JP3474559B2 - Vessel motion reduction device and control method - Google Patents

Description

Detailed Description of the Invention

[0001]

This invention relates to a device for reducing ship motion that automatically controls the liquid braking of an anti-rolling tank, and to a method for controlling this device, in order to prevent the adverse effect of the liquid in the tank not functioning effectively as an anti-rolling tank when the ship makes a sharp turn, becoming free water and adversely affecting the ship's stability.

[0002]

2. Description of the Related Art Conventionally, a passive anti-rolling tank (hereinafter referred to as ART) of U-tube type has been used as a device for reducing the rolling of a ship.
In this ART, in order to obtain an effective anti-rolling moment, the free surface of the liquid in the ART (hereinafter also referred to as the free surface second moment) relative to the ship's stability is
Although there are ways to increase the value of , it cannot be increased indiscriminately for the following reason: This free surface moment of second does not adversely affect stability when the liquid has an appropriate phase lag, but if the phase lag becomes significantly out of whack, the liquid needed to reduce roll becomes uncontrollable free water, raising the apparent center of gravity and reducing stability accordingly.

Another cause of free water is a steady heel state (hereafter referred to as heel), in which the hull is tilted at a certain angle relative to the horizontal. This state generally occurs when the weight balance between the left and right sides is lost due to cargo shifting or a marine accident, or when a steady external force acts downwind due to a crosswind, or when the ship makes a sharp turn to significantly change course to avoid a collision or for other reasons.

Therefore, in order to detect in advance the occurrence of free water during sharp turns and minimize the adverse effect on stability, an anti-rolling tank or a control method thereof has been invented that is equipped with a valve for liquid braking, decodes rudder angle commands for turning and information such as ship speed, and automatically brakes the valve. For example, see Patent No. 3125141 (hereinafter referred to as Cited Example 1), Japanese Patent Laid-Open No. 2002-079993 (hereinafter referred to as Cited Example 2), Japanese Patent Laid-Open No. 2002-104281 (hereinafter referred to as Cited Example 3), and Japanese Patent Laid-Open No. 2002-104281 (hereinafter referred to as Cited Example 4).
3),

[0005]

[Problem to be solved by the invention] The basic matter common to Cited References 1 and 2 is described as a control method in which a decision is made based on rudder angle command information and ship speed information as to whether or not a sharp turn will occur, and the opening and closing of a valve with an air duct for liquid braking is automatically controlled.

However, when a ship is sailing, the bow yaws (moves left and right) due to the influence of the wind and waves it encounters.
Or, the ship will deviate from its course due to a lateral movement. Course deviations are particularly frequent in rough seas, so steering measures are automatically implemented to deal with this.

The rudder angle command for this turning and the initial rudder angle command for making a sharp turn are almost identical in content and indistinguishable from each other. Therefore, in a voyage in rough weather, a rudder angle command signal output simply for course correction may be mistaken for a sharp turn, and the valve may be closed and deactivated even though an anti-rolling effect is actually required and the liquid in the tank does not adversely affect the stability. In the control methods of Cited References 1 and 2,
Cited Reference 3 points out that this is a defective operation method that is not suitable for RT.

[0008] Therefore, in Cited Document 3, as a means of predicting and understanding the rolling conditions that a ship is encountering, a rolling sensor that obtains information on the ship's pitching, a wind vane and anemometer that obtains marine weather information, and a control unit that decodes the information output from these and processes control signals, etc. have been added to the rolling reduction device of the above cited documents, and it is claimed that a ship rolling reduction device has been invented that eliminates the shortcomings of Cited Documents 1 and 2.

[0009] Cited Example 3 is an excellent ship motion reduction device that decodes information on the ship's motion, rudder angle commands for turning, and ship speed information, as well as information on wind direction and speed, to grasp the situation the ship will encounter, and based on pre-set conditions, ensures the safety of the ship when the ART liquid has a negative effect on its stability, or automatically executes control specifications such as period variation and liquid braking as necessary.However, when focusing only on dealing with sharp turns, it was noted that the wind direction and speed information and its decoding means can be omitted.

[0010]

[Purpose] When a ship is making a sharp turn, centrifugal force inevitably causes a steady list toward the outside of the turning center. At this time, the list moment generated by the moving liquid in the ART is added to the centrifugal force, further increasing the hull list angle. The purpose of this system is to provide a ship motion reduction device and control method that eliminates this drawback of the ART.

[0011]

[Means for solving the problem] The present invention focuses on the fact that when manipulating the steering wheel during a sharp turn, the steering wheel section is switched to manual mode, and the steering angle command information, which is one of the conditions for determining a sharp turn, is decoded from information that is only output in manual mode.

[0012] In order to achieve the above object, a steering wheel section equipped with a means for switching between manual and automatic operation is provided with a means such as a potentiometer for detecting rudder angle command information, a means for obtaining ship speed information, a control section which deciphers whether the content is a sharp turn or a normal turn from the rudder angle command information and ship speed information output only when the ship is turned manually, and an opening and closing device means for closing the valve of the air duct which brakes the liquid, and if the control section determines that a sharp turn operation is being performed, the valve of the air duct is forcibly closed to brake the liquid in the tank.

[0013]

[Embodiments of the Invention] The following describes embodiments of the present invention with reference to the drawings. The basic structure of the ART itself to achieve the above-mentioned object is, as shown in Figure 2, a pair of at least two wing tanks 12a, 12b set on both sides of the hull, connected to the bottoms of these wing tanks 12a, 12b by liquid ducts 13 that move liquid 17 left and right, and also equipped with air ducts 14 that communicate with the tops of the wing tanks 12a, 12b via valves 15, and with equipment necessary for a water tank such as water inlet and outlet pipes, sounding pipes, air vent pipes, etc., not shown.
The RT main body 16 is provided with closing means for all pipes leading to the outside, such as the above-mentioned inlet and outlet pipes, sounding pipes, and air vent pipes, to enable a sealed state.

The valve 15 is opened and closed by a power-driven system that allows remote control for automatic control, and a control mechanism for the valve opening and closing operation is provided as shown in FIG.

The control device mechanism is broadly divided into a steering wheel section 1 that issues rudder angle commands, a speedometer that obtains ship speed information, a control section 2 that handles numerical calculations and control signals, and an opening/closing device section 3 that remotely drives the valve 15.

The steering wheel unit 1 is provided with a means for switching between manual and automatic operation, and a means such as a potentiometer 4 for detecting steering angle command information, and only when switched to manual operation is the steering angle command information transmitted to the control unit 2 as an electrical signal.

The control unit 2 includes a potentiometer 4
The rudder angle command information and ship speed information transmitted from the control circuit 6 are received and decoded by the calculation decoding circuit 5, which controls whether to close or open a preset valve based on the decoded value, and a control signal is sent to the opening and closing device unit 3 via the control execution circuit 18. The operating status of each device is grasped one by one by the information processing circuit 7 via the device operating status confirmation circuit 19, and is confirmed by the control circuit 6, and the information is stored in IC memory.

When the valve 15 of the air duct 14 is closed via the valve opening/closing device 10, the air flow inside the tank is blocked, and the voids above the liquid surface of the left and right wing tanks are sealed, preventing the movement of liquid inside the tank. In other words, the ART is in an inoperative state, and an alarm (buzzer, etc.) is sounded to notify the inoperative state.
At the same time as issuing the signal, it can be displayed on a control panel (not shown).

The calculation decoding circuit 5 determines that a sharp turn is occurring when the rudder angle command signal information and boat speed information, which are output only when the steering wheel unit is switched to manual operation, satisfy all of the following conditions, but cancels the sharp turn if the conditions are no longer satisfied even while the sharp turn response specifications are being executed: (1) When a preset command rudder angle value is detected. (2) When this state is maintained for a preset required time from the time when the command rudder angle value that is determined to be a sharp turn is detected. (3) When a preset boat speed value is detected.

[0020] The means for obtaining ship speed information is generally obtained from a speedometer or the like equipped on the ship, so there is no need to provide a ship speedometer or the like for this system, but if there is no water speedometer, a means for determining water speed is provided.

The opening and closing device unit 3 comprises a drive source 8, a solenoid valve 9, a valve 15, a valve opening and closing device 10, a limit switch 11, and the like.

The operation of the opening and closing device unit 3 until the valve is closed after detecting the execution command for the sharp turn specification is as follows: the control signal sent from the control circuit 6 of the control unit 2 starts the drive source 8 through the control execution circuit 18 → solenoid valve 9 → valve opening and closing device 10 → valve 15 → limit switch 11 →
The control ends with the process of stopping the drive source 8.

The time required for the journey depends on the size of the ship, but experiments have shown that the optimum time is about 2 to 3 seconds, but this is not a particular restriction.

Some mechanisms do not require the drive source 8. For example, if the drive source can be received from another supply source, the steps of starting and stopping the drive source 8 can be omitted.

In this embodiment, the drive system is hydraulically driven, but if a pneumatic or electric drive system is used, any parts of the opening and closing device that can be omitted depending on the system may be omitted. Also, although the air ducts 14 are connected in this example, as shown in Figure 3, the left and right air ducts 14 may not be connected, and each may be opened to the atmosphere independently, by providing a valve 15 for each, or
The same effect can be obtained by providing one valve 15 on each side.

[0026]

[Effects of the Invention] As is clear from the above explanation, according to the present invention, the operation that can be switched between manual and automatic operation is
The steering wheel (1) receives a rudder angle command signal for controlling the anti-rolling tank.
The rudder angle indicator for controlling the anti-rolling tank is provided with a means for outputting the rudder angle indicator.
The command information is only used when manually turning the ship.
The signal is output to the control unit (2),
The control unit receives the information on the rudder angle command signal and the ship speed information output only when the ship is turned manually.
However, if the preset conditions are met, the valve is forced
The brake automatically closes to stop the moving fluid.
Since the control means is characterized by controlling
and the second cited reference, the rudder angle command for maintaining the course
Do not confuse the steering angle command information for sharp turns with the steering angle command information for sharp turns.
Furthermore, it is possible to easily determine the turning information required by the present invention without incorporating information such as wind direction and wind speed.

[0027] Even in a vessel not equipped with a wind vane and anemometer, it becomes possible to incorporate operations for handling sharp turns.

This is a fatal flaw of ART, that is, the increase in heel angle during sharp turns.
This can easily eliminate the adverse effects of T. It also makes it possible to install the ART above the center of gravity of the hull, resulting in a high anti-rolling moment. Therefore, even when making sudden emergency turns to avoid collisions or during enforcement, it is possible to maneuver the ship without worrying about the shortcomings of the ART, and it has the effect of always providing a stable anti-rolling effect, making it a very effective invention.

[Brief explanation of the drawings]

FIG. 1 is a block diagram showing the configuration of a control mechanism for valve opening and closing operations according to the present invention.

FIG. 2 is a diagram showing the overall configuration of the ART.

FIG. 3 is a diagram showing the overall configuration of the ART.

[Explanation of symbols]

1... Steering wheel section 2... Control section 3... Switching mechanism section 4... Potentiometer 5... Calculation decoding circuit 6... Control circuit 7... Information processing circuit 8... Drive source 9... Solenoid valve 10... Valve switching device 11... Limit switch 12a, 12b... Wing tanks (tanks) 13... Liquid passage (liquid duct) 14... Air duct 15... Valve 16... Anti-rolling tank (ART main body) 17... Transport liquid 18... Control execution circuit 19... Equipment operation status confirmation circuit

Claims (6)

(57) [Claims] [Claim 1] A vessel having a pair of at least two wing tanks (12a, 12b) set on both sides of the hull, a liquid passage (13) connecting the bottoms of these wing tanks to move a liquid (17) in the left and right directions, an air duct (14) communicating through a means such as a remotely operated valve (15) for the purpose of braking the liquid (17) provided between the tops of the two wing tanks, or an air duct (14) with a remotely operated valve (15) provided near the top of each wing tank (12a, 12b) that can be opened to the atmosphere, further comprising a potentiometer (4) or other means for outputting rudder angle command information for a steering wheel unit (1), a means for outputting ship speed information, a control unit (2) that interprets the contents of these and outputs a control signal, and a valve (15) based on the control signal from the control unit (2).
and an opening and closing device unit (3) for remotely driving the steering wheel unit (1) which can be switched between manual and automatic operation.
means for outputting a rudder angle command signal for controlling the anti-rolling tank
The rudder angle command information for controlling the anti-rolling tank is manually
The control unit is operated only when turning the ship.
The control unit (2) is characterized in that the control unit (2) is used to manually control the ship's turning operation.
If the rudder angle command signal information and ship speed information output only when the operation is performed meet the pre-set conditions,
A device for reducing motion of a ship, characterized in that braking, which stops the moving liquid (17) by forcibly closing a valve (15), is automatically controlled. [Claim 2] The control unit (2) executes braking when the rudder angle command signal information and the ship speed information satisfy all three conditions: (1) when a predetermined command rudder angle value is detected, (2) when the state is maintained for a predetermined required time from the time when a command rudder angle value that is judged to be a sharp turn is detected, and (3) when a predetermined ship speed value is detected.A ship motion reduction device as described in claim 1, characterized in that [Claim 3] A ship motion reduction device as described in Claim 2, characterized in that the control unit (2) releases the braking when any of the conditions (1) to (3) is no longer met, even if the braking is being performed to forcibly close the valve (15) and stop the moving liquid (17). [Claim 4] A vessel having a pair of at least two wing tanks (12a, 12b) set on both sides of the hull, a liquid passage (13) connecting the bottoms of these wing tanks to move a liquid (17) in the left and right directions, an air duct (14) communicating through a means such as a remotely operated valve (15) for the purpose of braking the liquid (17) provided between the tops of both wing tanks, or an air duct (14) with a remotely operated valve (15) provided near the top of each wing tank (12a, 12b) that can be opened to the atmosphere, further comprising a means such as a potentiometer (4) for outputting rudder angle command information for a steering wheel unit (1), a means for outputting ship speed information, a control unit (2) for decoding the contents of these and outputting a control signal, and a control unit (3) for controlling the valve (15) based on the control signal from the control unit (2).
In a ship motion reduction device that can automatically move or stop a liquid (17) and is equipped with an opening and closing device unit (3) that remotely drives the steering wheel unit (1) that can be switched between manual and automatic operation ,
means for outputting a rudder angle command signal for controlling the anti-rolling tank
The rudder angle command information for controlling the anti-rolling tank is manually
The control unit is operated only when turning the ship.
(2) is characterized in that the signal is output to (3) only when the ship is turned manually.
This method for controlling a ship motion reduction device is characterized in that, when rudder angle command signal information and ship speed information satisfy predetermined conditions, the valve (15) is forcibly closed to automatically control braking to stop the moving liquid (17). [Claim 5] The control method for a ship motion reduction device described in Claim 4, characterized in that the predetermined conditions are that the information on the rudder angle command signal and the ship speed information satisfy all three conditions: (1) when a predetermined command rudder angle value is detected, (2) when a command rudder angle value that is judged to be a sharp turn is detected and that state is maintained for a predetermined required time, and ( 3 ) when a predetermined ship speed value is detected. [Claim 6] A control method for a ship motion reduction device as described in Claim 6, characterized in that even if braking is being performed to forcibly close the valve (15) and stop the moving liquid (17), the braking is released when any of the conditions (1) to (3) is no longer met.