JP7634293B2 - Single-screw, twin-rudder vessel equipped with a controllable pitch propeller - Google Patents

Description

The present invention relates to a single-shaft, twin-rudder ship equipped with a controllable pitch propeller, 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.

However, on diesel-engine fixed-pitch propeller (FPP) ships, it is not common to precisely control the propeller speed over time, and it is difficult to frequently adjust maximum thrust during control in an automatic positioning system.

In addition, if the propeller speed required to output the desired thrust is close to the main engine's dangerous speed, there is a problem in that it is not possible to output an appropriate propeller thrust.

The present invention aims to solve the above-mentioned problems, and aims to provide a single-shaft, twin-rudder ship equipped with a controllable pitch propeller that can adjust the propeller thrust to an appropriate value when maneuvering to maintain position at low speeds, thereby enabling maneuvering to maintain position with high performance in maintaining a fixed position.

In order to solve the above-mentioned problems, the single-shaft, twin-rudder ship equipped with the controllable pitch propeller 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 controllable pitch propeller propeller located at the stern, a pair of left and right high-lift rudders located behind the propulsion propeller, and a pair of steering gears that drive each high-lift rudders, the observation system comprises a position measuring device that measures the ship's position, the steering system comprises a positioning motion control unit and a positioning control unit, and the positioning control unit calculates the blade angle of the propulsion propeller when the propulsion propeller rotates at a constant speed in the forward direction at low speeds and the rudder angle of the two high-lift rudders is a hover rudder angle that does not produce a forward speed component. The system is characterized in that it sets the angle at a neutral angle, calculates the adjustment rudder angle to be applied to the two high-lift rudders according to the position deviation of the current ship position from the target ship position, calculates the rudder angle deviation of the adjustment rudder angle from the hover rudder angle, and calculates the adjustment blade angle having a blade angle deviation from the neutral angle required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation, and the ship positioning motion control unit has a ship positioning steering control unit that controls each of the pair of steering gears and controls the direction of ship motion by combining the rudder angles of the two high-lift rudders, and a blade angle control unit that variably controls the blade angle of the propulsion propeller, and the ship positioning steering control unit controls the two high-lift rudders to the adjustment rudder angle input from the ship positioning control unit, and the blade angle control unit controls the blade angle of the propulsion propeller to the adjustment blade angle input from the ship positioning control unit.

In addition, in the single-shaft, twin-rudder ship equipped with the controllable pitch propeller of the present invention, the blade angle deviation is a value obtained by multiplying the rudder angle deviation by an arbitrary proportionality coefficient.

The above configuration allows ship positioning at low speeds, i.e. the propellers are rotated at a constant speed in the forward direction at low speeds, and the two high-lift rudders are steered near a hover rudder angle where no forward speed component is generated. If the ship deviates from the target ship position at the hover rudder angle, the rudder angles of the two high-lift rudders required to cause the ship to move toward the target ship position are calculated as adjustment rudder angles. This adjustment rudder angle increases according to the positional deviation of the current ship position from the target ship position.

The greater the propeller thrust at this adjusted rudder angle, the quicker the ship can return to the target position. Therefore, the blade angle of the propulsion propeller is adjusted to increase the propeller thrust as the position deviation increases. In other words, the rudder angle deviation of the adjusted rudder angle relative to the hover rudder angle is calculated, and the blade angle of the propulsion propeller required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation is calculated as an adjusted blade angle with a blade angle deviation relative to the neutral angle.

As a result, in a single-shaft, twin-rudder ship equipped with a controllable pitch propeller, the propeller thrust can be adjusted to an appropriate value to perform maneuvering to maintain a fixed position with high performance, making it possible to safely control the movement of the ship 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 ship, 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-shaft, twin-rudder ship equipped with a controllable pitch propeller 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 block diagram showing a configuration of a ship steering stand according to 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.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(Configuration of the embodiment)
The single-shaft, twin-rudder ship equipped with a controllable pitch propeller 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 hull motion state of the ship, as shown in Figures 1 to 8.

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 ship's bow-stern speed, ship's width speed, and turning angular velocity, a position measuring device 313 that measures the ship's position using GPS, and a direction measuring device 314 that measures the ship's bow direction.

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, and a direction measuring device 314 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 operates 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 electronic chart display unit 282 that displays an electronic chart for navigation on the display device 262, a course line setting unit 283 that sets the planned route of the ship on the electronic chart for navigation, and a course correction unit 284 that eliminates the positional deviation of the ship relative to the course line. The system is also equipped with a positioning control steering unit 660 that controls the movement of the ship to a specified position and direction with high precision.

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 streamline and direction of movement are explained in Figure 8.

In Figure 8, 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 are given for combinations of these rudder angles. The propeller wake is shown with a thin arrow, and the resulting propulsion direction of the ship is shown with 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, a bow thruster 108, and a controllable pitch propeller 101 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 ship positioning steering unit 660 is equipped with a ship positioning control unit 661 and a ship positioning motion control unit 662.

The vessel positioning control unit 661 controls the rudder angle of each of the two high-lift rudders 102, 103 within a set rudder angle range, which is a rudder angle range of about 10 degrees around the hover rudder angle, with the port rudder at -75° and the starboard rudder at +75°, at which the vessel stops in place, as the central rudder angle.

Then, the blade angle of the propulsion propeller 101 when the propulsion propeller 101 rotates at a constant speed in the forward direction at a low speed range and the rudder angle of the two high-lift rudders 102, 103 is a hover rudder angle that does not generate a forward speed component is defined as a neutral angle, and the adjustment rudder angle to be given to the two high-lift rudders is calculated according to the position deviation of the current ship position from the target ship position. Furthermore, the rudder angle deviation of the adjustment rudder angle from the hover rudder angle is calculated, and an adjustment blade angle having a blade angle deviation from the neutral angle required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation is calculated. Here, the blade angle deviation is a value obtained by multiplying the rudder angle deviation by an arbitrary proportionality coefficient. In addition, the adjustment thruster control amount is calculated.

The vessel positioning motion control unit 662 includes a vessel positioning thruster control unit 663 that uses the thruster control device 109 to adjust the thrust of the bow thruster 108 to control the turning angular speed, a vessel positioning steering control unit 664 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 blade angle control unit 665 that variably controls the blade angle of the propulsion propeller 101.

Then, the two high-lift rudders are controlled by the positioning steering control unit 664 to the adjusted rudder angle input from the positioning control unit 661, the adjustment thruster control amount input from the positioning control unit 661 is controlled by the positioning thruster control unit 663, and the blade angle control unit 665 controls the blade angle of the propulsion propeller 101 to the adjusted blade angle input from the positioning control unit 661. Note that the adjustment thruster control amount is controlled as necessary. The operation of the above configuration will be described 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 relative to the course line when the ship's bow heading on the navigational electronic chart is parallel to the course line on the navigational electronic chart due to autopilot steering.

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.

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.

Ship positioning steering mode In the joystick steering mode, when the joystick lever 254 is in a neutral position where it is not tilted, the ship positioning steering unit 660 is activated. Ship positioning steering in the low speed range, that is, the propeller 101 is rotated at a constant speed in the forward direction in the low speed range, and the two high-lift rudders 102, 103 are steered near a hover rudder angle where no forward speed component is generated. Then, when the ship deviates from the target ship position at the hover rudder angle, the rudder angle of the two high-lift rudders 102, 103 required to cause the ship to move toward the target ship position is calculated as an adjustment rudder angle. This adjustment rudder angle increases according to the position deviation of the current ship position from the target ship position.

The greater the propeller thrust at this adjusted rudder angle, the quicker the ship can return to the target position. Therefore, the blade angle of the propulsion propeller 101 is adjusted to increase the propeller thrust as the position deviation increases. In other words, the rudder angle deviation of the adjusted rudder angle relative to the hover rudder angle is calculated, and the blade angle of the propulsion propeller 101 required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation is calculated as an adjusted blade angle having a blade angle deviation relative to the neutral angle.

The ship's positioning motion control unit 662 controls the two high-lift rudders to the adjusted rudder angle input from the ship's positioning control unit 661 using the ship's positioning steering control unit 664, controls the adjustment thruster control amount input from the ship's positioning control unit 661 as necessary using the ship's positioning thruster control unit 663, and controls the blade angle of the propulsion propeller 101 to the adjusted blade angle input from the ship's positioning control unit 661 using the blade angle control unit 665, thereby maintaining the ship's position and heading at the target ship's position.

As a result, in a single-shaft, twin-rudder ship equipped with a controllable pitch propeller, the propeller thrust can be adjusted to an appropriate value to perform maneuvering to maintain a fixed position with high performance, making it possible to safely control the movement of the ship 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 ship, such as rip currents, tidal forces of 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 section 260 Mode changeover switch 261 Mode changeover section 262 Display device 263 Image control section 264 Emergency stop button 265 Emergency stop section 266 Nautical chart display image 267 Gyro bearing display image 268 Bearing display section operation image 269 Auto ship steering operation image 280 Rudder angle indication section 282 Electronic chart display section 283 Course line setting section 284 Course correction section 300 Observation system 310 Ship radar device 311 Warning signal output section 312 Ship speed measurement device 313 Position measurement device 314 Heading measurement device 660 Ship positioning steering section 661 Ship positioning control section 662 Ship positioning motion control section 663 Positioning thruster control unit 664 Positioning steering control unit 665 Wing angle control unit

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 comprises a single controllable pitch propeller disposed at the stern, a pair of left and right high-lift rudders disposed aft of the propulsion propeller, and a pair of steering gears for driving each high-lift rudders,
The observation system is equipped with a position measuring device for measuring the position of the ship itself,
The maneuvering system is equipped with a ship positioning motion control unit and a ship positioning control unit.
The ship positioning control unit sets the blade angle of the propulsion propeller to a neutral angle when the propulsion propeller rotates at a constant speed in the forward direction in a low speed range and the rudder angle of the two high-lift rudders is a hover rudder angle that does not generate a forward speed component,
Calculating adjustment rudder angles to be applied to two high-lift rudders in accordance with the position deviation of the current ship position from the target ship position, calculating the rudder angle deviation of the adjustment rudder angle from the hover rudder angle, and calculating an adjustment blade angle having a blade angle deviation from the neutral angle necessary to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation,
The vessel positioning motion control unit has a vessel positioning steering control unit which controls each of the pair of steering gears and controls the direction of vessel motion by combining the rudder angles of the two high-lift rudders, and a blade angle control unit which variably controls the blade angle of the propulsion propeller,
A single-shaft, twin-rudder ship equipped with a controllable pitch propeller, characterized in that a positioning steering control unit controls two high-lift rudders to an adjusted rudder angle input from a positioning control unit, and a blade angle control unit controls the blade angle of a propulsion propeller to an adjusted blade angle input from the positioning control unit. A single-shaft, twin-rudder ship equipped with a controllable pitch propeller according to claim 1, characterized in that the blade angle deviation is a value obtained by multiplying the rudder angle deviation by an arbitrary proportionality coefficient.

Images