JP2611573B2 - Offshore structure rocking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine structure rocking apparatus used for restraining the movement of marine structures such as ships, barges and other floating bodies.

[0002]

2. Description of the Related Art Such a type of rocking device in a ship includes:
ART (reduced water tank) and fin stabilizer are known. That is, ART is intended to restrain the ship from rolling using a water tank, and as schematically shown in FIG.
Above the center of gravity of the main hull a, a U-tube type water tank c whose upper end is communicated with the air communication pipe b is installed, and the water d in the water tank c is passively supplied as the main hull a rolls. It is designed so that it resonates and the phase has a delay of 90 ° with respect to the roll. As shown schematically in FIG. 6, the fin stabilizer is provided with a movable fin f which can be moved by a driving device e at a bilge portion below the water surface substantially at the center of the main hull a in the fore-and-aft direction. The angle of movement, angular velocity, and angular acceleration of the movable fin f are detected by the sensor g to change the angle of attack of the movable fin f to active, and the roll of the main hull a is restrained by the lift generated on the movable fin f according to the ship speed. Things.

[0003]

However, the above-mentioned ART
In general, the total weight of a small boat is 3-4% of the ship's displacement,
For large ships, 1-2% is required, and due to the damping mass of water, a large space must be secured on the upper deck, which impairs maneuvering and rear view, and for small ships, the center of gravity rises. There can affect the restoration performance of the ship, but in waves can be expected to the swinging motion reducing effect, in still water is free
Conversely, increasing the side effect due to the increase in the influence of water , noise is generated when air passes through the communication pipe as the water moves, which often affects habitability,
There are problems such as.

[0004] On the other hand, when a fin stabilizer is used, it is not possible to expect a damping effect up to the ship speed at which the fin lifts (at low speed, there is no effect when the ship is stopped), and rigging work on the hull is complicated. And that they are very expensive (about 5 times) as compared with ART.

Accordingly, the present invention solves the above-mentioned problems caused by the ART and the fin stabilizer, gives the kinetic energy of the vibration damping mass to the marine structure with a simple structure, and deprives the structure of the oscillating energy. By controlling the phase of the damping mass to be optimal for the marine structure with a simple circuit configuration, it is possible to quickly suppress the oscillation of the marine structure.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method in which a solid mass curved and formed in an arc shape such that a center of curvature is located on an offshore structure is subjected to single-string vibration. It is arranged so as to be swingable via a supporting roller so as to be able to perform, a spring system using gravity is provided, a driving device for applying a driving force to the solid mass is installed, and the movement of the marine structure is detected. And a control device that sends a drive command to the drive device by controlling the phase of the signal from the shake detection sensor.

[0007]

When the motion of the marine structure is detected by the motion detection sensor, the signal is phase-controlled by the control device and then output to the solid mass drive device. Therefore,
The solid mass oscillates in a single string with a delay of 90 ° with respect to the motion of the marine structure, and the solid mass can be used as the damping mass, thereby obtaining a vibration damping effect.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 to FIG. 4 show an embodiment of the present invention. A base 3 is provided at the bottom of a ship 1 in an engine room 2 of a marine structure as a marine structure. A metal solid mass 4 serving as a vibration damping mass that is curved and formed in an arc shape so as to be located above is singly vibrated (pendulum motion) in the left-right direction (toward the front) via a support roller 5 provided on the base 3. ) To form a spring system based on a restoring force using gravity without using a mechanical spring, and protrusions 6 provided at both side ends of the solid mass 4 are provided. The vibration region of the solid mass 4 is restricted within a range where the solid mass 4 comes into contact with the left and right buffers 8 on the gantry 7 installed at a position sandwiching the front and rear of the solid mass 4. A rack 9 is provided along the vibration direction on the upper surface of the solid mass 4, and a shaft 10 disposed above the rack 9 so as to be orthogonal to the rack 9 is provided as a driving device via a speed reducer 11. A pinion 13 is attached to an intermediate portion of the shaft 10 so as to mesh with the rack 9, and the pinion 13 is rotated via the shaft 10 by driving the servomotor 12 so that the solid mass 4 is moved together with the rack 9. Can be moved in a required cycle.

Further, a motion detection sensor 15 and a control device 16 are installed in a steering room 14 of the boat 1, and a signal output from the control device 16 based on a signal from the motion detection sensor 15 is used to control the servo motor 12. , And the oscillating energy of the marine vessel 1 is consumed by arbitrarily controlling the single-string vibration of the solid mass 4 with respect to the oscillating motion of the marine vessel 1 by the driving force of the servo motor 12.

The driving force of the servo motor 12 is a power for accelerating the solid mass 4 to a required displacement (amplitude), and a damping force for maintaining the solid mass 4 at the required amplitude. It is also the braking force that gives. That is, since the energy given to the solid mass 4 as a single-string vibration due to the shaking of the ship 1 is diverged unless a control force is given, the servo motor 12 drives the solid mass 4 to accelerate to the required amplitude. And a braking force for suppressing divergence.

FIG. 4 shows a control block diagram for performing the above control. That is, the control device 16
The motion signal of the boat 1 detected by the motion detection sensor 15 is calculated, and a 90 ° delay phase and a displacement signal with respect to the motion of the boat 1 are transmitted to the drive unit 17 that drives the servomotor 12. In this embodiment,
Using an acceleration sensor as the motion detection sensor 15,
The controller 16 integrates the acceleration twice to generate a displacement signal. However, the control signal 16 may be integrated once to generate a speed signal, and the speed signal may be used as an inversion signal to be used as the displacement signal of the solid mass 4.

In the above configuration, when the ship 1 shakes (rolls), the shaking energy is transmitted to the solid mass 4, so that the single-string vibration starts with a delay of 90 ° with respect to the shake of the ship 1. In this case, the movement of the solid mass 4 includes:
Since the solid mass 4 itself adopts the principle of a pendulum that attempts to repeatedly move in an arc shape, reliable operation can be obtained. Therefore, the solid mass 4 can be made to act as a damping mass that gives a force in the opposite direction to the force entering the marine vessel 1 and the sway of the marine vessel 1 can be suppressed. Since the control signal is diverged if not controlled, the servo motor 12 is driven forward or reverse based on the signal output from the control device 16. That is, when the motion of the boat 1 is detected by the motion detection sensor 15, a displacement signal phase-controlled based on the signal is sent from the control device 16 to the drive unit 17, and the servomotor 12 is driven forward and reverse. As a result, the solid mass 4 is moved right and left via the speed reducer 11, the shaft 10, the pinion 13, and the rack 9. In this case, the solid mass 4
After the solid mass 4 is accelerated to the required amplitude, the driving force of the servo motor 12 may be applied as a braking force after the solid mass 4 is accelerated to the required amplitude. Only as a braking force, the effect of reducing rocking can be obtained, and it is possible to quickly respond to changes in the amount of rocking or the cycle of the boat 1.

In the above embodiment, the case where the solid mass 4 is arranged so as to swing in the left-right direction so as to cope with the roll is shown. It is possible to cope with shaking, and if two units are arranged so as to swing back and forth, left and right, it is possible to cope with vertical and horizontal shaking. In the embodiment, an example of application to a ship is shown. It is needless to say that the present invention can be similarly applied to an offshore structure, and that various changes can be made without departing from the gist of the present invention.

[0015]

As described above, according to the vibration damping device for an offshore structure of the present invention, a solid mass that is curved and formed in an arc shape such that the center of curvature is located above the offshore structure is simply obtained. Arranged swingably via a supporting roller so as to perform string vibration, constitute a spring system using gravity, and install a driving device for applying a driving force to the solid mass, and Since the configuration is provided with the motion detection sensor for detecting the motion and the control device for controlling the phase of the signal of the motion detection sensor and transmitting a drive command to the drive device, the following excellent effects are exhibited. Since the solid mass can be reliably operated by the principle of the pendulum, the oscillating energy of the offshore structure can be easily converted to the kinetic energy of the solid mass and can be used as the damping mass, and the driving force of the drive unit can be reduced. It can act as a control force, can quickly respond to the sway of the marine structure, and provide an excellent anti-rolling effect. Controlling the damping mass by driving force (active function)
As a result, the oscillation of the offshore structure can be damped in a wide frequency range, and the passive function can be possessed by making the single-string oscillation period of the damping mass almost close to the oscillation period of the offshore structure, It becomes possible to control large vibration at the tuning point (resonance point) with a small control force. Since the damping mass is a solid mass, the installation space can be made smaller than that of the anti-oscillation tank (about 1/3 or less), and when it is used in a ship, it can be installed inside the main hull. . As a result, it is possible to improve the marine vessel maneuverability, improve the stability of the ship, and effectively use the space in the main hull. By fixing the solid mass to the optimum position or moving the solid mass by the driving device, it is possible to prevent the marine structure from tilting in horizontal water. Since the structure is simple and a small and compact design is possible, it can be manufactured at low cost and can sufficiently take measures against noise in the movable part. The effect can be expected over a wide range from when the ship is stopped to when traveling at high speed. By selecting the number of installations and the number of installations, it is possible to deal with sway in all directions.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an arrangement of a marine structure rocking apparatus according to an embodiment of the present invention on a ship.

FIG. 2 is a schematic diagram of a central longitudinal section of FIG.

FIG. 3 is an enlarged perspective view of the rocking device.

FIG. 4 is a block diagram of a control system.

FIG. 5 is a schematic view showing an example of a conventional rocking device.

FIG. 6 is a schematic view showing another example of the conventional rocking device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ship (marine structure) 4 Solid mass 12 Servo motor (drive device) 15 Motion detection sensor 16 Control device

Claims (1)

(57) [Claims] 1. A solid mass which is curved and formed in an arc shape so that a center of curvature is located on an offshore structure, and is swingably arranged via a support roller so as to perform single-string vibration. Constructing a spring system using gravity, installing a driving device for applying a driving force to the solid mass, and detecting a motion of the marine structure with a motion detection sensor, and controlling a phase of a signal of the motion detection sensor. And a control device for sending a drive command to the drive device.