Tagline system and method for motion control of a suspended load

Abstract

Tagline system (20) for controlling motion of a load (46) suspended from a crane boom (36). A sagittal plane of the load extends perpendicular to a load body axis and through a centre of mass of the load. The system includes first and second taglines (51, 52) spanned from first and second exit points (61, 62) at / near the boom, in forward direction (+YB), up to first and second coupling points (54, 55) at the load on opposite sides of the sagittal plane; a third tagline (53) spanned from a third exit point (63) associated with the boom, in lateral direction (±XB), up to a third coupling point (56) at the load on one side of the sagittal plane; a pose sensor (40) for dynamically determining a momentary load pose and exit point locations and generating momentary pose measurement signals, and a controller (22) for controlling motions of the load in three selected DOF by dynamically adjusting individual tagline lengths based on the pose measurement signals.

Description

Tagline System and Method for Motion Control of a Suspended LoadTechnical Field

[0001] The invention relates to a system and a method for controlling motion of a suspended load. Furthermore, the invention relates to a computer program product configured to perform the proposed method, and a computer readable medium comprising such a computer program.Background Art

[0002] Methods and systems for damping / minimizing motion of a load that is suspended from an installation vehicle and relative to a target are known in the art. Motion control with high precision is particularly important when the suspended load includes a component that must be installed or disassembled within a constrained space and / or using connections that require tight tolerances.

[0003] A common method for stabilizing motion of a load that is suspended from a crane at considerable height involves adding taglines to the load and controlling the taglines to dampen or mitigate the pendulation motion of the suspended load.

[0004] Patent document WO2015 / 165463A1 describes a known method and device for automatically controlling rotation and displacement of a load that is suspended from a main wire of a crane and guided by taglines. A central control unit sends control signals to the tagline actuators, based on measurements of position and angles of the load by an inertial measurement unit (IMU) located on the load. The central control unit calculates desired lengths of the taglines and sends control signals to the actuators to adjust the lengths of the taglines and thereby change the momentary position and orientation of the load.

[0005] It would be desirable to provide a system and method that allows motion compensation control with improved selectivity and accuracy.Summary of Invention

[0006] Therefore, according to a first aspect there is provided a tagline system configured to control motion of a load that is suspended from a crane boom. The load defines opposite lateral ends that jointly span a nominal load body axis which extends predominantly in lateral directions away from the boom. A nominal sagittal plane of the load extends perpendicular to the load body axis and through a centre of mass (COM) of the load. During hoisting operation, the load may be suspended from the boom such that the load body axis crosses a further nominal body axis corresponding to a length direction of the boom. The tagline system includes first, second and third taglines, a pose sensor and a controller. The tagline system is configured to let the first and second taglines be attached between the boom and the load in such a way that these taglines span respectively from first and second exit points provided at or near the boom, predominantly in a forward direction away from the boom, up to corresponding first and second coupling points located at the load on opposite first and second sides of the sagittal plane. The tagline system is further configured to let the third tagline be attached between the boom and the load in such away that this tagline spans from a third exit point associated with the boom, predominantly in one of the lateral directions, up to a third coupling point located at the load on the first or second side of the load sagittal plane. The pose sensor is configured to dynamically determine a momentary pose of the load and momentary locations of the tagline exit points, and to generate therefore momentary pose measurement signals. The controller is configured to control motion of the load in three selected DOF by dynamically adjusting individual lengths of the first, second and third taglines, based on the momentary pose measurement signals received from the pose sensor.

[0007] The dynamic and individually controlled adjustments of tensions in the taglines to control motions of the load are, in addition to being based on the momentary pose of the load, also based on the momentary locations of the three tagline exit points (i.e. each momentary location of each of the three tagline exit points). The proposed system provides automatic closed-loop control wherein the momentary poses of the suspended load and tagline exit points are measured and used as feedback by the control system. The system may further include tension sensors configured to measure momentary magnitudes of tension forces in the respective taglines. Alternatively, or in addition, the third coupling point may for instance be located on a sleeve that is temporarily attached at or near a lateral distal end of the load.

[0008] In embodiments, the first and second taglines may be configured to exert first and second tensile forces on the load predominantly along a rearward direction towards the boom, and the third tagline may be configured to exert a third tensile force on the load predominantly towards the other of the lateral directions. The third tagline may be configured to exert a tensile force via the third coupling point onto the load and predominantly towards the sagittal plane, to move the load into an offset position including a translation towards the second or first lateral direction. The third coupling point may for instance be located on a sleeve that is temporarily attached at or near a lateral distal end of the load.

[0009] In embodiments, when the boom and the load are in operational hoisting positions, the third tagline is maintained at tension and oriented within an angular range corresponding to angles a relative to the load body axis with magnitudes smaller than 40°. The angular range may be maintained smaller than 20°, or even smaller than 10° (e.g. substantially parallel with the load body axis).

[0010] In embodiments, the third coupling point is located distinctly more distally from the COM of the load than the first and second coupling points. The term “distinctly more” refers herein to a selected placement of attachment points such that the attachment point of the third tagline is not merely shifted more distally for practical purposes, but that the third attachment point is placed more profoundly distally to obtain a smaller / sharper angle a for the third tagline approaching its coupling point, relative to the load body axis.

[0011] In embodiments, the first and second coupling points may be mutually spaced at a lateral distance Di ,2 viewed along the load body axis. In this case, the third coupling point may be at a further lateral distance D3 away from the load COM, the further lateral distance being at least two times the lateral distance (i.e. D3 > 2- Di ,2). Alternatively, the further lateral distance may be larger than half of the lateral distance (i.e. D3 > % ■ Di ,2).

[0012] In embodiments, the pose sensor may include a sensorthat is coupled to the boom and is configured to acquire spatiotemporal image data of the load and the exit points. The pose sensor may further include a processor configured to dynamically determine, from the image data, the momentary load pose and the momentary tagline exit point locations with respect to a boom reference frame or to an external reference frame.

[0013] In embodiments, the system may further include first and second tagline guiding members, which are provided at or on the boom and which define the first and second exit points. The first and second guiding members and exit points may be moveable up and down along the boom independently from each other and predominantly co-directionally with the boom body axis.

[0014] In embodiments, the system may further include a structure that is connectable to the boom, and which carries the third tagline exit point. This structure may be a protruding structure (60) that is connectable to the boom to project forward from the boom towards the load. This protruding structure may define a distal tip where the third exit point is provided closer to the load body axis than the first and second exit points. The protruding structure may for instance be formed as an arm or outrigger, adapted to be connected to a medial portion of the boom.

[0015] In a further embodiment, the structure and third exit point may all be moveable up and down along the boom and predominantly co-directionally with the boom body axis. The structure with third exit point may for instance be moveable independently from the first and second guiding members with the first and second exit points.

[0016] In yet a further embodiment, each of the first, second and third taglines may extend substantially parallel with a same reference plane. In this case, the controller may further be configured to dynamically adjust the positions of the guiding members and the protruding structure in response to a change in a boom luffing angle and / or a change in a hoisting distance between a hoist coupling point on the load and a hoist suspension point on the boom, to maintain the taglines substantially parallel with the reference plane during operation.

[0017] By maintaining of the three taglines substantially parallel with an initially selected reference plane in response to a changing boom luffing angle and / or load hoisting distance, the initial selection of the three DOF along which motion control is to be exerted may be maintained, by ensuring that the three taglines stay close to their initially selected directions, thereby minimizing the directional impact on the spatial interdependencies and required magnitudes of the three tagline tensions to be applied when controlling motion (compensation) of the load when the luffing angle and / or height is being changed. The reference plane may for instance be a horizontal plane or a plane that is tilted at a small angle relative to the horizontal plane. The portion of tagline tensions that can be effectively applied onto the load to induce translation and / or rotation along the three selected DOF is thereby maximized.

[0018] The phrase "maintaining the taglines substantially parallel with the reference plane" refers herein to holding both taglines in essentially the same orientation as the predetermined reference plane while only dynamically changing overall distance from that plane (or at least maintaining the taglines within slight tilt offsets to be considered sufficiently parallel to the reference plane as is realistically achievable when controlling the tagline exit points and tensions,i.e. within a tolerance of ±5°, or ±2%°, or possibly even within ±1° of the orientation of the reference plane).

[0019] In further embodiments, the protruding structure and one or both of the guiding members may be integrated or rigidly interconnected to form a cart member that is configured to move the third exit point and one or both of the first and second exit points together and with identical speeds along the boom.

[0020] In embodiments, the pose sensor may include a sensorthat is coupled to the boom. In this case, the sensor may be configured to acquire spatiotemporal image data of the load. The guiding members and the protruding structure may define structural features, such as corners and / or edges, located at or near the corresponding exit points and directed towards and located within a field of view of the sensor. Alternatively, or in addition, the guiding members and the protruding structure may be provided with markers located at or near the corresponding exit points and directed towards and located within the sensor field of view. The sensor may be configured to dynamically determine, from the image data, momentary poses of the structural features and / or of the markers. The sensor may be further be configured to derive therefrom the momentary poses of the exit points, and to generate the momentary pose measurement signals therefrom.

[0021] In embodiments, the imaging sensor has a field of view that is sufficiently wide to allow concurrently capturing of the load, the guide members, and the protruding structure within the same image data. Moreover, the field of view may be sufficiently wide to capture (part of) the target as well.

[0022] Alternatively, any other known method for performing object matching may be used based on imaging or on point-cloud data (such as matching LIDAR-based point cloud data with a CAD or other type of 3D model).

[0023] In embodiments, the protruding structure may be an outrigger that is collapsible or retractable towards boom, to allow the outrigger to be placed along or inside the peripheral surface of the boom when the crane is in a non-operational mode.

[0024] In embodiments, the protruding structure may define a distal tip that is dynamically extendable in forwards direction away from the boom and / or retractable in rearwards direction towards the boom, to dynamically decrease and / or increase a radial distance of the third exit point relative to the load body axis.

[0025] In embodiments, the load includes a rotor blade of a wind turbine, the rotor blade defining a distal end corresponding to a blade tip. In this case, the tagline system may further include a sleeve configured to be placed temporarily around and engage the blade at or near the distal end, so that the third coupling point is arranged at the sleeve.

[0026] In a further embodiment, the system may further include an auxiliary line and a winch configured to remove the sleeve from the blade and to reel in the third tagline and the sleeve after the blade has been placed at a target position.

[0027] In embodiments, the load may include a rotor blade of a wind turbine. The rotor blade defines a proximal end corresponding to a blade root provided with blade mounting members,such as bolts, for connecting the rotor blade to a rotor hub. In this case, the third coupling point may be located at one of the blade mounting members. The tagline system may then further include one or more spacers, each configured to be placed temporarily around a blade mounting member to create an interspacing between, on the one hand, the third tagline at its third coupling point, and on the other hand, an end flange of the blade root. Such a spacer may include a splittable cylindrical body or a C-shaped semi-cylindrical body defining a lateral insertion slot and an inner space with a cross-sectional size matching a diameter of a mounting bolt provided at a blade root.

[0028] In embodiments, the load may include a first portion and a second portion that are interconnected by a pitching joint. The pitching joint includes a pitch actuator configured to rotate the second portion about a nominal pitch axis, which extends in a forward direction perpendicular to the nominal load body axis.

[0029] In embodiments, the system may further include tension sensors configured to measure momentary tension magnitudes of tension forces in the respective taglines. In this case, the controller may be further configured to calculate a desired distribution of momentary tagline tension magnitudes for moving the load from a current load pose to a desired load pose.

[0030] In embodiments, one or more of the taglines may be formed by a multi-reeved arrangement, with multiple tagline sections extending back and forth between the boom and the load. The multi-reeved tagline arrangement may for instance be a double-reeved, triple-reeved, or quadruple-reeved arrangement.

[0031] According to a second aspect, there is provided a method for compensating motion of a load suspended from a hoisting arrangement, using a tagline system according to the first aspect.

[0032] In an embodiment, the controller may be configured to dynamically control the motions of the load in the three selected DOF by- applying pre-tensions to one or more selected from the first, second and third taglines, thereby placing the load into a determined offset pose with a translation offset component in rearward direction towards the boom and / or with a translation offset component in a lateral direction that is opposite to the direction from the load COM to the third coupling point, and by- dynamically adjusting selected lengths of the first, second, and third taglines concurrently but independently from each other, to dynamically control or adjust the pose of the load by one or more of a rotation along a vertical axis, a translation in forward or rearward direction, and a translation in lateral direction.

[0033] In a further aspect, there is provided a computer program product configured to provide instructions to carry out the method according to the second aspect, when loaded on a computer arrangement.

[0034] Yet a further aspect pertains to a computer readable medium (for instance a non-transitory computer readable medium) comprising the computer program product according to the previous aspect.

[0035] Term “position” is used herein to refer to a three-dimensional set of coordinates or a translation vector relative to a given coordinate reference frame. The position of an object - or arepresentative point for this object like its centre of mass - may be represented in 3D space by a vector in IK3. The term “orientation” is used herein to refer to the three-dimensional rotational state of the object around a predefined axis, which may either be expressed relative to the object’s own local reference frame or relative to an external reference frame. The orientation of an object may be represented in 3D space by orthonormal rotation matrices, Euler angles, roll-pitch-yaw angles, unit-quaternions, matrix exponentials, or any other known rotational representation that may be applied. The combination of the position and the orientation of an object is referred to herein as the “pose” of the object.

[0036] The term “wrench” is used herein to indicate a joint 6-vector representation of a net three-dimensional (3D) linear force vector and the net 3D torque vector acting on an object.

[0037] A "frame of reference" or "reference frame" refers to an abstract coordinate system for which the origin and orientation are specified by a reference point and directional unit vectors.

[0038] The term "load" refers herein to a composite object that is suspended with the hoist line from the hoisting arrangement, and which includes a specific load that is to be installed or moved (such as a rotor blade or other component) as well as the load carrier that is temporarily fixed to the specific load while carrier and specific load are suspended from the hoist line.

[0039] The term "line" (as e.g. in "hoist line" and "tagline") is used herein to refer generally to any kind of elongated connection like a wire, cable, 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 term “tagline” is used herein to refer to a line attached and configured to exert a pulling force on a suspended load for purposes of controlling motions of the load during handling operations. The tagline may be structurally composed of a single continuous line, a group of parallel lines, and / or a series of interconnected line segments. Irrespective of this structure, the tagline is assumed to have an off-axis flexibility that renders it unsuitable to exert a pushing force. The phrase "connected to the load” may - but does not necessarily - mean that the end of the tagline is rigidly fixed to the load. Alternatively, the tagline may be passed through a sheave connected to the load and then passed back to its original attachment point (e.g. the vessel) in for instance a double reeved configuration.

[0040] Any known mechanism may be used for adjusting a length of the tagline, such as for instance a winch around which part of the tagline is wound or a linear drive (e.g. a spindle or rack-and-pinion mechanism) to which a distal end of the tagline is attached. The term "winch" is used to refer to any machine or instrument for hauling or pulling and includes a drum or spool from / on which a line may be (un)wound by means of a rotational actuator, possibly powered by e.g. an electric, pneumatic, hydraulic, or combustion drive.

[0041] The term "tagline exit point" is used herein to refer to the point where a respective tagline exits the corresponding guide member (e.g. via a diverter sheave) and proceeds toward the load. A “tagline exit direction” is the direction towards which the tagline extends after departing from the corresponding exit point.

[0042] The term "decoupled" refers herein to a controlled way of adjusting the pose and / or orientation of the load (assembly) in such a way that generated movement of the load (assembly)in one selected direction of the two selectable DOFs does not induce or influence motion of the load (assembly) already taking place in the non-selected other DOF.

[0043] The term "dynamically measuring" refers herein to a repeated measurement i.e. continuous or intermittent sampling of one or more physical quantities or properties associated with the observed system, to produce a series of measurements that have a well-defined time ordering.Brief Description of Drawings

[0044] 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.

[0045] Figure 1 schematically shows a perspective view of a tagline system according to an embodiment, which forms part of a jack-up vessel with a crane used during construction of an offshore wind turbine.

[0046] Figures 2a and 2b schematically show perspective and top views of the exemplary tagline system from Figure 1.

[0047] Figure 3 schematically shows a perspective view of a protruding structure forming part of a tagline system according to an embodiment.

[0048] Figure 4 schematically shows a side view of a tagline system according to an embodiment.

[0049] Figures 5-9 schematically show top views of arrangements with taglines, exit points, and coupling points according to various embodiments.

[0050] Figure 10 schematically shows a blade sleeve for use in tagline systems according to embodiments.

[0051] Figure 11 schematically shows a spacer for use in tagline systems according to embodiments.

[0052] Figures 12-15 schematically show further examples of arrangements with taglines, exit points, and coupling points.

[0053] Figure 16 schematically shows a component diagram for a control arrangement forming part of a tagline system according to an embodiment.

[0054] 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

[0055] The following is a description of certain embodiments of the invention, given byway of example only and with reference to the figures.

[0056] Figure 1 schematically shows an exemplary embodiment of a tagline system 20, which is configured to compensate motion perturbations for a suspended load 46 in three selected degrees of freedom (DOF), among which are a linear DOF in longitudinal directions ±Y, a linear DOF in transverse directions ±X, and a rotational DOF about a nominal axis in vertical directionZ. In this example, the system 20 is installed in a crane 30 that is mounted on an offshore jack-up vessel 24. The vessel 24 is configured to install various components, e.g. 11, 12, 13, 14 of a wind turbine 10 at sea 19. In the exemplary operation shown in Figure 1 , the system 20 is used to facilitate positioning of a suspended rotor blade 14c, to allow the blade 14c to be mounted to a rotor hub 13 of a nacelle 12 that is part of the offshore wind turbine 10. The exemplary vessel 24 is temporarily positioned in a fixed pose on the seabed by extending its four jack-up legs 26, so that a relation between a reference frame {Cv}, which is associated with the vessel 24, and an external reference frame {CE} which is fixed with respect to earth, remains (approximately) constant, at least during the installation procedure.

[0057] In this example, the crane 30 includes a fixed pedestal 32 that is mounted to a deck 28 of the vessel 24, and a moveable turret 34 that is rotatably mounted to the pedestal 32 and is configured to perform in-plane rotational motion (“slewing”) about a vertical slew axis A(p substantially perpendicular to a horizontal reference plane of the deck 28. The crane 30 further includes a boom 36 with a base 37 that is rotatably coupled to the turret 34, such that the boom 36 may dynamically adjust its elevation angle (“luffing”) in upward-downward rotational directions about a transverse luff axis Ay and relative to a transverse plane associated with the deck 28. In alternative examples wherein the crane is land-based, the transverse plane may be associated with a chassis or an earth-fixed base of the vehicle. This transverse plane may be in a fixed orientation (e.g. parallel or slanted) or be moving relative to the earth horizontal plane PH.

[0058] A distal end of the boom 36 forms or is provided with a jib portion 38, which is inclined forwards relative to the main portion of the boom 36. A hoist line 42 is suspended at or near a distal end 39 of the jib 38. During installation, the suspended rotor blade 14c is rigidly held by a carrier 48, which in this example is formed as a blade cradle 48. The suspended cradle 48 and blade 14c are jointly referred to as the load 46. An upper portion of the cradle 48 is connected via the hoist line 42 to a suspension point 43 at or near the distal end 39 of the jib 38. Depending on the required hoist line strengths and acceptable hoisting speeds, the hoist line may alternatively be located at a mid-portion and / or at a proximal part of the jib 38. The hoist line 42 is dynamically extendable / retractable, for instance using a winch mechanism (not indicated) that is controlled by an operator in / on the crane 30 or the vessel 24, to raise or lower the load 46 as needed to move the blade 14c towards a blade mounting ring on the rotor hub 13. Optionally, the hoist line may be equipped with passive or active heave compensation devices to further influence the hoist height of the load, as required by a variety of applications.

[0059] The exemplary system 20 also includes an outrigger 60, which forms a protruding structure that in this example is attached to a medial section of the boom 36, and which projects in a forward direction +YB from the boom to define a distal tip that is closer to the load 46.

[0060] The exemplary system 20 further includes a sleeve member 18 (see e.g. figure 10), which is temporarily arranged around the rotor blade 14c near the distal blade end 15 and remote from the cradle 48.

[0061] The exemplary system 20 includes three taglines 51 , 52, 53. The first and second taglines 51 , 52 extend upwards along a portion of the boom 36 and then deflect towards the load46 where each tagline 51 , 52 is connected to a corresponding coupling point (see Figures 2a-b). The third tagline 53 extends upwards along the boom 36, then partly forwards along and towards the tip of the outrigger 60, and then in lateral direction -XB towards the blade sleeve 18. In alternative embodiments wherein the structure with third exit point does not protrude further out toward the load than the first and second exit points, the third tagline may omit a portion that extends forwards along the outrigger.

[0062] The lengths of the individual taglines 51-53 are independently and dynamically controlled by the system 20 to exert dynamically adjustable tensile forces on the load 46, based in part on measurements of momentary tensions in the individual taglines 51-53 using tagline tension sensors. The tagline control helps stabilizing the pose of the load 46 by dynamically counteracting externally induced motion disturbances of the vessel 24 and the load 46, and / or causes a desired motion that allows the load 46 to approach a (possibly moving) target point on the wind turbine 10, for instance the blade mounting ring on the rotor hub 13.

[0063] In the example of Figure 1 , a pose sensor with a camera 40 is provided at or near the distal end 39 of the jib 38. The camera 40 is pointed with its field of view directed generally downwards along the boom 36 and is configured to acquire visual data of the load 46 from a top / plan view perspective. The pose sensor 40 is configured to determine a pose (possibly in at least three of the six possible DOF) of the load 46 expressed in a reference frame {CB} of the boom 36. The boom reference frame {CB} may have its origin defined on / at / nearthe boom 36 and with determined orientations of orthogonal unit vectors relative to the boom 36. The pose sensor 40 is further configured to acquire visual data of exit points where the taglines 51-53 depart from the boom 36 and from the outrigger 60, and continue towards the load 46. The pose sensor 40 may further be configured to determine the departure directions of the taglines 51-53 towards the load 46.

[0064] Figure 2a schematically shows a perspective view of geometric relations between the crane 30, the hoist line 42, the taglines 51-53, and the load 46 in an exemplary embodiment. Figure 2b schematically shows a top view of the exemplary system from Figure 2a.

[0065] Again, but merely for illustration purposes, the operation shown involves hoisting of a rotor blade 14c, which is held in a cradle 48 and is suspended by the crane 30, in the vicinity of a rotor hub 13 of a partially finished offshore wind turbine 10. An upper portion of the cradle 48 is connected at a hoist coupling point 44 to the hoist line 42. The hoist line 42 is held taut by the combined weight of the load 46 (and in alternative embodiments possibly also a weight of a lower hoist block and hook which may be arranged around a lower end of the hoist line) and extends from the suspension point 43 at the distal upper jib end 39, along a linear trajectory in predominantly downward and slightly rearward directions, up to the hoist coupling point 44. In this example, the cradle 48 is composed of two portions interconnected by a pitching joint 49 and provided with an actuator 50 configured to cause the portion holding the blade 14c to perform pitch rotation adjustments.

[0066] The jib 38 is oriented with its nominal body axis Aj in a forward slanted direction relative to the nominal body axis AB of the main part of the boom 36. In this example, the body axes Ajand AB form nominal centrelines of the jib 38 and boom 36, and jointly span a nominal sagittal boom plane PSB. This plane PSB generally extends in forward / rearward directions ±YB and upward / downward directions ±ZB of the boom reference frame {CB}, and divides the boom 36 and jib 38 into two lateral halves on opposite lateral sides of the plane PSB that correspond with the lateral directions ±XB of the boom reference frame {CB}.

[0067] The load 46 defines opposite lateral ends 15, 16, which in this example correspond to the tip 15 and the root 16 of the rotor blade 14c. These lateral ends 15, 16 jointly span a nominal load body axis AL which spans in lateral directions ±XL associated with the local reference frame {CL} of the load 46. A nominal sagittal plane PSL of the load 46 extends through a centre of mass COM of the load 46 and perpendicular to the load body axis AL. The vector Fg represents the momentary gravitational pull acting on the load 46.

[0068] The first and second taglines 51 , 52 span from respective first and second exit points 61 , 62 located on two respective guide members 58, 59 at the boom 36, towards two respective coupling points 54, 55 located on the cradle 48. The third tagline 53 spans from the third exit point 63 located on the outrigger 60, towards the third coupling point 56 located on the blade sleeve 18. The respective taglines 51 , 52 and 53 are fixed to their corresponding coupling points 54, 55 and 56 on the cradle 48 and on the sleeve 18, respectively.

[0069] During operation, each of the taglines 51 , 52, 53 may be held taut to exert tensile forces F1 , F2, F3 (vectors) with corresponding magnitudes T1 , T2, T3 (scalars) on the load 46.

[0070] The two guide members 58, 59 are connected to the boom 36 in a displaceable manner that allows each member 58, 59 to move in substantially linear trajectories along the boom 36 and predominantly parallel with the boom axis AB or predominantly parallel with the lateral bounding surface of the boom 36. In this example, the first guide member 58 and its corresponding exit point 61 is provided on one lateral side of the boom sagittal plane PSB, whereas the second guide member 59 and its corresponding exit point 62 are provided on the opposite lateral side of the boom sagittal plane PSB.

[0071] Each of the first and second taglines 51, 52 is routed in a slidable or rollable manner (with low friction e.g. by a sheave) through a corresponding guide member 58, 59. The respective tagline 51 , 52 is thereby divided into a lower section 51 f, 52f that runs along the boom 36 towards the respective exit point 61 , 62, and an upper section 51s, 52s that departs from this exit point 61 , 62 in a substantially forward direction +YB towards the load 46.

[0072] The third tagline 53 is routed in a slidable or rollable manner through the outrigger 60. The tagline 53 is thereby divided into a lower section 53f that runs along the boom 36, a medial section 53m (see e.g. figure 3) that runs in predominantly forward direction +YB along the outrigger 60 towards the third exit point 63, and an upper section 53s that departs from the exit point 63 and extends at an angle sideways and in a substantially negative lateral direction -XB towards the load 46.

[0073] In this example, the lower tagline sections 51 f, 52f, 53f are routed downwards towards respective tagline actuators 68, 69, 70, which in this example are located near the base 37 of the boom 36. Each of the actuators 68-70 may for instance be implemented as a tugger winch, whichmay be actuated by a dedicated electric or hydraulic drive or other wire reeling actuator means known in the art. In alternative embodiments, the actuators may be implemented as linear tagline extension / retraction mechanisms. In alternative embodiments, the winches may be located elsewhere on the boom (e.g. upwards at or near the jib), elsewhere on the crane or vessel / vehicle, and / or on the load.

[0074] In the example in Figures 2a-b, the taglines 51-53, the coupling points 54-56 and the exit points 61-63 are located within the same half-space on a side of the load 46 that faces towards the main portion of the boom 36. By contrast, the hoist suspension point 43 on the jib 38 is on an opposite side of the load 46 that faces away from the main boom portion 36.

[0075] In the example shown in Figures 2a-b, the first and second coupling points 54, 55 are mutually spaced by a lateral distance Di ,2 viewed along the load body axis AL. In this case, each of the first and second coupling points 54, 55 is located at half the lateral distance Di ,2 but in opposite lateral directions ±XL away from the load centre of mass COM. By contrast, the third coupling point 56 is located at the blade sleeve 18 near the blade tip 15, and at a further lateral distance D3 in negative lateral direction -XL away from the load centre of mass COM. In this example, the further lateral distance D3 is about four to five times the lateral distance DI^2.

[0076] In the example shown in Figures 2a-b, the upper sections 51s, 52s of the first and second taglines 51 , 52 extend substantially in the same tagline plane PT, but in a mutually oblique (i.e. non-parallel) and non-crossing constellation. In the example of Figure 2b, the tagline sections 51s, 52s extend at respective slant angles p1 and p2 relative to the sagittal plane PSB of the boom 36. The slant angles p1 and p2 may have substantially equal magnitudes but opposite signs p1 = -p2. The upper section 53s of the third tagline 53 extends at an angle a relative to the load body axis AL. During operation, a magnitude of the angle a is kept preferably smaller than 40°, and preferably below 20° or even below 10°. The indicated tagline angles a, p1 , p2 pertain to the initially applied offset position of the load 46, but may change during operation due to offset compensations applied onto the load 46, and / or due to changing external influences like wind and wave motion acting on the blade, the boom, and / or the vessel.

[0077] In the present example, when the load 46 is suspended from the crane 30 in a baseline hoisting position, the lateral directions ±XL corresponding to the reference frame {CL} of the load 46 and the lateral directions ±XB corresponding to the reference frame {CB} of the boom 36 are substantially co-directional, and the body axis AL of the load 46 crosses the body axis AB of the boom 36 in substantially orthogonal directions. When the taglines 51-53 are held slack, the load 46 will assume a rest pose 46R subject to gravity Fg but without tagline tensions or other external influences. In this rest pose 46R, the sagittal planes PSL, PSB of the load 46 and the boom 36 will largely coincide.

[0078] During motion control, the applied tagline tensions displace the load 46 away from the rest pose 46R and move it into an offset pose 46o. In this example, the first and second taglines 51 , 52 are persistently and dynamically controlled by the winches 68, 69 to exert inwards pulling forces F1 , F2 onto the suspended load 46, such that the taglines 51 , 52 pull the coupling points 54, 55 towards the boom 36, thereby causing the load 46 to perform a longitudinal translation -Tyin rearward direction -YB. In addition, the third tagline 53 is persistently and dynamically controlled by the winch 70 to exert a transverse pulling force F3 onto the suspended load 46, such that the tagline 53 pulls the coupling point 56 towards the sagittal plane PSB of the boom 36, thereby causing the load 46 to perform a transverse translation +Tx in a lateral direction +XB. During motion control, the system strives to keep the load 46 in or as close as possible to a pre-loaded offset pose 46o.

[0079] Part of the gravitational force Fg that is not cancelled by the combined tensile forces exerted by the hoist line 42 and taglines 51-53 will give rise to a restitution force, which urges the load 46 back towards its rest pose 46R. In the absence of other external forces, the tensile forces F1-F3, hoist force Fh and gravity Fg will cancel each other out, so that the load 46 remains suspended in the predetermined offset pose 46o.

[0080] Relaxing all of the taglines 51 , 52, 53 allows the load 46 to translate back towards the rest pose 40R. Tightening one of the first and second taglines (e.g. 51 or 52) while relaxing the other of the two taglines (e.g. 52 or 51) causes the load 46 to rotate about the coupling point 44 and perform a rotational motion +Rz or-Rz about a vertical axis Az ("yawing").

[0081] By dynamically adjusting the individual tagline tension magnitudes T1-T3 around baseline values that correspond to the offset pose, the inability of the taglines 51-53 to exert pushing forces on the suspended load 46 is overcome, and motion compensation for the suspended load 46 is also allowed to include outward translation +Ty away from the boom 36, sideways deflection -Tx away from the sagittal plane PSB, and rotations ±Rz about the vertical axis Az.

[0082] In the example of Figures 2a-b, each of the distal ends of the upper tagline sections 51s-53s is provided with a tension sensor 72-74 located at or near the corresponding coupling point 54-56. Each respective sensor 72-74 is configured to (continuously or intermittently) measure a magnitude T1-T3 of the momentary tensile force F1-F3 applied by the corresponding tagline 51-53 onto the load 46. The tension sensors 72-74 are thus configured to acquire series of tension values as function of time.

[0083] Figure 2a illustrates that the exemplary system 20 includes a control device 22, S10 which is in signal connection with the tension sensors 72-74 to receive measurement signals indicative of the momentary tensile force magnitudes T1-T3 applied by the respective taglines 51-53 onto the load 46. The control device 22 is also in signal connection with the winches 68-70 and configured to actuate the winches 68-70 to reel the corresponding tagline 51-53 in (or out), thereby increasing (decreasing) the tension and decreasing (increasing) the wire length of the corresponding tagline 51-53 and hence the spanning distance of each upper tagline section 51s-53s between its exit point 61-63 and coupling point 54-56. The control device 22 may also be in signal connection with the sensor 40, in order to determine the exact poses of the cable exit points 61-63 and the load momentary pose in order to determine the required actuator commands of the winches 68-70. The control of each winch 68-70 is configured to be executed in a concurrent but mutually independent manner, that is, the tagline lengths may be adjusted simultaneously but independently from each other at each moment in time.

[0084] The tagline tension settings and resulting offset pose 46o are adjusted in real-time based on incoming data from the sensors 72-74 and 40 at a relatively high dynamic rate, to ensure that the desired instantaneous offset pose continues to provide enough leeway for yawing rotations and for outward and transverse translational motions.

[0085] The computation of the desired tagline tension magnitudes T1-T3 to be applied by each winch 68-70 relies, in part, on the momentary pose of each tagline exit point 61-63 and the momentary pose of each tagline coupling point 54-56 at the load 46, from which the momentary directional unit vectors for the taglines 51-53 may be derived. The computation of the desired tagline tensions further relies on the momentary pose of the load 46. From the poses of the coupling and exit points 54-56, 61-63, analytic matrix equations may be constructed for computing the desired tagline tension magnitudes, which take as input a vector of desired wrench components to be exerted on the load 46.

[0086] Functionality of the proposed tagline system 20 may be coupled or integrated with an existing control system of the crane 30 (schematically illustrated by element 22 in Figure 1), to allow a crane operator to control luffing / slewing motions of the crane 30, hoisting and motion compensation of the suspended load 46 together via a single user interface (e.g. at an operator console).

[0087] In order to determine the poses of the tagline coupling points 61-63 and exit points 54-56, the system 20 further includes a pose sensor 40 which in this example includes a camera configured to dynamically acquire spatiotemporal image data of objects within its field of view 76. The photogrammetric camera 40 is arranged at the tip 39 of the jib 38. This camera 40 may be mounted - by a fixed or repositionable mounting (e.g. gimbal or pan-tilt drive) - to point substantially downwards towards the load 46, and to maintain at least an upward portion of the carrier 48, the blade 14c, and the three tagline exit points 61-63 in its field of view 76 during operation. Preferably, this view onto the carrier 48 and blade 14c is maintained from load-out at the quayside, during pick-up above deck, and up to and including the installation of the load 46. The camera 40 may further be configured to maintain an upward portion of the wind turbine (or other target) 10 within view while the load 46 is approaching its target position.

[0088] The camera 40 may be configured to determine momentary poses of objects detected in the acquired images relative to its own sensor reference frame. Alternatively, the camera 40 may be configured to transmit the acquired images to an associated image processor, which is configured to post-process the images to determine poses of the objects in the images relative to the sensor reference frame.

[0089] Figure 2b schematically shows a peripheral contour of the camera field of view 76 at a height corresponding with a reference plane PR that is surrounded by the taglines 51-53 (see figure 4). By positioning the camera 40 high on the jib 38 and above the load 46 - and by choosing appropriate settings and elements for the camera optics - the camera 40 may maintain a largely unobstructed view on multiple constituents of the tagline system 20. For instance, the camera 40 may have a field of view 76 that is sufficiently wide (e.g. using a fisheye lens) to allow the blade cradle 48, (most of) the blade 14c, the guide members 58, 59, the protruding structure60, and the sleeve 18 (and possibly also part of the target 10) to be simultaneously captured within the same image. In this way, the camera 40 and / or the image processor may concurrently detect the respective individual objects in the same image and may determine the poses of each object relative to a camera reference frame.

[0090] The load reference frame {CL} may be defined by a determined origin on / at / nearthe load 46, and with a determined orientation and scale relative to the load 46. The momentary position of each tagline coupling point 54-56 on the load 46 may be expressed as a positional vector relative to the load reference frame {CL}.

[0091] Active and / or passive optical markers 78 may be arranged in a known spatial pattern across the carrier 48. In addition, the blade sleeve 18 may be provided with an optical marker 79. In this case, the camera 40 may be configured to maintain an unobstructed view of these markers 78, 79. The camera 40 may be configured to detect and determine the momentary poses of the markers 78, 79 in the acquired images, and to use these poses to derive the pose of the carrier 48, the sleeve 18 and the tagline coupling points 54-56 relative to the sensor reference frame. Assuming the markers 78, 79 remain fixed on the carrier 48 and sleeve 18 during operation, their relative positions with respect to the load reference frame {CL} may be defined beforehand. The carrier 48 with markers 78 and coupling points 54, 55 as well as the sleeve 18 with marker 79 and coupling point 56 may be surveyed beforehand (for instance by the camera 40 or by a total station or other method known in the art of pose surveying) to establish the required transformation from the markers to the load reference frame {CL}. Moreover, the camera 40 may be surveyed and calibrated to determine its internal image calibration parameters, such as the focal length, horizontal and vertical sensor offsets, radial lens distortion or any other known camera calibration parameter. The locations of the markers 78, 79 and momentary pose of the suspended load 46 derived from the acquired image may then be used to transform the positions of the tagline coupling points 54-56 (which are known in the load frame {CL}) into the sensor reference frame, for each time that the camera 40 has acquired an image e.g. using known marker matching techniques. Alternatively, a marker-less method may be used that relies on image segmentation and / or edge detection techniques, or on any other known pose detection technique (e.g. texture based) to detect the pose of the carrier 48 (and / or the sleeve 18) in the relevant DOFs and / or the individual poses of the tagline coupling points 54-56.

[0092] The coordinate transformation from sensor reference frame to boom reference frame {CB} may also be determined offline by surveying (e.g. using a total-station or other known survey measurement techniques).

[0093] In the example shown in Figures 2a-b, the guide members 58, 59 are implemented as trolleys (cart mechanisms) that are arranged to be moved in a controlled manner up and down along guiding tracks 66, 67 (see e.g. figure 3). Their positions may be measured also with sensors such as encoders along the tracks.

[0094] The momentary position of each tagline exit point 61-63 may be expressed as a positional vector relative to the boom reference frame {CB}. The reference starting positions and full range of possible positions of the exit points 61-63 may be determined through prior surveymeasurements. The (changing) momentary positions assumed by the exit points 61-63 along the boom during operation may then be followed as function of time by online measurement of positional changes using calibrated displacement sensors and / or by online measurements using remote sensing techniques.

[0095] The trolleys 58, 59 and outrigger 60 may also be provided with markers 82, 83, 84. The camera 40 may be configured to detect these markers 82-84 in the acquired images and to measure the respective poses of these markers 82-84 directly in the sensor reference frame concurrently with detecting the pose of the carrier 48 and / or sleeve 18 with blade 14c. Suitable transformations for re-expressing the measured trolley poses in sensor reference frame into the boom reference frame {CB} and possibly into the external reference frame {CE} may be determined via similar procedures as described above for the load marker measurements.

[0096] The proposed system and method allow the motions of the load 46 to be stabilized against external disturbances, such as for instance induced by winds, by dynamically and individually controlling the tensions applied by the taglines as well as the positions of the tagline guide members on the boom. Motion control can be superimposed in addition.

[0097] Figure 3 schematically shows a perspective view of a protruding structure 60 for an exemplary tagline system, for instance the tagline system shown in Figures 2a-b.

[0098] In this example, the outrigger 60 is connected to the boom 36 and projects in forward direction +YB from the boom 36 towards the load 46. The outrigger 60 has a distal tip 64 with a double rotatable sheave that defines the third exit point 63. In this example, the exit point 63 is located at a radial distance Dp from to the body axis AL of the load 46, this radial distance Dp being smaller than the distances between either one of the respective first and second exit points 61 , 62 and the load body axis AL.

[0099] The outrigger 60 is provided with hinge joints to form a four-bar linkage, which allows the outrigger 60 to be collapsed sideways and retracted towards the boom 36, and to be placed along / againstthe peripheral contour of the boom 36 when the crane 30 is in a non-operational state. The four-bar linkage may be realized in such ways that two of the links form an over-centre mechanism that locks the linkage in place once deployed. The outrigger 60 includes a sliding joint with an actuator 65 configured to dynamically extend (and / or retract) the distal tip 64 in forwards (rearwards) direction +YB (-YB) away from (towards) the boom 36, to dynamically decrease (increase) the radial distance Dp. By adjusting the radial distance Dp, the angle a (e.g. figure 2b) between the upper tagline section 53s and the load body axis AL, can thereby be reduced or increased at will, thus allowing the system 20 to adjust the degree of parallelism between the third tagline section 53s and the load body axis AL. This may especially be important between different luffing angles. In alternative embodiments, other joint mechanisms may be employed to render the outrigger selectively extendable / retractable relative to the boom 36.

[0100] In this example, the trolleys 58, 59 and protruding structure 60 with corresponding exit points 61-63 are moveable up and down along the boom 36, in directions largely or fully parallel with the body axis AB of the boom 36. The guiding members 58, 59 and base of the outrigger 60 are formed with trolley carts that are linearly repositionable with drives and lockable with brakesalong guiding tracks 66, 67. In this example, the tracks 66, 67 are implemented as rigid rails provided along the boom 36. The mechanically rigidity of the rails allows accurate determination of momentary linear positions of the trolleys 58, 59 and outrigger 60 during operation. Each trolley 58, 59 and the outrigger 60 may be provided with positional encoders configured to dynamically provide indications of momentary positions of the trolleys and / or outrigger relative to the corresponding tracks 66, 67. A processor may be configured to dynamically determine, from these indications, the momentary poses of each of the three exit points 61-63.

[0101] The protruding structure 60 may be rigidly connected to or integrated with one or both guiding members 58, 59, thus forming a cart member (also referred to as a “traverse system”) which is configured to move the third exit point 63 and one or both of the first and second exit points 61 , 62 simultaneously and uniformly up or down along the boom 36. A traverse system may also be located on the backside of a crane, for as long as it may have outriggers, e.g. on either side 58, 59 and a mid-section that allows to realize the exit point 63 from the front (which could be connected sideways to the back-located trolley).

[0102] As alternatives to using wheeled trolleys and rail bars, the guiding members and guiding tracks may be implemented using spindle or rack-and-pinion mechanisms, telescoping members, or any other guiding track arrangement known in the art.

[0103] Figure 4 schematically shows a side view of a tagline system, for instance the tagline system 20 from Figures 2a-b. In this exemplary system, the boom 36 is oriented at a luffing angle y and the load 46 is positioned at a hoisting distance H. The boom 36 is rotatable over variable luffing angles y relative to a transverse plane associated with the pedestal 32, with a fixed platform (e.g. the deck 28) of the vessel 24, or relative to a horizontal plane PH perpendicular to the gravity vector Fg. The hoisting distance H is a vertical distance between the suspension point 43 on the boom jib 38 and the coupling point 44 on the load 46. This hoisting distance H is also dynamically adjustable by changing a length of the hoist line 42. The luffing angle y and / or hoisting distance H may change during hoisting operation.

[0104] The tagline system 20 may be configured (e.g. using controller 22) to dynamically reposition the trolleys 58, 59 and / or the outrigger 60 along the boom 36 while either or both the luffing angle y and the hoisting distance H are changed, to maintain the taglines 51-53 substantially aligned with the reference plane P . The load 46 thus remains held with position offset (e.g. 46o in Figure 2b) sideways and towards the boom 36. In this example, the taglines 51-53 are maintained substantially parallel with a reference plane PR, which is oriented at a relatively small angle qi relative to the horizontal plane PH.

[0105] The guide members 58, 59 and outrigger 60 are dynamically repositionable upwards (downwards) along the rails 66, 67 when the hoisting distance H decreases (increases), respectively and / or when the luffing angle y increases (decreases). The upwards ordownwards repositioning of the trolleys 58, 59 and / or outrigger 60 causes the taglines 51-53 to be held substantially oriented parallel with the reference plane PR while the distance H and / or angle y changes. The travel distances of the trolleys 58, 59 and outrigger 60 along the boom 36 may forinstance be (approximately) proportional to the instantaneous value of the hoisting distance H and inversely proportional to the sine of the instantaneous luffing angle y.

[0106] The camera 40 may be configured to maintain the load 46 as well as the trolleys 58, 59 and outrigger 60 within its field of view 76 while the boom 36 progresses through various luffing angles y. The camera 40 may thus track the momentary poses of the trolleys 58, 59 and outrigger 60, to allow the system 20 to correct positions of the trolleys 58, 59 and outrigger 60.

[0107] In addition, the system 20 may be configured (e.g. using controller 22) to dynamically command the winches 68-70 to reel in or out, in order to (concurrently but independently) change the lengths of the three taglines 51-53 in conjunction with the commanded positional changes for the trolleys 58, 59 and / or outrigger 60, in order to compensate for changes in tagline path lengths from the respective winch 68-70 via the guide member 58-60 to the load 46, and to ensure that the tensile force magnitudes T1 , T2, T3 remain essentially constant.

[0108] Figure 5 schematically shows a top view of an exemplary tagline system including three taglines 51 , 52 and 53 and a blade sleeve 18 that is temporarily fixed around the blade 14 near a distal blade tip 15. In this embodiment, the third tagline 53 extends from the exit point 63 and laterally away from the sagittal plane PSL of the load towards the blade sleeve 18. The third tagline 53 is coupled with its distal end to a third coupling point 56 on the sleeve 18. By contrast, the first and second taglines 51 , 52 extend from their respective exit points 61 , 62 predominantly forwards and in a mutually converging arrangement towards the load 46, and are connected with their distal ends to first and second coupling points 54, 55 provided on the blade cradle 48.

[0109] Figure 6 schematically shows a perspective view of an alternative tagline system which also includes three taglines 151-153 and a blade sleeve 118, in a constellation similar to figure 5. In this example, each of the taglines 151-153 is provided as a double-reeved arrangement, wherein each tagline includes an outgoing section i (e.g. 151 i) which extends from a tagline actuator at or near the boom towards the coupling point on the load 146, and a returning section j (e.g. 151 j) which extends from the coupling point on the load 146 back towards a tagline anchor point at or near the boom. In this example, each of the coupling points 154-156 is formed using a low-friction rolling or sliding coupling (e.g. a snatch-block with a pulley) that allows the corresponding incoming tagline section to be routed back into the returning tagline section. In this example, the outgoing and returning sections i,j of each tagline extend in predominantly co-directional wire segments. In this case, the respective exit points 161 , 162, 163 are formed using double-wheeled sheaves that accommodate and reroute both the outgoing and returning sections of the corresponding tagline. A load sensor may be placed in such case between the sheaves and the coupling points 154, 155, 156.

[0110] Figure 7 schematically shows a top view of an alternative tagline system with three taglines 251-253. In this embodiment, the third tagline 253 extends from its exit point 263 and laterally away in opposite direction from the load sagittal plane PSL. The third tagline 253 is temporarily fixed to the blade root 216, at a third coupling point 256 that may for instance be provided by blade mounting members (e.g. bolts) that are provided for connecting the blade 214 to the rotor hub. In such case, the actual method of coupling may be realized by providing an eyeguided around a bolt or alternatively by a mechanism that clamps the line to a pre-existing structure. The second tagline 252 extends from its exit point 262 partly forwards and partly sideways towards the load 246, and is connected with a distal end to a second coupling point 255 on the blade cradle 248. Similarly, the first tagline 251 extends from its exit point 261 partly forwards and partly sideways towards the load 246 and is connected at a second coupling point 255 provided on the cradle 248. In this case, the cradle 248 is provided with an additional arm 247 that protrudes sideways from the centre of mass and along the load body axis AL, to provide a first coupling point 254 that lies further outwards from the load sagittal plane PSL such that the first and second taglines extend essentially in same directions from their exit points 261 , 262 towards corresponding coupling points 254, 255. Here, a similar protruding arm may also be used on the second tagline 252 without changing the principle.

[0111] Figure 8 schematically shows a top view of yet an alternative tagline system, which in this case has four taglines 351, 352, 353a and 353b. The arrangement of first, second and third taglines 351 , 352, 353a is similar as the example of figure 5, but a further third tagline 353b and corresponding exit point 363b and connection point 356b on the blade root 316 are provided, similar as in the example of figure 7.

[0112] Figure 9 schematically shows a top view of yet another tagline system. In this example, the third tagline 453 extends sideways from a third exit point 463 towards a third coupling point 456 on the blade root, similar as in figure 7. However, in this example the exit point 463 and spanning section 453s of the tagline 453 extend directly above (or underneath) the blade 414, in order to decouple as much as possible from the in-plane motion control exerted by the first and second taglines 452, 453. An alternative configuration is envisioned in which the third tagline is coupled to a sleeve provided on the blade tip instead of being coupled to the blade root.

[0113] Figure 10 shows an example of a blade sleeve 18, adapted for use in combination with a tagline system, for instance one of the examples shown in figures 1-2b, 5-6 or 8 (or analogous modifications of figures 7 and 9 if provided with a sleeve and third coupling point at or near the distal blade tip and third tagline coupled thereto). The exemplary blade sleeve 18 is snugly fit around a region near the distal tip 15 of the rotor blade 14. In this example, the sleeve 18 is formed as a bracket with a cross-sectional C-shape that is composed of two parts which are hingeably connected on one side, and which partly envelop (soft) material inlays with curved inner surfaces. When closed, the brackets with enclosed inlays surround an inner space with a cross-sectional shape that predominantly matches the aerofoil-shaped peripheral contour of the rotor blade 14. When opened, the brackets define a lateral insertion slot that can be made large enough to insert the rotor blade 14 into the inner space. The shape of the sleeve prevents the sleeve from sliding along the blade from reaching a certain cross-section diameter of the blade and is therefore “self-locking” along the longitudinal axis of a blade.

[0114] In this embodiment, the third tagline 53 terminates in a loop (an “eye”) at its distal end. The sleeve 18 includes a fastener (e.g. an eyelet bolt), adapted to temporarily fix the two sleeve brackets at their distal ends located opposite to the hinge connection, so that the insertion slot and sleeve 18 are held firmly closed. The tagline 53 is connected with this loop directly to theeyelet bolt, thereby forming the third coupling point 56. A third tension sensor 74 is provided near this loop (or alternatively inside the eyelet bolt) and is configured to measure a momentary tension magnitude within this tagline 53. In addition, an auxiliary line 92 may also be connected to the sleeve 18, e.g. at or near the coupling point 56. An optical marker 79 may be provided at the sleeve 18, for example at or near a top side.

[0115] During motion-compensated positioning of the rotor blade 14 with the tagline system, the sleeve 18 is temporarily fixed to the rotor blade 14, to provide the coupling point 56 for the third tagline 53 near the distal blade tip 15 without compromising a structural integrity of the blade 14. Once the rotor blade 14 has been moved into position and then fixed to the rotor hub (see e.g. figure 1), the blade 14 may be rotated downwards, an auxiliary winch 93 may be energized to exert a pulling force on the sleeve 18 via the auxiliary line 92 (see e.g. figure 2a) to cause the sleeve 18 to slide off the blade tip 15.

[0116] Figure 11 shows an example of a spacer 294, adapted for use in combination with a tagline system, for instance one of the examples shown in figures 7-9. Figure 11 shows that the exemplary spacer 294 is snugly fit around one of the rigid mounting bolts 217a-c, the latter being provided at the blade root 216 for the purpose of fixing the rotor blade 214 to the rotor hub. In this example, the spacer 294 is formed as a splittable cylindrical solid body, that defines an inner space with a cross-sectional size that matches the typical diameter of the mounting bolt 217. The body includes premade longitudinal fault lines that allow the body to be split in half along the length direction to facilitate removal after pre-insertion of the blade root in e.g. a nacelle receptable. In an alternative embodiment, the spacer may be formed as a (semi-)cylindrical solid body with cross-sectional C-shape that is congruent across the length of the spacer, and defining a lateral insertion slot and an inner space with a cross-sectional size matching the typical diameter the mounting bolt.

[0117] In one embodiment, the third tagline 253 terminates in a loop at its distal end and is coupled with this loop directly to one of the bolts 217d which has smaller length than the other bolts 217a-c, thereby forming a third coupling point 256. A third tension sensor 274 is provided near this loop, configured to measure a momentary tension magnitude within this tagline 253. This is only an example, and other methods may be used to attach the third tagline to the blade root. Such methods may include attaching the tagline directly to one or multiple spacers, or to latch the tagline inside the blade-root ring (without loading one or multiple of the bolts) via a retainer. Any method used to secure a rope on an end of a cylindrical body that is known in the art may be used here.

[0118] During motion-compensated positioning of the rotor blade 214 using the tagline system, one or more of the spacers 294 are temporarily fixed onto one or more corresponding longer bolts 217, to maintain a minimal clearing between the blade root 216 and the rotor hub (e.g. 13 in figure 1) once the rotor blade 214 has been moved into position close to the rotor hub and with the longer bolts 217a-c partially inserted in corresponding through holes in a mounting ring of the rotor hub. The interspacing temporarily created by the spacers 294 allows the tagline 253 loop (or different attachment means) to be removed from the lower bolt, after which the spacers 294 canbe split and removed from the bolts 217. Finally, the blade root 216 is placed fully against the mounting ring of the rotor hub by tightening the bolts 217.

[0119] Figures 12-15 schematically show perspective views of further arrangements with taglines, exit points and coupling points.

[0120] Figures 12 and 13 show examples of three-tagline systems, in which the third tagline 553, 653 extends towards a third coupling point 556, 656 on a root side of the blade 514. In these examples, the third tagline 553, 653 and corresponding exit point lie close to a nominal coronal plane Pc which extends in vertical-lateral directions and intersects the load 546, 646 through the load body axis AL. In figure 12, the third tagline 553 approaches the blade 514 and coupling point 556 from above, whereas in figure 13 the third tagline 653 approaches the blade 614 and coupling point 656 from below. These examples allow controlling motion of the load along forward-rearward translations ±Ty, sideways translations ±Txand in-plane rotations ±Rz similar to the arrangements shown in figures 5-9.

[0121] Figures 14 and 15 show examples of four-tagline systems, similar as the tagline example shown in figure 8 which included a third tagline and further third tagline extending to coupling points on both ends of the blade. However, in the present examples, all third taglines 753a-b, 853a-b and corresponding coupling points 756a-b, 856a-b lie close to the nominal coronal plane Pc extending vertically and laterally through the load body axis AL, and approach the blade 714, 814 either from above (figure 14) or from below (figure 15).. These examples allow controlling motion of the load along forward-rearward translations ±Ty, vertical rotations ±Ry and in-plane rotations ±Rz.

[0122] Figure 16 shows a logical diagram with components and their interactions in an exemplary control arrangement S10 that is configured to control a tagline system, for instance any of the exemplary systems 20 from the previous figures. The arrangement S10 in figure 16 is discussed with reference to system elements mentioned in figures 1-5, but it should be understood that the arrangement may also be part of different system embodiments.

[0123] In the exemplary arrangement S10 of Figure 16, control of the tagline tension magnitudes T1 , T2, T3 proceeds in conjunction with closed-loop control for the motion of the load 46, which uses the measured poses of the tagline exit points 61 ,62, 63 on the boom 36 and outrigger 60, and the measured poses of the tagline coupling points 54, 55, 56 on the load 46.

[0124] In the example shown in Figure 16, the control arrangement S10 includes a load trajectory calculator S14, a load motion controller S18, a tension and exit-point calculator S22, a pose sensor system S34 including an imaging sensor 40, a trolley-and-outrigger controller S42 coupled to the trolleys 58, 59 and outrigger 60, and a winch controller S50 coupled to three winches 68, 69, 70 with tension sensors 72, 73, 74.

[0125] The exemplary control arrangement S10 from Figure 16 is adapted to receive measurements that are continuously or intermittently acquired by various sensors. The load trajectory calculator S14 is configured to calculate a desired pose of the load 46 relative to a boom reference frame {CB}, or alternatively relative to an external reference frame {CE}, or alternatively relative to a target reference frame {CT}, based on measurement signals from avariety of sensors, and to calculate a desired spatial trajectory (or a set-point) and corresponding temporal sequence (or single instances) of desired poses S16 that the load 46 ought to follow in order to move the load 46 from a current pose toward a final desired pose during operation. Depending on the particular reference relative to which the load is to be moved in a motion compensated manner, and on the presence of further sensors for dynamically measuring spatial relations between various reference frames, the desired load poses S16 may be expressed relative to the vessel reference frame {Cv}, relative to the (fixed) external reference frame {CE}, or to a reference frame of a target that may also be slowly moving in time (e.g. the top of a wind turbine 10).

[0126] The load trajectory calculator S14 is in signal communication with various sensors provided on the crane 30 and configured to receive pose data S12 representing momentary orientation (or, if applicable, elevation) of the crane 30. This may include sensors for measuring a momentary slewing angle (p and / or momentary luffing angle y of the boom 36 relative to the external reference {CE}, and a hoist sensor for measuring a momentary height H between a coupling point 44 on the load 46 and a suspension point 43 on the boom 36. A sensor may be included to measure elevation if the crane 30 would be configured to change its length, such as e.g. a telescopic boom crane. The load trajectory calculator S14 may additionally or alternatively receive pose / orientation data of a moving vessel 24 onto which the crane 30 may be mounted. From this momentary crane pose S12, whether calculated directly from sensors on the boom or indirectly from vessel pose information, the load trajectory calculator S14 then calculates the desired load pose S16.

[0127] In embodiments, the various calculated desired load poses S16 may be expressed relative to the boom reference frame {CB}. In other embodiments wherein the system 20 includes means to determine momentary poses of the crane 30 relative to the external reference frame {CE}, the desired load pose S16 may be expressed directly in the external reference frame {CE}. The required coordinate transforms (as function of time) may be determined for instance based on measurements of an IMU provided on the boom 36 and configured to express the pose of the boom 36 in coordinates of the external reference frame {CE}. In other embodiments wherein the system 20 includes means to determine momentary poses of the crane 30 and target 10. The desired load pose S16 may be expressed relative to the target reference frame (optional signal connection between imaging sensor 40 and load trajectory calculator S14 now shown in Figure 16).

[0128] The image sensor 40 of the pose sensor system S34 continuously or intermittently acquires spatiotemporal image data of the load 46 (and potentially also of the trolleys 58, 59, the outrigger 60, the sleeve 18 and the target 10). From this image data, the pose sensor system S34 determines the momentary pose S36 of the load 46 in real time, preferably at a rate comparable to the image sample rate (e.g. at a rate of several tens of Hertz e.g. 75 Hertz).Spatial transformation of the image data and / or pose data S36 from the sensor reference frame to the boom reference frame {CB} may occur instantaneously, for instance by determining inadvance the sensor pose relative to the boom reference frame {CB} through surveying techniques.

[0129] The image sensor 40 may be configured to detect a marker pattern 78 on the load 46, and to generate the image data used for determining the momentary pose of the load 46. In addition, the image sensor 40 may be configured to concurrently detect other marker patterns, such as the markers 82, 83, 84 on the trolleys 58, 59 and the outrigger 60, and / or the marker 80 on or near the target 10 or the marker on the sleeve 18.

[0130] The load motion controller S18 is configured to compare the desired load pose S16 with the currently measured load pose S36 received from the pose sensor system S34 to determine an error based on which a controller acts. The load motion controller S18 derives from the error a desired wrench S20 that should be exerted on the load 46 in three selected DOF to reposition it toward the desired load pose S16, which preferably includes an offset (e.g. 46o in Figure 2b).

[0131] The poses (e1 , e2, e3) of the tagline exit points 61 , 62, 63 are caused to change dynamically during operation, as a result of the proposed control methodology and in response to a change of the boom luffing angle y and / or a change of the hoisting height H. Furthermore, the poses (c1 , c2, c3) of the tagline coupling points 54, 55, 56 are expected to change dynamically during the operation with respect to e.g. the external reference frame {CE} or to the boom reference frame {CB}, caused by the various controlled and uncontrolled motions of the suspended load 46.

[0132] The pose sensor system S34 is configured to determine, from the available data acquired by the imaging sensor 40 and from prior surveying, the momentary poses S38 of the coupling points 54, 55, 56 in the load reference frame {CL}, and to re-express in real time these poses S38 via online transformations into the sensor reference frame and into the boom reference frame {CB}.

[0133] In addition, the pose sensor system S34 is configured to determine the poses S40 of the exit points 61 , 62, 63 expressed in the boom reference frame {CB}, which may be measured using a trolley displacement (such as a positional encoder) and kinematic calculations involving survey data. Alternatively, or in addition, the exit point poses S40 may be measured by the image sensor 40 via detecting of the markers 82, 83, 84 on the trolleys 58, 59 and the outrigger 60, and subsequent transformation of those poses into the boom reference frame {CB}.

[0134] The tension and exit point calculator S22 is configured to derive desired tagline tension magnitudes T1 , T2, T3 that are needed to make the measured load pose S36 coincide with the desired load pose S16. The tagline tension magnitudes T1 , T2, T3 either serve to counteract undesired translations and rotations of the suspended load 46, or may cause a motion, depending on the output of the load trajectory calculator S14 and the external loads on the controlled system and load.

[0135] The tension and exit point calculator S22 receives from the pose sensor system S34 the momentary poses S40 of the tagline exit points 61 , 62, 63 and the momentary poses S38 of the tagline coupling points 54, 55, 56 measured relative to the boom reference frame {CB}.

[0136] Based in part on the calculated desired wrench S20, the tension and exit-point calculator S22 uses a tension distribution algorithm to derive how the desired wrench S20 is to be effectuated, by controlling the winches 68, 69, 70 to dynamically adjust the individual tagline lengths until desired tension values S26 in the three taglines 51 , 53, 53 are realized. A further function inside the tension and exit-point calculator S22 is the determination of the required exit point poses S40 as for controlling the desired positions S24 of the trolleys 58, 59 and the outrigger 60, which may be relied on to maintain the taglines 51 , 52, 53 substantially aligned with the reference plane PR even when the boom luffing angle y and / or the hoisting height H changes. For this purpose, the tension and exit-point calculator S22 is supplied with the crane’s luffing angle y, the hoist height H and potentially also a crane’s or vessel’s IMU information (for additional out of axis roll and pitch compensation to be done by the exit points).

[0137] The separation of the desired tension values S26 for each winch 68, 69, 70 and desired exit point poses S24 for the respective trolleys 58, 59 and outrigger 60 may be determined using analytic matrix equations that take into account the measured momentary positions S38 of tagline coupling points 54, 55, 56 relative to the boom reference frame {CB}, the measured momentary pose S36 of the load 46 relative to the boom reference frame {CB}, and the measured momentary positions S40 of the tagline exit points 61 , 62, 63 relative to the boom reference frame {CB}. The desired tension values S26 may then be applied preferably in an external reference frame {CE} or in a target reference frame by selecting one of the three desired references (crane, external, or target) to be also the reference in which the desired load pose S16 is expressed by the load trajectory calculator S14.

[0138] The tension and exit-point calculator S22 is configured to determine the tagline directions and their norms, and to use this information to construct a coupling matrix, based on the selected degrees of freedom, that maps the tagline tension magnitudes into forces and torques exerted on the load 46 in the boom reference frame {CB} via derivation of the tagline lengths and directional information. The tension and exit-point calculator S22 is further configured to multiply the coupling matrix with a desired motion input wrench. This coupling matrix includes information about the pose of the load 46 and measured exit point poses S40 relative to the boom reference frame {CB}.

[0139] As shown in the examples in figures 2a-4, the tagline guiding members 58, 59 and protruding structure 60, and corresponding tagline exit points 61 , 62, 63 may be dynamically repositionable up- or down- along the crane boom 36. Figure 16 illustrates that the exemplary control arrangement S10 may then further include means for monitoring and controlling the momentary poses S40 of the exit points 61 , 62, 63 relative to the crane boom 36. Current positions S44 for the tagline guiding members 58, 59 and / or protruding structure 60 may be measured by positional encoders in the motor units of the guiding members and protruding structure and / or by image data including the markers 82, 83, 84 acquired by the imaging sensor 40.

[0140] The exemplary arrangement S10 includes a trolley-and-outrigger controller S42, configured to receive desired exit point poses S24 from the tension and exit-point calculator S22as well as the momentary positions S48 of the trolleys and outrigger, based on which the controller S42 generates error signals, and based on which signals the controller S42 generates command signals that correspond to new desired positions S44 for the trolleys and outrigger and their tagline exit points to ensure that the taglines 51 , 52, 53 remain spanned substantially along the reference plane PR, also when the momentary luffing angle y or slewing angle (p of the boom 36 and / or the hoist distance H of the load 46 changes. The trolley controller S42 transmits the desired trolley pose commands S44 in real time to the actuators of the trolleys and outrigger, which upon receipt energize actuators to move the guiding members 58, 59 and outrigger 60 to the desired positions S44.

[0141] Figure 16 illustrates that - in addition to the trolley control and feedback loop S42 - the exemplary control arrangement S10 further includes a tagline control and feedback loop. The tension and exit-point calculator S22 issues instructions to the winch controller S50, to command the individual winches 68, 69, 70 to actuate their drives to achieve the newly set desired tension S26 for the respective winch. Meanwhile, each tension sensor 72, 73, 74 continuously or intermittently measures the momentary tension S56 in the corresponding tagline 51 , 52, 53 at successive times. Each respective winch 68, 69, 70 then compares its currently measured tension S56 and determines a momentary error between the desired tension S52 and actual tension S56, to determine whether the winch drive needs to continue changing the tagline length or whether the setpoint has been reached.

[0142] Figure 16 thus illustrates that the proposed arrangement and method may involve a hierarchy of active feedback control loops, with the tension feedback control loop S50 for the individual tagline sensors and the positional feedback control loop S42 for the individual trolleys are being nested inside the pose feedback control loop for the load motion controller S18.

[0143] The currently set tension vectors F1 , F2, F3, for which the magnitudes T1 , T2, T3 have been established by the winches 68, 69, 70 and for which the vector directions have been established by the currently set trolley positions S46, finally act via the three taglines 51 , 52, 53 and at the positions of the tagline coupling points 54, 55, 56 on the suspended load 46. These tensions F1 , F2, F3 exert linear forces on the load 46 in the selected translational DOF Ty, Tx and / or torque on the load 46 in the selected rotational DOF Rz. The linear force and / or angular torque cause the load 46 to change (or maintain) its pose S36 towards the desired pose S16.

[0144] 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.

[0145] In the non-limiting examples discussed with reference to the figures, the hoisting arrangement was formed as a jib crane. In alternative embodiments, however, the proposed system may be installed in / on or otherwise be used to augment any type of crane that includes one or several booms, jibs, or arms (either solid or lattice structure, fixed or telescoping) which is / are configured to exhibit a luffing motion and / or a hoisting of a suspended load.

[0146] In other method embodiments, the tagline system may be used to install a nacelle suspended from the hoisting arrangement on a pre-installed tower, transition piece and monopile of a wind turbine. The ability to perform precise rotational adjustments ±Rz of the suspended nacelle independently from horizontal translations ±Txand ±Ty reduces installation complexity by obviating the need to power the horizontal slewing actuator in the nacelle in order to align the nacelle base with the monopile. In this case, the nacelle may be provided with another outrigger that allows the third tagline to approach the nacelle under a relatively small angle a relative to a body axis AL extending through the nacelle.

[0147] In alternative method and / or system embodiments, the vehicle may be a floating vessel, platform, or pontoon. The proposed systems may also be used in a land-based crane (e.g. a wheeled, railroad-based, or caterpillar tracked crane, or a fixed tower crane), for instance during hoisting and mounting of a prefab element (such as a concrete floor slab) on a pre-assembled house or civil structure. In such settings, detection of the pose of the suspended load might only be needed in a horizontal plane, such as determining the ±Tx and ±TY translational positions and the ±Rz rotational position of the prefab element which may be done by direct image processing techniques known in the art.

[0148] In yet an alternative method and / or system embodiments, the vehicle may be a jack-up or a floating vessel. The proposed systems may also be used to install any secondary steel components onto a bottom-fixed ora floating structure of e.g. a partially assembled wind turbine generator. In such settings, the proposed system may make use of motion compensation to install ladders or concrete platforms onto monopiles or transition pieces or any other construction element intended to conclude a construction of an offshore asset and additional outriggers may be placed either on one or more of the cable exit points and / or on one or more of the coupling points such as to ensure a sufficiently small angle a with a hoisted load axis.

[0149] In yet an alternative method and / or system embodiment, the three taglines may be used without a load suspended on a crane, but coupled either directly or indirectly via an outrigger to a lower-block of a crane of a jack-up or floating vessel, in order to minimize the swinging of the lower-block of such a crane above deck. In such embodiments, the third tagline cable will be provided via a larger outrigger that may extend sideways from a boom, essentially parallel to a body axis AL.

[0150] The exemplary system shown in figures 1-4 included an outrigger attached to a medial section of the boom. In other embodiments, the outrigger may be attached to one or more different sections of the boom. Alternatively, or in addition, the load may be provided with one or more laterally protruding arms that allow the corresponding one or more tagline coupling points to be arranged laterally further outwards relative to the sagittal plane of the load. Hence, either the boom or the load or both may be provided with protruding structures for providing third tagline exit and / or coupling points further laterally outwards from a sagittal plane of the boom or of the load respectively.

[0151] The displaceable tagline guide members may be implemented as trolley carts that are linearly repositionable with drives and lockable with brakes along guiding tracks implemented asrigid rails provided along the boom. In alternative embodiments, actuation of the trolley positions and / or outrigger along the boom may be implemented using winches and tug lines attached to the trolleys and / or outrigger (e.g. via pad-eyes). In yet alternative embodiments, the trolleys and / or outrigger may be implemented by pulleys that are slidable along guidewires that are spanned along the longitudinal direction of the boom, between a proximal end near the base of the boom and a remote part towards a distal end of the boom. In yet alternative embodiments, the first and second tagline guiding members and protruding structure may be integrated to form a rigid structure that is moveable as a single unit along guiding tracks provided on the boom.

[0152] In the exemplary tagline systems shown in figures 1-5, 7-9, 12-15, at least three singlereeved taglines were present. In alternative embodiments, individual ones or all of the taglines may be double-, triple-, or quadruple-reeved, or have an even higher number of tagline sections going back and forth between the boom and the load. In each case, providing the tagline actuator unit(s) and / or the load sensor(s) at or near the boom allows connecting the actuator unit(s) and / or load sensor(s) to the controller using wired signal connections.

[0153] In further examples, auxiliary taglines may be connected to the load or a lower hoistblock of a crane hoist line and to the boom, which extend in slanted directions upwards or downwards from the boom towards the load or lower block attachment point. Such auxiliary taglines may be held at substantially constant tensions during motion control operation, to ensure that the suspended load remains stabilized against upwards or downwards perturbing forces caused by sudden wind jerks acting on the suspended load.

[0154] In the example shown in Figures 1-2b and 5-8, the first and second taglines extended in a non-parallel non-crossing arrangement between the respective exit points on the boom and the coupling points on the load carrier. In alternative embodiments, the first and second taglines may be arranged to cross each other at a position between their exit points and coupling points, so that both taglines depart from their respective exit point, then intersect the sagittal boom plane at a location in front of the boom, before proceeding to their coupling points located on laterally opposite sides of the sagittal load plane. In such embodiments, the positions of the tagline guiding members may additionally be controlled to maintain a vertical offset between the first and second taglines.

[0155] In the examples shown in the figures, the locations of the tagline coupling points relative to the load reference frame {CL} were static. This is not required, though. In alternative embodiments, the tagline coupling points may be implemented in a moveable manner on the load (e.g. on the load carrier, the blade sleeve, and / or the blade root), for instance by pulleys or arms that may change length, shape and / or orientation. In such embodiments, similar advance surveying techniques and online position measurement (e.g. with position encoders) as were described for the tagline exit points, may be employed to establish momentary positions of the tagline coupling points relative to the load reference frame.

[0156] In the examples shown in figures 1-2b, the pose sensor was implemented using only a single camera 40. In alternative embodiments, the pose sensor may be implemented by an assembly of cameras that are mutually and algorithmically coupled, each camera including anoptical system (e.g. lens) with either the same or a different field of view to allow the various objects to be imaged and their momentary poses to be determined across a wide range of distances between these objects and the camera’s. Using such a composite imaging sensor allows the method to be used for a wide range of hoisting configurations at small and large hoisting distances, without needing to adjust the imaging sensor during the operation.

[0157] In yet alternative embodiments, the pose sensor may be implemented using one or multiple laser sensors (for instance a LIDAR sensors), configured to dynamically acquire sparse point cloud image data of objects within their field of view. The acquired point cloud data may then be compared with available geometric data of known objects (for instance 3D CAD models of the load carrier and / or the load) by known computer vision techniques involving optimizing a similarity metric while iterating through pose transformation parameters between the model and the current point-cloud data to find the best matching poses for the objects (e.g. load carrier and / or load) relative to the (common) sensor reference frame.

[0158] 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 applicable national laws and / or intergovernmental agreements.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 target (e.g. wind turbine)11 pile12 nacelle13 rotor hub14 rotor blade15 distal end (e.g. blade tip)16 proximal end (e.g. blade root)17 mounting member (e.g. bolt)18 blade sleeve19 body of water (e.g. sea)20 tagline system22 controller (e.g. crane computer)24 vehicle (e.g. offshore vessel)26 leg28 deck30 crane32 pedestal34 turret36 boom37 base38 jib39 tip40 pose sensor (e.g. camera)42 hoist line43 hoist suspension point44 hoist coupling point46 load (e.g. blade and cradle)46o load in offset pose46R load in rest pose48 carrier (e.g. blade cradle)49 pitching joint50 pitch actuator51 1sttagline51 f / s 1sttagline feed / spanning section52 2ndtagline52f / s 2ndtagline feed / spanning section53 3rdtagline53f / s 3rdtagline feed / spanning section 54 1stcoupling point55 2ndcoupling point56 3rdcoupling point58 1stguiding member (e.g. trolley) 59 2ndguiding member (e.g. trolley) 60 protruding structure (e.g. outrigger) 61 1stexit point62 2ndexit point63 3rdexit point64 distal tip65 extension actuator66 1stguiding track (e.g. rail)67 2ndguiding track (e.g. rail)68 1stwinch69 2ndwinch70 3rdwinch72 1sttension sensor73 2ndtension sensor74 3rdtension sensor76 sensor FOV78 load marker79 sleeve marker80 target marker82 1sttrolley marker83 2ndtrolley marker84 protrusion marker88 linkage89 snatch block (pulley)90 motor92 auxiliary line93 auxiliary winch294 spacer247 cradle armS10 control arrangementS12 measured crane poseS14 load trajectory calculatorS16 desired load poseS18 load motion controllerS20 desired 3DOF wrenchS22 tension and exit point calculator S24 desired exit point posesS26 desired tagline tensionsS28 boom sensorS30 hoist line sensorS32 measured load heightS34 pose sensor systemS36 measured load poseS38 measured coupling point poses S40 measured exit point posesS42 trolley / outrigger controllerS44 desired trolley / outrigger positions S46 current trolley / outrigger positions S48 measured trolley / outrigger positions S50 winch controllerS52 desired winch tensionsS54 current winch tensionsS56 measured winch tensionsAB boom body axisAj jib body axisAL load body axisAT target body axisAz load vertical axisAy luff axisA(p slew axisCOM load centre of massDi ,2 coupling point interspacingD3 coupling point distanceDp radial distanceFg gravity forceFh hoisting forceF1 1sttagline tension vectorF2 2ndtagline tension vectorF3 3rdtagline tension vectorT1 Intension magnitudeT2 2ndtension magnitudeT3 3rdtension magnitudeH hoisting distancePSB sagittal plane of boomPSL sagittal plane of loadPc coronal planePR tagline reference planePH horizontal planeX lateral directionY longitudinal directionZ vertical directionTx first translational DOFTy second translational DOFTz third translational DOFRx first rotational DOFRy second rotational DOFRz third rotational DOFa 3rdtagline anglep1 1sttagline anglep2 2ndtagline angley luff angleqj angle between P and PH{CL} load reference frame{CB} boom reference frame{CT} target reference frame{CE} external reference frame (e.g. ECEF)

Claims

- 32 - Claims1. A tagline system (20) for controlling motion of a load (46, 48, 14c) that is suspended from a crane boom (36), the load defining opposite lateral ends (15, 16) that jointly span a nominal load body axis (AL), wherein a nominal sagittal plane (PSL) of the load extends perpendicular to the load body axis and through a centre of mass (COM) of the load;wherein the tagline system comprises:first and second taglines (51 , 52) configured to be spanned from respective first and second exit points (61 , 62) provided at or near the boom, predominantly in a forward direction (+YB) away from the boom, up to corresponding first and second coupling points (54, 55) located at the load on opposite first and second sides of the sagittal plane;a third tagline (53) configured to be spanned from a third exit point (63) associated with the boom, predominantly in a lateral direction (±XB), up to a third coupling point (56) located at the load on the first or second side of the sagittal plane (PSL);a pose sensor (40) configured to dynamically determine a momentary load pose and momentary tagline exit point locations, and to generate momentary pose measurement signals therefrom, anda controller (22) configured to control motions of the load in three selected DOF by dynamically adjusting individual lengths of the first, second and third taglines (51-53), based on the momentary pose measurement signals received from the pose sensor.

2. The tagline system (20) according to claim 1 , wherein the third tagline (53) is configured to exert a tensile force (F3) via the third coupling point (56) onto the load and predominantly towards the sagittal plane (PSL), to move the load into an offset position including a translation (±Tx) towards the second or first lateral direction.

3. The tagline system (20) according to claim 1 or 2, wherein, in operational hoisting positions of the boom (36) and the load (46), the third tagline (53) is maintained at tension and oriented within an angular range (Aa) corresponding to angles (a) relative to the load body axis (AL) with magnitudes smaller than 40°, or smaller than 20°, or preferably smaller than 10°.

4. The tagline system (20) according to any one of claims 1 -3, wherein the first and second coupling points (54, 55) are mutually spaced at a lateral distance (Di .2) viewed along the load body axis (AL), and wherein the third coupling point (56) is at a further lateral distance (D3) away from the load centre of mass (COM), the further lateral distance being at least two times the lateral distance (Di .2).

5. The tagline system (20) according to any one of claims 1 -4, wherein the pose sensor (40) includes a sensorthat is coupled to the boom (36) and is configured to acquire spatiotemporal image data of the load and the exit points (61-63), and a processor configured to- 33 -dynamically determine from the image data the momentary load pose and the momentary tagline exit point locations with respect to a boom reference frame ({CB}) or to an external reference frame ({CE}).

6. The tagline system (20) according to any one of claims 1-5, further comprising first and second guiding members (58, 59) provided at or on the boom (36) and defining the first and second exit points (61 , 62), the first and second guiding members and exit points being moveable up and down along the boom independently from each other and predominantly co-directionally with the boom body axis (AB).

7. The tagline system (20) according to any one of claims 1 -6, further comprising a protruding structure (60), for instance formed as an arm or outrigger, the protruding structure being connectable to the boom (36) to project forward from the boom towards the load, the protruding structure defining a distal tip (64) where the third exit point (63) is provided closer to the load body axis (AL) than the first and second exit points (61 , 62).

8. The tagline system (20) according to claim 7, wherein the protruding structure (60) and third exit point (63) are moveable up and down along the boom (36) and predominantly co-directionally with the boom body axis (AB), and optionally wherein the protruding structure (60) and third exit point (63) are moveable independently from the first and second guiding members (58, 59) and the first and second exit points (61 , 62).

9. The tagline system (20) according to claim 8, wherein each of the first, second and third taglines (51-53) extends substantially parallel with a same tagline plane (PR), and wherein the controller (22) is further configured to dynamically adjust the positions of the guiding members (58, 59) and the protruding structure (60) in response to a change in a boom luffing angle (y) and / or a change in a hoisting distance (H) between a hoist coupling point (44) on the load and a hoist suspension point (43) on the boom (36), to maintain the taglines substantially parallel with the reference plane (P ) during operation.

10. The tagline system (20) according to any one of claims 7-9, wherein the protruding structure (60) and one or both of the guiding members (58, 59) are integrated or rigidly interconnected to form a cart member that is configured to move the third exit point (63) and one or both of the first and second exit points (61 , 62) simultaneously and uniformly along the boom (36).

11. The tagline system (20) according to any one of claims 1 -10, wherein the pose sensor (40) includes a sensorthat is coupled to the boom (36), wherein the guiding members (58, 59) and the protruding structure (60) are provided with markers (82, 83, 84) and / or define structural features located at or near the corresponding exit points (61 , 62, 63) and directed towards andlocated within a field of view (76) of the sensor (40);wherein the sensor is configured to acquire spatiotemporal image data of the load and of the markers and / or the structural features; and to dynamically determine, from the image data, momentary poses of the markers and / or features and to derive therefrom the momentary poses (S40) of the exit points, and to generate the momentary pose measurement signals therefrom.

12. The tagline system (20) according to any one of claims 7-11 , wherein the protruding structure (60) is an outrigger that is collapsible or retractable towards boom, to allow the outrigger to be placed along or substantially inside the peripheral surface of the boom when the crane is in a non-operational mode.

13. The tagline system (20) according to any one of claims 7-12, wherein the protruding structure (60) defines a distal tip (64) that is dynamically extendable in forwards direction (+YB) away from the boom (36) and / or retractable in rearwards direction (-YB) towards the boom, to dynamically decrease and / or increase a radial distance (Dp) of the third exit point (63) relative to the load body axis (AL).

14. The tagline system (20) according to any one of claims 1-13, wherein the load (46) includes a rotor blade (14c) of a wind turbine (10), the rotor blade defining a distal end (15) corresponding to a blade tip, wherein the tagline system further includes a sleeve (18) configured to be placed temporarily around and engage the blade (14c) at or near the distal end (15), the third coupling point (56) being arranged at the sleeve.

15. The tagline system (20) according to claim 14, further comprising an auxiliary line (92) and winch (93) configured to remove the sleeve (18) from the blade (14c) and to reel in the third tagline (53) and the sleeve after the blade (14c) has been placed at a target position.

16. The tagline system (120) according to any one of claims 1-15, wherein the load (146) includes a rotor blade (114c) of a wind turbine (110), the rotor blade defining a proximal end (116) corresponding to a blade root provided with blade mounting members (117), such as bolts, for connecting the rotor blade to a rotor hub (113);wherein the third coupling point (156) is located at or near one of the blade mounting members, andwherein the tagline system further includes one or more spacers (294), each configured to be placed temporarily around blade mounting members to create an interspacing between, on the one hand, the third tagline (153) at its third coupling point, and on the other hand, an end flange of the blade root,optionally wherein the spacer includes a splittable cylindrical body or a C-shaped semi-cylindrical body defining a lateral insertion slot and an inner space with a cross-sectional size matching a diameter of a mounting bolt (217) provided ata blade root (216).

17. The tagline system (20) according to any one of claims 1 -16, wherein the load (46) includes a first portion (46) and a second portion (14c) that are interconnected by a pitch joint (49), the pitch joint including a pitch actuator (50) configured to cause the second portion (14c) to rotate about an nominal pitch axis that extends in a forward direction (YL) perpendicular to the nominal load body axis (AL).

18. The tagline system (20) according to any one of claims 1 -17, further comprising tension sensors (72, 73, 74) configured to measure momentary tension force magnitudes (T1, T2, T3) in the respective taglines (51 , 52, 53), and wherein the controller (22) is further configured to calculate (S26) a desired distribution of momentary tagline tension magnitudes for moving the load (46) from a current load pose (S36) to a desired load pose (S16).

19. The tagline system (20) according to any one of claims 1 -18, wherein one or more of the taglines (151, 152, 153) are formed by a multi-reeved arrangement, for instance a doublereeved, triple-reeved, or quadruple-reeved arrangement, with multiple tagline sections (151 i, 151 j, 152i, 152j, 153i, 153j) extending back and forth between the boom and the load (146).

20. The tagline system (20) according to any one of claims 1 -19, installed in or on a crane (30) that is provided on a platform or vehicle (24).

21. A method for controlling motion of a load (46, 48, 14c) that is suspended from a crane boom (36) using a tagline system (20) according to any one of claims 1-20.

22. The method according to claim 21 , wherein the controller (22) is configured to dynamically control the motions of the load (46) in the three selected DOF (±Ty, ±Tx, ±Rz) by: applying pre-tensions to one or more selected from the first, second and third taglines (51 , 52, 53), thereby placing the load into a determined offset pose with a translation offset component (-Ty) in rearward direction (-YB) towards the boom (36) and / or with a translation offset component (±Tx) in a lateral direction (±XB) that is opposite to the direction from the load centre of mass (COM) to the third coupling point (56);dynamically adjusting selected lengths of the first, second, and third taglines (51 , 52, 53) concurrently but independently from each other, to dynamically control or adjust the pose of the load by one or more of a rotation (±Rz) along a vertical axis, a translation (±Ty) in forward or rearward direction, and a translation (±Tx) in lateral direction.

23. A computer program product configured to provide instructions to carry out a method according to claim 21 or 22 when loaded on a computer arrangement.

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