JP7598653B2 - Positioning system for single-propeller, twin-rudder ships - Google Patents

Description

This invention relates to a single-propeller, twin-rudder ship, and to technology that enables highly accurate maneuvering while maintaining a fixed position.

Conventionally, there is an emergency maneuvering method for a ship described in Patent Document 1 as a technology for applying braking force to a ship. In an emergency, this method activates an emergency steering means and controls the rudder control means in priority to any normal steering mode, giving two high-lift rudders a rudder angle that maximizes the propeller wake as reverse thrust, and this reverse thrust gives the ship a reverse force that counters the inertial force in the forward direction of the ship, allowing for an emergency stop or emergency reverse. With the propeller operating in a single forward direction, reverse thrust can be obtained immediately, and the ship can be stopped or reversed in a short time and over a short distance with few steps.

Furthermore, Patent Document 2 proposes a ship steering device that realizes special movements such as moving straight across, moving diagonally forward and backward, and turning on the spot when maneuvering to maintain ship position and heading, and that requires high maneuvering accuracy in terms of position, speed, etc. In this ship steering device, in the maneuvering assistance mode, the command unit commands the ship's hull motion control unit to steer the ship with a commanded direction of movement, a commanded turning angular velocity, a commanded speed in the bow-stern direction, and a commanded speed in the width direction, and the thrust distribution unit distributes the hull control force and turning hull control force to a target propeller thrust generated by a combination of the thrust of a propeller propeller rotating constantly forward and the rudder angle of two high-lift rudders, and a target thruster thrust generated by a bow thruster.

Japanese Patent Application Publication No. 7-52887 Patent Publication 2017-052297

Conventionally, the Dynamic Positioning System (DPS) has been used to control the movement of ships and floating structures in deep waters with high precision to a set position, direction, and course, and uses propellers and side thrusters to provide control force against external forces from disturbances such as wind, waves, and currents.

In addition, for a ship to navigate safely in a harbor with many surrounding obstacles such as quays and other ships, it is necessary to carefully maneuver the ship while always being aware of the distance between the ship and obstacles, while taking into consideration the external forces that affect the ship, such as rip currents, onshore currents, tidal forces, and wind forces.

The present invention aims to solve the above-mentioned problems and provide a positioning device for a single-propeller, twin-rudder ship that can perform positioning maneuvering with high precision.

In order to solve the above-mentioned problems, the positioning device for a single-shaft, twin-rudder ship of the present invention comprises a thrust system, a steering system that controls the thrust system, and an observation system that observes the ship's hull motion state. The thrust system comprises a single propulsion propeller disposed at the stern, a pair of left and right high-lift rudders disposed aft of the propulsion propellers, a pair of steering gears that respectively drive each high-lift rudders, a bow thruster, and a thruster control device that controls the bow thruster. The observation system comprises a ship speed measuring device that measures the ship's bow-stern speed, widthwise speed, and turning angular velocity, and a ship speed measuring device that measures the ship's position by GPS. The ship steering system comprises a positioning control unit and a positioning motion control unit, the positioning control unit controls the rudder angle of each of the two high-lift rudders within a set rudder angle range, the set rudder angle range being a rudder angle range of several tens of degrees around the hover rudder angle, with hover rudder angles δph and δsh of port rudder -75° and starboard rudder +75° at which the ship stops on the spot as central rudder angles, and the following calculations are performed assuming that the bow-stern thrust XHR and transverse thrust YHR generated when steering around the hover rudder angle and the thruster thrust _YB generated by the thrusters are the bow-stern speed, transverse speed and turning angular velocity of the ship are sufficiently small and that the propeller thrust and thruster thrust generated by the propellers and the pair of high-lift rudders do not change depending on the ship motion, and Step 1. Calculate the x-axis position deviation xn and y-axis position deviation yn on the GPS coordinates between the ship's current position and the target position measured by the position measuring device, and the heading deviation ψn in the x-axis direction between the current heading and the target heading measured by the direction measuring device, Step 2. Calculate the x-axis position deviation xn, y-axis position deviation yn, and heading deviation ψn to determine the x-axis thrust Xreq, y-axis thrust Yreq, and turning moment Nreq required for adjusted hull motion to return from the current position to the target position by correcting the x-axis position deviation xn, y-axis position deviation yn, and heading deviation ψn, Step 3. Calculate the distribution of the thruster thrust _YB generated by the bow thruster, and the bow-stern thrust _XHR , transverse thrust _{YHR, and thruster thrust YB generated by the propeller and a pair of high-lift rudders required to realize the x-axis thrust Xreq, y-axis thrust Yreq ,} and turning moment Nreq, The adjustment rudder angle control amounts δp, δs around the hover rudder angle and the adjustment thruster control amount _nB for generating the obtained bow-stern thrust _XHR , transverse thrust _YHR , and thruster thrust _YB are obtained, and the positioning motion control unit has a positioning steering control unit which controls each of the steering gears and controls the bow-stern speed and transverse speed by combining the rudder angles of the two high-lift rudders, and a positioning thruster control unit which controls the turning angular speed by adjusting the thruster thrust of the bow thruster with a thruster control device, and the adjustment thruster control amount and adjustment rudder angle control amount input from the positioning control unit are controlled by the positioning steering control unit and the positioning thruster control unit.

In the positioning device for a single-propeller, twin-rudder ship of the present invention, in step 2, the positioning control unit calculates the x-axis thrust force Xreq, the y-axis thrust force Yreq, and the turning moment Nreq using the following formula 1:

ステップ３．において、船首尾方向推力Ｘ_ＨＲと船幅方向推力Ｙ_ＨＲとスラスター推力Ｙ_Ｂの配分を、次式２で求め、

In step 3, the distribution of the bow-stern thrust force _XHR , the transverse thrust force _YHR , and the thruster thrust force _YB is calculated using the following formula 2:

ステップ４．において、調整舵角制御量δｐ、δｓと調整スラスター制御量ｎ_Ｂを、次式３で求め、

In step 4, the adjustment rudder angle control amounts δp, δs and the adjustment thruster control amount _nB are calculated using the following equation 3:

船位保持運動制御部は、式３で求めた調整スラスター制御量と調整舵角制御量を、船位保持操舵制御部および船位保持スラスター制御部により制御することを特徴とする。

The ship positioning motion control section is characterized in that the adjustment thruster control amount and adjustment rudder angle control amount calculated by Equation 3 are controlled by the ship positioning steering control section and the ship positioning thruster control section.

The above configuration allows the adjustment thruster control amount and adjustment rudder angle control amount to be calculated from the deviation between the ship's current position and the target position, and the bow-stern thrust, widthwise thrust Y, and thruster thrust can be controlled with high precision. This makes it possible to safely control the movement of the ship's hull to a specified position and direction with high precision in deep water areas or in harbors with many surrounding obstacles such as quays and other ships, while taking into account the external forces that affect the hull, such as rip currents, tidal forces of onshore currents, tides, and wind forces.

FIG. 1 is a schematic diagram showing a thrust system, a steering system, and an observation system of a single-propeller, twin-rudder ship according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a propulsion device, a high-lift rudder, and a bow thruster in the embodiment. FIG. 2 is a perspective view showing the configuration of the stern portion in the embodiment; FIG. 2 is a schematic diagram showing a steering stand of a single-propeller, twin-rudder ship according to the embodiment; FIG. 2 is a perspective view showing a three-degree-of-freedom joystick lever in the embodiment; FIG. 2 is a block diagram showing a configuration of a ship steering stand according to the embodiment; FIG. 2 is a block diagram showing the configuration of an automatic berthing maneuvering unit in the embodiment; FIG. 2 is a block diagram showing a configuration of a berthing maneuvering section in the embodiment; FIG. 2 is a block diagram showing the configuration of a ship positioning steering unit according to the embodiment; FIG. 4 is a schematic diagram showing the operating range of a high-lift rudder in the embodiment; FIG. 4 is a schematic diagram showing the combined rudder angle and turning direction of the high-lift rudder in the embodiment. FIG. 2 is a schematic diagram showing how a ship avoids collisions and docking is performed in the embodiment; FIG. 4 is a schematic diagram showing the relationship between the current ship position and the target ship position in the embodiment; FIG. 2 is a schematic diagram showing the ship in the embodiment;

Hereinafter, an embodiment of a rudder system according to the present invention will be described with reference to the drawings.
(Configuration of the embodiment)
The single-propeller, twin-rudder ship with automatic docking function in this embodiment is equipped with a thrust system 100, a steering system 200 that controls the thrust system 100, and an observation system 300 that observes the ship's hull motion state, as shown in Figures 1 to 10.

The thrust system 100 is comprised of a single propeller 101 mounted at the stern of the hull 110 and two high-lift rudders 102 and 103 mounted behind the propeller 101.

Each high-lift rudders 102, 103 is configured to be able to steer 105° outboard (outboard side) and 35° inboard (inboard side). Then, while the single-shaft propeller 101 continues to rotate forward, the pair of two high-lift rudders 102, 103 can be operated independently at various angles, and by changing the combination of rudder angles of the high-lift rudders 102, 103 on both sides, the propeller wake can be distributed in the desired direction, and the thrust in each direction can be freely changed.

Therefore, by freely changing the thrust in each direction, the propeller wake can be controlled to control the thrust around the stern in all directions 360°, allowing the ship to move forward or backward, stop, turn forward, turn backward, etc., and the ship's movement can be freely controlled.

The thrust system 100 further includes rotary vane steering gears 104, 105 that drive the high-lift rudders 102, 103, rudder control devices (servo amplifiers) 106, 107 that control the rotary vane steering gears 104, 105, a bow thruster 108 arranged on the bow side of the hull 110, and a thruster control device 109 that controls the bow thruster 108.

In addition, pump units 151, 152, rudder angle transmitters 153, 154, and feedback units 155, 156 are connected to the rotary vane steering gears 104, 105, respectively, and the feedback units 155, 156 are connected to the rudder control devices 106, 107.

The observation system 300 is equipped with a ship speed measuring device 312 that measures the bow-stern speed, widthwise speed, and turning angular velocity of the ship 501, a position measuring device 313 that measures the position of the ship 501 using GPS, a direction measuring device 314 that measures the bow heading of the ship 501, and a quay distance measuring device 315 that measures the bow distance between the bow of the ship 501 and the target quay 700 and the stern distance between the stern of the ship 501 and the target quay 700.

The maneuvering system 200 is stored in a maneuvering stand 250, to which a gyrocompass 251, a ship radar device 310, a ship speed measuring device 312, a position measuring device 313, a direction measuring device 314, and a quay distance measuring device 315 are connected.

When a collision with another ship is predicted, the ship radar device 310 transmits a collision warning signal from the warning signal output unit 311 to the ship steering system 200 of the ship steering stand 250.

The maneuvering system 200 includes the following items integrated into the stand housing: a gyro direction display unit 252 that displays the gyro direction of a gyro compass 251, an auto-steering unit 253 that steers the ship in an autopilot steering mode using a GPS compass, a joystick steering unit 255 that steers the ship in a steering mode using a joystick lever 254, a manual steering unit 257 that steers the ship in a steering mode using a manual steering wheel 256, a non-follow-up steering unit 259 that steers the ship in a steering mode using non-follow-up steering levers 258a, 258b, and a mode switching unit 261 that switches between the various steering units using a mode switching switch 260.

Furthermore, the system is equipped with a display device 262 with a touch panel on the screen, an image control unit 263 that controls the image displayed on the display device 262, an emergency stop unit 265 that steers the ship in a steering mode that takes priority over all steering modes and stops the ship urgently by operating an emergency stop button 264, a rudder angle instruction unit 280 that gives an instruction rudder angle to the rotary vane steering gears 104, 105 via the rudder control devices 106, 107, an avoidance maneuvering unit 281 that steers the ship in a steering mode in which the ship navigates while keeping the other ship on its starboard side when two ships cross each other's course and there is a risk of collision when navigating a congested sea area, an electronic chart display unit 282 that displays an electronic navigation chart on the display device 262, a course line setting unit 283 that sets the ship's planned route on the electronic navigation chart, and a course correction unit 284 that eliminates the positional deviation of the ship relative to the course line.

The system also includes a steering support unit 290 that calculates the appropriate steering angle required for sailing along the planned route and outputs the calculated appropriate steering angle to the steering angle instruction unit 280 as an instruction rudder angle, an automatic berthing steering unit 600 that automatically performs berthing maneuvering by operating the automatic berthing button 271, and a positioning steering unit 660 that controls the movement of the hull to a specified position and direction with high precision.

It further has a docking maneuvering button 351, a three-degree-of-freedom joystick lever 352, and a docking maneuvering section 650 that steers the ship in a maneuvering mode using the three-degree-of-freedom joystick lever 352 by operating the docking maneuvering button 351.

The image control unit 263 selectively displays or simultaneously displays a chart display image 266 that displays an electronic navigational chart, a gyro orientation display image 267 that displays a gyro orientation, an orientation display unit operation image 268 for touch-operating the gyro orientation display unit 252 on the monitor screen, and an auto-pilot operation image 269 for touch-operating the auto-pilot unit 253 on the monitor screen.

The joystick operation unit 255 is configured so that the joystick lever 254 can be operated in either the X-Y direction, and the tilt direction of the joystick lever 254 controls the commanded direction of the hull movement, and the tilt angle in the tilt direction controls the commanded speed in the bow-stern direction and the commanded speed in the hull turning direction.

The joystick steering unit 255 controls the rudder angles of the high-lift rudders 102, 103 on both sides to rudder angles set according to the tilt direction of the joystick lever 254, and by combining the rudder angles of the high-lift rudders 102, 103 on both sides, the thrust of the propeller wake is diverted toward the desired direction, and the rudder angles of the high-lift rudders 102, 103 on both sides are controlled by both rotary vane steering gears 104, 105 within a range of 105° outboard and 35° inboard.

The basic combinations of rudder angles for the high-lift rudders 102 and 103, as well as the state of the joystick lever 254, their names, and the propeller wake and direction of movement are explained in Figure 10.

In Figure 11, the rudder is shown in horizontal cross section, with the rudder angle of each rudder shown to the side or below. Rudder angles are shown as positive (+) when the stern is turned to the right, and negative (-) when turned to the left, and names for combinations of these rudder angles are given. The propeller wake is shown by a thin arrow, and the resulting propulsion direction of the ship is shown by a thick hollow arrow.

By the way, "forward left turn" is port rudder -35° and starboard rudder -35°, "forward left turn" is port rudder -70° and starboard rudder -35°, "astern left" is port rudder -105° and starboard rudder +45° to +75°, "astern left turn" is port rudder -105° and starboard rudder +75° to +105°, "forward" is port rudder 0° and starboard rudder 0°, and "hover" (the ship stops in place) is port rudder -105° and starboard rudder +75° to +105°. Rudder -75°, starboard rudder +75°; "astern" is port rudder -105°, starboard rudder +105°; "forward starboard turn" is port rudder +35°, starboard rudder +35°; "forward starboard turn" is port rudder +35°, starboard rudder +70°; "astern right" is port rudder -45° to -75°, starboard rudder +105°; "astern right turn" is port rudder -75° to -105°, starboard rudder +105°.

In addition, if the thrust of the bow thruster 108 is applied in the starboard direction during "forward turn to the left," thereby increasing the left turning speed, it becomes an "on-the-spot turn to the left," and if the thrust of the bow thruster 108 is applied in the port direction during "forward turn to the right," thereby increasing the right turning speed, it becomes an "on-the-spot turn to the right."

Similarly, if the thrust of the bow thruster 108 is applied in the port direction during "astern shift to the left" to increase the right turning speed, this results in "turning to the right on the spot," and if the thrust of the bow thruster 108 is applied in the starboard direction during "astern shift to the right" to increase the left turning speed, this results in "turning to the left on the spot."

The center of turning can also be moved by adjusting the thrust of the bow cluster 108 thrusters.

In this way, a single-shaft, twin-rudder ship equipped with two high-lift rudders 102, 103 and a bow thruster 108 can freely vary the direction and magnitude of the thrust in all directions of the ship by varying the combined rudder angle of the high-lift rudders 102, 103, and can achieve on-the-spot turning by combining this with the thrust of the bow thruster 108.

The auto-pilot unit 253 guides and controls the ship to a predetermined course based on the ship's current position information, guidance route information, and stationary holding position information from the GPS compass and electronic chart system.

When the emergency stop button 264 is pressed in an emergency, the emergency stop unit 265 cancels the rudder angle related to the current maneuvering, regardless of the maneuvering state indicated by the joystick lever 254 or the maneuvering mode, and turns the port rudder 103 to the starboard rudder direction (clockwise direction as seen from above) and the starboard rudder 102 to the starboard direction (counterclockwise direction as seen from above) until they are hard over (fully turned), applying a braking force to the ship to stop it.

The manual steering unit 257 steers the ship by controlling the rudder angles of the two high-lift rudders 102, 103 through the rotation of the manual steering wheel 256.

The non-follow-up steering unit 259 steers to starboard or port depending on the time that the non-follow-up steering levers 258a, 258b are operated left or right.

The avoidance maneuvering unit 281 automatically controls the direction of propulsion and ship speed according to the situation at the time, based on the position information of the ship 501 and one or more other ships 401, 402 obtained from the gyrocompass 251 and the ship radar device 310, the direction information of the ship 501 and the other ships 401, 402, the distance information to the other ships 401, 402, and the relative speed information to the other ships 401, 402.

The course correction unit 284 calculates the minimum distance from the ship to the course line as the positional deviation of the ship's position relative to the course line when the ship's bow heading reproduced on the navigational electronic chart by the digital twin calculation unit 291 described later is parallel to the course line, and when the minimum distance exceeds a set tolerance range, outputs to the rudder angle indication unit 280 the course correction rudder angle set to orient the ship's bow heading along a course that intersects the course line.

The ship steering support unit 290 has a digital twin calculation unit 291, a simulation calculation unit 292, a resultant external force calculation unit 293, and a command rudder angle calculation unit 294.

The digital twin calculation unit 291 collects the ship's speed measured by the ship speed measurement device 312, the ship's position measured by the position measurement device 313, and the ship's bow direction measured by the direction measurement device 314 in real time, and reproduces the actual ship's hull motion realized at the current steering angle on the navigational electronic chart.

The simulation calculation unit 292 displays the assumed ship motion of the ship calculated based on the current steering angle on the electronic navigation chart.

The resultant external force calculation unit 293 calculates the direction and magnitude of the resultant external force acting on the hull based on the difference in ship speed, ship position, and bow heading between the actual ship motion and the expected ship motion.

The command steering angle calculation unit 294 calculates a correction steering angle to resist the resultant force of the external forces, and calculates the appropriate steering angle by correcting the current steering angle with the correction steering angle.

The automatic docking maneuvering unit 600 has an automatic docking command unit 610, a vessel motion control unit 620, and a sensor unit 630. The sensor unit 630 inputs the output of each measuring device of the observation system 300 to the vessel motion control unit 620.

The automatic docking command unit 610 has a wharf approach steering unit 611 that is responsible for docking navigation toward the target wharf 700, and a wharf docking steering unit 612 that causes the ship to approach the target wharf 700 from a position close to the target wharf 700.

The wharf approach steering unit 611 issues a command to the vessel motion control unit 620 for the vessel motion direction to direct the vessel 501 to the docking course leading to the target wharf 700 selected and set on the navigational electronic chart, as well as the command speed in the bow-stern direction and the command speed in the width direction required for the vessel motion.

The quay docking steering unit 612 aligns the bow and stern direction of the ship 501 with the target quay 700 when it is close to the target quay 700, and commands the ship motion control unit 620 to steer the ship 501 closer to the target quay 700 while maintaining this parallel state, in order to dock the ship 501 at the target quay 700.

The hull motion control unit 620 has a steering control unit 621 that controls each of the rotary vane steering gears 104, 105 and controls the direction of hull motion by combining the rudder angles of the two high-lift rudders 102, 103, and a thruster control unit 622 that controls the bow direction by adjusting the thruster thrust of the bow thruster 108 using the thruster control device 109.

As shown in FIG. 12, under the command of the quay approach steering unit 611, the hull motion control unit 620 realizes the motion command direction, bow/stern command speed, and ship width command speed using the steering control unit 621 and thruster control unit 622, and navigates to a position a set distance away from the target quay 700.

Then, under the command of the quay docking steering unit 612, the steering control unit 621 and thruster control unit 622 perform steering to turn the ship on the spot so that the bow distance and stern distance measured by the quay clearance distance measuring device 315 become equal and the ship's bow and stern direction becomes parallel to the target quay 700, and further, while maintaining this parallel state, steering to move directly abeam to move the ship 501 closer to the target quay 700 for docking.

The docking maneuvering unit 650 has a feedback controller 651 and a docking hull motion control unit 652.

The three-degree-of-freedom joystick lever 352 constitutes a docking maneuvering command device, and by tilting the lever, it indicates the bow-stern direction command speed and the width direction command speed as continuous values, and by twisting the lever around its axis, it indicates the turning command angular velocity as a continuous value.

In other words, the 3-DOF joystick lever 352 is configured so that it can be operated in either the X-Y direction and can be twisted around the axis of the lever in the Z direction. The tilt direction of the 3-DOF joystick lever 352 controls the command speed in the commanded direction of movement, i.e., the ratio of the bow-stern command speed component and the ship's width command speed component, the tilt angle in the tilt direction controls the bow-stern command speed and the ship's width command speed, and the turning command angular speed is controlled by twisting the lever around the axis.

In addition, the 3-degree-of-freedom joystick lever returns to a neutral position where it is not tilted, causing the vessel to stop quickly and stop on the spot. At this time, the vessel's position-keeping maneuvering, which will be described later, is carried out.

The feedback controller 651 calculates the command rudder angle and command thrust force required to achieve the bow-stern command speed, width command speed, and turning command angular velocity commanded by the three-degree-of-freedom joystick lever 352 from the current hull motion state.

The observation system 300 inputs the current bow-stern speed, current widthwise speed, and current turning angular speed of the actual hull motion measured by the ship speed measuring device 312 to the feedback controller 651, and the feedback controller 651 calculates the commanded rudder angle and commanded thruster thrust so as to minimize the integral value of the error between the actual hull motion state and the target hull motion state at every moment when transitioning from the current hull motion state to the target hull motion state.

The calculation of the commanded rudder angle and commanded thruster thrust is performed with the rotation speed of the propulsion propeller 101 fixed constant, i.e., the thrust of the propulsion propeller 101 is performed under slow operating speed conditions when maneuvering to approach a berth.

The docking hull motion control unit 652 has a docking steering control unit 653 that controls each of the rotary vane steering gears 104, 105 and controls the bow-stern speed and the widthwise speed by combining the rudder angles of the two high-lift rudders 102, 103, and a docking thruster control unit 654 that controls the turning angular speed by adjusting the thruster thrust of the bow thruster 108 using the thruster control device 109.

The docking hull motion control unit 652 then realizes the command rudder angle and command thruster thrust force input from the feedback controller 651 through control by the docking steering control unit 653 and the docking thruster control unit 654.

The docking steering control unit 653 of the docking hull motion control unit 652 controls the rudder angles of the two high-lift rudders 102, 103 within a set rudder angle range. The set rudder angle range is a rudder angle range of about 10 degrees around the hover rudder angle, with the hover rudder angle of port rudder -75° and starboard rudder +75° at which the hull stops on the spot as the center rudder angle.

The ship positioning steering unit 660 includes a ship positioning control unit 661 and a ship positioning movement control unit 662, and the ship positioning movement control unit 662 includes a ship positioning thruster control unit 663 and a ship positioning steering control unit 664.

As shown in Figures 13 and 14, the ship positioning control unit 661, like the docking steering control unit 653, controls the rudder angles δp, δs of the two high-lift rudders 102, 103 within a set rudder angle range, which is a rudder angle range of several tens of degrees around the hover rudder angles δph, δsh, with the port rudder at -75° and starboard rudder at +75°, at which the hull stops on the spot, as the central rudder angles, and is shown here as the asymptotic values of δp and δs.

Then, the following calculations are performed on the assumption that the bow-stern thrust _XHR , the transverse thrust _YHR, and the thruster thrust _YB generated by the bow thruster 108 when steering around the hover rudder angle are such that the bow-stern speed, transverse speed, and turning angular velocity of the ship are sufficiently small, and that the propeller thrust and thruster thrust generated by the propeller 101 and the pair of high-lift rudders 102, 103 do not change depending on the ship motion:
Step 1. Calculate the x-axis position deviation xn and y-axis position deviation yn on the GPS coordinates between the current ship position and the target ship position measured by the position measuring device, and the x-axis heading deviation ψn between the current heading and the target heading measured by the direction measuring device,
Step 2. Calculate the x-axis thrust Xreq, the y-axis thrust Yreq, and the turning moment Nreq required for the adjusted hull motion to return from the current ship position to the target ship position by correcting the x-axis position deviation xn, the y-axis position deviation yn, and the heading deviation ψn,
Step 3. Calculate the distribution of the thruster thrust _YB generated by the bow thruster required to realize the x-axis thrust Xreq, the y-axis thrust Yreq, and the turning moment Nreq, and the thruster thrust YB generated by the propeller and a pair of high-lift rudders, among the bow-stern thrust _XHR , the widthwise thrust _YHR , and the thruster thrust _YB , in accordance with step 2;
Step 4. Calculate the adjustment rudder angle control amounts δp and δs around the hover rudder angle and the adjustment thruster control amount _nB for generating the obtained bow-stern thrust force _XHR , the vessel widthwise thrust force _YHR , and the thruster thrust force _YB .
The positioning movement control unit has a positioning steering control unit that controls each of the steering gears and controls the bow-stern speed and widthwise speed by combining the rudder angles of the two high-lift rudders, and a positioning thruster control unit that controls the turning angular speed by adjusting the thruster thrust of the bow thruster using a thruster control device, and the adjustment thruster control amount and adjustment rudder angle control amount input from the positioning control unit are controlled by the positioning steering control unit and the positioning thruster control unit.

In step 2, the ship positioning control unit calculates the x-axis thrust Xreq, the y-axis thrust Yreq, and the turning moment Nreq, for example, using the following formula 1:

ステップ３．において、船首尾方向推力Ｘ_ＨＲと船幅方向推力Ｙ_ＨＲとスラスター推力Ｙ_Ｂの配分を、例えば次式２で求め、

In step 3, the distribution of the bow-stern thrust force _XHR , the transverse thrust force _YHR, and the thruster thrust force _YB is calculated, for example, by the following formula 2:

ステップ４．において、調整舵角制御量δｐ、δｓと調整スラスター制御量ｎ_Ｂを、例えば次式３で求め、

In step 4, the adjustment rudder angle control amounts δp, δs and the adjustment thruster control amount _nB are calculated, for example, by the following equation 3:

船位保持運動制御部６６２は、ロータリーベーン舵取機１０４、１０５のそれぞれを制御し、２枚の高揚力舵１０２、１０３の舵角を組み合わせて船首尾方向速度と船幅方向速度を制御する船位保持操舵制御部６６４と、スラスター制御装置１０９により船首スラスター１０８のスラスター推力を調整して回頭角速度を制御する船位保持スラスター制御部６６３を有し、船位保持コントロール部６６１から入力する調整スラスター制御量ｎ_Ｂ（漸近値）と調整舵角制御量δｐ、δｓ（漸近値）を、船位保持操舵制御部６６４および船位保持スラスター制御部６６３により制御する。

The positioning movement control unit 662 has a positioning steering control unit 664 that controls each of the rotary vane steering gears 104, 105 and controls the bow-stern speed and widthwise speed by combining the rudder angles of the two high-lift rudders 102, 103, and a positioning thruster control unit 663 that controls the turning angular speed by adjusting the thruster thrust of the bow thruster 108 using the thruster control device 109, and the adjustment thruster control amount n _B (asymptotic value) and adjustment rudder angle control amounts δp, δs (asymptotic values) input from the positioning control unit 661 are controlled by the positioning steering control unit 664 and the positioning thruster control unit 663.

The operation of the above configuration is explained below.

Joystick Steering Mode Joystick steering mode is selected by operating the mode switch 260. The joystick steering unit 255 uses the joystick lever 254 to command the direction of hull movement, bow/stern command thrust, and width command thrust.

In this maneuvering, the propeller 101 remains in forward rotation, and the high-lift rudders 102, 103 are independently operated at various angles to control the propeller wake and control the thrust around the stern in all directions of 360°. This control allows the ship to move forward or backward, stop, turn forward, turn backward, etc., improving maneuverability in maneuvering.

In other words, by changing the combination of rudder angles on both sides, it is possible to orient the propeller wake in a desired direction and change the thrust in that direction. The rudder angle combinations listed here are just an example, and the rudder angle combinations can be changed as desired to obtain the desired propulsion direction and thrust.

In this way, there is no need to reverse the thrust of the propellers (reverse the propellers) when maneuvering the ship, and all ship maneuvering control can be performed with the main engine always rotating forward.By adjusting the rudder angles of both rudders, the ship's speed can be controlled steplessly and precisely from the maximum forward speed corresponding to the propeller speed at that time, to the maximum astern speed, without having to adjust the main engine speed.

Steering mode by emergency stopping unit With a single action of pressing the emergency stop button 264, the emergency stopping unit 265 can be activated, and the ship can be stopped urgently, taking priority over all steering modes. That is, regardless of the steering mode of the joystick lever 254 or other steering modes, the emergency stopping unit 265 switches to crash astern mode ("ASTERN" where the port rudder is steered 105° to the left and the starboard rudder is steered 105° to the starboard) and generates very large braking and reversing forces with both rudders, so that the ship can be stopped in a much shorter time and distance than steering by reversing the propeller.

In addition, even in crash astern mode, there is no need to stop the main engine and restart it in reverse, so the ship will not enter an uncontrollable state during maneuvering, making it possible to respond quickly to emergencies during navigation.

Furthermore, if the ship needs to turn due to ship characteristics or disturbances while maneuvering using the emergency stop unit 265, or if it is necessary to change the ship's heading and other forward direction as needed, the ship can be steered freely using the joystick lever 254 in the same way as with normal joystick operation, to navigate around the obstacle.

Autopilot Steering Mode In normal ship navigation, the mode selector switch 260 is operated to select the autopilot steering mode.

An auto-piloting operation image 269 is displayed on the monitor screen of the display device 262, and the ship's position, the direction to go, the position to be reached, or the bow-stern line direction are input to the auto-pilot unit 253 by touching the monitor screen, and the ship is automatically guided and steered along the set course.

Furthermore, the electronic chart display unit 282 displays the electronic navigation chart as a chart display image 266 on the monitor screen of the display device 262, and the course line setting unit 283 sets the ship's planned route on the electronic navigation chart.

The autopilot 253 controls the rudder angle appropriately based on the ship's current position information, guidance route information, and anchorage holding position information. The autopilot maintains the course indicated by the gyrocompass as the desired heading or bow/stern line heading set in the autopilot operation image 269.

However, since it does not keep the ship's position on the course line, while the bow heading remains parallel to the course line on the navigational electronic chart, the ship's position may deviate from the course line due to wind pressure, ocean currents, etc.

The course correction unit 284 calculates the minimum distance from the ship to the course line as the positional deviation of the ship's position relative to the course line when the ship's bow direction reproduced on the navigational electronic chart by the digital twin calculation unit is parallel to the course line on the navigational electronic chart due to steering by autopilot.

When the minimum separation distance exceeds the set tolerance range, autopilot steering is temporarily suspended, and the course correction rudder angle set to orient the bow to a course that intersects the course line is output to the rudder angle indicator 280.

The rudder angle instruction unit 280 applies a course correction rudder angle to the rotary vane steering gears 104, 105 via the rudder control devices 106, 107, and the course correction unit 284 returns to autopilot operation when the ship's position reaches the course line.

The ship steering support unit 290 uses the digital twin calculation unit 291 to collect in real time the ship's speed measured by the ship speed measurement device 312, the ship's position measured by the position measurement device 313, and the ship's bow direction measured by the direction measurement device 314, and reproduces the actual ship's hull motion achieved at the current steering angle on the electronic navigation chart displayed on the monitor screen of the display device 262.

The actual hull motion of the ship that the digital twin calculation unit 291 reproduces on the electronic navigation chart is determined by the driving force applied to the hull by the current steering angle and various external forces acting on the hull such as water resistance, wind force, tidal force, etc.

Although it is not possible to measure each and every external force acting on a ship's hull individually, the actual ship's motion reproduced on an electronic navigation chart appears as the result of the influence of all the external forces acting on the ship's hull.

The simulation calculation unit 292 displays the assumed ship motion of the ship calculated based on the current steering angle on the electronic navigation chart.

The assumed hull motion of the ship that the simulation calculation unit 292 displays on the navigational electronic chart is calculated by calculating the driving force applied to the hull at the current steering angle, i.e., the force generated by the combination of the thrust of the propeller 101 and the rudder angle of the high-lift rudders 102, 103, and calculating this driving force as the force acting on the hull. The calculations by the simulation calculation unit 292 here do not take into account any external forces. However, while it is possible to incorporate individual measurable external forces into the calculations by the simulation calculation unit 292, incorporating individual external forces into the calculations of the simulation calculation unit 292 is cumbersome, and since there are external forces that cannot be measured, it is impossible to incorporate all external forces into the calculations of the simulation calculation unit 292.

Therefore, when the digital twin calculation unit 291 compares the actual hull motion reproduced on the navigational electronic chart based on the ship's own speed, position, and bow direction collected in real time, with the assumed hull motion displayed on the navigational electronic chart by the simulation calculation unit 292, this is a comparison of the actual hull motion resulting from the action of controllable driving forces and uncontrollable external forces with the assumed hull motion resulting from a calculation that assumes that only controllable driving forces are acting.

Therefore, without calculating the individual external forces acting on the hull, such as wind, waves, and ocean currents, the direction and magnitude of the resultant force acting on the hull can be determined from the difference in movement between the actual hull motion and the assumed hull motion.

Then, the external force resultant calculation unit 293 calculates the direction of action and magnitude of the resultant force of external forces acting on the hull based on the difference in ship speed, ship position, and bow heading between the actual ship motion and the expected ship motion. Based on the direction of action and magnitude of this resultant force of external forces, the instructed rudder angle calculation unit 294 calculates a correction rudder angle to resist the resultant force of external forces, and calculates the appropriate steering angle, i.e., the steering angle required to navigate the planned route set on the electronic navigation chart, by correcting the current steering angle with the correction rudder angle. The maneuvering support unit 290 outputs the calculated appropriate steering angle to the rudder angle instruction unit 280 as the instructed rudder angle.

When maneuvering the ship to stop relative to an object on the course line, the auto-steering unit 253 keeps the propeller 101 rotating forward at all times, applies a rudder angle to both high-lift rudders 102, 103 to convert the propeller wake thrust into reverse thrust, and uses the reverse thrust to decelerate the ship 501 against the inertial force in the forward direction of the ship 501, and controls the rudder angle applied to both high-lift rudders 102, 103 in a range from a rudder angle that maximizes the propeller wake as reverse thrust to a rudder angle that eliminates the forward thrust of the propeller wake.

The effects of external forces are also taken into consideration during this stopping maneuver, and based on the resultant force of external forces calculated by the resultant force calculation unit 293, the command rudder angle calculation unit 294 calculates the appropriate steering angle of both high-lift rudders 102, 103 required to slow down the ship to the appropriate ship speed required to stop between the ship 501 and the target object.

Manual Steering Mode The mode change switch 260 is operated to select a steering mode using the manual steering wheel 256. In this steering mode, the rudder angles of the two high-lift rudders 102, 103 are instructed to the manual steering unit 257 by rotating the manual steering wheel 256, and the rudder angles of the two high-lift rudders 102, 103 are controlled to steer the ship.

Non-follow-up steering mode A steering mode using the non-follow-up steering levers 258a, 258b is selected by operating the mode changeover switch 260. In this steering mode, the non-follow-up steering unit 259 steers each of the rotary vane steering gears 104, 105 corresponding to the non-follow-up steering levers 258a, 258b to the starboard or port side depending on the time that the non-follow-up steering levers 258a, 258b are operated to the left or right.

Steering Mode for Collision Avoidance Maneuver When navigating a congested sea area, the mode change switch 260 is operated to select the steering mode by the collision avoidance maneuvering unit 281.

In the maneuvering mode for avoidance maneuvers while navigating this congested sea area, if the other ships 401, 402 cross the course line 502 of the ship 501 and there is a risk of collision, the ship radar device 310 transmits a collision warning signal, and the avoidance maneuvering unit 281 performs avoidance maneuvers.

As shown in FIG. 8, in the avoidance maneuvering mode for navigating a congested sea area, when the other ships 401, 402 cross the course line 502 of the ship 501 on the navigation electronic chart and there is a risk of collision, the avoidance maneuvering unit 281 receives a collision warning signal from the ship radar device 310, and continues to navigate the current course line 502 of the ship 501 while keeping the other ships 401, 402 on the starboard side, while keeping the propeller 101 always rotating forward, applies a rudder angle to both high-lift rudders 102, 103 to make the thrust of the propeller wake astern thrust, and decelerates the ship 501 against the inertial force in the forward direction of the ship 501 using the astern thrust to avoid collision with the other ships 401, 402.

The rudder angle that the avoidance maneuvering unit 281 gives to both high-lift rudders 102, 103 ranges from the rudder angle that maximizes the propeller wake as backward thrust to the rudder angle that eliminates the forward thrust of the propeller wake. Then, while maintaining a constant forward rotation of the propeller propeller 101, the backward thrust that increases or decreases according to the rudder angle is controlled according to the distance to the other ships 401, 402, and the ship speed is reduced to a level that ensures the time required for the other ships 401, 402 to cross and pass the course line 502 of the ship 501.

Even in this avoidance maneuver, the influence of external forces is taken into consideration, and based on the resultant force of external forces calculated by the resultant force calculation unit 293, the command rudder angle calculation unit 294 calculates the appropriate steering angle of both high-lift rudders 102, 103 required to slow down the ship to an appropriate ship speed to avoid the target ships 401, 402 within the distance between the ship 501 and the target ships 401, 402.

Next, after the other ships 401, 402 have crossed and passed the course line 502 of the ship 501, the rudder angles of both high-lift rudders 102, 103 are controlled to use the thrust from the propeller wake as forward thrust to continue sailing along the course line 502.

Automatic Berthing Steering Mode When maneuvering the ship to automatically dock at the target quay 700, the automatic berthing button 271 is operated to start the automatic berthing steering unit 600.

The automatic docking maneuvering unit 600 inputs the output of each measuring device of the observation system 300 to the vessel motion control unit 620 via the sensor unit 630.

The wharf approach steering unit 611 of the automatic docking command unit 610 commands the vessel motion control unit 620 to specify the vessel motion command direction for directing the vessel 501 to the docking course leading to the target wharf 700 selected and set on the navigational electronic chart, as well as the bow-stern command speed and width command speed required for the vessel motion.

Under the command of the quay approach steering unit 611, the hull motion control unit 620 receives from the sensor unit 630 the bow-stern speed and widthwise speed of the ship 501, the position of the ship 501, the bow direction of the ship 501, the bow distance between the bow of the ship 501 and the target quay 700, and the stern distance between the stern of the ship 501 and the target quay 700, and realizes the motion command direction, bow-stern command speed, and widthwise command speed using the steering control unit 621 and thruster control unit 622, and navigates to a position a set distance away from the target quay 700.

The quay docking operation unit 612 aligns the bow and stern direction of the ship 501 with the target quay 700 when it is close to the target quay 700, and commands the ship motion control unit 620 to steer the ship 501 closer to the target quay 700 while maintaining this parallel state, in order to dock the ship 501 at the target quay 700.

Under the command of the quay docking steering unit 612, the ship motion control unit 620 receives from the sensor unit 630 the bow-stern speed and widthwise speed of the ship 501, the position of the ship 501, the bow direction of the ship 501, the bow distance between the bow of the ship 501 and the target quay 700, and the stern distance between the stern of the ship 501 and the target quay 700, and performs steering by the steering control unit 621 and the thruster control unit 622 so that the bow distance and stern distance measured by the quay separation distance measuring device 315 become equal and the ship's bow-stern direction becomes parallel to the target quay 700, and further performs steering to move directly abeam to move the ship 501 closer to the target quay 700 while maintaining this parallel state.

This steering is performed as follows. For example, when "astern and pull to the left," applying thrust from the bow thruster 108 toward the starboard side results in left lateral movement, and when "astern and pull to the right," applying thrust from the bow thruster 108 toward the port side results in right lateral movement.

As a result, under the command of the quay approach steering unit 612, the ship can navigate to a position close to the target quay when approaching the target quay with its bow and stern facing the target quay, and the approach to the target quay 700 can be made in a short time in a narrow water area and along a short route, reducing the external forces that affect the hull when approaching, such as tidal forces of rip currents and onshore currents, tides, wind forces, etc.

In addition, when docking, the steering angle can be corrected taking into account external forces acting on the ship, such as wind, waves, and ocean currents, allowing for highly accurate docking maneuvers.

In other words, the maneuvering support unit 290 described above functions as a matter of course, and by comparing the actual hull motion of the ship 501 reproduced on the navigational electronic chart by the digital twin calculation unit 291 with the assumed hull motion of the ship 501 displayed on the navigational electronic chart by the simulation calculation unit 292, it is possible to grasp the direction and magnitude of the resultant force of all external forces acting on the hull without calculating the individual external forces acting on the hull, such as wind, waves, and ocean currents. Therefore, by correcting the current steering angle with a correction rudder angle to resist the resultant force of the external forces, it is possible to calculate the appropriate steering angle required for docking navigation.

A ship's motion characteristics vary depending on the state of its cargo (weight and loading position). Even when steering with the same rudder angle at the same ship speed, the ship's motion based on steering will differ depending on the state of the cargo. In other words, even if the bow heading change is set to the optimal steering amount for a certain loading state, if the loading state changes, the ship's motion characteristics will change to correspond to the loading state at that time, and the steering amount will overshoot or undershoot, even if the same steering amount is applied.

Therefore, the actual hull motion characteristics and expected motion characteristics based on steering are constantly measured and the data is saved, and in subsequent steering, the amount of steering is adjusted to correct the difference so that the expected hull motion characteristics match the actual hull motion characteristics, allowing optimal steering to be performed.

This not only improves safety but also improves propulsion performance by eliminating unnecessary steering during normal navigation.

Naturally, it is possible to carry out the same maneuvers as for avoidance maneuvers when approaching a dock.

Berthing maneuvering mode Manual berthing maneuvering is performed when the ship 501 is approaching the target quay 700. When performing manual berthing maneuvering, the berthing maneuvering button 351 is operated to start the berthing maneuvering unit 650 and the three-degree-of-freedom joystick lever 352. When the berthing maneuvering unit 650 is started, the automatic berthing maneuvering unit 600 is terminated.

The operator operates a single three-degree-of-freedom joystick lever 352, and controls the command speed in the commanded direction of motion, i.e., the ratio of the bow-stern command speed component and the width-direction command speed component, by the tilt direction of the three-degree-of-freedom joystick lever 352, controls the bow-stern command speed and width-direction command speed by the tilt angle in the tilt direction, controls the turning command angular velocity by twisting the lever around its axis, and commands the target motion state using multiple actuators.

Then, the feedback controller 651 calculates the command rudder angle and command thruster thrust required to realize the bow-stern command speed, ship's width command speed, and turning command angular speed commanded by the three-degree-of-freedom joystick lever 352 from the current hull motion state, and the docking steering control unit 653 and docking thruster control unit 654 of the docking hull motion control unit 652 control the bow-stern speed, ship's width command speed, and turning angular speed.

When maneuvering a single-shaft, twin-rudder ship in this embodiment, the propulsion propeller 101 always rotates forward, allowing any type of maneuvering control to be performed, and the ship speed can be finely and steplessly controlled from the maximum forward speed to the maximum reverse speed corresponding to the propeller speed at that time by adjusting the rudder angle of both rudders without adjusting the main engine speed.

Therefore, by simply tilting the 3-DOF joystick lever 352, the bow-stern command speed and width command speed for translational motion in the forward, backward, left and right directions can be specified as continuous values, and the turning command angular speed for turning motion can be specified as continuous values by twisting the lever, allowing for highly flexible maneuvering by controlling the bow-stern speed, width direction speed and turning angular speed of the hull motion, and allowing for careful and appropriate control of the approach speed in the bow-stern and width directions in relation to the distance to the quay when docking. In addition, the hull can be stopped quickly and stopped on the spot by returning the 3-DOF joystick lever to a neutral position where it is not tilted.

Positioning maneuvering mode When the 3-degree-of-freedom joystick lever returns to a neutral position where it is not tilted, the positioning maneuvering unit 660 is activated. The positioning motion control unit 662 controls the adjustment thruster control amount nB (asymptotic value) and adjustment rudder angle control amounts δp, δs (asymptotic values) input from the positioning control unit 661 using the positioning steering control unit 664 and the positioning thruster control unit 663 according to the above-mentioned algorithm, and maintains the ship's position and heading at the target position.

As a result, in deep water areas or in ports with many surrounding obstacles such as quays and other ships, the movement of the ship can be safely controlled with high precision to a specified position and direction while taking into account the external forces that affect the ship, such as the tidal forces of rip currents and onshore currents, tides, and wind forces.

REFERENCE SIGNS LIST 100 Thrust system 110 Hull 101 Propulsion propeller 102, 103 High-lift rudder 104, 105 Rotary vane steering gear 106, 107 Rudder control device 108 Bow thruster 109 Thruster control device 151, 152 Pump unit 153, 154 Rudder angle transmitter 155, 156 Feedback unit 200 Steering system 250 Steering stand 251 Gyro compass 252 Gyro direction display unit 253 Auto steering unit 254 Joystick lever 255 Joystick steering unit 256 Manual steering wheel 256
257 Manual steering unit 257
258a, 258b Non-follow-up steering lever 259 Non-follow-up ship steering unit 260 Mode changeover switch 261 Mode changeover unit 262 Display device 263 Image control unit 264 Emergency stop button 265 Emergency stop unit 266 Nautical chart display image 267 Gyro bearing display image 268 Bearing display unit operation image 269 Auto ship steering operation image 271 Automatic berthing button 280 Rudder angle indication unit 281 Collision avoidance maneuvering unit 282 Electronic chart display unit 283 Course line setting unit 284 Course correction unit 290 Ship steering support unit 291 Digital twin calculation unit 292 Simulation calculation unit 293 External force resultant force calculation unit 294 Instructed rudder angle calculation unit 300 Observation system 310 Ship radar device 311 Warning signal output unit 312 Ship speed measuring device 313 Position measuring device 314 Direction measuring device 315 Berth distance measuring device 351 Berthing maneuvering button 352 3-degree-of-freedom joystick lever 401, 402 Other ship 501 Own ship 502 Course line 600 Automatic berthing maneuvering unit 610 Automatic berthing command unit 611 Berth approach operation unit 612 Berth docking operation unit 620 Ship motion control unit 621 Steering control unit 622 Thruster control unit 630 Sensor unit 650 Berthing maneuvering unit 651 Feedback controller 652 Berthing ship motion control unit 653 Berthing steering control unit 654 Berthing thruster control unit 660 Ship positioning maneuvering unit 661 Ship positioning control unit 662 Ship positioning operation control unit 663 Ship positioning thruster control unit 700 Target quay

Claims (2)

The vessel is equipped with a thrust system, a steering system that controls the thrust system, and an observation system that observes the vessel's own hull motion state.
The thrust system includes a single propulsion propeller disposed at the stern, a pair of left and right high-lift rudders disposed aft of the propulsion propeller, a pair of steering gears for driving each of the high-lift rudders, a bow thruster, and a thruster control device for controlling the bow thruster;
The observation system includes a vessel speed measuring device that measures the vessel's bow-stern speed, vessel's widthwise speed, and heading angular velocity, a position measuring device that measures the vessel's position using a GPS, and a heading measuring device that measures the vessel's bow direction,
The maneuvering system is equipped with a vessel positioning control unit and a vessel positioning motion control unit.
The vessel positioning control unit controls the rudder angles of the two high-lift rudders within a set rudder angle range, and the set rudder angle range is set to a rudder angle range of several tens of degrees around the hover rudder angles, with the hover rudder angles δph and δsh being the central rudder angles of -75° port rudder and +75° starboard rudder at which the vessel stops on the spot. The following calculations are performed assuming that the bow-stern thrust XHR and transverse thrust YHR generated when steering around the hover rudder angle and the thruster thrust _YB generated by the thrusters are the bow-stern speed, transverse speed and turning angular velocity of the vessel's own vessel are sufficiently small, and that the propeller thrust and thruster thrust generated by the propellers and the pair of high-lift rudders do not change depending on the vessel motion,
Step 1. Calculate the x-axis position deviation xn and y-axis position deviation yn on the GPS coordinates between the current ship position and the target ship position measured by the position measuring device, and the x-axis heading deviation ψn between the current heading and the target heading measured by the direction measuring device,
Step 2. Calculate the x-axis thrust Xreq, the y-axis thrust Yreq, and the turning moment Nreq required for the adjusted hull motion to return from the current ship position to the target ship position by correcting the x-axis position deviation xn, the y-axis position deviation yn, and the heading deviation ψn,
Step 3. Calculate the distribution of the thruster thrust _YB generated by the bow thruster required to realize the x-axis thrust Xreq, the y-axis thrust Yreq, and the turning moment Nreq, and the distribution of the bow-stern thrust _XHR , the widthwise thrust _YHR , and the thruster thrust _YB generated by the propeller and the pair of high-lift rudders;
Step 4. Calculate the adjustment rudder angle control amounts δp and δs around the hover rudder angle and the adjustment thruster control amount _nB for generating the obtained bow-stern thrust force _XHR , the vessel widthwise thrust force _YHR , and the thruster thrust force _YB .
The positioning movement control section has a positioning steering control section which controls each of the steering gears and controls the bow-stern speed and the widthwise speed by combining the rudder angles of the two high-lift rudders, and a positioning thruster control section which controls the turning angular speed by adjusting the thrust of the bow thruster using a thruster control device, and the positioning device for a single-shaft, twin-rudder ship is characterized in that the adjustment thruster control amount and adjustment rudder angle control amount input from the positioning control section are controlled by the positioning steering control section and the positioning thruster control section. The positioning control unit is
In step 2, the x-axis thrust force Xreq, the y-axis thrust force Yreq, and the turning moment Nreq are calculated using the following equation 1:

In step 3, the distribution of the bow-stern thrust force _XHR , the transverse thrust force _YHR , and the thruster thrust force _YB is calculated using the following formula 2:

In step 4, the adjustment rudder angle control amounts δp, δs and the adjustment thruster control amount _nB are calculated using the following equation 3:

A positioning device for a single-propeller, twin-rudder ship as described in claim 1, characterized in that the ship's positioning movement control unit controls the adjustment thruster control amount and adjustment rudder angle control amount calculated by equation 3 using a ship's positioning steering control unit and a ship's positioning thruster control unit.

Images