Open-loop and / or closed-loop control unit and arrangement for damping the rolling movement of a floating body

Abstract

In order to provide an open-loop and / or closed loop control unit (7) for open-loop and / or closed loop control of an arrangement (1) for damping a rolling movement of a floating body (2), wherein the arrangement (1) has damping means (3) for generating a counter-rolling moment with a damping characteristic and tuning means (8, 9) for setting a target damping characteristic, wherein the open-loop and / or closed loop control unit (7) is configured for setting the target damping characteristic depending on a function of at least one property of the floating body (2), and an arrangement (1) for damping a rolling movement of a floating body (2), comprising damping means (3) for generating a counter-rolling moment with a damping characteristic, tuning means for setting a target damping characteristic and an open-loop and / or closed loop control unit (7) for setting the target damping characteristic depending on at least one property of the floating body (2), which enable good roll damping even before the start of the journey, in particular before leaving port, it is proposed that the property comprises stability data of the floating body (2).

Description

[0001] Control and / or regulation unit and arrangement for damping a rolling movement of a floating body

[0002] The present invention relates to a control and / or regulating unit for controlling and / or regulating an arrangement for damping a rolling movement of a floating body, wherein the arrangement has damping means for generating a counter-rolling moment with a damping characteristic and tuning means for setting a desired damping characteristic, wherein the control and / or regulating unit is configured to set the desired damping characteristic depending on at least one property of the floating body.

[0003] The present invention also relates to an arrangement for damping a rolling movement of a floating body, comprising damping means for generating a counter-rolling moment with a damping characteristic, tuning means for setting such a damping characteristic and a control and / or regulating unit for setting the desired damping characteristic as a function of at least one property of the floating body.

[0004] Control and / or regulation units and arrangements of the aforementioned type have long been known in the shipping industry. They serve to dampen the rolling motion, particularly of ships. Cuboid-shaped roll damping tanks, also known commercially as flume tanks or flume stabilization systems, are often used as damping means to generate a counter-roll moment. A detailed description of the functionality of such roll damping tanks can be found, for example, in US Pat. No. 3,951,089.

[0005] The basic principle is always that fluid in the roll damping tank moves in antiphase to the ship's rolling motion due to the ship's rolling motion and thus creates a counter-roll moment that counteracts the ship's rolling motion.

[0006] In practice, however, to achieve sufficient roll damping, it is necessary to vary the damping characteristics of the roll damping tank in order to adapt them to the equally varying roll characteristics of the floating body to be damped. The control variable for setting the desired damping characteristic of the roll damping tank is primarily the fill level of the roll damping tank. Therefore, in the current state of the art, the ship's roll period is determined using appropriate sensors. Subsequently, the required fill level of the roll damping tanks is determined based on the measured roll period using tables developed for the respective tank.

[0007] Determining the optimal fill level of the roll damping tank therefore requires knowledge of the roll period of the buoyancy body. However, in practice, determining this by measurement is often not readily possible. In particular, it is usually not possible to determine the exact roll period of a ship while in port, as measuring the roll period naturally requires a measurable roll motion of the ship. A reliable measurement for the minimal roll motions that a ship experiences while in port is virtually impossible.

[0008] It is therefore an object of the present invention to provide a control and / or regulating unit and an arrangement of the type mentioned at the outset, which enable good roll damping even before the start of the journey, in particular before leaving the port.

[0009] With regard to a control and / or regulation unit of the type mentioned above, the underlying problem is solved in that the property comprises stability data of the floating body. In the case of ships, such stability data of the floating body are often determined during loading using the loading computer. The invention takes advantage of the fact that a correlation exists between the stability data of the floating body and its roll period. According to the invention, a target damping characteristic of the damping means for generating the required counter-roll moment can therefore be carried out already in the harbor, without the ship to be damped actually having to execute a rolling movement. On the one hand, the metrologically difficult determination of a roll period on an essentially stationary floating body is advantageously eliminated.Secondly, the required damping characteristics can be adjusted in port, for example, which increases safety. In particular, when using roll damping tanks or flume tanks, the required tank level can be determined based on the stability data.

[0010] In an embodiment of the unit according to the invention, the stability data includes a mass distribution of the floating body and / or a buoyancy distribution of the floating body. These data are physically related to the rolling period of the floating body, which is crucial for determining the damping properties. The physical relationship can be determined once and stored in tables characterizing the respective floating body. In this way, the rolling period can be determined indirectly according to the invention in order to adjust the damping means to a desired target damping characteristic, in particular to determine a suitable fill level of a rolling damping tank.

[0011] In a preferred embodiment of the unit according to the invention, the stability data includes a metacentric height of the floating body. The metacentric height specifies the distance from the center of mass to the metacenter of a ship. The metacenter of the floating body is the intersection point of the buoyancy vectors associated with two adjacent angular positions of the floating body. In connection with rolling movements of the floating body, the latitudinal metacenter for rotations around the longitudinal axis is important within the meaning of the present invention. Based on the metacentric height, the roll period can be deduced, which in turn is used to determine the required counter-roll moment of the damping means, in particular to determine the required fill level of a roll damping tank.

[0012] In a particularly advantageous embodiment of the unit according to the invention, the damping means comprise a roll damping tank whose target damping characteristic is functionally related to the fill level of the roll damping tank, with sensor means being provided for determining the fill level. According to this embodiment of the invention, the sensor means enable the current fill level of the roll damping tank to be determined. The damping characteristic of the roll damping tank as a function of the fill level can be determined in advance in model tests and recorded in a table.

[0013] According to the invention, a relationship can be established between the measured fill level and the metacentric height or other stability characteristics, which can preferably be determined in a charge calculator.

[0014] In order to determine the damping characteristic based on the measured current fill level, a measuring system can be used within the scope of the invention that can determine the phase relationship between the ship's rolling motion (excitation) and the resulting tank fluid movement. Using suitable evaluation technology, the damping characteristic can then be determined from the measured current fill level. This allows the required target damping characteristic to be determined, in particular the required fill level of a flume tank for roll stabilization of the floating body.

[0015] The sensor means of the unit according to the invention preferably comprise fill level sensor means, volume sensor means, and / or mass sensor means. When varying the fill level of a roll damping tank for the purpose of setting a target damping characteristic, it is thus possible, using the sensor means according to the invention, to set the target damping characteristic determined from the stability data, i.e., the required fill level.

[0016] In a further development of the unit according to the invention, the property comprises one or more selected from the tank fill level, tank volume, tank mass, roll period of the float, stability of the float, and radius of gyration of the float. In conjunction with the stability data of the float, the aforementioned properties can be used within the scope of the invention to ensure a refined determination of the required target damping characteristic, for example, the required fill level of a flume tank.

[0017] In order to make the stability data of the floating body available for adjusting the target damping characteristics of the unit according to the invention, the unit preferably has an interface to a loading computer for reading the stability data from the loading computer. In practice, stability data is already available to the loading computer when the ship is being loaded in port, i.e., in a state in which the ship is essentially not rolling. This data can thus be utilized to optimize the ship's roll damping behavior while still in port.

[0018] If, according to a favorable embodiment, the unit according to the invention has a database containing a functional relationship for the floating body between the stability data and the target damping characteristic and / or a database containing a functional relationship for the floating body between a displacement of the floating body and the target damping characteristic, the unit according to the invention can determine the required target damping characteristic directly from the stability data. In particular, a fill level for a roll damping tank, in particular a flume tank, can be stored in said database within the scope of the invention.

[0019] In an advantageous embodiment of the unit according to the invention, the tuning means comprise means for filling and / or emptying a roll damping tank of the floating body, wherein the unit is designed to control said means. For example, a flume tank as a roll damping tank can be provided with pumps and blow-out means, which can be controlled via the unit according to the invention in order to set a fill level for the roll damping tank determined by the unit according to the invention based on the stability data of the floating body.

[0020] The advantageous properties of the unit according to the invention are further enhanced if it is configured to adjust the target damping characteristic depending on environmental parameters, in particular wave height, weather data, and / or route data of the floating body. Based on the aforementioned environmental parameters, a fine adjustment of the damping characteristic, in particular the fill level of a flume tank, can be made after the start of the journey, starting from the basic setting, which could already have been made, for example, in port based on the stability data of the floating body. In particular, within the scope of the invention, a roll period of the ship determined by sensors can be used to fine-tune the damping characteristic.

[0021] The unit according to the invention is further improved if the property includes a roll period of the floating body, wherein the unit preferably includes an inertial measurement sensor. Instead of an inertial measurement sensor, the unit according to the invention can also include an inertial measurement system, a pendulum sensor, or the like, according to one embodiment. Within the scope of the invention, any measurement sensor system that allows the determination of the ship's roll period is suitable.

[0022] This embodiment of the invention enables adjustment of the target damping characteristic, in particular, an adjustment of the fill level of a control damping tank, after the start of the voyage when the floating body, in particular the ship, actually performs rolling movements. In this way, the target damping characteristic, previously determined exclusively based on stability data of the floating body, for example, in port, can be compared with the values ​​that result when the ship actually performs a rolling movement.

[0023] In particular, in a preferred embodiment, the unit according to the invention can be configured to determine a roll period of the floating body from the stability data. The roll period thus calculated can in turn be stored in the unit according to the invention, in particular in a database, based on tabulated data. The calculated roll period can be used, for example, to determine a required fill level in the roll damping tank. Likewise, a comparison of the roll period determined from the stability data with a roll period measured, for example, by means of an inertial measurement sensor is possible in order to make appropriate corrections in the roll damping system. Alternatively or in addition to an inertial measurement sensor, an inertial measurement system or measurement sensor technology can be used within the scope of the invention to determine the roll period.

[0024] In particular, the unit according to the invention can be configured to adjust the desired damping characteristics depending on data on the movements of the floating body. For example, movements other than rolling can also be measured and used to determine the optimal fill level of a flume tank based on tabulated values.

[0025] The unit according to the invention is further improved if it comprises an artificial intelligence to determine, on the basis of a continuous historical recording of the rolling period of the floating body and associated stability data and / or environmental parameters and / or movement data and / or loading data, a relationship between the aforementioned data and the rolling period for the floating body that enables increasingly precise predictions.

[0026] The object directed to an arrangement of the type mentioned above is achieved according to the invention by such an arrangement in which the control and / or regulating unit is designed according to one of the preceding claims. In a preferred embodiment of the arrangement according to the invention, the damping means comprise a roll damping tank, in particular a rectangular one.

[0027] The arrangement according to the invention is further improved if the tuning means comprise means for filling and / or emptying the roll damping tank of the floating body, in particular pumps and / or blow-out devices.

[0028] According to one aspect, the invention relates to a functional relationship between the roll damping tank and stability data, which in particular also takes into account a reduction in lashing forces and a possibly increased payload during the planning phase. This relationship is stored, for example, in the load calculator, for example in the form of a table. In particular, a table can depict the relationship between the metacentric height (GM) and the fill level, optionally including a reduction in roll accelerations, in particular specified as a percentage.

[0029] The invention is described by way of example in a preferred embodiment with reference to a drawing, wherein further advantageous details can be taken from the figures of the drawing.

[0030] Functionally identical parts are provided with the same reference symbols.

[0031] The figures in the drawing show in detail:

[0032] Figure 1 : Diagram of a functional model that can be stored in a database

[0033] Relationship for a ship between a metacentric height and a target level of a roll damping tank; Figure 2: Diagram of a functional

[0034] Relationship for a given ship between a displacement of the ship and a metacentric height and a target filling level for a roll damping tank;

[0035] Figure 3: Schematic representation of a controller architecture under

[0036] Use of a control and / or regulating unit according to an embodiment of the invention;

[0037] Figure 4: schematic representation of another system architecture incorporating a control and / or regulating unit according to the invention in another preferred embodiment;

[0038] Figure 5: schematic representation of the basic principle of a

[0039] Arrangement according to the invention for damping a rolling motion of a ship.

[0040] Figure 5 shows a purely schematic representation of an arrangement 1 for damping the rolling motion of a floating body 2. The arrangement 1 comprises a roll damping tank 3 arranged in the floating body 2 as a damping means. The roll damping tank 3 has flow plates on the starboard and port sides in a manner known per se. These restrict the fluid flow and ensure that the phase angle of 90 degrees is maintained over a larger frequency range. The roll damping tank 3 is partially filled with ballast water 4 up to a level 5.

[0041] As illustrated in the lower part of Figure 5, the floating body 2 performs a rolling motion under the influence of waves on the water surface 6. Due to the free surfaces of the ballast water 4 in the roll damping tank 3, the ballast water 4 in the roll damping tank 3 oscillates out of phase with the rolling motion of the floating body 2. In this way, the ballast water 4 acts to dampen the rolling motion of the floating body 2.

[0042] The damping effect of the ballast water 4 in the roll damping tank 3 depends in particular on the fill level 5 of the ballast water 4 in the roll damping tank 3. The arrangement 1 therefore has a control unit 7. The control unit 7 serves to adjust the damping characteristics of the ballast water 4 in the roll damping tank 3 by varying the fill level 5 of the ballast water 4 in the roll damping tank 3.

[0043] To adjust the fill level 5, the control unit 7 is in operative connection with remote-controlled valves 8 or

[0044] Blow-out devices 9, which are shown only very schematically in Figure 5. By means of the valves 8 and blow-out devices 9, which are operatively connected to the control unit 7, the control unit 7 is able to vary the fill level 5 of the ballast water 4 in the roll damping tank 3 in a manner not shown in detail but known to those skilled in the art.

[0045] The control unit 7 is also operatively connected to fill level sensors 10, which are also shown only very schematically, and an inertial measurement sensor 11. The fill level sensors 10 are arranged in the roll damping tank 3 in order to measure the fill level 5 and transmit it to the control unit 7. The inertial measurement sensor 11 is arranged in the floating body 2 in order to determine its movements, in particular rolling movements, and to transmit corresponding values ​​to the control unit 7. According to the invention, the control unit 7 is configured to automatically adjust the fill level 5 to control the damping characteristics of the arrangement 1 depending on stability data of the floating body 2. According to the invention, the control unit 7, in the exemplary embodiment, accesses a database 12 for this purpose.According to the exemplary embodiment of the control unit 7 according to the invention presented here, correlation data according to Figure 1 are stored in the database 12, which indicate a relationship between a metacentric height GM, measured in meters, and a target fill level 13 in the roll damping tank 3 specifically for the floating body 2.

[0046] A target fill level 13 of the ballast water 4 in the roll damping tank 3 correlates with a roll damping characteristic that is characteristic of the given floating body 2. The graphic shown in Figure 1 illustrates the relationship stored in the database 12 between the metacentric height GM as an input variable and the associated target fill level 13. In the diagram shown in Figure 1, the target fill level 3 of the ballast water 4 in the roll damping tank 3 of the floating body 2 is, for example, 4 m if the metacentric height is between 4.5 m and 12 m. On the other hand, the target fill level 13 for the ballast water 4 in the roll damping tank 3 of the floating body 2 is only 3.3 m if the metacentric height of the floating body 2 is in the range of 3.0 m to 4.5 m.The relationships shown in Figure 1 between the metacentric height of the hull 2 ​​and the corresponding target filling level 13 are based on data obtained empirically specifically for the given floating body 2.

[0047] Figure 2 shows a further functional relationship between stability data of the floating body 2 and the target fill level 13 for the ballast water 4 in the roll damping tank 3 of the floating body 2. Accordingly, the target fill level 13 depends both on the metacentric height GM, which is plotted on the horizontal axis of the diagram in Figure 2, and on the displacement measured in tons, which is plotted on the vertical axis. For example, the target fill level is 132.0 m if the metacentric height GM of the floating body 2 is 3.0 m and the displacement of the floating body 2 is approximately 10,800 t.

[0048] Figure 3 schematically illustrates, in a first embodiment of the invention, a system architecture into which a control unit 7 according to the invention can be integrated. Accordingly, the control unit 7 is operatively connected to a loading computer 14. The control unit 7 receives data on the metacentric height 15 of the floating body 2 via the loading computer 14. Based on the functional relationships stored in the database 12 according to the diagram in Figure 1 between the metacentric height and the associated target fill level 13 and / or the functional relationships according to the diagram in Figure 2 between the metacentric height, the displacement, and the associated target fill level 13, the control unit 7 then determines the target fill level 13 of the ballast water 4 in the roll damping tank 3 of the floating body 2. Corresponding control commands to the valves 8 and / or blow-out devices 9 are generated via the AMS of the floating body 2.Via the level sensors 10, feedback about the actual fill level 5 of the ballast water 4 in the roll damping tank 3 is sent to the control unit 7 via the AMS.

[0049] Figure 4 shows another possible system architecture into which the control unit 7 according to the invention can be integrated. In this case, the loading computer 14 supplies data on the metacentric height MG of the floating body 2 to the control unit 7 via the AMS. The control unit 7, in turn, exchanges control and regulation signals with the valves 8, blow-out devices 9, and / or level sensors via the AMS in order to adjust the fill level 5 to the target fill level 3 for the ballast water 4 in the roll damping tank 3 of the floating body 3.

[0050] In the outlined structure of the system architecture and the control unit 7, the control unit 7 advantageously utilizes the fact that the metacentric height of the floating body 2, which in the exemplary embodiments is provided as an input variable by the loading computer 14, is proportional to the roll period of the floating body 2. Based on a mathematical determination of the roll period of the floating body 2 starting from the metacentric height GM, the required target fill level 13 for the ballast water 4 in the roll damping tank 3 can be determined using the functional relationships from the database 12 according to the diagrams in Figures 1 and 2 in order to obtain optimal damping of the rolling movement of the floating body 2 relative to the water surface 6.

[0051] Further control and regulation signals that the control unit 7 processes or outputs according to the invention can include the volume or mass of the roll damping tank 3, as well as radii of gyration of the floating body 2. Within the scope of the invention, the arrangement 1 for damping a rolling movement can also be combined with a device for heeling damping (anti-heeling) or other.

[0052] The control unit 7 according to the invention can also incorporate additional data, such as environmental data such as air pressure, wave height, and route data, in order to adjust the fill level 5 to a correspondingly adjusted target fill level 13 via the valves 8 and / or blow-out devices 9. Further input data suitable within the scope of the invention for the control unit 7 to determine an optimal target fill level 13 can be phase data of the rolling movement of the floating body 2.

[0053] In the control unit 7, parameters can be calculated when determining the target level 13, such as a torque of the floating body 2 based on the relationships

[0054] - Float moment = displacement x metacentric height GM x roll angle;

[0055] - Tank moment = volume displacement of the integral of tank sensor height x lever;

[0056] - Damping = (float moment / tank moment).

[0057] In addition, the control unit 7 can also use a measured roll period of the floating body 2 to determine the target fill level 13. This is generally available as soon as the floating body 2 is underway and performing actual rolling movements. A preset target fill level 13 based on stability data, in particular based on the metacentric height of the floating body 2, can be preset while the floating body 2 is still in port and not performing any rolling movements. The additional inclusion of a measured roll period enables the refinement of the appropriate target fill level 13.

[0058] The control unit 7 can carry out a continuous recalculation of the optimal target fill level 13 based on the input sensors, such as fill level sensor 10, inertial measurement sensor 11 and the like, and can adjust the fill level 9 to the target fill level 13 based on the actuators, in particular valves 8 or blow-out devices 9.

[0059] The control unit 7 can either be operated in automatic mode, in which it automatically adjusts the fill level 5 via the actuators according to the calculated target fill level 13. Alternatively, the control unit 7 can simply display the calculated target fill level 13 to the operator in a suitable manner, enabling the operator to manually adjust the fill level 5 of the ballast water 4 in the roll damping tank 3 of the floating body 2 to the target fill level 13.

[0060] With the control unit 7 according to the invention and the arrangement 1 according to the invention for damping a rolling movement, the operation of the floating body 2 can advantageously be made particularly safe, since the target fill level 13 and the corresponding adjustment of the fill level 5 can already be carried out in the harbor, without the floating body 2 having to perform a rolling movement with a roll period. Based on the stability data of the floating body 2, in particular based on the metacentric height GM of the floating body 2, the roll period can be calculated according to the invention in order to adjust the damping characteristics of the roll damping tank 3 by varying the fill level 5 of the ballast water 4.

[0061] LIST OF REFERENCE SYMBOLS

[0062] 1 Arrangement for damping a rolling movement

[0063] 2 floats

[0064] 3 Roll damping tank 4 Ballast water

[0065] 5 Fill level

[0066] 6 Water surface

[0067] 7 Control unit

[0068] 8 Valve 9 Blow-out device

[0069] 10 Level sensor

[0070] 11 Inertial measurement sensor

[0071] 12 Database

[0072] 13 Target fill level 14 Charging calculator

[0073] 15 Metacentric height data

Claims

PATENT CLAIMS 1 . Control and / or regulating unit (7) for controlling and / or regulating an arrangement (1) for damping a rolling movement of a floating body (2), wherein the arrangement (1) has damping means (3) for generating a counter-rolling moment with a damping characteristic and tuning means (8, 9) for setting a desired damping characteristic, wherein the control and / or regulating unit (7) is set up to set the desired damping characteristic as a function of at least one property of the floating body (2), characterized in that the property comprises stability data of the floating body (2).

2. Unit according to claim 1, characterized in that the stability data comprise a mass distribution of the floating body (2) and / or a buoyancy distribution of the floating body (2).

3. Unit according to claim 1 or 2, characterized in that the stability data include a metacentric height of the floating body (2).

4. Unit according to one of the preceding claims, characterized in that the damping means (3) comprise a roll damping tank (3), the desired damping characteristic of which is functionally related to a filling state of the roll damping tank (3), wherein sensor means (10) are provided for determining the filling state (5).

5. Unit according to one of the preceding claims, characterized in that the sensor means comprise level sensor means (10), volume sensor means and / or mass sensor means.

6. Unit according to one of the preceding claims, characterized in that the property comprises one or more selected from tank level (5), tank volume, tank mass, roll period of the floating body (2), stability of the floating body (2), radius of gyration of the floating body (2).

7. Unit according to one of the preceding claims, characterized in that it has an interface to a loading computer (14) for reading the stability data from the loading computer (14).

8. Unit according to one of the preceding claims, characterized in that it has a database (12) containing a functional relationship for the floating body (2) between the stability data and the desired damping characteristic and / or a database (12) containing a functional relationship for the floating body (2) between a displacement of the floating body (2) and the desired damping characteristic.

9. Unit according to one of the preceding claims, characterized in that the tuning means (8, 9) comprise means for filling (8) and / or emptying (9) a roll damping tank (3) of the floating body (2), wherein the control and / or regulating unit (7) is arranged to control said means (8, 9).

10. Unit according to one of the preceding claims, characterized in that it is designed to adjust the desired damping characteristic as a function of environmental parameters, in particular wave state, weather data and / or route data, of the floating body (2).

11. Unit according to one of the preceding claims, characterized in that the property comprises a rolling period of the floating body (2), wherein the control and / or regulating unit (7) preferably comprises an inertial measuring sensor (11).

12. Unit according to one of the preceding claims, characterized in that it is arranged to determine a rolling period of the floating body (2) from the stability data.

13. Unit according to one of the preceding claims, characterized in that it is arranged to adjust the desired damping characteristic as a function of data relating to movements of the floating body (2).

14. Unit according to one of the preceding claims, characterized in that it comprises an artificial intelligence for determining, on the basis of a continuous historical recording of the rolling period of the floating body (2) and associated stability data and / or environmental parameters and / or movement data and / or loading data, a relationship between the aforementioned data and the rolling period for the floating body (2) enabling increasingly precise predictions.

15. Arrangement (1) for damping a rolling movement of a floating body (2), with damping means (3) for generating a counter-rolling moment with a damping characteristic, tuning means for setting a desired damping characteristic and a control and / or regulating unit (7) for setting the desired damping characteristic depending on at least one property of the floating body (2), characterized in that the control and / or regulating unit (7) is designed according to one of the preceding claims.

16. Arrangement (1) according to claim 15, characterized in that the damping means (3) comprise a roll damping tank (3), in particular a rectangular one.

17. Arrangement (1) according to claim 15 or 16, characterized in that the tuning means (8, 9) comprise means for filling and / or emptying the roll damping tank (3) of the floating body (2), in particular pumps (8) and / or blow-out devices (9).

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