateral deflections that allow exerting sufficient transverse control (translations as well as rotations) between the upper and lower surfaces.

[0039] In further embodiments that includes six hoist lines, the upper and intermediate polygons and the first line portions of the six hoist lines interconnecting the vertices of the upper and intermediate polygons jointly span either a trigonal antiprism wherein the upper and lower polygons form mutually rotated upper and lower triangles and wherein the first line portions form edges of triangular side faces, with each pair of adjacent first line portions meeting each other in a vertex of an upper or lower triangle. In alternative embodiments with six hoist lines, the upper and intermediate polygons and the first line portions of the six hoist lines interconnecting the vertices of the upper and intermediate polygons jointly span a truncated trigonal antiprism (or distorted ditrigonal trapezo-prism) wherein the upper and lower polygons form mutually rotated upper and lower non-uniform convex hexagons and wherein the first line portions form edges of trapezoidal side faces.

[0040] In an embodiment, the line guides are arranged in or on the line reconfiguration member in an intermediate point distribution that spans and forms the vertices of an intermediate polygon in an intermediate plane, and the lower line connections are arranged in or on the lower carrier in a lower point distribution that spans and forms the vertices of a lower polygon in a lower plane. In this case, the intermediate polygon, the lower polygon, and the second line portions interconnecting the vertices of these intermediate and lower polygons may jointly span a polygonal prism.

[0041] In a further embodiment that includes six hoist lines, the intermediate and lower polygons and the second line portions of the six hoist lines interconnecting the vertices of the intermediate and lower polygons jointly span a hexagonal prism, with upper and lower hexagonal surfaces corresponding to the intermediate plane and lower plane, and with the second line portions forming edges of quadrilateral side faces. In an equilibrium position, the upper and lower polygonal surfaces are preferably rotationally aligned to ensure parallelism of the lines interconnecting these surfaces. The quadrilateral side faces may for instance have rectangular shapes when the lower carrier and load are suspended. This may change into parallelogram shapes when the lower carrier and load are rotated due to temporary external perturbations or motion compensation adjustments initiated by the controller unit.

[0042] The described six-line constellations yield efficiently reconfigurable hoisting arrangements that provide accurate 6DOF motion compensation in the first mode and high hoisting capacity in the second mode, with low structural and logical redundancy. For example, the line arrangement may transition from a predominantly truncated trigonal antiprism spanned mainly by the first line portions in the first mode, to a predominantly hexagonal prism spanned by the second line portions in the second mode.

[0043] According to a second aspect, and in accordance with advantages and effects described herein above with reference to the first aspect, there is provided a moveable platform carrying a crane with a hoisting arrangement according to the first aspect. The moveable platform may for instance be one of an offshore vessel, such as a construction ship with a deck that supports the crane, a railway cart, a pontoon, a barge, a jack-up barge, a truck, helicopter, airplane or any other movable device used to construct objects.

[0044] In a third aspect, and in accordance with advantages and effects described herein above with reference to the first aspect, there is provided a method for hoisting and / or compensating motion of an object suspended from a hoisting arrangement in accordance with the first aspect.

[0045] According to an embodiment, the method may include first operating the hoisting arrangement in the second mode to move and position a relatively heavy object, then transitioning the hoisting arrangement from the second mode to the first mode, followed by using the hoisting arrangement in the first mode to move and position a second object relative to the first object in a motion-compensated manner, the second object being lighter than the first object. Alternative combinations of moving and positioning certain objects whilesequentially operating the hoisting arrangement in the first or the second mode are also contemplated.

[0046] The first object may for instance be a nacelle of a wind turbine, and the second object may be a rotor blade of the wind turbine. In the second (i.e. heavy hoist) mode, the nacelle is lifted onto the already present pile, transition piece, tower or foundation.Subsequently, when the hoisting arrangement is in the first (i.e. motion compensation) mode, the rotor blade is lifted in a 6DOF motion-compensated manner to an intended coupling point on the installed nacelle, so that the rotor blade can be attached.

[0047] Yet further aspects pertain to a computer program product configured to provide instructions to carry out the method according to the third aspect, when loaded on a computer arrangement, and to a (non-transitory) computer readable medium including the computer program product.Brief Description of Drawings

[0048] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts. In the drawings, like numerals designate like elements. Multiple instances of an element may each include separate labels appended to the reference number (for instance “41 a” and “41c”). The reference number may be used without an appended label (e.g. “41”) to generally refer to an unspecified instance or to all instances of that element.

[0049] Figures 1 a-1 b schematically show a vessel with a dual-mode hoisting arrangement, according to an embodiment;

[0050] Figures 2a-2c schematically show side views of a crane transitioning from a first mode to a second mode of operation, according to an embodiment;

[0051] Figures 3a-3b schematically show side views of a jib-linkage operation in the crane from figures 2a-c.

[0052] Figures 4a-4b schematically show perspective views of a portion of a crane in a first mode and a second mode of operation, according to an embodiment;

[0053] Figure 5 schematically shows a perspective view of a line connection provided on an upper carrier of a hoisting arrangement, according to an embodiment;

[0054] Figure 6 schematically shows a perspective view of a single-reeved line guide provided on a line reconfiguration member of a hoist arrangement, according to an embodiment;

[0055] Figure 7a schematically shows a double-reeved hoist line arrangement, in an alternative embodiment;

[0056] Figure 7b schematically shows a quintuple-reeved reconfiguration wire arrangement, as may be used the embodiment from figure 7a, and

[0057] Figure 8 schematically shows a triple-reeved hoist line arrangement, in yet an alternative embodiment.

[0058] The figures are meant for illustrative purposes only, and do not serve as restriction of the scope or the protection as laid down by the claims.Description of Embodiments

[0059] The following is a description of certain embodiments of the invention, given by way of example only and with reference to the figures.

[0060] Figures 1 a and 1 b show an exemplary vessel 10 that is floating at the surface of a body of water 11 , and which includes a hoisting arrangement 16 for lifting and moving a load 36 in a controlled manner. In the shown example, the hoisting arrangement is part of a jib crane 16, which includes a pedestal 18, a turret 20, a boom 22, and a jib 24. The hoisting arrangement with a reconfigurable hoisting and motion compensating mechanism 32, 34, 38 will be described in more detail below.

[0061] The crane pedestal 18 is fixed in an upright position to a deck 12 of the vessel 10. The crane turret 20 is rotatably coupled to the pedestal 18 via a slewing joint 19 and a corresponding actuator (not shown), which are adapted to pivot (or “slew”) the turret 20 sideways in a controlled manner about a nominal vertical axis As relative to the pedestal 18, to allow the turret 20 - together with the boom 22, the jib 24, and the hoisting mechanism 32, 34, 38 - to be positioned at different slewing angles relative to the vessel deck 12.

[0062] The crane boom 22 is with a proximal end rotatably coupled to the turret 20 via another joint 21 . This joint 21 and corresponding actuator (not shown) are adapted to pivot (or “luff’) the boom 22 up- and downwards about a nominal luffing axis Al relative to the turret 20, to allow the boom 22 - together with the jib 24 and the mechanism 32, 34, 38 - to be positioned at different luffing angles relative to a reference plane associated with the deck 12.

[0063] The jib 24 is rotatably coupled to a distal end of the boom 20 via a yet another joint 23. This joint 23 and corresponding actuator (not shown) are adapted to pivot the jib 24 up- and downwards about a nominal axis Aj relative to the boom 20.

[0064] The hoisting arrangement includes an upper carrier 32, a lower carrier 34 and a plurality of hoist lines 38. The hoist lines 38 extend downwards from the jib 24 in a generally three-dimensional configuration, and towards an underlying region where the lower carrier 34 is suspended. Different loads 36 may be temporarily attached to the lower carrier 34 via one or more temporary connectors, such as grippers, magnets, cable rigging, a hook, or other means known in the art. After a selected load 36 has been connected to the lower carrier 34, the crane 16 may actuate the hoist lines 38 to hoist the lower carrier 34 with the attached load 36 up or down relative to the vessel 10. The crane 16 may further rotate the turret 20 to move the suspended load 36 in a circular arc about the slew axis As and across the deck 12, and / or luff the boom 22 up or downwards about the luff axis Al to move the suspended load 36 closer to or away from the slew axis As.

[0065] The configuration of lines 38 in the hoisting arrangement is dynamically adjustable to allow changing the mode of operation of the crane 16.

[0066] In the configuration shown in figure 1 a, the crane 16 is configured to operate in a heavy hoisting mode. In this mode, the crane 16 is capable of hoisting and positioning relatively heavy loads 36, for instance objects with a weight in a range of 500 to 2000 metric or even up to 5000 metric tonnes such as a tower-section or a nacelle 14 of a wind turbine 13 or other heavy objects (e.g. a drill or oil platform). Due to the large mass and lower susceptibility of such heavy loads 36 to external influences, these objects require less motion compensation performance. Nevertheless, some capability for heave compensation and possibly also roll / pitch motion compensation may still be of interest and be provided by the hoisting arrangement in this heavy hoisting mode.

[0067] In the line arrangement shown in figure 1 b, the crane 16 is configured to operate in a motion compensation mode. In this mode, the crane 16 is capable of hoisting and positioning relatively lighter loads 36, for instance objects with a weight in a range of 250 to 500 metric tonnes such as a turbine blade 15 or gearbox or rotor or any other component, while providing full motion compensation in 6DOF against undesired positional deviations (e.g. heave, sway, surge, roll, pitch and yaw).

[0068] Figures 2a-2c illustrate the operation and reconfiguration of an exemplary hoisting arrangement. The hoisting arrangement includes an upper carrier 32, a lower carrier 34, a plurality of hoisting lines 38, and a line reconfiguration member 58.

[0069] In this example, the upper carrier 32 forms part of the jib 24 of the crane 16 and includes several upper line connections 49. The lower carrier includes several lower line connections 56 and is adapted to be selectively connected to the load 36 and to be suspended together with the load 36 from the upper carrier 32, subject to gravity and external influences.

[0070] The line reconfiguration member 58 is also suspended from the jib 24 and is adapted to be vertically repositioned between the upper carrier 32 and the lower carrier 34 to reconfigure the operational state of the crane 16 between a motion compensated mode and a heavy-lift mode via a relatively quick and automated procedure.

[0071] The lines 38 interconnect the upper carrier 32, the reconfiguration member 58, and the lower carrier 34. Each respective line 38 extends between a corresponding pair of upper and lower line connections 49, 56. The reconfiguration member 58 includes several line guides 69, each guide providing passage to a corresponding line 38 which approaches the guide 69 from an upper line connection 49 and proceeds towards a lower line connection 56.

[0072] The crane 16 includes a plurality of winches 44, which in this example are arranged in the turret 20 but may be located also elsewhere, for instance on the jib 24 or on the boom 22. Each respective winch 44 is associated with a particular line 38, and each winch 44 can be individually actuated to reel its corresponding line 38 in or out, thereby adjusting a length of this line 38. Each of the hoist lines 38 extend from a corresponding winch 44 at the turret 20, along the boom 22 and the jib 24, via various line routers and sheaves, to the upper line points 49 located on distal ends of the jib 32, and then downwards towards their corresponding guides 69 and connection points 56.

[0073] The crane 16 further includes a controller unit 17, which in this example is housed in the crane base 18. The controller unit 17 is in signal connection with the winches 44 and is configured to actuate each winch 44 separately from the other winches.

[0074] Figure 2a illustrates the first mode of operation of the crane 16. In this mode, the line reconfiguration member 58 is lowered to rest on the lower carrier 34, which allows the lines 38 to assume a spatial configuration in which the lines 38 extend in mutually different oblique directions. Each respective line guide 69 on the reconfiguration member 58 provides passage to a corresponding line 38, thereby redirecting and dividing the line 38 into first and second line portions 41 , 42, which extend in mutually different directions. In the first mode in figure 2a, the first line portions 41 have maximal lengths L1 , while the second line portions 42 have minimal (possibly vanishing) lengths L2. Each respective first line portion 41 extends obliquely, i.e. with considerable non-zero transverse components in both the vertical direction Z and the transverse directions X, Y from its upper line connection 49 to its respective line guide 69.

[0075] In this mode, the controller unit 17 may coordinate individual actuations of the winches 44 to extend or retract individual lines 38, thereby allowing the oblique line portions 41 to exert horizontal force components on the reconfiguration member 58 and the lower carrier 34 directly below it, as required for motion compensation in linear horizontal directions Tx, Ty and in rotations Rz about axes in vertical direction Z. The exemplary embodiments shown in figures 2a-3b represent various alternatives, in which for instance three, four, five, or six hoist lines 38 are present. When at least three lines 38 are provided in mutually independent directions with upward components, and assuming gravity is acting downwards on the lower carrier 34 and load 36, the controller unit 17 and lines 38 will be able to provide at least 3DOF motion compensation to counteract determined translations and rotations of the lower carrier 34 and load 36 relative to an external frame of reference {Qe}. Preferably, six hoisting lines 38 are present to allow 6DOF motion compensation control i.e. for translations Tx, Ty, Tz in three different directions and for rotations Rx, Ry, Rz about axes in three different directions. In one example, hoisting loads up to 250 metric tonnes may be handled and motion compensated in all six principal directions, within a workspace in the order of ±2 to ±10 meters.

[0076] Figure 2b illustrates a transition of the exemplary crane 16 from the first to the second operational mode. The crane 16 includes a reconfiguration winch 64 and wire 65 for moving the line reconfiguration member 58 up and down between the upper and lower carriers 32, 34. The wire 65 is fixed to the line reconfiguration member 58 via a connection point 66 on or in the body 60, which is located at or directly above a centre of mass of the reconfiguration member 58. The wire 65 extends via one or more pulleys (not indicated) on the jib 32, along the boom 22, and towards the winch 64 located in the crane turret 20. The controller unit 17 is also in signal connection with this winch 64, to actuate the winch 64 and reel the wire 65 in or out to move the reconfiguration member 58 upwards or downwards between the jib 32 and the lower carrier 34.

[0077] Due to the line redirection function provided by the line guides 69 on the reconfiguration member 58, the first line portions 41 above the member 58 and the second line portions 42 below the member 58 extend in mutually different directions. Moving the reconfiguration member 58 upwards will reduce the lengths L1 and increases the slope of the upper line portions 41 , while at the same time increase the lengths L2 of the lower line portions 42.

[0078] Figure 2c illustrates the second mode of operation of the crane 16. In this second mode, the line reconfiguration member 58 has been positioned fully upwards, so that the member 58 abuts or is (partially) accommodated in a recess 59 in the jib body 33 and held fixed in this position. The line reconfiguration member 58 and the jib body 33 are provided with a locking mechanism 67, 68, for temporarily fixing the body 60 of member 58 to the jib body 33 when the crane is in this second mode. This locking mechanism 67, 68 is sufficiently strong to bear a combined downwards force exerted by the reconfiguration member 58, the lower carrier 34, the connected load 36, and by the first and second line portions 41 , 42. The locking mechanism 67, 68 may for instance be formed by one or more repositionable pins 67 provided in the jib body 33, for instance provided along radially inwards peripheral walls of the body 33 that surround the recess 59. The body 60 of member 58 may include receiving apertures 68 located on radially outwards surfaces of this body 60, which mutually align with the pins 67 in the upwards configuration of the second mode. The pins 67 may then be moveable radially inwards into the aligned receiving apertures 68, to hold the member 58 fixed to the jib body 33. It should be understood that other known locking means, such as latches, clamps, electromagnetic couplings, or form-fit may be used as alternative or in addition.

[0079] In the second mode, the first line portions 41 (not shown in figure 2c) extend with relatively large non-zero components in transverse directions X, Y radially inwards from a respective upper line connection 49 to a corresponding line guide 69 on the reconfiguration member 58 enclosed by the jib. The member 58 and line connections 49 are now essentially level, so the first line portions 41 have (almost) vanishing components in the vertical direction Z. By contrast, each respective second line portion 42 extends predominantly in vertical direction Z from a respective line guide 69 in the (raised and hidden) member 58, downwards to a line connection 56 on the lower carrier 34. Preferably, the second line portions 42 extend essentially vertical and mutually parallel. In this second mode, the lines 38 are jointly extendable and / or retractable to operate as a heavy load hoisting mechanism for the lower carrier 34 and the connected load 36. The controller unit 17 coordinates synchronized actuation of the winches 44, to predominantly simultaneously extend / retract the lines 38 downwards / upwards, thus moving the lower carrier 34 and load 36 downwards / upwards and / or counteracting undesired vertical heave Tz of the carrier 34 and load 36 relative to the external frame of reference {Qe}. In this second mode, the controller unit 17 may additionally actuate selected groups or individual winches 44, to extend or retract corresponding groups orindividual lines 38 to counteract undesired pitch rotation Rx and / or roll rotation Ry of the lower carrier 34 and the load 36.

[0080] In this heavy-lift configuration of the crane 16, the generally vertical and mutually parallel arrangement of the second line portions 42 ensures that the crane 16 can lift heavy objects. In an example wherein each individual hoisting line 38 is adapted to lift approximately 250 metric tonnes, the combined lines 38 should be able to jointly lift a load of approximately 1200 to 1500 metric tonnes. In this heavy-lift configuration, however, no active 6DOF motion compensation will be viable but only parts of heave and / or roll- / pitch compensation.

[0081] Figures 3a-3b schematically show an embodiment of a crane 16 with a hoisting arrangement similar to the crane 16 in figures 2a-2c. In this example, the jib body 33 and its distribution of line connections 49 extend predominantly along a nominal jib plane Pj. The boom 22 is rotatably connected to the base 18, and is repositionable into different luff angles 0, 0’ relative to a horizontal reference plane P0 that extends through the luffing joint 21 and is parallel with the deck 12. If the jib 32 is independently rotatable via jib joint 23, the combined (adjustable) rotation angles of the boom 22 and the jib 24 can be expressed as an elevation angle a of the jib plane Pj relative to the reference plane P0. The nominal planes P0, P0’ and P0” shown in figures 3a-3b are mutually parallel, implying that the angle a relative to either of these planes is the same.

[0082] In the present example, the crane 16 further comprises a jib-levelling linkage 26. This linking structure 26 is configured to maintain the jib 24 fixed at its initial elevation angle a relative to the reference plane P0, irrespective of a momentary luff angle 0 of the boom 22. In this example, the linkage is formed as a parallelogram with four edges defined by an A-frame 27 on the crane turret 20, the boom 22, an A-frame 29 on the jib 32, and a jib load-off line 28 spanned between distal ends of the two A-frames 27, 29. In the example of figures 3a-b, the jib load-off line 28 is formed as an additional line 28, which is at one end 31 coupled to a distal tip of the jib 32, and which is with an opposite end wound around a controllable winch 30 that is adapted to reel the line 28 in or out to adjust the elevation angle a of the jib plane Pj. The elevation angle a may for instance be set to a value in a range of 0° to ±10° (positive implying that the distal jib tip is moved slightly upwards relative to the jib joint 23).

[0083] Figure 3b illustrates that the jib-levelling linkage 26 causes the jib elevation angle a to maintain a fixed value, even when the boom 22 has been rotated downwards to a reduced luff angle 0’.

[0084] Figures 4a-4b present detailed perspective views of an exemplary hoisting arrangement, which includes an upper carrier 32, a lower carrier 34, exactly six independently actuatable hoisting lines 38, and a line reconfiguration member 58 that is repositionable via a reconfiguration wire 65.

[0085] The six hoisting lines 38 extend from the crane turret (not shown), along the boom 22 and the jib 32, and exit the jib 32 at distal ends of the jib body 33. The lines 38 continue downward from the upper carrier 32 and are connected via the reconfiguration member 58 tothe lower carrier 34. The reconfiguration member 58, the lower carrier 34 - and possibly the load 36 connected thereto - are thus suspended from the upper carrier 32 via the lines 38. The member 58, carrier 34, and load 36 are thereby allowed to translate and rotate in all three dimensions to a limited extent, subject to the tensional forces exerted via the lines 38 on the member 58, the carrier 34, and the load 36 in upwards and lateral directions +Z, ±X, ±Y, and subject to the gravitational force acting generally in downwards direction -Z. Temporary imbalances between these forces may be caused by transient and / or periodical perturbation forces in various directions, such as those caused by wind acting on the lower carrier 34 and load 36 and / or waves acting on the vessel or platform carrying the crane 16.

[0086] In this example, the upper carrier 32 is formed as an integral part of the crane jib 24, similar as the crane 16 shown in figures 2a-3b above. The body 33 of the crane jib 24 is formed by a triangular star-like structure, possibly with distal ends of its three legs that are truncated, yielding for instance a concave hexagon that is essentially symmetric relative to a midline along the Y-direction. This exemplary jib body 33 includes three legs that protrude from a centre portion of the body 33. A first leg protrudes from the centre portion in a forward direction +Y, and the two lateral legs protrude in opposite lateral directions ±X and slightly rearward towards a negative direction -Y. A rear side of the centre portion of the body 33 is pivotably coupled to the crane boom 22 via a rotary joint 23, which includes a plurality of sheaves 46. Each of these sheaves 46 is independently rotatable and adapted to guide a corresponding one of the lines 38 to allow that line 38 to slide along the joint 23 independently from the other lines 38 and each of the sheaves of the crane may be sensed by an encoder or other measurement device to measure its amount of rotation. The portions of the lines 38 that extend along the boom 22 up to the sheaves 46 are indicated with reference numerals 39. Any jib A-frame 29 as in the example of figures 2a-3b is not shown here for simplicity.

[0087] In this example, the upper carrier 32 includes four central line deflectors 48 and six line guiding connections 49, which are all formed by pulley structures. The guiding connections 49 are connected in adjacent pairs to the distal ends of the legs of the body 33, and include wheels that are independently rotatable. The line deflectors 48 are located near the central portion of the body 33 and include independently rotatable wheels that are adapted to re-direct two pairs of outermost lines 38 that approach from the sheaves 46 in the Y- direction towards the two pairs of line guides 49a-b and 49e-f located on the two lateral legs. By contrast, the central pair of lines 38 extends directly to the line guides 49c-d on the central leg. The portions of the lines 38 that extend along the jib body 33 up to the guides 49 are indicated with reference numerals 40.

[0088] The line reconfiguration member 58 is suspended below the jib 32. In this example, the line reconfiguration member 58 includes a body 60 shaped as a hexagonal prism, with hexagonal upper and lower surfaces 61 , 62. The reconfiguration member 58 includes a plurality of line guides 69, which are located along the lateral edges of the hexagonal prism body 60. Each respective line guide 69 provides passage to a corresponding line 38, and ispivotable around a local yaw axis Ap that extends with a component in vertical direction Z, and which allows the guide 69 to swivel around this axis Ap and in an intermediate plane Pr that extends predominantly in horizontal directions. Each respective line 38 extends from a respective line guide 69 to a corresponding lower line connection 56 on the lower carrier 34. The portions of the lines 38 that extend from the line guides 69 down to the line connections 56 are indicated with reference numerals 42. Each line guide 69 redirects the line 38 passing therethrough, thereby causing the upper line portion 41 and lower line portion 42 to extend in mutually different directions.

[0089] The reconfiguration member 58 is suspended from the jib body 33 by the reconfiguration wire 65, which extends downwards from a separate (set of) pulleys (not indicated) on the jib body 33 and is fixed at an attachment point 66 in a central region on the body 60 of the member 58 (so that is does not extend further downwards to the lower carrier 34). The height of the reconfiguration member 58 between the jib body 33 and the lower carrier 34 is adjustable by extending or retracting the wire 65, to change the line configuration of the crane 16 and thereby switch between two modes of operation. When the vertical position of the member 58 changes, the relative partitioning of the cables 38 into upper and lower line portions 41 , 42 changes and hence the relative lengths and directions between the upper and lower line portions 41 , 42 also changes.

[0090] The lower carrier 34 is suspended below the jib 32 as well as below the reconfiguration member 58. This carrier 34 is adapted to be selectively connected 37 to a load 36, by means of releasable connectors 37 provided on a lower side of the carrier 34, such as retractable locking pins, grippers, magnets, cable rigging, hooks, or other means known in the art.

[0091] Figure 4a shows a first operational configuration, in which the lines 38 are independently extendable and / or retractable to operate as a 6DOF positioning and motion compensation mechanism for the lower carrier 34 and the connected load 36. In this first mode, the reconfiguration member 58 is nearest to the lower carrier 34, and preferably abuts or may even be co-located or locked with this carrier 34. Each respective first line portion 41 extends obliquely, with non-zero vector components in the vertical direction Z as well as in transverse directions X, Y, between an upper line connection 49 and a respective line guide 69. The configuration of six hoisting lines 38 in figure 4a supports and controls the lower carrier 34 and load 36 in all 6DOF, with minimal deviations in rotation or translation. This configuration yields a useable work volume that confines horizontal motion of the platform centre-of-gravity to a circle inscribed inside the hexagon (truncated triangle) formed by the three line connection pairs 49 on the jib 32. The second line portions 42 have been drawn in figure 4a with non-zero lengths only to show the lower carrier 34. However, it may be preferred that the second line portions 42 have vanishing lengths and the reconfiguration member 58 rests directly on or in the lower carrier 34 in the first mode, to ensure that the oblique first line portions 41 can exert optimal control over the 6DOF position of the lower carrier 34.

[0092] From figure 4a, it can be inferred that the upper line connections 49 are arranged on and along the jib body 33 as an upper distribution of points that jointly span an upper plane P1 (corresponding with the jib plane Pj from figures 3a-b), and which are essentially centred on a nominal vertical axis spanned by the vertical portion of the reconfiguration wire 65. Similarly, the line guides 69 are arranged along the member body 60 in an intermediate distribution of points that jointly span an intermediate plane Pr (here essentially parallel with surface 61), and which are also centred on the reconfiguration wire 65. This intermediate point distribution falls entirely within the boundaries of a downwards projection of the upper point distribution onto the intermediate plane Pr. In alternative embodiments, the reconfiguration wire 65 may be arranged differently, for instance as multiple wires that extend alongside the nominal centreline but leaving the centreline unobstructed and available for other wire elements (such as e.g. electrical connections, umbilical winches, etc.).

[0093] As shown in figure 4a, the upper point distribution 49, the intermediate point distribution 69 and the first line portions 41 interconnecting the upper and intermediate point distributions, jointly span a truncated trigonal antiprism with mutually rotated convex hexagonal (or truncated triangular) upper and lower surfaces along the upper and intermediate planes P1 , Pr, and with the first line portions 41 forming edges of trapezoidal side faces. The upper hexagonal surface associated with the upper plane P1 is substantially larger than the rotated lower hexagonal surface associated with the intermediate plane Pr, thus causing the trapezoidal side faces to be slanted with their surface normal vectors partially in a downwards direction -Z.

[0094] Figure 4b shows a second operational configuration, in which the lines 38 are jointly extendable and / or retractable to operate as a heavy hoisting mechanism for the lower carrier 34 and the connected load 36. In this mode, the reconfiguration member 58 has been lifted by the wire 65 up to the body 33 of the jib, so that the intermediate plane Pr is close to the upper plane P1 . In alternative embodiments, the jib body may define a recess that can completely accommodate the reconfiguration member in the second mode, such that the upper plane P1 and the intermediate plane Pr can be made to completely coincide (see e.g. figure 2c).

[0095] From figure 4b, it can be inferred that the lower line connections 56 are arranged on and along the body of the lower carrier 34 in a lower distribution of points that span a lower plane P2. This lower point distribution substantially coincides with a downwards projection of the intermediate point distribution 69 of the reconfiguration member 58 onto the lower plane P2. The intermediate point distribution 69, the lower point distribution 56 and the second line portions 42 interconnecting the intermediate and lower point distributions, jointly span a hexagonal prism with hexagonal upper and lower surfaces along the intermediate plane Pr and lower plane P2, and with the second line portions 42 forming edges of quadrilateral side faces. The upper hexagonal surface associated with the intermediate plane Pr is substantially congruent to the lower hexagonal surface associated with the lower plane P2, so that the quadrilateral side faces are essentially straight and with their surface normal vectors pointingin horizontal directions X, Y. When the hoisting lines 38 are individually actuated in this second mode to also cause a certain motion compensation in a roll or pitch direction of the lower carrier, then, the quadrilateral side faces may be skewed or in a trapezoidal shape.

[0096] In alternative embodiments, different locations for the sheaves / pulleys / line guiding points and / or different guiding routes for the hoisting lines and reconfiguration wire may be implemented along the various components of the crane - possibly including multiple reroutes via multiple sheaves / pulleys.

[0097] Figure 5 illustrates an exemplary upper / outer line connection 49 that is formed as a swivel pulley 49. Such a pulley 49 may for instance be part of the exemplary cranes 16 shown in the preceding figures and be mounted on a distal end of one of the arms of the jib body 33.

[0098] The pulley 49 in figure 5 includes a pulley cage 50, a roll-pivot joint 51 , a wheel 53, and a counterweight 55. The wheel 53 is rotatably suspended by an axle 54 that is coupled to side faces of the cage 50, and which defines a nominal axis A1 extending substantially horizontally through a centre of mass of the wheel 53, allowing the wheel 53 to rotate and vary a fleet-angle y1 of the line portion 41 .

[0099] The roll-pivot joint 51 allows the whole cage 50 including the wheel 53 to rotate about a nominal roll axis Ar. This roll axis Ar extends with a component in a horizontal direction and radially outward from the jib body 33, thereby allowing the wheel 53 to roll and thereby tilt upwards / downwards away from the upper plane P1 . The cage 50 is thus rotatably attached to the jib body 33, which allows the wheel 53 to swivel sideways and upwards over angular deflections p1 - which in this example may be in a range of -45° to +°45 or more relative to the vertically downwards equilibrium direction Z - without the cage 50 clashing into an adjacent pulley 49’.

[0100] The pulley 49 defines a passageway 52, which is formed as a cylindrical through hole that extends along the roll axis Ar through the cage 50 and the roll-pivot joint 51 . This passageway 52 allows a corresponding line 38 to extend, from an inner region of the upper carrier 32, into a longitudinally inward side of the roll-pivot joint 51 , entirely through the rollpivotjoint 51 , and then to exit the roll-pivot joint 51 from a longitudinally distal side and via the wheel 53 downwards towards the line reconfiguration member 58 located below (see e.g. figure 4a).

[0101] The wheel 53 is positioned with a non-zero vertical offset downwards from the roll axis Ar. The counterweight 55 provided on the cage 50 is positioned upwards of the roll axis Ar, such that the combined centre of mass of the pulley cage 50, the wheel 53, and the counterweight 55 lies at (or substantially near) the roll axis Ar, to minimize a net torque exerted by the pulley structure 49 relative to the roll axis Ar. Counterweights 55 of distinct pulleys 49 may be shaped differently than depicted in the example of figure 5, to prevent adjacent pulleys from colliding with each other during rolling motions (not shown).

[0102] Figure 6 shows an exemplary line guide 69 that is also formed as a swivel pulley 69. Such swivel pulley 69 may for instance be mounted along a lateral edge of the body 60 of a line reconfiguration member 58 as shown in figure 4a.

[0103] The exemplary pulley 69 in figure 6 includes a pulley cage 70, a yaw-pivot joint 71 , and a wheel 73. The wheel 73 is rotatably suspended by an axle 74 that is coupled to side faces of the cage 70, and which defines a nominal axis A2 extending substantially horizontally along the intermediate plane Pr and through a centre of mass of the wheel 73, thus allowing the wheel 73 to rotate and vary a fleet-angle y2 of the line portion 41 .

[0104] The yaw-pivot joint 71 is adapted to let the cage 70 and wheel 73 rotate jointly about a nominal yaw axis Ap that is normal to the intermediate plane Pr, thereby allowing the case and wheel to swivel sideways about the yaw axis Ap and relative to the body 60 over angular deflections p2.

[0105] This pulley 69 also defines a passageway 72, which is formed as a cylindrical bore hole that extends along the yaw roll axis Ap through at least part of the cage 70 and the yawpivotjoint 71. In this case, however, the passageway 72 opens on a radial surface portion of the cage 70 located directly above the wheel 73, to allow the upper line portion 41 to enter the cage 70 from a lateral direction that has a component along the intermediate plane Pr. The passageway 72 allows an upper portion 41 to enter via the wheel 73, into a lateral side of the yaw-pivot joint 71 , extend through the yaw-pivot joint 71 , and then to exit the joint 71 from a lower side 62 of the body 60 to continue as a lower line portion 42 towards the lower carrier 34.

[0106] In this example, the reconfiguration member 58 includes locking apertures 68, which are provided at lateral surfaces of the body 60. In this case, the aperture 68 is located near a centre of the longer edge surface of the body 60, to provide a mechanically balanced locking connection with the jib body 33 in the heavy hoisting mode. In alternative embodiments, the locking members may be implemented with different mechanisms known in the art and / or be arranged in different locations.

[0107] In the example of figures 6, the arrangement of the hoist lines 38 extending from the jib body 33 via the reconfiguration member 58 to the lower carrier 34 is single-reeved, in that each line 38 extends only once through its respective line guide 69 on the line reconfiguration member 58.

[0108] Figures 7a-b illustrate an alternative embodiment of a hoisting arrangement, wherein each of the plurality of lines 138 and corresponding upper and lower connections 149, 156 are formed as a double-reeved hoisting line arrangement. Features in the arrangement that have already been described above with reference to the hoisting arrangements in figures 1-6 may also be present in the arrangement shown in figures 7a-7b and will not all be discussed here again. For the discussion with reference to figures 7a-7b, like features are designated with similar reference numerals preceded by 100, to distinguish the embodiments.

[0109] Figure 7a illustrates that each line 138 extends, after being paid-out from the corresponding winch and guided via the boom 122 to the jib pulley exits 149, with a first upper line portion 141 down to a first one of the line guides 169 on the reconfiguration member 158. The line 138 passes through this line guide 169, and continues downwards with a first lower line portion 142 to the lower carrier 134, where the line 138 is received in a return sheave 156 on the lower carrier 134, and routed back up as a secondary lower line portion 142’. This portion 142’ extends back to a secondary line guide 169’ located proximate to the line guide 169 on the member 158. Both the line guides 169, 169’ are allowed to rotate in yaw directions in the horizontal plane, and may be individually formed by a pulley as shown in figure 6. The line 138 then continues as a secondary upper line portion 141 ’ upwards towards a line fixation point 157 located on the jib body 133 and near the jib pulley 149. This double-reeving increases the available hoisting force by reducing the line with a factor of two.

[0110] Figure 7b illustrates an embodiment of a reconfiguration actuator for raising and lowering the line reconfiguration member 158, wherein the reconfiguration wire 165 and corresponding connections are formed as a quintuple-reeved line arrangement. In this case, the jib body 133 carries a set of four upper sheaves 175, the body 160 of the reconfiguration member 158 carries a set of four lower sheaves 176, and the reconfiguration wire extends from its initial guiding point on the jib 132, repeatedly up and down as an interconnected series of wire portions 165, 165’, 165” between the upper and lower sheaves 175, 176, and then back up to an anchor point on the jib body 133. In cases where the repositioning speed of the member 158 between the upper and lower carriers 132, 134 is allowed to stay low, the multiple-reeved arrangement allows using a low-power reconfiguration actuator. In alternative embodiments, a reeving with any number of returning wire portions may be employed and the final wire portion may be fixed to an anchor point that is either on the jib body or on the body of the reconfiguration member.

[0111] Figure 8 illustrates an alternative embodiment of a hoisting arrangement, wherein which each of the plurality of lines 238 and corresponding upper connections 249, line guides 269, and lower connections 256 are formed as a triple-reeved hoisting line arrangement. Features in the arrangement that have already been described above with reference to the previous figures, for instance figure 7a, may also be present in the arrangement shown in figure 8. Like features are designated with similar reference numerals preceded by 200 to distinguish the embodiments. In this case, the arrangement includes three closely spaced guide pulleys 269, 269’, 269” that are allowed to rotate in yaw directions along the horizontal plane, and two closely spaced upper connection pulleys 249, 249’ that are allowed to rotate in roll directions. In this example, the last upper line portion 241 ”, last guide pulley 269”, and last lower line portion 242” are placed in-between their first and secondary counterparts, and the final lower line portion 242” is fixed to a line anchor 257 located on the lower carrier 234. Each of the three pulleys 269, 269’, 269” may for instance be formed as a pulley shown in figure 6, and / or at least pulley 249 may for instance be formed as shown in figure 5.

[0112] In alternative embodiments, a reeving with any number returning line portions may be employed and the final line portion may be fixed to an anchor point that is either on the jib body or on the body of the lower carrier.

[0113] The present invention may be embodied in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. It will be apparent to the person skilled in the art that alternative embodiments of the invention can be conceived and reduced to practice. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope, to the extent permitted by national law.

[0114] In the examples, the hoisting line connections were generally distributed along horizontal planes corresponding with the upper carrier, the line reconfiguration member, and the lower carrier. The present disclosure is, however, not limited to such planar line connection distributions. The only requirement is that the lines are arranged in a configuration that allows the tensional forces by the lines together with the gravitational pull exerted on the lower carrier and load to form an independent (although not necessarily orthogonal) vector basis for the required solution space (i.e. three, four, five, or six degrees of freedom) of the motion compensation mechanism and algorithm. The hoisting arrangement may for example include exactly three or four or five or more independently actuatable hoisting lines. The n hoist lines are coupled to the upper carrier, the lower carrier, and the reconfiguration member, thereby forming three groups of n coupling points, wherein preferably each of the three groups of n coupling points is distributed across the corresponding body in a non-collinear arrangement.

[0115] In the examples discussed with reference to the figures, the hoisting arrangement formed part of a crane on a vessel for constructing offshore wind turbine generators, and configured to hoist and position piles, transition pieces, towers, nacelles, rotors, and rotor blades of wind-turbines or any other component thereof (e.g. spare parts).

[0116] The proposed hoisting arrangement and methods of use may generally be used when installing other systems that are composed of several objects, part of which require motion compensation in multiple degrees of freedom, and another part requiring large hoisting forces, and for which quick dynamic hoisting mode configurations are beneficial. A crane with the proposed hoisting arrangement may for instance be fixed to a pontoon, an offshore floating platform, a jack-up vessel, a train, plane, helicopter, etc. or may even be installed on a fixed reference structure (e.g. on earth or soil). Hoisting and positioning of components of sub-sea installations (e.g. sub-sea stations, line distribution stations, etc.) are also contemplated as well as hoisting objects from one vessel to another or the hoisting of large structures such as entire drill-rigs, production platforms, hydrogen (H2) generator platforms, tidal power plant components or any other equipment from another respective field.List of Reference SymbolsSimilar reference numbers that have been used in the description to indicate similar elements (but differing only in the hundreds) have been omitted from the list below but should be considered implicitly included.10 vessel11 body of water (e.g. sea)12 deck13 wind turbine14 nacelle15 turbine blade16 crane (e.g. jib crane)17 motion compensation controller18 base (pedestal)19 slewing joint20 turret21 turret-boom joint22 boom23 boom-jib joint24 jib26 jib levelling linkage27 A-frame28 jib offload line29 jib A-frame30 offload line actuator31 offload line coupling32 upper carrier33 upper carrier body34 lower carrier35 lower carrier body36 load37 load coupling38 hoist line39 root portion of hoist line40 jib portion of hoist line41 1st(medial) line portion42 2nd(distal) line portion44 hoist line winch46 boom-jib joint sheave48 inner line guide (e.g. fixed pulley)49 upper line connection (e.g. roll pulley)50 pulley cage51 cage roll joint52 passageway53 wheel54 wheel rotation joint55 counterweight56 lower line connection58 line reconfiguration member59 recess in jib60 further body61 upper surface62 lower surface64 reconfiguration winch65 reconfiguration wire66 line connection point67 1stlocking means (e.g. pin)68 2ndlocking means (e.g. aperture)69 line guide on reconfiguration member (e.g. yaw pulley)70 pulley cage71 cage yaw joint72 passageway73 wheel74 wheel rotation joint157 line anchor175 upper sheaves176 lower sheavesX 1stdirectionY 2nddirectionZ 3rddirectionY1 pulley swivel axisXI 1stload deflection directionYl 2ndload deflection directionAs slew axisAl luff axisAj jib elevation axisAr pulley roll axisA1 wheel axisAp pulley yaw axisA2 further wheel axisL1 1st(medial) line lengthL2 2nd(distal) line lengthPO reference plane Pj jib planeP1 upper carrier planeP2 lower carrier planePr intermediate plane0 luff angle a jib elevation angleP1 pulley roll angleY1 fleet angle p2 pulley yaw angleY2 further fleet angle {Qe} external frame of reference{Qc} lower carrier frame of reference

Claims

Claims1 . A hoisting arrangement, comprising: an upper carrier (32) adapted to be fixed to or forming part of a jib (24) of a crane or to be fixed to a boom (22) of a crane (16); a lower carrier (34) adapted to be releasably connected (37) to a load (36) and to be suspended together with the load from the upper carrier; a plurality of lines (38) interconnecting the upper and lower carriers; a line reconfiguration member (58), repositionable between the upper and lower carriers to change an operational configuration of the hoisting arrangement between: a first mode wherein the lines (38) are extendable and retractable in oblique directions to operate as a positioning mechanism for the lower carrier (34) and the load (36) with at least four degrees of freedom, DOF, and a second mode wherein the lines (38) extend predominantly parallel and are extendable and retractable predominantly in vertical direction to operate as a heavy load hoisting mechanism for the lower carrier and the load.

2. The hoisting arrangement according to claim 1 , wherein the line reconfiguration member (58) comprises line guides (69), each respective line guide providing passage (72) to a corresponding line (38), thereby dividing the line into first and second line portions (41 ; 42) that extend in mutually different directions; wherein in the first mode, each respective first line portion (41) extends in an oblique direction from a respective upper line connection (49) on the upper carrier (32) to a corresponding line guide (69), and wherein in the second mode, each respective second line portion (42) extends predominantly in a vertical direction (Z) from a respective line guide (69) to a corresponding lower line connection (56) on the lower carrier (34).

3. The hoisting arrangement according to claim 1 or 2, wherein the lines (38) include four, five, or six hoist lines (38), each hoist line interconnecting a respective upper line connection (49) on the upper carrier (32), via a respective line guide (69) on the line reconfiguration member (58), with a respective lower line connection (56) on to the lower carrier (34), and wherein, in the first mode, the lines (38) are extendable and retractable in oblique directions to operate as a positioning mechanism for the lower carrier (34) and the load (36) with four DOF or five DOF or six DOF.

4. The hoisting arrangement according to claim 3, wherein the four, five, or six hoist lines and corresponding line connections (49, 56) and line guides (69) span a first polyhedron in the first mode and a different polyhedron in the second mode.

5. The hoisting arrangement according to any one of claims 1—4, further comprising: winches (44), each respective winch being individually actuatable to adjust a respective length of a corresponding one of the lines (38), and a controller device (17) configured to: actuate the winches (44) in the first mode, to individually extend or retract the corresponding lines (38) to counteract translations and rotations of the lower carrier (34) and the load (36) relative to an external frame of reference ({Qe}) in at least four DOF; actuate the winches (44) in the second mode, to simultaneously extend or retract the lines (38) to translate the lower carrier and the load downwards or upwards and / or to counteract vertical translations relative to the external frame of reference ({Qe}).

6. The hoisting arrangement according to any one of claims 1-5, wherein the line reconfiguration member (58) and the upper carrier (32) are provided with a locking / unlocking mechanism (67, 68) that is adapted to temporarily fix a body (60) of the line re-arrangement member (58) to the upper carrier in the second mode, and which is sufficiently strong to bear a combined downwards force exerted by the line reconfiguration member (58), the lower carrier (34), and the connected load (36).

7. The hoisting arrangement according to any one of claims 2-6, comprising a reconfiguration actuator (64, 65) for repositioning the line reconfiguration member (58) between the upper and lower carriers (32, 34), wherein the reconfiguration actuator (64, 65) includes: a reconfiguration wire (65) that is fixed (66) to the line reconfiguration member (58) and is movably coupled to the upper carrier (32), and a reconfiguration winch (64) for retracting and extending the reconfiguration wire (65) to raise and lower the line reconfiguration member between the upper and lower carriers (32, 34).

8. The hoisting arrangement according to any one of claims 1-7, wherein at least one of the lines (138; 238) and corresponding upper and lower line connections are formed as a multiple-reeved hoisting line arrangement, for instance a double-reeved hoisting line arrangement (140, 141 , 142, 169, 156, 157) or a triple-reeved hoisting line arrangement (240, 241 , 242, 269, 256, 257).

9. The hoisting arrangement according to any one of claims 1-8, wherein each respective upper line connection (49) is formed as a pulley (49) that is connected to arespective distal end of the carrier body (33) and includes: a wheel (53) that is rotatable about a wheel axis (A1), and a roll-pivot joint (51) with a nominal roll axis (Ar) that extends with a component in a horizontal plane (P1) and allows the wheel (53) and the wheel axis (A1) to tilt upwards / downwards relative to the horizontal plane.

10. The hoisting arrangement according to claim 9, wherein the pulley (49) defines a passageway (52) for the line (38) to extend along the roll axis (Ar) through the roll-pivot joint (51).11 . The hoisting arrangement according to claim 9 or 10, wherein the wheel (53) has a non-zero offset from the roll axis (Ar) and the pulley includes a counterweight (55) for reducing a net torque exerted relative to the roll axis (Ar).

12. The hoisting arrangement according to any one of claims 1-11 , wherein each respective line guide (69) on the line reconfiguration member (58) is formed as a further pulley that is connected to the body (60) and includes: a further wheel (73) that is rotatable about a further wheel axis (A2) extending substantially in a further horizontal plane (Pr); a yaw-pivot joint (71) with a nominal swivel axis (Ap) that extends with a component in a vertical direction (Z) and allows the wheel (73) with the further wheel axis (A2) to yaw relative to the further horizontal plane (Pr).

13. The hoisting arrangement according to claim 12, wherein the further pulley (69) defines a further passageway (72) for the line (38) to extend along the swivel axis (Ap) through the yaw-pivot joint (71).

14. The hoisting arrangement according to any one of claims 2-13 when dependent on claim 2; wherein the upper line connections (49) in or on the upper carrier (32) are arranged in an upper point distribution that spans an upper polygon in an upper plane (P1); wherein the line guides (69) in or on the line reconfiguration member (58) are arranged in an intermediate point distribution that spans an intermediate polygon in an intermediate plane (Pr); and wherein the upper polygon, the intermediate polygon, and the first line portions (41) interconnecting the upper and intermediate polygons jointly span a polygonal antiprism or a truncated polygonal antiprism.

15. The hoisting arrangement according to claim 14, wherein the lines (38) include sixhoist lines (38) that are extendable and retractable in oblique directions to operate as a positioning mechanism for the lower carrier (34) and the load (36) with six DOF in the first mode, and wherein the first line portions (41) of the six hoist lines (38) and the corresponding upper and intermediate polygons jointly span: a trigonal antiprism wherein the upper and intermediate polygons form mutually rotated triangles along the upper and intermediate planes (P1 , Pr) and wherein the first line portions form edges of triangular side faces, or a truncated trigonal antiprism wherein the upper and intermediate polygons form mutually rotated non-uniform convex hexagons along the upper and intermediate planes (P1 , Pr) and wherein the first line portions form edges of trapezoidal side faces.

16. The hoisting arrangement according to any one of claims 2-15 when dependent on claim 2; wherein the line guides (69) in or on the line reconfiguration member (58) are arranged in an intermediate point distribution that spans an intermediate polygon in an intermediate plane (Pr); wherein the lower line connections (56) in or on the lower carrier (34) are arranged in a lower point distribution that spans a lower polygon in a lower plane (P2); and wherein the intermediate polygon, the lower polygon, and the second line portions (42) interconnecting the intermediate and lower polygons jointly span a polygonal prism.

17. The hoisting arrangement according to claim 16, wherein the lines (38) include six hoist lines (38), and wherein the second line portions (42) of the six hoist lines (38) and corresponding intermediate and lower polygons jointly span a hexagonal prism wherein the intermediate and lower polygons form hexagons along the intermediate and lower planes (Pr, P2) and wherein the second line portions form edges of quadrilateral side faces.

18. The hoisting arrangement according to any one of claims 1-17, wherein the hoisting arrangement is or is part of a crane (16), the crane comprising a base (18) and a jib (24) that is directly or indirectly rotatably connected to the base, wherein the carrier body (33) of the upper carrier (32) is an integral part of the jib (24).

19. The hoisting arrangement according to claim 18, wherein the crane (16) further comprises a boom (22) that is rotatably connected to the base (18), wherein the boom is repositionable into different luff angles (0) relative to a reference plane (P0) associated with the base (18); and wherein the crane comprises a linkage (26) interconnecting the base, the boom, and the jib, the linkage being configured to maintain the jib at a fixed elevation angle (a)relative to the reference plane (P0) under different momentary luff angles (0) of the boom relative to the reference plane.

20. A moveable platform (10) carrying a crane (16) with a hoisting arrangement according to any one of claims 1-19.21 . The moveable platform according to claim 20, wherein the platform is one of: an offshore vessel (10), such as a floating installation vessel, a jack-up vessel, or a semi-submersible heavy lift ship; a railway carriage; a pontoon; a truck or a caterpillar track vehicle; a helicopter or an aerial platform, such as a balloon; an earth-fixed structure, such as an earth-based crane; a fixed work platform at sea.

22. A method for hoisting and / or compensating motion of an object (36) suspended from a hoisting arrangement in accordance with any one of claims 1-19.

23. The method according to claim 22, including first using the hoisting arrangement in the second mode operation to move and position a first object (14) that is relatively heavy, then transitioning the hoisting arrangement from the second to the first mode, followed by using the hoisting arrangement in the first mode to move and position a second object (15) relative to the first object in a motion-compensated manner, the second object being lighter than the first object.

24. The method according to claim 23, wherein the first object is a nacelle (14) of a wind turbine (13), and the second object is a rotor blade (15) of the wind turbine (13).

25. A computer program product configured to provide instructions to carry out a method according to any one of claims 22-24 when loaded on a computer arrangement, wherein the computer arrangement may for instance form part of or be in signal communication with a motion compensation controller device (17).

26. A computer readable medium including the computer program product according to claim 25.

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