EP3243735B1 - Swell compensation device - Google Patents

Description

The invention relates to a sea state compensation device according to the preamble of claim 1.

Such sea state compensation devices are used, for example, in naval technology to deposit a load by means of a crane from a ship on a fixed, for example, on the shore or on the seabed supported object, such as a drilling platform. Conversely, a crane may also be disposed on the drilling platform or the like, so that the load on the ship or a corresponding object acted upon by the sea is to be set down. A similar task is, for example, when a drill string is lowered from a floating platform and this is raised or lowered by the sea.

The movements of a load caused by the swell can be compensated by the Heave Compensation Unit, so that the relative position of the load to a target level (deposit position on land or on the ship) is kept substantially constant despite waves.

Such a sea state compensation device is for example in the EP 2 414 218 B1 disclosed. In this known solution, the device has a platform or the like, which carries the load to be taken over or put down or on which a crane or the like is arranged. This platform is over an active cylinder arrangement supported on a ship deck. The ship movements due to the sea state are detected by a suitable sensor and passed on to a control unit. This then controls the stroke of the active cylinder so that the platform is held in the desired relative position.

In the EP 1 993 902 B1 a generic swell compensation device is shown in which a load-bearing platform is designed as a Stewart platform. Such an arrangement has six obliquely to each other employed active cylinder, via which the platform can be held in the desired relative position. To support the dead weight of the platform and / or the load arranged thereon, the active cylinders can be associated with passive cylinders.

A similar solution is in the EP 1 869 282 B1 shown. In this solution, a hydraulic active cylinder and a pneumatically prestressed passive cylinder are each designed as a unit.

The advantage of such systems, in which a Heave Compensation by means of an active cylinder assembly and the load is supported by passive cylinder, is that the active cylinder can be chosen smaller than in a conventional solution in which they must support the load. For these smaller active cylinder then pumps can be used with less volume, so that the device-technical effort for the active support of the platform is reduced. Another advantage is that due to the smaller cylinder and associated low pressure medium flow rates the compensating movement takes place with a higher dynamics.

Particularly in the case of sea state compensation devices where heavy loads (> 600 tons) are to be accommodated, there is a problem that when supporting different loads on the passive side a considerable effort must be made to adapt the respective passive support to the load - this is both from the time and from the technical equipment effort her view extremely expensive. For some solutions then a compromise has been made that the active cylinders in turn have to absorb a portion of the load - this leads to a deterioration of the dynamics and possibly also to the need to use larger cylinders with associated larger pumps, etc.

In contrast, the invention has for its object to provide a sea state compensation device that allows for low device complexity, a simple adaptation to different loads.

This object is achieved by a sea state compensation device with the features of claim 1.

Advantageous developments of the invention are the subject of the dependent claims.

The sea state compensation device according to the invention has a platform that can be moved by at least one active actuator. This is controlled by a control unit to compensate for the swell or the like caused relative movements of the platform with respect to a target position. The active actuator is associated with a passive system with at least one actuator, via which the weight of the platform and / or a load arranged on this is supported. According to the invention, the sea state compensation device is designed with a bracket or lever arrangement which can be pivoted about a joint device. On the one hand, the pivotally mounted passive actuator engages on the console. On the other hand, the console engages directly or indirectly on the platform and is designed such that a lever arm of the passive actuator with respect to the hinge device changes in response to an extension or retraction movement of the actuator. The term "console" means a device that makes it possible to bring the actuator with a variable lever in operative connection with the platform.

In contrast to conventional solutions, the supporting force applied by the passive actuator to the platform is variable and preferably depends indirectly on it Hub or the extension or retraction movement of the actuator and thus also from the pivot angle of the console and from the translation / lever ratios. This console is preferably designed so that when unloaded platform, the above-mentioned lever is relatively low - in other words said, the passive actuator attacks with a comparatively unfavorable transmission ratio to the platform. In the case of a load, the platform is accordingly lowered slightly - this leads to a pivoting of the console and a concomitant increase in the support lever, so that with constant force transmission through the active cylinder due to the cheaper translation increased support force is transmitted to the platform to the higher Load to carry.

As a result, the system according to the invention automatically adapts itself very quickly to different loads - the disadvantages of conventional systems explained at the outset are thus eliminated.

In a preferred embodiment of the invention, the passive actuator is hereinafter referred to as actuator only - a cylinder, preferably a hydraulic cylinder, which is biased by means of a gas reservoir at least in the direction of support. This gas storage then acts as a pneumatic spring.

Nitrogen is preferably used as the gas.

A variant of the invention provides that the actuator, the hinge device and a supporting device carrying the platform attack at a distance from each other on the console, wherein the attack areas span approximately a triangle and are thus arranged offset to each other.

When using a gas storage, the usual non-linear dependence of the volume of the gas on the applied pressure can be compensated for by an appropriate mechanism, which ensures that the pV dependence (gas curve) in the operating range is approximately linear.

This mechanism may be, for example, a handlebar assembly which carries the support means and which is supported on the console and on the hinge means. This link assembly may, for example, have a handlebar which is mounted on the console. A second link can then be mounted on the hinge device and connected via a knee joint with the first link. The support device is then supported in the region of the knee joint.

The stability of the device is improved when two such handlebar assemblies are provided parallel to each other.

As already explained, the kinematics of this link arrangement is chosen so that the non-linear p-V dependence of the gas (gas curve) is approximately compensated.

In a particularly preferred embodiment, three active actuators act on the platform, to each of which a passive system according to the invention is then assigned.

The structure is particularly compact when the passive actuators, preferably three passive actuators are supported on a central support block.

The active actuators can be in operative connection with the passive actuators such that the actuating movement of the active actuators is supported by the passive system. For example, an active cylinder can be held on the pivotable console, so that the pivoting movement of the console supports the adjusting movement. Alternatively, the pivoting movement of the console can be used to additionally drive an active actuator designed as a motor in the direction of adjustment. In an electric drive, the DC bus elements of the electric drives can be coupled.

• Figur 1 eine 3D-Darstellung eines Modells eines ersten Ausführungsbeispiels einer Seegangkompensationseinrichtung,
• Figur 2 eine Prinzipskizze eines Passivsystems für eine Seegangkompensationseinrichtung,
• Figur 3 eine detailreichere Darstellung eines Passivsystems gemäß Figur 2,
• Figur 4 eine Prinzipdarstellung eines Passivsystems der Seegangkompensationseinrichtung aus Figur 1,
• Figur 5 eine detailreichere Darstellung eines Passivsystems gemäß Figur 4 und
• Figur 6 die Seegangkompensationseinrichtung gemäß Figur 1 in einem Zustand, in dem sie mit einer hohen Last beaufschlagt ist.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it

• FIG. 1 a 3D representation of a model of a first embodiment of a sea state compensation device,
• FIG. 2 a schematic diagram of a passive system for a sea state compensation device,
• FIG. 3 a more detailed representation of a passive system according to FIG. 2 .
• FIG. 4 a schematic diagram of a passive system of the sea state compensation device FIG. 1 .
• FIG. 5 a more detailed representation of a passive system according to FIG. 4 and
• FIG. 6 the sea state compensation device according to FIG. 1 in a state in which it is subjected to a high load.

In FIG. 1 is a three-dimensional schematic diagram of an embodiment of an inventive Seegangkompensationseinrichtung (Heave Compensation Unit) 1 - hereinafter called Unit 1 - shown. As explained above, this is arranged for example on the deck of a ship and serves to compensate for relative movements of the ship caused by waves with respect to a fixed position (target position). The unit 1 has a platform 2 on which a load is to be deposited or from which such a load is to be taken over. In principle, it is also possible to arrange on this platform 2 a crane or the like, are taken over the loads from a stationary system, such as a drilling platform and then sold on the ship.

The ship deck is in the illustration according to FIG. 1 provided with the reference numeral 4. The support of the platform 2 on the ship deck 4 takes place on the one hand via an active system with a large number of active actuators. In the illustrated embodiment, three Aktivaktuatoren 6, 8, 10 are used, which in FIG. 1 only indicated by dash-dotted lines. At the in FIG. 1 shown embodiment, the platform 2 is triangular in the broadest sense, in which case the Aktivaktuatoren 6, 8, 10 attack in the corner areas. Such a solution is in the aforementioned EP 2 414 218 B1 disclosed. The actuation of the active actuators 6, 8, 10 takes place via an indicated control unit 12, which outputs control signals to the active actuators 6, 8, 10 via the illustrated signal lines to the platform 2 to hold in the predetermined relative position while compensating the sea state. This is detected by a suitable sensor 14 and processed by the control unit 12.

In addition, a passive system 16 is provided for supporting the weight of the platform 2 and the load arranged thereon. The active actuators 6, 8, 10 then serve essentially only to move the platform 2 to compensate for the swell - the weight of the platform 2 and the load arranged thereon is supported by the passive system 16. The active actuators 6, 8, 10 may have, for example, hydraulic cylinders, hydraulic motors or electric drives. In this case, a passive actuator assembly 18, 20, 22 of the passive system 16 is assigned to each of these active actuators 6, 8, 10.

FIG. 2 shows a first embodiment of a Passivaktuator arrangement 18, 20, 22 for a passive system 16 for passive support of the dead weight of a platform 2 or loads arranged thereon.

In the FIG. 2 shown Passivaktuator arrangement 18 has a hydraulic cylinder 24 which is biased in the extension direction - for example via a gas reservoir 26. The hydraulic cylinder 24 may be formed, for example, as a differential cylinder, wherein an annular space may be connected to a hydraulic accumulator or the like, so that during an actuating movement of the hydraulic cylinder 24, the pressure medium displaces from the decreasing pressure chamber in the direction of the connected hydraulic accumulator and pressure medium from another, for example acted upon by the gas reservoir 26, hydraulic accumulator flows into the increasing pressure chamber.

In principle, it is also possible to dispense with the gas reservoir 26, so that the pressure chamber acting in the extension direction must be biased in a different manner. The hydraulic cylinder 24 is shown in FIG FIG. 2 pivotally mounted on a deck-side cylinder joint A. A piston rod 28 of the hydraulic cylinder 24 or another actuating element of the actuator acts on a console 30, which is mounted pivotably about a further joint device 4 supported on the ship deck 4 is. The piston rod 28 is shown in the illustration FIG. 2 connected to the console 30 via a hinge H.

At one of the hinge device C and the hinge H remote and arranged offset end portion of the console 30 engages a support means 32 which is formed for example as a rigid support strut. This support means 32 is in turn articulated via a joint G to the console 30. The support device 32 engages on the platform 2 via a joint E and thus supports it against the ship deck 4. To the stabilization of the platform 2 during the compensating movement and also in the stationary state is - as from EP 2 414 218 B1 known - arranged a cross member 35, which acts on the one hand on the platform 2 and on the other hand is articulated via a support joint D to the ship deck 4. Accordingly, the joints D, A and C are arranged ship deck side.

As in FIG. 2 shown, the joint device C and the two joints designated H and G are arranged approximately triangular to each other - the console 30 then has a corresponding geometry, the outer contours can of course be rounded or formed in any other way.

Depending on the stroke of the piston, the bracket 30 pivots about the hinge device C around, wherein the hydraulic cylinder 24 pivots about the cylinder joint A. In this case, the joint H moves along a movement path 34 which extends between the end positions J and K.

In FIG. 2 shown is the position of the console 30 with almost completely retracted hydraulic cylinder 24 - this position is taken at maximum load. As explained above, this load can be in the 3- to 4-digit ton range. In this end position (maximum load) is the lever L, with which the hydraulic cylinder 24 engages the rotatable about the joint device C console 30, maximum. The actuating force of the hydraulic cylinder 24 is thus transmitted in accordance with this large lever L on the console 30 and thus also on the support means 32, so that the platform 2 is supported with a relatively large force.

Now the platform 2 opposite to the in FIG. 2 relieved state shown, the passive system 16 must only carry the weight of the platform 2 - in conventional solutions then had the bias of the hydraulic cylinder 24, for example, the gas pressure in the gas storage 26, to be adjusted in order to avoid overcompensation. This gas pressure then in turn must be increased consuming when exposed to a load - as explained above, this adjustment is time consuming and costly.

In the illustrated embodiment, this is not necessary, since the hydraulic cylinder 24 is pivoted at unloaded platform 2, the console 30 about the hinge device C and thus the end of the piston rod 28 and accordingly the joint H moves along the trajectory 34 to the end point K out. In this area, a significantly lower lever I is effective. The hydraulic cylinder 24 pivots when pivoting the console 30 about its cylinder joint A. The resulting from the bias force of the hydraulic cylinder 24 is transmitted with a very small lever I on the console 30 and thus the support means 32. This means that the support force is much lower than when retracted hydraulic cylinder (position J). The resulting support force is thus adjusted without changing the bias of the hydraulic cylinder 24 automatically to the actual load conditions.

The geometry of the console 30 and the pivoting of the hydraulic cylinder 24 are designed so that adjust the required leverage to support the dead weight of the platform 2 in the minimum case and the maximum load provided (for example> 1000 tons) without the passive Active actuators make a significant contribution.

FIG. 3 again shows in a somewhat more realistic representation of the basic structure of the passive system according to the invention 16, wherein only two passive actuator assemblies 18, 20 are shown, over which the platform 2 is supported passively. On this is to be taken over or stored by means of a not influenced by the swell crane, of which only the crane hook, a load 36. In FIG. 3 on the right is the detail X showing the passive actuator assembly 18. Accordingly, the platform 2 is supported via the support means 32, which acts on the platform 2 via the joint E and the joint G on the console 30. The latter is - as explained - pivotable about the supported on the ship's deck 4 joint device C. Furthermore, on the bracket 30, the piston rod 28 of the hydraulic cylinder 24 engages via the joint H, which in turn passes over the cylinder joint A (see FIG FIG. 3 left) is pivotally mounted on the ship deck 4. In the illustration according to FIG. 3 acts a load 36 with the maximum weight on the platform 2, so that in accordance with the maximum lever L is effective to transmit the force of the hydraulic cylinder 24 to the platform 2.

According to the invention, therefore, the force of a passive actuator, for example a hydraulic cylinder, is transmitted to the platform 2 via a lever system, the effective lever being larger at high load than in the unloaded state.

FIG. 4 shows a variant in which the bias of the hydraulic cylinder 24 via the gas reservoir 26 takes place. This is filled with nitrogen. This gas reservoir 26 thus acts as a gas spring, so that the pressure changes depending on the load. Due to the compressibility of gases, the gas characteristic, ie the pressure-volume characteristic, is not linear, so that pressure changes are not proportional to the volume changes. Such deviations of the "gas curve" are compensated in the illustrated embodiment via a link assembly 38, which is arranged mechanically between the support means 32 and the console 30. This link assembly 38 has a first link 40 which is articulated via the joint G to the console 30. A second link 42 is pivotally mounted on the one hand via a link B on the ship's deck 4 and on the other hand connected via a knee joint F to the first link 40. In the area of this knee joint F and the support means 32 is hinged pivotally. This attacks - as in the embodiment described above - via the joint E on the platform 2. The support in the transverse direction is again via a transverse strut 35.

The kinematics of the handlebar assembly 38, for example, the length of the handlebars 40, 42 is selected so that the deviations from the ideal line resulting from the characteristic of the gas curve can be compensated. Otherwise, this corresponds to FIG. 4 illustrated embodiment that of the Figures 2 and 3 , so that further explanations are dispensable with reference to the above statements.

FIG. 5 shows a slightly more detailed representation of the in FIG. 4 illustrated embodiment of the passive actuator assembly 18 (20, 22). As stated above, the platform 2 is supported by the respective supporting device 32, which is articulated to the platform 2 via the joint E. The strut-shaped support means 32 is in turn connected via the knee joint F with the handlebar assembly 38. Here, the knee joint F is formed so that it connects the two arms 40, 42 articulated and further also pivoting of the support means 32 at least in the plane according to FIG. 5 allows. The first link 40 is articulated via the joint G to the console 30. The second link 42 is mounted on the steering joint B. The piston rod 28 of the hydraulic cylinder 24 or the other actuator engages on the hinge H on the console 30. As explained, the hydraulic cylinder 24 is biased via the gas reservoir 26 to a predetermined pressure. The piston rod-side pressure chamber of the hydraulic cylinder 24 is - as already explained above - connected to a hydraulic accumulator 44. In this respect, the embodiment corresponds to FIG. 5 from that one FIG. 4 , so that further explanations are dispensable.

At the in FIG. 5 illustrated embodiment, the function of the Aktivaktuatoren 6, 8, 10 are supported by the passive system 16 at peak loads, for example, when compensating a caused by the swell lowering movement of the ship. As explained, as active actuators 6, 8, 10 electric motors, hydraulic motors or hydraulic cylinders or the like can be used.

In FIG. 5 on the right is exemplified as a hydraulic cylinder running Aktivaktuator 6, the piston rod 46 engages the joint H and thus with the console 30 is connected. The actuation of this Aktivaktuators 6 takes place - as in FIG. 5 indicated on the right - via a zero-adjustable hydraulic pump 48 which is driven by a motor 50 to the active actuator 6 (hydraulic cylinder) in response to the control signal of the control unit 12 on or extend. The maximum power of the active system requiring extension of the active actuator 6 when lowering the ship (Heave) is supported by the passive system 16, since the console 30 then also pivots in the direction of enlargement of the lever arm L.

In FIG. 5 on the left an alternative variant is shown. In this variant, the Aktivaktuatoren 6 are formed by hydraulic motors 52, the actuating elements, such as spindles or the like, drive to hold the platform 2 in the desired relative position. The drive of the hydraulic motors 52 is carried out as in the previously described variant via a pivotable about zero pump 48 and a controlled by the control unit 12 electric drive 50. In the in FIG. 5 On the left, the hydraulic motor 52 is additionally drivable via a pinion 54, which meshes with external teeth 56 of the console 30, so that upon pivoting of the console 30 about the hinge device C via the pinion 54, the hydraulic motor 52 is additionally driven, so that this is supported by the passive system 16 in its function to compensate for large load changes with high dynamics can.

With such solutions, the function of at least one Aktivaktuators can be supported by the passive system, so that there "saved" energy can be used to adjust the other Aktivaktuatoren. In principle, of course, all Aktivaktuatoren be supported by the passive system in the manner described above.

This in FIG. 1 illustrated embodiment is with a passive system 16 according to FIG. 4 executed, this being shown in its functional position, which it occupies with unloaded platform 2.

As shown in FIG. 1 the joint device C is supported via joint cheeks 58 on the ship deck 4. The unilaterally rounded bracket 30 is mounted between these two joint cheeks 58. The link assembly 38 is hinged on the one hand via the link B to the joint cheeks 58 and on the other hand via the joint G to the console 30. The links 40, 42 are connected via the knee joint F with each other. As in FIG. 1 recognizable, two such link assemblies 38, 38 'as a 4-link arrangement are provided parallel to each other, so that the knee joint F, the two link assemblies 38, 38' connects. In this connection region, the supporting device 32 designed as a support strut is supported, which in turn acts on the platform 2 via the joint E. The transverse support is in each case via a transverse strut 35, which is articulated on the one hand via a strut joint J to the platform 2 and on the other hand is supported on the ship deck 4 via the support joint D. The hydraulic cylinders 24 of the passive actuator assemblies 18, 20, 22 are supported in the illustrated embodiment via the cylinder joint A to a deck-side support block 60, on which the other hydraulic cylinders 24 of the other passive actuator assemblies 18, 20, 22 are supported. This support block 60 is located as shown in FIG FIG. 1 approximately in the middle below the in the broadest sense triangular platform 2.

In the illustration according to FIG. 1 the hydraulic cylinders 24 are each extended, so that the minimum lever I is effective - accordingly, no weight on the platform 2 is arranged.

FIG. 6 shows the state in which the maximum load 36 acts on the platform 2. As stated above, the biased by the gas reservoir 26 hydraulic cylinders 24, so that the consoles 30 from the in FIG. 1 pivot position shown inwardly, pivot towards the support block 60 and corresponding to the maximum lever L (see FIG. 2 ) is effective to support the load 36 - the platform 2 takes her in FIG. 6 shown lower position. In the illustration according to the FIGS. 1 and 6 Furthermore, the active actuators 6, 8, 10 designed as hydraulic cylinders are also indicated, which are provided on the one hand via joints (with reference numbers in FIG FIG. 6 only the joints K, L) attack on the platform 2 and On the other hand, for example, at the joint H, are supported on the respective console 30.

Disclosed is a sea state compensation device with an active system and a passive system. In the passive system, actuators are connected via a hinge device to a platform carrying a load. About this hinge device, the effective lever with which the actuators support the platform passive, be changed depending on the load condition.

LIST OF REFERENCE NUMBERS

1

Swell Compensation Device (Unit)

2

platform

4

deck

6

Aktivaktuator

8th

Aktivaktuator

10

Aktivaktuator

12

control unit

14

sensors

16

passive system

18

Passivaktuator arrangement

20

Passivaktuator arrangement

22

Passivaktuator arrangement

24

hydraulic cylinders

26

gas storage

28

piston rod

30

console

32

support means

34

trajectory

35

crossmember

36

load

38

link arrangement

40

first handlebar

42

second handlebar

44

hydraulic accumulator

46

piston rod

48

pump

50

engine

52

hydraulic motor

54

pinion

56

external teeth

58

joint cheek

60

support block

Claims (12)

1. Swell compensation device with a platform (2) which is movable by at least one active actuator (6, 8, 10) which is activatable via a control unit (12) in order to compensate for relative movements of the platform (2) caused by the swell or the like with respect to a target position, wherein the active actuators (6, 8, 10) are assigned a passive system (16) having at least one actuator via which the weight of the platform (2) and/or of a load (36) arranged on the latter is at least partially supported, characterized by a bracket (30) which is pivotable about an articulation device (C) and on which the pivotably mounted actuator acts and which indirectly or directly acts on the platform (2) and is designed in such a manner that a lever arm (L, I) of the actuator changes with respect to the articulation device (C) depending on an extension or retraction movement of the actuator.
2. Swell compensation device according to Patent Claim 1, wherein the actuator is a hydraulic cylinder (24) which is preferably prestressed by means of a gas accumulator (26).
3. Swell compensation device according to Patent Claim 2, wherein the gas accumulator (26) is filled with nitrogen.
4. Swell compensation device according to one of the preceding patent claims, wherein the actuator, the articulation device (C) and a supporting device (32) supporting the platform (2) act at a distance from and offset with respect to one another, wherein said regions of actuation of the components approximately form a triangle.
5. Swell compensation device according to Patent Claim 4, wherein the supporting device (32) for its part is supported on the bracket (30) and the articulation device (C) via a link arrangement (38).
6. Swell compensation device according to Patent Claims 5, wherein the link arrangement (38) has a first link (40) which is mounted on the bracket (30), and has a second link (42) which is mounted in the region of the articulation device (C) or on the deck side and which is connected to the first link (40) via a toggle joint (F), the supporting device (32) being supported in the region of the toggle joint (F).
7. Swell compensation device according to Patent Claim 5 or 6, with two parallel link arrangements (38, 38').
8. Swell compensation device according to one of Patent Claim 5 to 7, wherein a transmission ratio of the link arrangement (38, 38') is selected in such a manner that a pressure/volume dependency of the storage medium of the gas accumulator (26) is approximately compensated for.
9. Swell compensation device according to one of the preceding patent claims, wherein passive actuator arrangements (18, 20, 22) of the passive system (16) are each formed with a transverse strut (35) which acts on the platform (2) preferably approximately transversely with respect to the supporting device or approximately transversely with respect to the actuating direction of the active actuator (6, 8, 10) .
10. Swell compensation device according to one of the preceding patent claims, with at least three active actuators (6, 8, 10) which are each assigned a passive system (16).
11. Swell compensation device according to Patent Claim 10, wherein hydraulic cylinders (24) of the passive systems (16) are supported on a central supporting block (60).
12. Swell compensation device according to one of the preceding patent claims, wherein the passive system (16) and the assigned active actuator (6, 8, 10) are operatively connected in such a manner that the passive system (16) directly supports the operation of the active actuators (6, 8, 10).

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